Merge branch 'master' into 2020-08-19-firelocks

# Conflicts:
#	Content.Server/GameObjects/Components/Atmos/AirtightComponent.cs
#	Content.Server/GameObjects/Components/Atmos/GridAtmosphereComponent.cs
#	SpaceStation14.sln.DotSettings

Content.Server/AI/Operators/Inventory/OpenStorageOperator.cs

@@ -1,4 +1,5 @@
-using Content.Server.AI.Utility;
+#nullable enable
+using Content.Server.AI.Utility;
 using Content.Server.AI.WorldState.States.Inventory;
 using Content.Server.GameObjects.Components.Items.Storage;
 using Content.Server.Utility;
@@ -34,7 +35,7 @@ namespace Content.Server.AI.Operators.Inventory
                 return Outcome.Failed;
             }
 
-            if (!container.Owner.TryGetComponent(out EntityStorageComponent storageComponent) ||
+            if (!container.Owner.TryGetComponent(out EntityStorageComponent? storageComponent) ||
                 storageComponent.IsWeldedShut)
             {
                 return Outcome.Failed;

Content.Server/AI/Operators/Inventory/PickupEntityOperator.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using Content.Server.GameObjects.Components.GUI;
 using Content.Server.GameObjects.Components.Items.Storage;
 using Content.Server.GameObjects.EntitySystems.Click;
@@ -20,11 +21,9 @@ namespace Content.Server.AI.Operators.Inventory
             _target = target;
         }
 
-        // TODO: When I spawn new entities they seem to duplicate clothing or something?
         public override Outcome Execute(float frameTime)
         {
-            if (_target == null ||
-                _target.Deleted ||
+            if (_target.Deleted ||
                 !_target.HasComponent<ItemComponent>() ||
                 ContainerHelpers.IsInContainer(_target) ||
                 !InteractionChecks.InRangeUnobstructed(_owner, _target.Transform.MapPosition))
@@ -32,7 +31,7 @@ namespace Content.Server.AI.Operators.Inventory
                 return Outcome.Failed;
             }
 
-            if (!_owner.TryGetComponent(out HandsComponent handsComponent))
+            if (!_owner.TryGetComponent(out HandsComponent? handsComponent))
             {
                 return Outcome.Failed;
             }

Content.Server/AI/Operators/Inventory/UseItemInInventoryOperator.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using Content.Server.GameObjects.Components.GUI;
 using Content.Server.GameObjects.Components.Items.Storage;
 using Robust.Shared.Interfaces.GameObjects;
@@ -7,12 +8,12 @@ namespace Content.Server.AI.Operators.Inventory
     /// <summary>
     /// Will find the item in storage, put it in an active hand, then use it
     /// </summary>
-    public class UseItemInHandsOperator : AiOperator
+    public class UseItemInInventoryOperator : AiOperator
     {
         private readonly IEntity _owner;
         private readonly IEntity _target;
 
-        public UseItemInHandsOperator(IEntity owner, IEntity target)
+        public UseItemInInventoryOperator(IEntity owner, IEntity target)
         {
             _owner = owner;
             _target = target;
@@ -20,18 +21,13 @@ namespace Content.Server.AI.Operators.Inventory
 
         public override Outcome Execute(float frameTime)
         {
-            if (_target == null)
-            {
-                return Outcome.Failed;
-            }
-
             // TODO: Also have this check storage a la backpack etc.
-            if (!_owner.TryGetComponent(out HandsComponent handsComponent))
+            if (!_owner.TryGetComponent(out HandsComponent? handsComponent))
             {
                 return Outcome.Failed;
             }
 
-            if (!_target.TryGetComponent(out ItemComponent itemComponent))
+            if (!_target.TryGetComponent(out ItemComponent? itemComponent))
             {
                 return Outcome.Failed;
             }

Content.Server/AI/Operators/Movement/MoveToEntityOperator.cs

@@ -16,12 +16,20 @@ namespace Content.Server.AI.Operators.Movement
         public float ArrivalDistance { get; }
         public float PathfindingProximity { get; }
 
-        public MoveToEntityOperator(IEntity owner, IEntity target, float arrivalDistance = 1.0f, float pathfindingProximity = 1.5f)
+        private bool _requiresInRangeUnobstructed;
+
+        public MoveToEntityOperator(
+            IEntity owner, 
+            IEntity target, 
+            float arrivalDistance = 1.0f, 
+            float pathfindingProximity = 1.5f,
+            bool requiresInRangeUnobstructed = false)
         {
             _owner = owner;
             _target = target;
             ArrivalDistance = arrivalDistance;
             PathfindingProximity = pathfindingProximity;
+            _requiresInRangeUnobstructed = requiresInRangeUnobstructed;
         }
 
         public override bool TryStartup()
@@ -32,7 +40,7 @@ namespace Content.Server.AI.Operators.Movement
             }
 
             var steering = EntitySystem.Get<AiSteeringSystem>();
-            _request = new EntityTargetSteeringRequest(_target, ArrivalDistance, PathfindingProximity);
+            _request = new EntityTargetSteeringRequest(_target, ArrivalDistance, PathfindingProximity, _requiresInRangeUnobstructed);
             steering.Register(_owner, _request);
             return true;
         }

Content.Server/AI/Operators/Nutrition/UseDrinkInInventoryOperator.cs

@@ -0,0 +1,73 @@
+#nullable enable
+using Content.Server.GameObjects.Components.GUI;
+using Content.Server.GameObjects.Components.Items.Storage;
+using Content.Server.GameObjects.Components.Nutrition;
+using Content.Shared.GameObjects.Components.Nutrition;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Random;
+using Robust.Shared.IoC;
+using Robust.Shared.Random;
+
+namespace Content.Server.AI.Operators.Nutrition
+{
+    public class UseDrinkInInventoryOperator : AiOperator
+    {
+        private readonly IEntity _owner;
+        private readonly IEntity _target;
+        private float _interactionCooldown;
+
+        public UseDrinkInInventoryOperator(IEntity owner, IEntity target)
+        {
+            _owner = owner;
+            _target = target;
+        }
+
+        public override Outcome Execute(float frameTime)
+        {
+            if (_interactionCooldown >= 0)
+            {
+                _interactionCooldown -= frameTime;
+                return Outcome.Continuing;
+            }
+
+            // TODO: Also have this check storage a la backpack etc.
+            if (_target.Deleted ||
+                !_owner.TryGetComponent(out HandsComponent? handsComponent) ||
+                !_target.TryGetComponent(out ItemComponent? itemComponent))
+            {
+                return Outcome.Failed;
+            }
+
+            DrinkComponent? drinkComponent = null;
+
+            foreach (var slot in handsComponent.ActivePriorityEnumerable())
+            {
+                if (handsComponent.GetItem(slot) != itemComponent) continue;
+                handsComponent.ActiveHand = slot;
+                if (!_target.TryGetComponent(out drinkComponent))
+                {
+                    return Outcome.Failed;
+                }
+
+                // This should also implicitly open it.
+                handsComponent.ActivateItem();
+                _interactionCooldown = IoCManager.Resolve<IRobustRandom>().NextFloat() + 0.5f;
+            }
+
+            if (drinkComponent == null)
+            {
+                return Outcome.Failed;
+            }
+
+            if (drinkComponent.Deleted ||
+                drinkComponent.Empty ||
+                _owner.TryGetComponent(out ThirstComponent? thirstComponent) &&
+                thirstComponent.CurrentThirst >= thirstComponent.ThirstThresholds[ThirstThreshold.Okay])
+            {
+                return Outcome.Success;
+            }
+
+            return Outcome.Continuing;
+        }
+    }
+}

Content.Server/AI/Operators/Nutrition/UseFoodInInventoryOperator.cs

@@ -0,0 +1,73 @@
+#nullable enable
+using Content.Server.GameObjects.Components.GUI;
+using Content.Server.GameObjects.Components.Items.Storage;
+using Content.Server.GameObjects.Components.Nutrition;
+using Content.Shared.GameObjects.Components.Nutrition;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Random;
+using Robust.Shared.IoC;
+using Robust.Shared.Random;
+
+namespace Content.Server.AI.Operators.Nutrition
+{
+    public class UseFoodInInventoryOperator : AiOperator
+    {
+        private readonly IEntity _owner;
+        private readonly IEntity _target;
+        private float _interactionCooldown;
+
+        public UseFoodInInventoryOperator(IEntity owner, IEntity target)
+        {
+            _owner = owner;
+            _target = target;
+        }
+
+        public override Outcome Execute(float frameTime)
+        {
+            if (_interactionCooldown >= 0)
+            {
+                _interactionCooldown -= frameTime;
+                return Outcome.Continuing;
+            }
+
+            // TODO: Also have this check storage a la backpack etc.
+            if (_target.Deleted ||
+                !_owner.TryGetComponent(out HandsComponent? handsComponent) ||
+                !_target.TryGetComponent(out ItemComponent? itemComponent))
+            {
+                return Outcome.Failed;
+            }
+
+            FoodComponent? foodComponent = null;
+
+            foreach (var slot in handsComponent.ActivePriorityEnumerable())
+            {
+                if (handsComponent.GetItem(slot) != itemComponent) continue;
+                handsComponent.ActiveHand = slot;
+                if (!_target.TryGetComponent(out foodComponent))
+                {
+                    return Outcome.Failed;
+                }
+
+                // This should also implicitly open it.
+                handsComponent.ActivateItem();
+                _interactionCooldown = IoCManager.Resolve<IRobustRandom>().NextFloat() + 0.5f;
+            }
+
+            if (foodComponent == null)
+            {
+                return Outcome.Failed;
+            }
+
+            if (_target.Deleted ||
+                foodComponent.UsesRemaining == 0 ||
+                _owner.TryGetComponent(out HungerComponent? hungerComponent) &&
+                hungerComponent.CurrentHunger >= hungerComponent.HungerThresholds[HungerThreshold.Okay])
+            {
+                return Outcome.Success;
+            }
+
+            return Outcome.Continuing;
+        }
+    }
+}

Content.Server/AI/Operators/Sequences/GoPickupEntitySequence.cs

@@ -11,7 +11,7 @@ namespace Content.Server.AI.Operators.Sequences
         {
             Sequence = new Queue<AiOperator>(new AiOperator[]
             {
-                new MoveToEntityOperator(owner, target),
+                new MoveToEntityOperator(owner, target, requiresInRangeUnobstructed: true),
                 new OpenStorageOperator(owner, target),
                 new PickupEntityOperator(owner, target),
             });

Content.Server/AI/Utility/Actions/Clothing/Gloves/EquipGloves.cs

@@ -26,7 +26,7 @@ namespace Content.Server.AI.Utility.Actions.Clothing.Gloves
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseItemInInventoryOperator(Owner, _entity),
             });
         }
 

Content.Server/AI/Utility/Actions/Clothing/Head/EquipHead.cs

@@ -26,7 +26,7 @@ namespace Content.Server.AI.Utility.Actions.Clothing.Head
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseItemInInventoryOperator(Owner, _entity),
             });
         }
 

Content.Server/AI/Utility/Actions/Clothing/OuterClothing/EquipOuterClothing.cs

@@ -26,7 +26,7 @@ namespace Content.Server.AI.Utility.Actions.Clothing.OuterClothing
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseItemInInventoryOperator(Owner, _entity),
             });
         }
 

Content.Server/AI/Utility/Actions/Clothing/Shoes/EquipShoes.cs

@@ -26,7 +26,7 @@ namespace Content.Server.AI.Utility.Actions.Clothing.Shoes
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseItemInInventoryOperator(Owner, _entity),
             });
         }
 

Content.Server/AI/Utility/Actions/Nutrition/Drink/PickUpDrink.cs

@@ -40,10 +40,6 @@ namespace Content.Server.AI.Utility.Actions.Nutrition.Drink
             
             return new[]
             {
-                considerationsManager.Get<FreeHandCon>()
-                    .BoolCurve(context),
-                considerationsManager.Get<ThirstCon>()
-                    .PresetCurve(context, PresetCurve.Nutrition),
                 considerationsManager.Get<TargetDistanceCon>()
                     .PresetCurve(context, PresetCurve.Distance),
                 considerationsManager.Get<DrinkValueCon>()

Content.Server/AI/Utility/Actions/Nutrition/Drink/UseDrinkInInventory.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using Content.Server.AI.Operators;
 using Content.Server.AI.Operators.Inventory;
+using Content.Server.AI.Operators.Nutrition;
 using Content.Server.AI.Utility.Considerations;
 using Content.Server.AI.Utility.Considerations.Inventory;
 using Content.Server.AI.Utility.Considerations.Nutrition.Drink;
@@ -27,7 +28,7 @@ namespace Content.Server.AI.Utility.Actions.Nutrition.Drink
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseDrinkInInventoryOperator(Owner, _entity),
             });
         }
  

Content.Server/AI/Utility/Actions/Nutrition/Food/UseFoodInInventory.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using Content.Server.AI.Operators;
 using Content.Server.AI.Operators.Inventory;
+using Content.Server.AI.Operators.Nutrition;
 using Content.Server.AI.Utility.Considerations;
 using Content.Server.AI.Utility.Considerations.Inventory;
 using Content.Server.AI.Utility.Considerations.Nutrition.Food;
@@ -27,7 +28,7 @@ namespace Content.Server.AI.Utility.Actions.Nutrition.Food
             ActionOperators = new Queue<AiOperator>(new AiOperator[]
             {
                 new EquipEntityOperator(Owner, _entity),
-                new UseItemInHandsOperator(Owner, _entity),
+                new UseFoodInInventoryOperator(Owner, _entity), 
             });
         }
 

Content.Server/AI/Utility/BehaviorSets/SpirateBehaviorSet.cs

@@ -14,7 +14,7 @@ namespace Content.Server.AI.Utility.BehaviorSets
                 // TODO: Ideally long-term we should just store the weapons in backpack
                 new EquipMeleeExp(),
                 new PickUpMeleeWeaponExp(),
-                new MeleeAttackNearbyPlayerExp(),
+                new MeleeAttackNearbyExp(),
             };
         }
     }

Content.Server/AI/Utility/Considerations/Combat/TargetHealthCon.cs

@@ -11,7 +11,7 @@ namespace Content.Server.AI.Utility.Considerations.Combat
         {
             var target = context.GetState<TargetEntityState>().GetValue();
 
-            if (target == null || !target.TryGetComponent(out IDamageableComponent damageableComponent))
+            if (target == null || target.Deleted || !target.TryGetComponent(out IDamageableComponent damageableComponent))
             {
                 return 0.0f;
             }

Content.Server/AI/Utility/Considerations/Movement/TargetDistanceCon.cs

@@ -9,7 +9,7 @@ namespace Content.Server.AI.Utility.Considerations.Movement
         {
             var self = context.GetState<SelfState>().GetValue();
             var target = context.GetState<TargetEntityState>().GetValue();
-            if (target == null || target.Transform.GridID != self.Transform.GridID)
+            if (target == null || target.Deleted || target.Transform.GridID != self.Transform.GridID)
             {
                 return 0.0f;
             }

Content.Server/AI/Utility/ExpandableActions/Combat/Melee/MeleeAttackNearbyExp.cs

@@ -4,17 +4,19 @@ using Content.Server.AI.Utility.Actions;
 using Content.Server.AI.Utility.Actions.Combat.Melee;
 using Content.Server.AI.Utility.Considerations;
 using Content.Server.AI.Utility.Considerations.Combat.Melee;
-using Content.Server.AI.Utils;
 using Content.Server.AI.WorldState;
 using Content.Server.AI.WorldState.States;
+using Content.Server.GameObjects.Components.AI;
 using Content.Server.GameObjects.Components.Movement;
-using Content.Shared.GameObjects.Components.Damage;
-using Robust.Server.GameObjects;
+using Content.Server.GameObjects.EntitySystems.AI;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.IoC;
 
 namespace Content.Server.AI.Utility.ExpandableActions.Combat.Melee
 {
-    public sealed class MeleeAttackNearbyPlayerExp : ExpandableUtilityAction
+    public sealed class MeleeAttackNearbyExp : ExpandableUtilityAction
     {
         public override float Bonus => UtilityAction.CombatBonus;
 
@@ -37,13 +39,10 @@ namespace Content.Server.AI.Utility.ExpandableActions.Combat.Melee
                 throw new InvalidOperationException();
             }
 
-            foreach (var entity in Visibility.GetEntitiesInRange(owner.Transform.GridPosition, typeof(IDamageableComponent),
-                controller.VisionRadius))
+            foreach (var target in EntitySystem.Get<AiFactionTagSystem>()
+                .GetNearbyHostiles(owner, controller.VisionRadius))
             {
-                if (entity.HasComponent<BasicActorComponent>() && entity != owner)
-                {
-                    yield return new MeleeWeaponAttackEntity(owner, entity, Bonus);
-                }
+                yield return new MeleeWeaponAttackEntity(owner, target, Bonus);
             }
         }
     }

Content.Server/AI/Utility/ExpandableActions/Combat/Melee/MeleeAttackNearbySpeciesExp.cs

@@ -1,24 +0,0 @@
-using System.Collections.Generic;
-using Content.Server.AI.Utility.Actions;
-using Content.Server.AI.Utility.Actions.Combat.Melee;
-using Content.Server.AI.WorldState;
-using Content.Server.AI.WorldState.States;
-using Content.Server.AI.WorldState.States.Mobs;
-
-namespace Content.Server.AI.Utility.ExpandableActions.Combat.Melee
-{
-    public sealed class MeleeAttackNearbySpeciesExp : ExpandableUtilityAction
-    {
-        public override float Bonus => UtilityAction.CombatBonus;
-
-        public override IEnumerable<UtilityAction> GetActions(Blackboard context)
-        {
-            var owner = context.GetState<SelfState>().GetValue();
-
-            foreach (var entity in context.GetState<NearbyBodiesState>().GetValue())
-            {
-                yield return new MeleeWeaponAttackEntity(owner, entity, Bonus);
-            }
-        }
-    }
-}

Content.Server/AI/Utility/ExpandableActions/Combat/Melee/UnarmedAttackNearbyPlayerExp.cs

@@ -8,8 +8,10 @@ using Content.Server.AI.Utils;
 using Content.Server.AI.WorldState;
 using Content.Server.AI.WorldState.States;
 using Content.Server.GameObjects.Components.Movement;
+using Content.Server.GameObjects.EntitySystems.AI;
 using Content.Shared.GameObjects.Components.Body;
 using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.IoC;
 
 namespace Content.Server.AI.Utility.ExpandableActions.Combat.Melee
@@ -37,13 +39,10 @@ namespace Content.Server.AI.Utility.ExpandableActions.Combat.Melee
                 throw new InvalidOperationException();
             }
 
-            foreach (var entity in Visibility.GetEntitiesInRange(owner.Transform.GridPosition, typeof(IBodyManagerComponent),
-                controller.VisionRadius))
+            foreach (var target in EntitySystem.Get<AiFactionTagSystem>()
+                .GetNearbyHostiles(owner, controller.VisionRadius))
             {
-                if (entity.HasComponent<BasicActorComponent>() && entity != owner)
-                {
-                    yield return new UnarmedAttackEntity(owner, entity, Bonus);
-                }
+                yield return new UnarmedAttackEntity(owner, target, Bonus);
             }
         }
     }

Content.Server/Administration/AGhost.cs

@@ -22,6 +22,12 @@ namespace Content.Server.Administration
             }
 
             var mind = player.ContentData().Mind;
+            if (mind == null)
+            {
+                shell.SendText(player, "You can't ghost here!");
+                return;
+            }
+
             if (mind.VisitingEntity != null && mind.VisitingEntity.Prototype.ID == "AdminObserver")
             {
                 var visiting = mind.VisitingEntity;

Content.Server/Atmos/AtmosCommands.cs

@@ -1,9 +1,11 @@
 #nullable enable
 using System;
 using Content.Server.GameObjects.Components.Atmos;
+using Content.Server.GameObjects.EntitySystems;
 using Content.Shared.Atmos;
 using Robust.Server.Interfaces.Console;
 using Robust.Server.Interfaces.Player;
+using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Map;
 using Robust.Shared.IoC;
@@ -58,7 +60,9 @@ namespace Content.Server.Atmos
         public string Help => "listgases";
         public void Execute(IConsoleShell shell, IPlayerSession? player, string[] args)
         {
-            foreach (var gasPrototype in Atmospherics.Gases)
+            var atmosSystem = EntitySystem.Get<AtmosphereSystem>();
+
+            foreach (var gasPrototype in atmosSystem.Gases)
             {
                 shell.SendText(player, $"{gasPrototype.Name} ID: {gasPrototype.ID}");
             }

Content.Server/Atmos/FireEvent.cs

@@ -0,0 +1,16 @@
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.Atmos
+{
+    public class FireActEvent : EntitySystemMessage
+    {
+        public float Temperature { get; }
+        public float Volume { get; }
+
+        public FireActEvent(float temperature, float volume)
+        {
+            Temperature = temperature;
+            Volume = volume;
+        }
+    }
+}

Content.Server/Atmos/GasMixture.cs

@@ -4,8 +4,10 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using Content.Server.Atmos.Reactions;
+using Content.Server.GameObjects.EntitySystems;
 using Content.Server.Interfaces;
 using Content.Shared.Atmos;
+using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.Interfaces.Serialization;
 using Robust.Shared.IoC;
 using Robust.Shared.Prototypes;
@@ -20,12 +22,17 @@ namespace Content.Server.Atmos
     [Serializable]
     public class GasMixture : IExposeData, IEquatable<GasMixture>, ICloneable
     {
+        private readonly AtmosphereSystem _atmosphereSystem;
+
         [ViewVariables]
         private float[] _moles = new float[Atmospherics.TotalNumberOfGases];
 
         [ViewVariables]
         private float[] _molesArchived = new float[Atmospherics.TotalNumberOfGases];
+
+        [ViewVariables]
         private float _temperature = Atmospherics.TCMB;
+
         public IReadOnlyList<float> Gases => _moles;
 
         [ViewVariables]
@@ -51,7 +58,7 @@ namespace Content.Server.Atmos
 
                 for (var i = 0; i < Atmospherics.TotalNumberOfGases; i++)
                 {
-                    capacity += Atmospherics.GetGas(i).SpecificHeat * _moles[i];
+                    capacity += _atmosphereSystem.GetGas(i).SpecificHeat * _moles[i];
                 }
 
                 return MathF.Max(capacity, Atmospherics.MinimumHeatCapacity);
@@ -68,7 +75,7 @@ namespace Content.Server.Atmos
 
                 for (var i = 0; i < Atmospherics.TotalNumberOfGases; i++)
                 {
-                    capacity += Atmospherics.GetGas(i).SpecificHeat * _molesArchived[i];
+                    capacity += _atmosphereSystem.GetGas(i).SpecificHeat * _molesArchived[i];
                 }
 
                 return MathF.Max(capacity, Atmospherics.MinimumHeatCapacity);
@@ -122,15 +129,21 @@ namespace Content.Server.Atmos
         [ViewVariables]
         public float Volume { get; set; }
 
-        public GasMixture()
+        public GasMixture() : this(null)
         {
         }
 
-        public GasMixture(float volume)
+        public GasMixture(AtmosphereSystem? atmosphereSystem)
+        {
+            _atmosphereSystem = atmosphereSystem ?? EntitySystem.Get<AtmosphereSystem>();
+        }
+
+        public GasMixture(float volume, AtmosphereSystem? atmosphereSystem = null)
         {
             if (volume < 0)
                 volume = 0;
             Volume = volume;
+            _atmosphereSystem = atmosphereSystem ?? EntitySystem.Get<AtmosphereSystem>();
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -215,12 +228,12 @@ namespace Content.Server.Atmos
         public GasMixture RemoveRatio(float ratio)
         {
             if(ratio <= 0)
-                return new GasMixture(Volume);
+                return new GasMixture(Volume, _atmosphereSystem);
 
             if (ratio > 1)
                 ratio = 1;
 
-            var removed = new GasMixture {Volume = Volume, Temperature = Temperature};
+            var removed = new GasMixture(_atmosphereSystem) {Volume = Volume, Temperature = Temperature};
 
             for (var i = 0; i < Atmospherics.TotalNumberOfGases; i++)
             {
@@ -243,7 +256,7 @@ namespace Content.Server.Atmos
         public void CopyFromMutable(GasMixture sample)
         {
             if (Immutable) return;
-            sample._moles.AsSpan().CopyTo(_moles.AsSpan());
+            sample._moles.CopyTo(_moles, 0);
             Temperature = sample.Temperature;
         }
 
@@ -274,7 +287,7 @@ namespace Content.Server.Atmos
                 if (!(MathF.Abs(delta) >= Atmospherics.GasMinMoles)) continue;
                 if (absTemperatureDelta > Atmospherics.MinimumTemperatureDeltaToConsider)
                 {
-                    var gasHeatCapacity = delta * Atmospherics.GetGas(i).SpecificHeat;
+                    var gasHeatCapacity = delta * _atmosphereSystem.GetGas(i).SpecificHeat;
                     if (delta > 0)
                     {
                         heatCapacityToSharer += gasHeatCapacity;
@@ -476,8 +489,7 @@ namespace Content.Server.Atmos
             var temperature = Temperature;
             var energy = ThermalEnergy;
 
-            // TODO ATMOS Take reaction priority into account!
-            foreach (var prototype in IoCManager.Resolve<IPrototypeManager>().EnumeratePrototypes<GasReactionPrototype>())
+            foreach (var prototype in _atmosphereSystem.GasReactions)
             {
                 if (energy < prototype.MinimumEnergyRequirement ||
                     temperature < prototype.MinimumTemperatureRequirement)
@@ -499,7 +511,7 @@ namespace Content.Server.Atmos
                 if (!doReaction)
                     continue;
 
-                reaction = prototype.React(this, holder);
+                reaction = prototype.React(this, holder, _atmosphereSystem.EventBus);
                 if(reaction.HasFlag(ReactionResult.StopReactions))
                     break;
             }
@@ -579,7 +591,7 @@ namespace Content.Server.Atmos
 
         public object Clone()
         {
-            var newMixture = new GasMixture()
+            var newMixture = new GasMixture(_atmosphereSystem)
             {
                 _moles = (float[])_moles.Clone(),
                 _molesArchived = (float[])_molesArchived.Clone(),

Content.Server/Atmos/GasSprayerComponent.cs

@@ -2,7 +2,6 @@
 using Content.Server.Interfaces;
 using Content.Shared.Chemistry;
 using Content.Shared.GameObjects.Components;
-using Content.Shared.GameObjects.Components.Pointing;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects;
 using Robust.Server.GameObjects.EntitySystems;
@@ -20,10 +19,8 @@ namespace Content.Server.Atmos
     [RegisterComponent]
     public class GasSprayerComponent : Component, IAfterInteract
     {
-#pragma warning disable 649
         [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
         [Dependency] private readonly IServerEntityManager _serverEntityManager = default!;
-#pragma warning restore 649
 
         //TODO: create a function that can create a gas based on a solution mix
         public override string Name => "GasSprayer";

Content.Server/Atmos/HighPressureMovementController.cs

@@ -1,6 +1,7 @@
 #nullable enable
 using System;
 using Content.Server.GameObjects.Components.Atmos;
+using Content.Shared.Atmos;
 using Robust.Shared.GameObjects.Components;
 using Robust.Shared.Interfaces.Physics;
 using Robust.Shared.Interfaces.Random;
@@ -24,7 +25,7 @@ namespace Content.Server.Atmos
         private const float ProbabilityBasePercent = 10f;
         private const float ThrowForce = 100f;
 
-        public void ExperiencePressureDifference(int cycle, float pressureDifference, Direction direction,
+        public void ExperiencePressureDifference(int cycle, float pressureDifference, AtmosDirection direction,
             float pressureResistanceProbDelta, GridCoordinates throwTarget)
         {
             if (ControlledComponent == null)
@@ -54,14 +55,14 @@ namespace Content.Server.Atmos
                     if (throwTarget != GridCoordinates.InvalidGrid)
                     {
                         var moveForce = maxForce * MathHelper.Clamp(moveProb, 0, 100) / 150f;
-                        var pos = ((throwTarget.Position - transform.GridPosition.Position).Normalized + direction.ToVec()).Normalized;
+                        var pos = ((throwTarget.Position - transform.GridPosition.Position).Normalized + direction.ToDirection().ToVec()).Normalized;
                         LinearVelocity = pos * moveForce;
                     }
 
                     else
                     {
                         var moveForce = MathF.Min(maxForce * MathHelper.Clamp(moveProb, 0, 100) / 2500f, 20f);
-                        LinearVelocity = direction.ToVec() * moveForce;
+                        LinearVelocity = direction.ToDirection().ToVec() * moveForce;
                     }
 
                     pressureComponent.LastHighPressureMovementAirCycle = cycle;

Content.Server/Atmos/IGridAtmosphereComponent.cs

@@ -1,4 +1,6 @@
 using System.Collections.Generic;
+using Content.Server.GameObjects.Components.Atmos.Piping;
+using Content.Server.GameObjects.Components.NodeContainer.NodeGroups;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
@@ -12,11 +14,6 @@ namespace Content.Server.Atmos
         /// </summary>
         int UpdateCounter { get; }
 
-        /// <summary>
-        ///     How many tiles have high pressure delta.
-        /// </summary>
-        int HighPressureDeltaCount { get; }
-
         /// <summary>
         ///     Control variable for equalization.
         /// </summary>
@@ -120,14 +117,14 @@ namespace Content.Server.Atmos
         /// </summary>
         /// <param name="indices"></param>
         /// <returns></returns>
-        TileAtmosphere GetTile(MapIndices indices);
+        TileAtmosphere GetTile(MapIndices indices, bool createSpace = true);
 
         /// <summary>
         ///     Returns a tile.
         /// </summary>
         /// <param name="coordinates"></param>
         /// <returns></returns>
-        TileAtmosphere GetTile(GridCoordinates coordinates);
+        TileAtmosphere GetTile(GridCoordinates coordinates, bool createSpace = true);
 
         /// <summary>
         ///     Returns if the tile in question is air-blocked.
@@ -158,5 +155,13 @@ namespace Content.Server.Atmos
         Dictionary<Direction, TileAtmosphere> GetAdjacentTiles(MapIndices indices, bool includeAirBlocked = false);
 
         void Update(float frameTime);
+
+        void AddPipeNet(IPipeNet pipeNet);
+
+        void RemovePipeNet(IPipeNet pipeNet);
+
+        void AddPipeNetDevice(PipeNetDeviceComponent pipeNetDevice);
+
+        void RemovePipeNetDevice(PipeNetDeviceComponent pipeNetDevice);
     }
 }

Content.Server/Atmos/Reactions/GasReactionPrototype.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using Content.Server.Interfaces;
 using Content.Shared.Atmos;
+using Robust.Shared.GameObjects;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
 using YamlDotNet.RepresentationModel;
@@ -64,13 +65,13 @@ namespace Content.Server.Atmos.Reactions
             serializer.DataField(ref _effects, "effects", new List<IGasReactionEffect>());
         }
 
-        public ReactionResult React(GasMixture mixture, IGasMixtureHolder holder)
+        public ReactionResult React(GasMixture mixture, IGasMixtureHolder holder, IEventBus eventBus)
         {
             var result = ReactionResult.NoReaction;
 
             foreach (var effect in _effects)
             {
-                result |= effect.React(mixture, holder);
+                result |= effect.React(mixture, holder, eventBus);
             }
 
             return result;

Content.Server/Atmos/Reactions/PhoronFireReaction.cs

@@ -1,8 +1,12 @@
 #nullable enable
 using System;
 using Content.Server.Interfaces;
+using Content.Server.Interfaces.GameObjects.Components.Interaction;
 using Content.Shared.Atmos;
+using Content.Shared.Maps;
 using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
 using Robust.Shared.Serialization;
 
 namespace Content.Server.Atmos.Reactions
@@ -10,7 +14,7 @@ namespace Content.Server.Atmos.Reactions
     [UsedImplicitly]
     public class PhoronFireReaction : IGasReactionEffect
     {
-        public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder)
+        public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder, IEventBus eventBus)
         {
             var energyReleased = 0f;
             var oldHeatCapacity = mixture.HeatCapacity;
@@ -71,9 +75,7 @@ namespace Content.Server.Atmos.Reactions
                 {
                     location.HotspotExpose(temperature, mixture.Volume);
 
-                    // TODO ATMOS Expose temperature all items on cell
-
-                    location.TemperatureExpose(mixture, temperature, mixture.Volume);
+                    eventBus.QueueEvent(EventSource.Local, new TemperatureExposeEvent(location.GridIndices, location.GridIndex, mixture, temperature, mixture.Volume));
                 }
             }
 

Content.Server/Atmos/Reactions/TritiumFireReaction.cs

@@ -1,7 +1,10 @@
 #nullable enable
 using Content.Server.Interfaces;
+using Content.Server.Interfaces.GameObjects.Components.Interaction;
 using Content.Shared.Atmos;
+using Content.Shared.Maps;
 using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
 using Robust.Shared.Serialization;
 
 namespace Content.Server.Atmos.Reactions
@@ -13,7 +16,7 @@ namespace Content.Server.Atmos.Reactions
         {
         }
 
-        public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder)
+        public ReactionResult React(GasMixture mixture, IGasMixtureHolder? holder, IEventBus eventBus)
         {
             var energyReleased = 0f;
             var oldHeatCapacity = mixture.HeatCapacity;
@@ -66,9 +69,7 @@ namespace Content.Server.Atmos.Reactions
                 {
                     location.HotspotExpose(temperature, mixture.Volume);
 
-                    // TODO ATMOS Expose temperature all items on cell
-
-                    location.TemperatureExpose(mixture, temperature, mixture.Volume);
+                    eventBus.QueueEvent(EventSource.Local, new TemperatureExposeEvent(location.GridIndices, location.GridIndex, mixture, temperature, mixture.Volume));
                 }
             }
 

Content.Server/Atmos/TemperatureExposeEvent.cs

@@ -0,0 +1,23 @@
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+
+namespace Content.Server.Atmos
+{
+    public class TemperatureExposeEvent : EntitySystemMessage
+    {
+        public MapIndices Indices { get; }
+        public GridId Grid { get; }
+        public GasMixture Air { get; }
+        public float Temperature { get; }
+        public float Volume { get; }
+
+        public TemperatureExposeEvent(MapIndices indices, GridId gridId, GasMixture air, float temperature, float volume)
+        {
+            Indices = indices;
+            Grid = gridId;
+            Air = air;
+            Temperature = temperature;
+            Volume = volume;
+        }
+    }
+}

Content.Server/Atmos/TileAtmosInfo.cs

@@ -1,4 +1,5 @@
 using System;
+using Content.Shared.Atmos;
 using Robust.Shared.Maths;
 using Robust.Shared.ViewVariables;
 
@@ -30,15 +31,15 @@ namespace Content.Server.Atmos
         [ViewVariables]
         public float TransferDirectionSouth;
 
-        public float this[Direction direction]
+        public float this[AtmosDirection direction]
         {
             get =>
                 direction switch
                 {
-                    Direction.East => TransferDirectionEast,
-                    Direction.West => TransferDirectionWest,
-                    Direction.North => TransferDirectionNorth,
-                    Direction.South => TransferDirectionSouth,
+                    AtmosDirection.East => TransferDirectionEast,
+                    AtmosDirection.West => TransferDirectionWest,
+                    AtmosDirection.North => TransferDirectionNorth,
+                    AtmosDirection.South => TransferDirectionSouth,
                     _ => throw new ArgumentOutOfRangeException(nameof(direction))
                 };
 
@@ -46,16 +47,16 @@ namespace Content.Server.Atmos
             {
                 switch (direction)
                 {
-                    case Direction.East:
+                    case AtmosDirection.East:
                          TransferDirectionEast = value;
                          break;
-                    case Direction.West:
+                    case AtmosDirection.West:
                         TransferDirectionWest = value;
                         break;
-                    case Direction.North:
+                    case AtmosDirection.North:
                         TransferDirectionNorth = value;
                         break;
-                    case Direction.South:
+                    case AtmosDirection.South:
                         TransferDirectionSouth = value;
                         break;
                     default:
@@ -64,10 +65,16 @@ namespace Content.Server.Atmos
             }
         }
 
+        public float this[int index]
+        {
+            get => this[(AtmosDirection) (1 << index)];
+            set => this[(AtmosDirection) (1 << index)] = value;
+        }
+
         [ViewVariables]
         public float CurrentTransferAmount;
 
-        public Direction CurrentTransferDirection;
+        public AtmosDirection CurrentTransferDirection;
 
         [ViewVariables]
         public bool FastDone;

Content.Server/Atmos/TileAtmosphere.cs

@@ -4,7 +4,6 @@ using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using Content.Server.Atmos.Reactions;
 using Content.Server.GameObjects.Components.Atmos;
-using Content.Server.GameObjects.EntitySystems;
 using Content.Server.GameObjects.EntitySystems.Atmos;
 using Content.Server.Interfaces;
 using Content.Shared.Atmos;
@@ -12,13 +11,13 @@ using Content.Shared.Audio;
 using Content.Shared.Maps;
 using Robust.Server.GameObjects.EntitySystems;
 using Robust.Shared.Containers;
+using Robust.Shared.GameObjects;
 using Robust.Shared.GameObjects.Components;
 using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Map;
 using Robust.Shared.Interfaces.Random;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Random;
@@ -28,18 +27,15 @@ namespace Content.Server.Atmos
 {
     public class TileAtmosphere : IGasMixtureHolder
     {
-        [Robust.Shared.IoC.Dependency] private IRobustRandom _robustRandom = default!;
-        [Robust.Shared.IoC.Dependency] private IEntityManager _entityManager = default!;
-        [Robust.Shared.IoC.Dependency] private IMapManager _mapManager = default!;
+        [Robust.Shared.IoC.Dependency] private readonly IRobustRandom _robustRandom = default!;
+        [Robust.Shared.IoC.Dependency] private readonly IEntityManager _entityManager = default!;
+        [Robust.Shared.IoC.Dependency] private readonly IMapManager _mapManager = default!;
 
 
-        private static readonly TileAtmosphereComparer _comparer = new TileAtmosphereComparer();
+        private static readonly TileAtmosphereComparer Comparer = new TileAtmosphereComparer();
 
-        [ViewVariables]
-        private int _archivedCycle = 0;
-
-        [ViewVariables]
-        private int _currentCycle = 0;
+        [ViewVariables] private int _archivedCycle;
+        [ViewVariables] private int _currentCycle;
 
         [ViewVariables]
         private static GasTileOverlaySystem _gasTileOverlaySystem;
@@ -51,13 +47,13 @@ namespace Content.Server.Atmos
         private float _temperatureArchived = Atmospherics.T20C;
 
         // I know this being static is evil, but I seriously can't come up with a better solution to sound spam.
-        private static int _soundCooldown = 0;
+        private static int _soundCooldown;
 
         [ViewVariables]
-        public TileAtmosphere PressureSpecificTarget { get; set; } = null;
+        public TileAtmosphere PressureSpecificTarget { get; set; }
 
         [ViewVariables]
-        public float PressureDifference { get; set; } = 0;
+        public float PressureDifference { get; set; }
 
         [ViewVariables(VVAccess.ReadWrite)]
         public float HeatCapacity { get; set; } = 1f;
@@ -66,13 +62,19 @@ namespace Content.Server.Atmos
         public float ThermalConductivity => Tile?.Tile.GetContentTileDefinition().ThermalConductivity ?? 0.05f;
 
         [ViewVariables]
-        public bool Excited { get; set; } = false;
+        public bool Excited { get; set; }
 
         [ViewVariables]
-        private GridAtmosphereComponent _gridAtmosphereComponent;
+        private readonly GridAtmosphereComponent _gridAtmosphereComponent;
+
+        /// <summary>
+        ///     Adjacent tiles in the same order as <see cref="AtmosDirection"/>. (NSEW)
+        /// </summary>
+        [ViewVariables]
+        private readonly TileAtmosphere[] _adjacentTiles = new TileAtmosphere[Atmospherics.Directions];
 
         [ViewVariables]
-        private readonly Dictionary<Direction, TileAtmosphere> _adjacentTiles = new Dictionary<Direction, TileAtmosphere>();
+        private AtmosDirection _adjacentBits = AtmosDirection.Invalid;
 
         [ViewVariables]
         private TileAtmosInfo _tileAtmosInfo;
@@ -80,7 +82,7 @@ namespace Content.Server.Atmos
         [ViewVariables]
         public Hotspot Hotspot;
 
-        private Direction _pressureDirection;
+        private AtmosDirection _pressureDirection;
 
         [ViewVariables]
         public GridId GridIndex { get; }
@@ -100,14 +102,16 @@ namespace Content.Server.Atmos
         [ViewVariables]
         public bool BlocksAir => _gridAtmosphereComponent.IsAirBlocked(GridIndices);
 
-        public TileAtmosphere(GridAtmosphereComponent atmosphereComponent, GridId gridIndex, MapIndices gridIndices, GasMixture mixture = null)
+        public TileAtmosphere(GridAtmosphereComponent atmosphereComponent, GridId gridIndex, MapIndices gridIndices, GasMixture mixture = null, bool immutable = false)
         {
             IoCManager.InjectDependencies(this);
             _gridAtmosphereComponent = atmosphereComponent;
             GridIndex = gridIndex;
             GridIndices = gridIndices;
             Air = mixture;
-            ResetTileAtmosInfo();
+
+            if(immutable)
+                Air?.MarkImmutable();
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -163,7 +167,7 @@ namespace Content.Server.Atmos
             }
         }
 
-        //[MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void HighPressureMovements()
         {
             // TODO ATMOS finish this
@@ -175,7 +179,6 @@ namespace Content.Server.Atmos
                         GridIndices.ToGridCoordinates(_mapManager, GridIndex), AudioHelpers.WithVariation(0.125f).WithVolume(MathHelper.Clamp(PressureDifference / 10, 10, 100)));
             }
 
-
             foreach (var entity in _entityManager.GetEntitiesIntersecting(_mapManager.GetGrid(GridIndex).ParentMapId, Box2.UnitCentered.Translated(GridIndices)))
             {
                 if (!entity.TryGetComponent(out ICollidableComponent physics)
@@ -195,7 +198,7 @@ namespace Content.Server.Atmos
 
             if (PressureDifference > 100)
             {
-                // Do space wind graphics here!
+                // TODO ATMOS Do space wind graphics here!
             }
 
             _soundCooldown++;
@@ -220,20 +223,22 @@ namespace Content.Server.Atmos
             }
         }
 
-        //[MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void EqualizePressureInZone(int cycleNum)
         {
             if (Air == null || (_tileAtmosInfo.LastCycle >= cycleNum)) return; // Already done.
 
-            ResetTileAtmosInfo();
-
+            _tileAtmosInfo = new TileAtmosInfo();
 
             var startingMoles = Air.TotalMoles;
             var runAtmos = false;
 
             // We need to figure if this is necessary
-            foreach (var (direction, other) in _adjacentTiles)
+            for (var i = 0; i < Atmospherics.Directions; i++)
             {
+                var direction = (AtmosDirection) (1 << i);
+                if (!_adjacentBits.HasFlag(direction)) continue;
+                var other = _adjacentTiles[i];
                 if (other?.Air == null) continue;
                 var comparisonMoles = other.Air.TotalMoles;
                 if (!(MathF.Abs(comparisonMoles - startingMoles) > Atmospherics.MinimumMolesDeltaToMove)) continue;
@@ -265,13 +270,15 @@ namespace Content.Server.Atmos
                     totalMoles += tileMoles;
                 }
 
-                foreach (var (_, adj) in exploring._adjacentTiles)
+                for (var j = 0; j < Atmospherics.Directions; j++)
                 {
+                    var direction = (AtmosDirection) (1 << j);
+                    if (!exploring._adjacentBits.HasFlag(direction)) continue;
+                    var adj = exploring._adjacentTiles[j];
                     if (adj?.Air == null) continue;
                     if(adj._tileAtmosInfo.LastQueueCycle == queueCycle) continue;
-                    adj.ResetTileAtmosInfo();
+                    adj._tileAtmosInfo = new TileAtmosInfo {LastQueueCycle = queueCycle};
 
-                    adj._tileAtmosInfo.LastQueueCycle = queueCycle;
                     if(tileCount < Atmospherics.ZumosHardTileLimit)
                         tiles[tileCount++] = adj;
                     if (adj.Air.Immutable)
@@ -326,47 +333,42 @@ namespace Content.Server.Atmos
             if (giverTilesLength > logN && takerTilesLength > logN)
             {
                 // Even if it fails, it will speed up the next part.
-                Array.Sort(tiles, 0, tileCount, _comparer);
+                Array.Sort(tiles, 0, tileCount, Comparer);
 
                 for (var i = 0; i < tileCount; i++)
                 {
                     var tile = tiles[i];
                     tile._tileAtmosInfo.FastDone = true;
                     if (!(tile._tileAtmosInfo.MoleDelta > 0)) continue;
-                    var eligibleDirections = ArrayPool<Direction>.Shared.Rent(4);
+                    var eligibleDirections = AtmosDirection.Invalid;
                     var eligibleDirectionCount = 0;
-                    foreach (var direction in Cardinal)
+                    for (var j = 0; j < Atmospherics.Directions; j++)
                     {
-                        if (!tile._adjacentTiles.TryGetValue(direction, out var tile2)) continue;
+                        var direction = (AtmosDirection) (1 << j);
+                        if (!tile._adjacentBits.HasFlag(direction)) continue;
+                        var tile2 = tile._adjacentTiles[j];
 
                         // skip anything that isn't part of our current processing block.
                         if (tile2._tileAtmosInfo.FastDone || tile2._tileAtmosInfo.LastQueueCycle != queueCycle)
                             continue;
 
-                        eligibleDirections[eligibleDirectionCount++] = direction;
+                        eligibleDirections |= direction;
+                        eligibleDirectionCount++;
                     }
 
                     if (eligibleDirectionCount <= 0)
                         continue; // Oof we've painted ourselves into a corner. Bad luck. Next part will handle this.
 
                     var molesToMove = tile._tileAtmosInfo.MoleDelta / eligibleDirectionCount;
-                    foreach (var direction in Cardinal)
+                    for (var j = 0; j < Atmospherics.Directions; j++)
                     {
-                        var hasDirection = false;
-                        for (var j = 0; j < eligibleDirectionCount; j++)
-                        {
-                            if (eligibleDirections[j] != direction) continue;
-                            hasDirection = true;
-                            break;
-                        }
+                        var direction = (AtmosDirection) (1 << j);
+                        if (!eligibleDirections.HasFlag(direction)) continue;
 
-                        if (hasDirection || !tile._adjacentTiles.TryGetValue(direction, out var tile2)) continue;
                         tile.AdjustEqMovement(direction, molesToMove);
                         tile._tileAtmosInfo.MoleDelta -= molesToMove;
-                        tile2._tileAtmosInfo.MoleDelta += molesToMove;
+                        tile._adjacentTiles[j]._tileAtmosInfo.MoleDelta += molesToMove;
                     }
-
-                    ArrayPool<Direction>.Shared.Return(eligibleDirections);
                 }
 
                 giverTilesLength = 0;
@@ -393,7 +395,7 @@ namespace Content.Server.Atmos
                     for (var j = 0; j < giverTilesLength; j++)
                     {
                         var giver = giverTiles[j];
-                        giver._tileAtmosInfo.CurrentTransferDirection = (Direction) (-1);
+                        giver._tileAtmosInfo.CurrentTransferDirection = AtmosDirection.Invalid;
                         giver._tileAtmosInfo.CurrentTransferAmount = 0;
                         var queueCycleSlow = ++_gridAtmosphereComponent.EqualizationQueueCycleControl;
                         var queueLength = 0;
@@ -405,9 +407,11 @@ namespace Content.Server.Atmos
                                 break; // We're done here now. Let's not do more work than needed.
 
                             var tile = queue[i];
-                            foreach (var direction in Cardinal)
+                            for (var k = 0; k < Atmospherics.Directions; k++)
                             {
-                                if (!tile._adjacentTiles.TryGetValue(direction, out var tile2)) continue;
+                                var direction = (AtmosDirection) (1 << k);
+                                if (!tile._adjacentBits.HasFlag(direction)) continue;
+                                var tile2 = tile._adjacentTiles[k];
                                 if (giver._tileAtmosInfo.MoleDelta <= 0) break; // We're done here now. Let's not do more work than needed.
                                 if (tile2._tileAtmosInfo.LastQueueCycle != queueCycle) continue;
                                 if (tile2._tileAtmosInfo.LastSlowQueueCycle == queueCycleSlow) continue;
@@ -441,15 +445,11 @@ namespace Content.Server.Atmos
                         for (var i = queueLength - 1; i >= 0; i--)
                         {
                             var tile = queue[i];
-                            if (tile._tileAtmosInfo.CurrentTransferAmount != 0 &&
-                                tile._tileAtmosInfo.CurrentTransferDirection != (Direction) (-1))
+                            if (tile._tileAtmosInfo.CurrentTransferAmount != 0 && tile._tileAtmosInfo.CurrentTransferDirection != AtmosDirection.Invalid)
                             {
-                                tile.AdjustEqMovement(tile._tileAtmosInfo.CurrentTransferDirection,
-                                    tile._tileAtmosInfo.CurrentTransferAmount);
-                                if (tile._adjacentTiles.TryGetValue(tile._tileAtmosInfo.CurrentTransferDirection,
-                                    out var adjacent))
-                                    adjacent._tileAtmosInfo.CurrentTransferAmount +=
-                                        tile._tileAtmosInfo.CurrentTransferAmount;
+                                tile.AdjustEqMovement(tile._tileAtmosInfo.CurrentTransferDirection, tile._tileAtmosInfo.CurrentTransferAmount);
+                                tile._adjacentTiles[tile._tileAtmosInfo.CurrentTransferDirection.ToIndex()]
+                                    ._tileAtmosInfo.CurrentTransferAmount += tile._tileAtmosInfo.CurrentTransferAmount;
                                 tile._tileAtmosInfo.CurrentTransferAmount = 0;
                             }
                         }
@@ -463,7 +463,7 @@ namespace Content.Server.Atmos
                     for (var j = 0; j < takerTilesLength; j++)
                     {
                         var taker = takerTiles[j];
-                        taker._tileAtmosInfo.CurrentTransferDirection = Direction.Invalid;
+                        taker._tileAtmosInfo.CurrentTransferDirection = AtmosDirection.Invalid;
                         taker._tileAtmosInfo.CurrentTransferAmount = 0;
                         var queueCycleSlow = ++_gridAtmosphereComponent.EqualizationQueueCycleControl;
                         var queueLength = 0;
@@ -475,10 +475,11 @@ namespace Content.Server.Atmos
                                 break; // We're done here now. Let's not do more work than needed.
 
                             var tile = queue[i];
-                            foreach (var direction in Cardinal)
+                            for (var k = 0; k < Atmospherics.Directions; k++)
                             {
-                                if (!tile._adjacentTiles.ContainsKey(direction)) continue;
-                                var tile2 = tile._adjacentTiles[direction];
+                                var direction = (AtmosDirection) (1 << k);
+                                if (!tile._adjacentBits.HasFlag(direction)) continue;
+                                var tile2 = tile._adjacentTiles[k];
 
                                 if (taker._tileAtmosInfo.MoleDelta >= 0) break; // We're done here now. Let's not do more work than needed.
                                 if (tile2._tileAtmosInfo.LastQueueCycle != queueCycle) continue;
@@ -512,16 +513,14 @@ namespace Content.Server.Atmos
                         for (var i = queueLength - 1; i >= 0; i--)
                         {
                             var tile = queue[i];
-                            if (tile._tileAtmosInfo.CurrentTransferAmount == 0 || tile._tileAtmosInfo.CurrentTransferDirection == Direction.Invalid)
+                            if (tile._tileAtmosInfo.CurrentTransferAmount == 0 || tile._tileAtmosInfo.CurrentTransferDirection == AtmosDirection.Invalid)
                                 continue;
 
                             tile.AdjustEqMovement(tile._tileAtmosInfo.CurrentTransferDirection, tile._tileAtmosInfo.CurrentTransferAmount);
 
-                            if (tile._adjacentTiles.TryGetValue(tile._tileAtmosInfo.CurrentTransferDirection, out var adjacent))
-                            {
-                                adjacent._tileAtmosInfo.CurrentTransferAmount += tile._tileAtmosInfo.CurrentTransferAmount;
-                                tile._tileAtmosInfo.CurrentTransferAmount = 0;
-                            }
+                            tile._adjacentTiles[tile._tileAtmosInfo.CurrentTransferDirection.ToIndex()]
+                                ._tileAtmosInfo.CurrentTransferAmount += tile._tileAtmosInfo.CurrentTransferAmount;
+                            tile._tileAtmosInfo.CurrentTransferAmount = 0;
                         }
                     }
 
@@ -537,9 +536,11 @@ namespace Content.Server.Atmos
                 for (var i = 0; i < tileCount; i++)
                 {
                     var tile = tiles[i];
-                    foreach (var direction in Cardinal)
+                    for (var j = 0; j < Atmospherics.Directions; j++)
                     {
-                        if (!tile._adjacentTiles.TryGetValue(direction, out var tile2)) continue;
+                        var direction = (AtmosDirection) (1 << j);
+                        if (!tile._adjacentBits.HasFlag(direction)) continue;
+                        var tile2 = tile._adjacentTiles[j];
                         if (tile2?.Air?.Compare(Air) == GasMixture.GasCompareResult.NoExchange) continue;
                         _gridAtmosphereComponent.AddActiveTile(tile2);
                         break;
@@ -555,69 +556,68 @@ namespace Content.Server.Atmos
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private void FinalizeEq()
         {
-            var transferDirections = new Dictionary<Direction, float>();
+            var transferDirections = new float[Atmospherics.Directions];
             var hasTransferDirs = false;
-            foreach (var direction in Cardinal)
+            for (var i = 0; i < Atmospherics.Directions; i++)
             {
-                var amount = _tileAtmosInfo[direction];
+                var amount = _tileAtmosInfo[i];
                 if (amount == 0) continue;
-                transferDirections[direction] = amount;
-                _tileAtmosInfo[direction] = 0;
+                transferDirections[i] = amount;
+                _tileAtmosInfo[i] = 0; // Set them to 0 to prevent infinite recursion.
                 hasTransferDirs = true;
             }
 
             if (!hasTransferDirs) return;
 
-            foreach (var (direction, amount) in transferDirections)
+            for(var i = 0; i < Atmospherics.Directions; i++)
             {
-                if (!_adjacentTiles.TryGetValue(direction, out var tile) || tile.Air == null) continue;
+                var direction = (AtmosDirection) (1 << i);
+                if (!_adjacentBits.HasFlag(direction)) continue;
+                var amount = transferDirections[i];
+                var tile = _adjacentTiles[i];
+                if (tile?.Air == null) continue;
                 if (amount > 0)
                 {
                     if (Air.TotalMoles < amount)
-                        FinalizeEqNeighbors(transferDirections.Keys);
+                        FinalizeEqNeighbors(transferDirections);
 
+                    tile._tileAtmosInfo[direction.GetOpposite()] = 0;
                     tile.Air.Merge(Air.Remove(amount));
                     UpdateVisuals();
                     tile.UpdateVisuals();
-                    ConsiderPressureDifference(direction, amount);
+                    ConsiderPressureDifference(tile, amount);
                 }
             }
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private void FinalizeEqNeighbors(IEnumerable<Direction> directions)
+        private void FinalizeEqNeighbors(in float[] transferDirs)
         {
-            foreach (var direction in directions)
+            for (var i = 0; i < Atmospherics.Directions; i++)
             {
-                var amount = _tileAtmosInfo[direction];
-                if(amount < 0 && _adjacentTiles.TryGetValue(direction, out var adjacent))
-                    adjacent.FinalizeEq();
+                var direction = (AtmosDirection) (1 << i);
+                var amount = transferDirs[i];
+                if(amount < 0 && _adjacentBits.HasFlag(direction))
+                    _adjacentTiles[i].FinalizeEq();  // A bit of recursion if needed.
             }
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private void ConsiderPressureDifference(Direction direction, float difference)
+        private void ConsiderPressureDifference(TileAtmosphere other, float difference)
         {
             _gridAtmosphereComponent.AddHighPressureDelta(this);
             if (difference > PressureDifference)
             {
                 PressureDifference = difference;
-                _pressureDirection = difference < 0 ? direction.GetOpposite() : direction;
+                _pressureDirection = ((Vector2i)(GridIndices - other.GridIndices)).GetDir().ToAtmosDirection();
             }
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private void AdjustEqMovement(Direction direction, float molesToMove)
+        private void AdjustEqMovement(AtmosDirection direction, float amount)
         {
-            _tileAtmosInfo[direction] += molesToMove;
-            if(direction != Direction.Invalid && _adjacentTiles.TryGetValue(direction, out var adj))
-                adj._tileAtmosInfo[direction.GetOpposite()] -= molesToMove;
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private void ResetTileAtmosInfo()
-        {
-            _tileAtmosInfo = new TileAtmosInfo {CurrentTransferDirection = Direction.Invalid};
+            _tileAtmosInfo[direction] += amount;
+            _adjacentTiles[direction.ToIndex()]._tileAtmosInfo[direction.GetOpposite()] -= amount;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -635,9 +635,13 @@ namespace Content.Server.Atmos
 
             _currentCycle = fireCount;
             var adjacentTileLength = 0;
-            foreach (var (direction, enemyTile) in _adjacentTiles)
+            for(var i = 0; i < Atmospherics.Directions; i++)
             {
-                // If the tile is null or has no air, we don't do anything
+                var direction = (AtmosDirection) (1 << i);
+                if (!_adjacentBits.HasFlag(direction)) continue;
+                var enemyTile = _adjacentTiles[i];
+
+                // If the tile is null or has no air, we don't do anything for it.
                 if(enemyTile?.Air == null) continue;
                 adjacentTileLength++;
                 if (fireCount <= enemyTile._currentCycle) continue;
@@ -685,11 +689,11 @@ namespace Content.Server.Atmos
                     // Space wind!
                     if (difference > 0)
                     {
-                        ConsiderPressureDifference(direction, difference);
+                        ConsiderPressureDifference(enemyTile, difference);
                     }
                     else
                     {
-                        enemyTile.ConsiderPressureDifference(direction.GetOpposite(), -difference);
+                        enemyTile.ConsiderPressureDifference(this, -difference);
                     }
 
                     LastShareCheck();
@@ -737,7 +741,7 @@ namespace Content.Server.Atmos
                 if (Air.Temperature > Atmospherics.FireMinimumTemperatureToSpread)
                 {
                     var radiatedTemperature = Air.Temperature * Atmospherics.FireSpreadRadiosityScale;
-                    foreach (var (_, tile) in _adjacentTiles)
+                    foreach (var tile in _adjacentTiles)
                     {
                         if(!tile.Hotspot.Valid)
                             tile.HotspotExpose(radiatedTemperature, Atmospherics.CellVolume/4);
@@ -771,17 +775,19 @@ namespace Content.Server.Atmos
             else
             {
                 var affected = Air.RemoveRatio(Hotspot.Volume / Air.Volume);
-                if (affected != null)
-                {
-                    affected.Temperature = Hotspot.Temperature;
-                    affected.React(this);
-                    Hotspot.Temperature = affected.Temperature;
-                    Hotspot.Volume = affected.ReactionResults[GasReaction.Fire] * Atmospherics.FireGrowthRate;
-                    AssumeAir(affected);
-                }
+                affected.Temperature = Hotspot.Temperature;
+                affected.React(this);
+                Hotspot.Temperature = affected.Temperature;
+                Hotspot.Volume = affected.ReactionResults[GasReaction.Fire] * Atmospherics.FireGrowthRate;
+                AssumeAir(affected);
             }
 
-            // TODO ATMOS Let all entities in this tile know about the fire?
+            var tileRef = GridIndices.GetTileRef(GridIndex);
+
+            if (tileRef == null) return;
+
+            _gridAtmosphereComponent.Owner.EntityManager.
+                EventBus.QueueEvent(EventSource.Local, new FireActEvent(Hotspot.Temperature, Hotspot.Volume));
         }
 
         private bool ConsiderSuperconductivity()
@@ -806,24 +812,24 @@ namespace Content.Server.Atmos
         public void Superconduct()
         {
             var directions = ConductivityDirections();
-            var adjacentTiles = _gridAtmosphereComponent.GetAdjacentTiles(GridIndices, true);
 
-            if (directions.Length > 0)
+            for(var i = 0; i < Atmospherics.Directions; i++)
             {
-                foreach (var direction in directions)
-                {
-                    if (!adjacentTiles.TryGetValue(direction, out var adjacent)) continue;
+                var direction = (AtmosDirection) (1 << i);
+                if (!directions.HasFlag(direction)) continue;
 
-                    if (adjacent.ThermalConductivity == 0f)
-                        continue;
+                var adjacent = _adjacentTiles[direction.ToIndex()];
 
-                    if(adjacent._archivedCycle < _gridAtmosphereComponent.UpdateCounter)
-                        adjacent.Archive(_gridAtmosphereComponent.UpdateCounter);
+                // TODO ATMOS handle adjacent being null.
+                if (adjacent == null || adjacent.ThermalConductivity == 0f)
+                    continue;
 
-                    adjacent.NeighborConductWithSource(this);
+                if(adjacent._archivedCycle < _gridAtmosphereComponent.UpdateCounter)
+                    adjacent.Archive(_gridAtmosphereComponent.UpdateCounter);
 
-                    adjacent.ConsiderSuperconductivity();
-                }
+                adjacent.NeighborConductWithSource(this);
+
+                adjacent.ConsiderSuperconductivity();
             }
 
             RadiateToSpace();
@@ -917,20 +923,20 @@ namespace Content.Server.Atmos
             }
         }
 
-        public Direction[] ConductivityDirections()
+        public AtmosDirection ConductivityDirections()
         {
             if(BlocksAir)
             {
                 if(_archivedCycle < _gridAtmosphereComponent.UpdateCounter)
                     Archive(_gridAtmosphereComponent.UpdateCounter);
-                return Cardinal;
+                return AtmosDirection.All;
             }
 
             // TODO ATMOS check if this is correct
-            return Cardinal;
+            return AtmosDirection.All;
         }
 
-        //[MethodImpl(MethodImplOptions.AggressiveInlining)]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void ExplosivelyDepressurize(int cycleNum)
         {
             if (Air == null) return;
@@ -947,14 +953,13 @@ namespace Content.Server.Atmos
 
             tiles[tileCount++] = this;
 
-            ResetTileAtmosInfo();
-            _tileAtmosInfo.LastQueueCycle = queueCycle;
+            _tileAtmosInfo = new TileAtmosInfo {LastQueueCycle = queueCycle};
 
             for (var i = 0; i < tileCount; i++)
             {
                 var tile = tiles[i];
                 tile._tileAtmosInfo.LastCycle = cycleNum;
-                tile._tileAtmosInfo.CurrentTransferDirection = Direction.Invalid;
+                tile._tileAtmosInfo.CurrentTransferDirection = AtmosDirection.Invalid;
                 if (tile.Air.Immutable)
                 {
                     spaceTiles[spaceTileCount++] = tile;
@@ -962,18 +967,19 @@ namespace Content.Server.Atmos
                 }
                 else
                 {
-                    foreach (var direction in Cardinal)
+                    for (var j = 0; j < Atmospherics.Directions; j++)
                     {
-                        if (!tile._adjacentTiles.TryGetValue(direction, out var tile2)) continue;
+                        var direction = (AtmosDirection) (1 << j);
+                        if (!tile._adjacentBits.HasFlag(direction)) continue;
+                        var tile2 = tile._adjacentTiles[j];
                         if (tile2.Air == null) continue;
                         if (tile2._tileAtmosInfo.LastQueueCycle == queueCycle) continue;
 
                         tile.ConsiderFirelocks(tile2);
 
                         // The firelocks might have closed on us.
-                        if (tile._adjacentTiles[direction]?.Air == null) continue;
-                        tile2.ResetTileAtmosInfo();
-                        tile2._tileAtmosInfo.LastQueueCycle = queueCycle;
+                        if (!tile._adjacentBits.HasFlag(direction)) continue;
+                        tile2._tileAtmosInfo = new TileAtmosInfo {LastQueueCycle = queueCycle};
                         tiles[tileCount++] = tile2;
                     }
                 }
@@ -991,18 +997,21 @@ namespace Content.Server.Atmos
                 var tile = spaceTiles[i];
                 progressionOrder[progressionCount++] = tile;
                 tile._tileAtmosInfo.LastSlowQueueCycle = queueCycleSlow;
-                tile._tileAtmosInfo.CurrentTransferDirection = Direction.Invalid;
+                tile._tileAtmosInfo.CurrentTransferDirection = AtmosDirection.Invalid;
             }
 
             for (var i = 0; i < progressionCount; i++)
             {
                 var tile = progressionOrder[i];
-                foreach (var direction in Cardinal)
+                for (var j = 0; j < Atmospherics.Directions; j++)
                 {
-                    if (!tile._adjacentTiles.TryGetValue(direction, out var tile2)) continue;
+                    var direction = (AtmosDirection) (1 << j);
+                    // TODO ATMOS This is a terrible hack that accounts for the mess that are space TileAtmospheres.
+                    if (!tile._adjacentBits.HasFlag(direction) && !tile.Air.Immutable) continue;
+                    var tile2 = tile._adjacentTiles[j];
                     if (tile2?._tileAtmosInfo.LastQueueCycle != queueCycle) continue;
                     if (tile2._tileAtmosInfo.LastSlowQueueCycle == queueCycleSlow) continue;
-                    if(tile2.Air.Immutable) continue;
+                    if(tile2.Air?.Immutable ?? false) continue;
                     tile2._tileAtmosInfo.CurrentTransferDirection = direction.GetOpposite();
                     tile2._tileAtmosInfo.CurrentTransferAmount = 0;
                     tile2.PressureSpecificTarget = tile.PressureSpecificTarget;
@@ -1014,10 +1023,11 @@ namespace Content.Server.Atmos
             for (var i = progressionCount - 1; i >= 0; i--)
             {
                 var tile = progressionOrder[i];
-                if (tile._tileAtmosInfo.CurrentTransferDirection == Direction.Invalid) continue;
+                if (tile._tileAtmosInfo.CurrentTransferDirection == AtmosDirection.Invalid) continue;
                 _gridAtmosphereComponent.AddHighPressureDelta(tile);
                 _gridAtmosphereComponent.AddActiveTile(tile);
-                if (!tile._adjacentTiles.TryGetValue(tile._tileAtmosInfo.CurrentTransferDirection, out var tile2) || tile2.Air == null) continue;
+                var tile2 = tile._adjacentTiles[tile._tileAtmosInfo.CurrentTransferDirection.ToIndex()];
+                if (tile2?.Air == null) continue;
                 var sum = tile2.Air.TotalMoles;
                 totalGasesRemoved += sum;
                 tile._tileAtmosInfo.CurrentTransferAmount += sum;
@@ -1025,7 +1035,7 @@ namespace Content.Server.Atmos
                 tile.PressureDifference = tile._tileAtmosInfo.CurrentTransferAmount;
                 tile._pressureDirection = tile._tileAtmosInfo.CurrentTransferDirection;
 
-                if (tile2._tileAtmosInfo.CurrentTransferDirection == Direction.Invalid)
+                if (tile2._tileAtmosInfo.CurrentTransferDirection == AtmosDirection.Invalid)
                 {
                     tile2.PressureDifference = tile2._tileAtmosInfo.CurrentTransferAmount;
                     tile2._pressureDirection = tile._tileAtmosInfo.CurrentTransferDirection;
@@ -1101,21 +1111,30 @@ namespace Content.Server.Atmos
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void UpdateAdjacent()
         {
-            foreach (var direction in Cardinal)
+            for (var i = 0; i < Atmospherics.Directions; i++)
             {
-                if (!_gridAtmosphereComponent.IsAirBlocked(GridIndices.Offset(direction)))
+                var direction = (AtmosDirection) (1 << i);
+
+                var otherIndices = GridIndices.Offset(direction.ToDirection());
+
+                var isSpace = _gridAtmosphereComponent.IsSpace(GridIndices);
+                var adjacent = _gridAtmosphereComponent.GetTile(otherIndices, !isSpace);
+                _adjacentTiles[direction.ToIndex()] = adjacent;
+                adjacent?.UpdateAdjacent(direction.GetOpposite());
+
+                if (adjacent != null && !_gridAtmosphereComponent.IsAirBlocked(adjacent.GridIndices))
                 {
-                    var adjacent = _gridAtmosphereComponent.GetTile(GridIndices.Offset(direction));
-                    _adjacentTiles[direction] = adjacent;
-                    adjacent.UpdateAdjacent(direction.GetOpposite());
+                    _adjacentBits |= direction;
                 }
             }
         }
 
-        public void UpdateAdjacent(Direction direction)
+        public void UpdateAdjacent(AtmosDirection direction)
         {
-            if (!_gridAtmosphereComponent.IsAirBlocked(GridIndices.Offset(direction)))
-                _adjacentTiles[direction] = _gridAtmosphereComponent.GetTile(GridIndices.Offset(direction));
+            if (!_gridAtmosphereComponent.IsAirBlocked(GridIndices.Offset(direction.ToDirection())))
+            {
+                _adjacentTiles[direction.ToIndex()] = _gridAtmosphereComponent.GetTile(GridIndices.Offset(direction.ToDirection()));
+            }
         }
 
         private void LastShareCheck()
@@ -1130,13 +1149,7 @@ namespace Content.Server.Atmos
             }
         }
 
-        private static readonly Direction[] Cardinal =
-            new Direction[]
-            {
-                Direction.North, Direction.East, Direction.South, Direction.West
-            };
-
-        public void TemperatureExpose(GasMixture mixture, float temperature, float cellVolume)
+        public void TemperatureExpose(GasMixture air, float temperature, float volume)
         {
             // TODO ATMOS do this
         }

Content.Server/Body/BodyCommands.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 using System.Linq;
 using Content.Server.GameObjects.Components.Body;
 using Content.Shared.Body.Part;
@@ -42,7 +42,7 @@ namespace Content.Server.Body
             }
 
             var prototypeManager = IoCManager.Resolve<IPrototypeManager>();
-            prototypeManager.TryIndex("bodyPart.Hand.BasicHuman", out BodyPartPrototype prototype);
+            prototypeManager.TryIndex("bodyPart.LHand.BasicHuman", out BodyPartPrototype prototype);
 
             var part = new BodyPart(prototype);
             var slot = part.GetHashCode().ToString();

Content.Server/Chat/ChatManager.cs

@@ -1,11 +1,9 @@
-using System.Linq;
-using Content.Server.GameObjects.Components.Observer;
+using Content.Server.GameObjects.Components.Observer;
 using Content.Server.GameObjects.EntitySystems;
 using Content.Server.Interfaces;
 using Content.Server.Interfaces.Chat;
 using Content.Shared.Chat;
 using Content.Shared.GameObjects.EntitySystems;
-using NFluidsynth;
 using Robust.Server.Console;
 using Robust.Server.Interfaces.GameObjects;
 using Robust.Server.Interfaces.Player;
@@ -13,6 +11,10 @@ using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Network;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using static Content.Server.Interfaces.Chat.IChatManager;
 
 namespace Content.Server.Chat
 {
@@ -33,14 +35,15 @@ namespace Content.Server.Chat
         /// </summary>
         private const string MaxLengthExceededMessage = "Your message exceeded {0} character limit";
 
-#pragma warning disable 649
-        [Dependency] private readonly IEntitySystemManager _entitySystemManager;
-        [Dependency] private readonly IServerNetManager _netManager;
-        [Dependency] private readonly IPlayerManager _playerManager;
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-        [Dependency] private readonly IMoMMILink _mommiLink;
-        [Dependency] private readonly IConGroupController _conGroupController;
-#pragma warning restore 649
+        //TODO: make prio based?
+        private List<TransformChat> _chatTransformHandlers;
+        
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
+        [Dependency] private readonly IServerNetManager _netManager = default!;
+        [Dependency] private readonly IPlayerManager _playerManager = default!;
+        [Dependency] private readonly ILocalizationManager _localizationManager = default!;
+        [Dependency] private readonly IMoMMILink _mommiLink = default!;
+        [Dependency] private readonly IConGroupController _conGroupController = default!;
 
         public void Initialize()
         {
@@ -51,6 +54,8 @@ namespace Content.Server.Chat
             var msg = _netManager.CreateNetMessage<ChatMaxMsgLengthMessage>();
             msg.MaxMessageLength = MaxMessageLength;
             _netManager.ServerSendToAll(msg);
+
+            _chatTransformHandlers = new List<TransformChat>();
         }
 
         public void DispatchServerAnnouncement(string message)
@@ -98,6 +103,12 @@ namespace Content.Server.Chat
                     return;
                 }
 
+            foreach (var handler in _chatTransformHandlers)
+            {
+                //TODO: rather return a bool and use a out var?
+                message = handler(source, message);
+            }
+
             var pos = source.Transform.GridPosition;
             var clients = _playerManager.GetPlayersInRange(pos, VoiceRange).Select(p => p.ConnectedClient);
 
@@ -217,5 +228,10 @@ namespace Content.Server.Chat
             response.MaxMessageLength = MaxMessageLength;
             _netManager.ServerSendMessage(response, msg.MsgChannel);
         }
+
+        public void RegisterChatTransform(TransformChat handler)
+        {
+            _chatTransformHandlers.Add(handler);
+        }
     }
 }

Content.Server/EntryPoint.cs

@@ -15,6 +15,7 @@ using Robust.Shared.Interfaces.Log;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Timing;
+using Content.Server.GameObjects.Components.Mobs.Speech;
 
 namespace Content.Server
 {
@@ -64,6 +65,7 @@ namespace Content.Server
             IoCManager.Resolve<IServerPreferencesManager>().StartInit();
             IoCManager.Resolve<INodeGroupFactory>().Initialize();
             IoCManager.Resolve<ISandboxManager>().Initialize();
+            IoCManager.Resolve<IAccentManager>().Initialize();
         }
 
         public override void PostInit()

Content.Server/GameObjects/Components/AI/AiFactionTagComponent.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+
+namespace Content.Server.GameObjects.Components.AI
+{
+    [RegisterComponent]
+    public sealed class AiFactionTagComponent : Component
+    {
+        public override string Name => "AiFactionTag";
+
+        public Faction Factions { get; private set; } = Faction.None;
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+            
+            serializer.DataReadWriteFunction(
+                "factions",
+                new List<Faction>(),
+                factions => factions.ForEach(faction => Factions |= faction),
+                () =>
+                {
+                    var writeFactions = new List<Faction>();
+                    foreach (Faction fac in Enum.GetValues(typeof(Faction)))
+                    {
+                        if ((Factions & fac) != 0)
+                        {
+                            writeFactions.Add(fac);
+                        }
+                    }
+
+                    return writeFactions;
+                });
+        }
+    }
+
+    [Flags]
+    public enum Faction
+    {
+        None = 0,
+        NanoTransen = 1 << 0,
+        SimpleHostile = 1 << 1,
+        SimpleNeutral = 1 << 2,
+        Syndicate = 1 << 3,
+        Xeno = 1 << 4,
+    }
+}

Content.Server/GameObjects/Components/Access/IdCardConsoleComponent.cs

@@ -1,8 +1,10 @@
-using System.Collections.Generic;
+#nullable enable
+using System.Collections.Generic;
 using System.Linq;
 using Content.Server.GameObjects.Components.Items.Storage;
 using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Server.Utility;
 using Content.Shared.Access;
 using Content.Shared.GameObjects.Components.Access;
 using Content.Shared.Interfaces.GameObjects.Components;
@@ -15,6 +17,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Prototypes;
+using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Access
 {
@@ -22,16 +25,13 @@ namespace Content.Server.GameObjects.Components.Access
     [ComponentReference(typeof(IActivate))]
     public class IdCardConsoleComponent : SharedIdCardConsoleComponent, IActivate
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-        [Dependency] private readonly IPrototypeManager _prototypeManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
 
-        private BoundUserInterface _userInterface;
-        private ContainerSlot _privilegedIdContainer;
-        private ContainerSlot _targetIdContainer;
-        private AccessReader _accessReader;
+        private ContainerSlot _privilegedIdContainer = default!;
+        private ContainerSlot _targetIdContainer = default!;
+
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(IdCardConsoleUiKey.Key);
 
         public override void Initialize()
         {
@@ -40,16 +40,30 @@ namespace Content.Server.GameObjects.Components.Access
             _privilegedIdContainer = ContainerManagerComponent.Ensure<ContainerSlot>($"{Name}-privilegedId", Owner);
             _targetIdContainer = ContainerManagerComponent.Ensure<ContainerSlot>($"{Name}-targetId", Owner);
 
-            _accessReader = Owner.GetComponent<AccessReader>();
+            if (!Owner.EnsureComponent(out AccessReader _))
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} didn't have a {nameof(AccessReader)}");
+            }
+
+            if (UserInterface == null)
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} doesn't have a {nameof(ServerUserInterfaceComponent)}");
+            }
+            else
+            {
+                UserInterface.OnReceiveMessage += OnUiReceiveMessage;
+            }
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(IdCardConsoleUiKey.Key);
-            _userInterface.OnReceiveMessage += OnUiReceiveMessage;
             UpdateUserInterface();
         }
 
         private void OnUiReceiveMessage(ServerBoundUserInterfaceMessage obj)
         {
+            if (obj.Session.AttachedEntity == null)
+            {
+                return;
+            }
+
             switch (obj.Message)
             {
                 case IdButtonPressedMessage msg:
@@ -72,13 +86,19 @@ namespace Content.Server.GameObjects.Components.Access
         }
 
         /// <summary>
-        /// Returns true if there is an ID in <see cref="_privilegedIdContainer"/> and said ID satisfies the requirements of <see cref="_accessReader"/>.
+        /// Returns true if there is an ID in <see cref="_privilegedIdContainer"/> and said ID satisfies the requirements of <see cref="AccessReader"/>.
         /// </summary>
         private bool PrivilegedIdIsAuthorized()
         {
+            if (!Owner.TryGetComponent(out AccessReader? reader))
+            {
+                return true;
+            }
+
             var privilegedIdEntity = _privilegedIdContainer.ContainedEntity;
-            return privilegedIdEntity != null && _accessReader.IsAllowed(privilegedIdEntity);
+            return privilegedIdEntity != null && reader.IsAllowed(privilegedIdEntity);
         }
+
         /// <summary>
         /// Called when the "Submit" button in the UI gets pressed.
         /// Writes data passed from the UI into the ID stored in <see cref="_targetIdContainer"/>, if present.
@@ -110,9 +130,9 @@ namespace Content.Server.GameObjects.Components.Access
         /// </summary>
         private void HandleId(IEntity user, ContainerSlot container)
         {
-            if (!user.TryGetComponent(out IHandsComponent hands))
+            if (!user.TryGetComponent(out IHandsComponent? hands))
             {
-                _notifyManager.PopupMessage(Owner.Transform.GridPosition, user, _localizationManager.GetString("You have no hands."));
+                _notifyManager.PopupMessage(Owner.Transform.GridPosition, user, Loc.GetString("You have no hands."));
                 return;
             }
 
@@ -133,9 +153,15 @@ namespace Content.Server.GameObjects.Components.Access
             {
                 return;
             }
-            if(!hands.Drop(hands.ActiveHand, container))
+
+            if (hands.ActiveHand == null)
             {
-                _notifyManager.PopupMessage(Owner.Transform.GridPosition, user, _localizationManager.GetString("You can't let go of the ID card!"));
+                return;
+            }
+
+            if (!hands.Drop(hands.ActiveHand, container))
+            {
+                _notifyManager.PopupMessage(Owner.Transform.GridPosition, user, Loc.GetString("You can't let go of the ID card!"));
                 return;
             }
             UpdateUserInterface();
@@ -185,17 +211,17 @@ namespace Content.Server.GameObjects.Components.Access
                     _privilegedIdContainer.ContainedEntity?.Name ?? "",
                     _targetIdContainer.ContainedEntity?.Name ?? "");
             }
-            _userInterface.SetState(newState);
+            UserInterface?.SetState(newState);
         }
 
         public void Activate(ActivateEventArgs eventArgs)
         {
-            if(!eventArgs.User.TryGetComponent(out IActorComponent actor))
+            if(!eventArgs.User.TryGetComponent(out IActorComponent? actor))
             {
                 return;
             }
 
-            _userInterface.Open(actor.playerSession);
+            UserInterface?.Open(actor.playerSession);
         }
     }
 }

Content.Server/GameObjects/Components/ActionBlocking/CuffableComponent.cs

@@ -0,0 +1,355 @@
+
+using Robust.Server.GameObjects;
+using Content.Shared.GameObjects.EntitySystems;
+using Content.Shared.Interfaces;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Localization;
+using Content.Server.GameObjects.EntitySystems.DoAfter;
+using Robust.Shared.ViewVariables;
+using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Shared.GameObjects.Components.ActionBlocking;
+using Content.Shared.GameObjects.Verbs;
+using Content.Server.GameObjects.Components.Items.Storage;
+using Robust.Shared.Log;
+using System.Linq;
+using Robust.Server.GameObjects.Components.Container;
+using Robust.Server.GameObjects.EntitySystems;
+using Content.Server.GameObjects.Components.Mobs;
+using Content.Shared.GameObjects.Components.Mobs;
+using Robust.Shared.Maths;
+using System;
+using System.Collections.Generic;
+using Content.Server.GameObjects.Components.GUI;
+
+namespace Content.Server.GameObjects.Components.ActionBlocking
+{
+    [RegisterComponent]
+    public class CuffableComponent : SharedCuffableComponent
+    {
+        [Dependency]
+        private readonly ISharedNotifyManager _notifyManager;
+
+        /// <summary>
+        /// How many of this entity's hands are currently cuffed.
+        /// </summary>
+        [ViewVariables]
+        public int CuffedHandCount => _container.ContainedEntities.Count * 2;
+
+        protected IEntity LastAddedCuffs => _container.ContainedEntities[_container.ContainedEntities.Count - 1];
+
+        public IReadOnlyList<IEntity> StoredEntities => _container.ContainedEntities;
+
+        /// <summary>
+        ///     Container of various handcuffs currently applied to the entity.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadOnly)]
+        private Container _container = default!;
+
+        private float _interactRange;
+        private IHandsComponent _hands;
+
+        public event Action OnCuffedStateChanged;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            _container = ContainerManagerComponent.Ensure<Container>(Name, Owner);
+            _interactRange = SharedInteractionSystem.InteractionRange / 2;
+
+            Owner.EntityManager.EventBus.SubscribeEvent<HandCountChangedEvent>(EventSource.Local, this, HandleHandCountChange);
+
+            if (!Owner.TryGetComponent(out _hands))
+            {
+                Logger.Warning("Player does not have an IHandsComponent!");
+            }
+        }
+
+        public override ComponentState GetComponentState()
+        {
+            // there are 2 approaches i can think of to handle the handcuff overlay on players
+            // 1 - make the current RSI the handcuff type that's currently active. all handcuffs on the player will appear the same.
+            // 2 - allow for several different player overlays for each different cuff type.
+            // approach #2 would be more difficult/time consuming to do and the payoff doesn't make it worth it.
+            // right now we're doing approach #1.
+
+            if (CuffedHandCount > 0)
+            {
+                if (LastAddedCuffs.TryGetComponent<HandcuffComponent>(out var cuffs))
+                {
+                    return new CuffableComponentState(CuffedHandCount,
+                       CanStillInteract,
+                       cuffs.CuffedRSI,
+                       $"{cuffs.OverlayIconState}-{CuffedHandCount}",
+                       cuffs.Color);
+                    // the iconstate is formatted as blah-2, blah-4, blah-6, etc.
+                    // the number corresponds to how many hands are cuffed.
+                }
+            }
+
+            return new CuffableComponentState(CuffedHandCount,
+               CanStillInteract,
+               "/Objects/Misc/handcuffs.rsi",
+               "body-overlay-2",
+               Color.White);
+        }
+
+        /// <summary>
+        /// Add a set of cuffs to an existing CuffedComponent.
+        /// </summary>
+        /// <param name="prototype"></param>
+        public void AddNewCuffs(IEntity handcuff)
+        {
+            if (!handcuff.HasComponent<HandcuffComponent>())
+            {
+                Logger.Warning($"Handcuffs being applied to player are missing a {nameof(HandcuffComponent)}!");
+                return;
+            }
+
+            if (!EntitySystem.Get<SharedInteractionSystem>().InRangeUnobstructed(
+                    handcuff.Transform.MapPosition,
+                    Owner.Transform.MapPosition,
+                    _interactRange,
+                    ignoredEnt: Owner))
+            {
+                Logger.Warning("Handcuffs being applied to player are obstructed or too far away! This should not happen!");
+                return;
+            }
+
+            _container.Insert(handcuff);
+            CanStillInteract = _hands.Hands.Count() > CuffedHandCount;
+
+            OnCuffedStateChanged.Invoke();
+            UpdateStatusEffect();
+            UpdateHeldItems();
+            Dirty();
+        }
+
+        /// <summary>
+        /// Check the current amount of hands the owner has, and if there's less hands than active cuffs we remove some cuffs.
+        /// </summary>
+        private void UpdateHandCount() 
+        {
+            var dirty = false;
+            var handCount = _hands.Hands.Count();
+
+            while (CuffedHandCount > handCount && CuffedHandCount > 0)
+            {
+                dirty = true;
+
+                var entity = _container.ContainedEntities[_container.ContainedEntities.Count - 1];
+                _container.Remove(entity);
+                entity.Transform.WorldPosition = Owner.Transform.GridPosition.Position;
+            }
+
+            if (dirty)
+            {
+                CanStillInteract = handCount > CuffedHandCount;
+                OnCuffedStateChanged.Invoke();
+                Dirty();
+            }
+        }
+
+        private void HandleHandCountChange(HandCountChangedEvent message)
+        {
+            if (message.Sender == Owner)
+            {
+                UpdateHandCount();
+            }
+        }
+
+        /// <summary>
+        /// Check how many items the user is holding and if it's more than the number of cuffed hands, drop some items.
+        /// </summary>
+        public void UpdateHeldItems()
+        {
+            var itemCount = _hands.GetAllHeldItems().Count();
+            var freeHandCount = _hands.Hands.Count() - CuffedHandCount;
+
+            if (freeHandCount < itemCount)
+            {
+                foreach (ItemComponent item in _hands.GetAllHeldItems())
+                {
+                    if (freeHandCount < itemCount)
+                    {
+                        freeHandCount++;
+                        _hands.Drop(item.Owner);
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Updates the status effect indicator on the HUD.
+        /// </summary>
+        private void UpdateStatusEffect()
+        {
+            if (Owner.TryGetComponent(out ServerStatusEffectsComponent status))
+            {
+                status.ChangeStatusEffectIcon(StatusEffect.Cuffed,
+                    CanStillInteract ? "/Textures/Interface/StatusEffects/Handcuffed/Uncuffed.png" : "/Textures/Interface/StatusEffects/Handcuffed/Handcuffed.png");
+            }
+        }
+
+        /// <summary>
+        /// Attempt to uncuff a cuffed entity. Can be called by the cuffed entity, or another entity trying to help uncuff them.
+        /// If the uncuffing succeeds, the cuffs will drop on the floor.
+        /// </summary>
+        /// <param name="user">The cuffed entity</param>
+        /// <param name="cuffsToRemove">Optional param for the handcuff entity to remove from the cuffed entity. If null, uses the most recently added handcuff entity.</param>
+        public async void TryUncuff(IEntity user, IEntity cuffsToRemove = null)
+        {
+            var isOwner = user == Owner;
+
+            if (cuffsToRemove == null)
+            {
+                cuffsToRemove = LastAddedCuffs;
+            }
+            else
+            {
+                if (!_container.ContainedEntities.Contains(cuffsToRemove))
+                {
+                    Logger.Warning("A user is trying to remove handcuffs that aren't in the owner's container. This should never happen!");
+                }
+            }
+
+            if (!cuffsToRemove.TryGetComponent<HandcuffComponent>(out var cuff))
+            {
+                Logger.Warning($"A user is trying to remove handcuffs without a {nameof(HandcuffComponent)}. This should never happen!");
+                return;
+            }
+
+            if (!isOwner && !ActionBlockerSystem.CanInteract(user))
+            {
+                user.PopupMessage(user, Loc.GetString("You can't do that!"));
+                return;
+            }
+
+            if (!isOwner &&
+                !EntitySystem.Get<SharedInteractionSystem>().InRangeUnobstructed(
+                    user.Transform.MapPosition,
+                    Owner.Transform.MapPosition,
+                    _interactRange,
+                    ignoredEnt: Owner))
+            {
+                user.PopupMessage(user, Loc.GetString("You are too far away to remove the cuffs."));
+                return;
+            }
+
+            if (!EntitySystem.Get<SharedInteractionSystem>().InRangeUnobstructed(
+                    cuffsToRemove.Transform.MapPosition,
+                    Owner.Transform.MapPosition,
+                    _interactRange,
+                    ignoredEnt: Owner))
+            {
+                Logger.Warning("Handcuffs being removed from player are obstructed or too far away! This should not happen!");
+                return;
+            }
+
+            user.PopupMessage(user, Loc.GetString("You start removing the cuffs."));
+
+            var audio = EntitySystem.Get<AudioSystem>();
+            audio.PlayFromEntity(isOwner ? cuff.StartBreakoutSound : cuff.StartUncuffSound, Owner);
+
+            var uncuffTime = isOwner ? cuff.BreakoutTime : cuff.UncuffTime;
+            var doAfterEventArgs = new DoAfterEventArgs(user, uncuffTime)
+            {
+                BreakOnUserMove = true,
+                BreakOnDamage = true,
+                BreakOnStun = true,
+                NeedHand = true
+            };
+
+            var doAfterSystem = EntitySystem.Get<DoAfterSystem>();
+            var result = await doAfterSystem.DoAfter(doAfterEventArgs);
+
+            if (result != DoAfterStatus.Cancelled)
+            {
+                audio.PlayFromEntity(cuff.EndUncuffSound, Owner);
+
+                _container.ForceRemove(cuffsToRemove);
+                cuffsToRemove.Transform.AttachToGridOrMap();
+                cuffsToRemove.Transform.WorldPosition = Owner.Transform.WorldPosition;
+
+                if (cuff.BreakOnRemove)
+                {
+                    cuff.Broken = true;
+
+                    cuffsToRemove.Name = cuff.BrokenName;
+                    cuffsToRemove.Description = cuff.BrokenDesc;
+
+                    if (cuffsToRemove.TryGetComponent<SpriteComponent>(out var sprite))
+                    {
+                        sprite.LayerSetState(0, cuff.BrokenState); // TODO: safety check to see if RSI contains the state?
+                    }
+                }
+
+                CanStillInteract = _hands.Hands.Count() > CuffedHandCount;
+                OnCuffedStateChanged.Invoke();
+                UpdateStatusEffect();
+                Dirty();
+
+                if (CuffedHandCount == 0)
+                {
+                    _notifyManager.PopupMessage(user, user, Loc.GetString("You successfully remove the cuffs."));
+
+                    if (!isOwner)
+                    {
+                        _notifyManager.PopupMessage(user, Owner, Loc.GetString("{0:theName} uncuffs your hands.", user));
+                    }
+                }
+                else
+                {
+                    if (!isOwner)
+                    {
+                        _notifyManager.PopupMessage(user, user, Loc.GetString("You successfully remove the cuffs. {0} of {1:theName}'s hands remain cuffed.", CuffedHandCount, user));
+                        _notifyManager.PopupMessage(user, Owner, Loc.GetString("{0:theName} removes your cuffs. {1} of your hands remain cuffed.", user, CuffedHandCount));
+                    }
+                    else
+                    {
+                        _notifyManager.PopupMessage(user, user, Loc.GetString("You successfully remove the cuffs. {0} of your hands remain cuffed.", CuffedHandCount));
+                    }
+                }
+            }
+            else
+            {
+                _notifyManager.PopupMessage(user, user, Loc.GetString("You fail to remove the cuffs."));
+            }
+
+            return;
+        }
+
+        /// <summary>
+        /// Allows the uncuffing of a cuffed person. Used by other people and by the component owner to break out of cuffs.
+        /// </summary>
+        [Verb]
+        private sealed class UncuffVerb : Verb<CuffableComponent>
+        {
+            protected override void GetData(IEntity user, CuffableComponent component, VerbData data)
+            {
+                if ((user != component.Owner && !ActionBlockerSystem.CanInteract(user)) || component.CuffedHandCount == 0)
+                {
+                    data.Visibility = VerbVisibility.Invisible;
+                    return;
+                }
+
+                data.Text = Loc.GetString("Uncuff");
+            }
+
+            protected override void Activate(IEntity user, CuffableComponent component)
+            {
+                if (component.CuffedHandCount > 0)
+                {
+                    component.TryUncuff(user);
+                }
+            }
+        }
+    }
+}

Content.Server/GameObjects/Components/ActionBlocking/HandcuffComponent.cs

@@ -0,0 +1,248 @@
+using Content.Server.GameObjects.EntitySystems.DoAfter;
+using Content.Shared.GameObjects.EntitySystems;
+using Content.Shared.Interfaces;
+using Content.Shared.Interfaces.GameObjects.Components;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.IoC;
+using Content.Server.GameObjects.Components.GUI;
+using Robust.Shared.Serialization;
+using Robust.Shared.Log;
+using Robust.Shared.Localization;
+using Robust.Shared.ViewVariables;
+using Robust.Server.GameObjects.EntitySystems;
+using Content.Shared.GameObjects.Components.ActionBlocking;
+using Content.Server.GameObjects.Components.Mobs;
+using Robust.Shared.Maths;
+using System;
+
+namespace Content.Server.GameObjects.Components.ActionBlocking
+{
+    [RegisterComponent]
+    public class HandcuffComponent : SharedHandcuffComponent, IAfterInteract
+    {
+        [Dependency]
+        private readonly ISharedNotifyManager _notifyManager;
+
+        /// <summary>
+        ///     The time it takes to apply a <see cref="CuffedComponent"/> to an entity.
+        /// </summary>
+        [ViewVariables]
+        public float CuffTime { get; set; }
+
+        /// <summary>
+        ///     The time it takes to remove a <see cref="CuffedComponent"/> from an entity.
+        /// </summary>
+        [ViewVariables]
+        public float UncuffTime { get; set; }
+
+        /// <summary>
+        ///     The time it takes for a cuffed entity to remove <see cref="CuffedComponent"/> from itself.
+        /// </summary>
+        [ViewVariables]
+        public float BreakoutTime { get; set; }
+
+        /// <summary>
+        ///     If an entity being cuffed is stunned, this amount of time is subtracted from the time it takes to add/remove their cuffs.
+        /// </summary>
+        [ViewVariables]
+        public float StunBonus { get; set; }
+
+        /// <summary>
+        ///     Will the cuffs break when removed?
+        /// </summary>
+        [ViewVariables]
+        public bool BreakOnRemove { get; set; }
+
+        /// <summary>
+        ///     The path of the RSI file used for the player cuffed overlay.
+        /// </summary>
+        [ViewVariables]
+        public string CuffedRSI { get; set; }
+
+        /// <summary>
+        ///     The iconstate used with the RSI file for the player cuffed overlay.
+        /// </summary>
+        [ViewVariables]
+        public string OverlayIconState { get; set; }
+
+        /// <summary>
+        ///     The iconstate used for broken handcuffs
+        /// </summary>
+        [ViewVariables]
+        public string BrokenState { get; set; }
+
+        /// <summary>
+        ///     The iconstate used for broken handcuffs
+        /// </summary>
+        [ViewVariables]
+        public string BrokenName { get; set; }
+
+        /// <summary>
+        ///     The iconstate used for broken handcuffs
+        /// </summary>
+        [ViewVariables]
+        public string BrokenDesc { get; set; }
+
+        [ViewVariables]
+        public bool Broken
+        {
+            get
+            {
+                return _isBroken;
+            }
+            set
+            {
+                if (_isBroken != value)
+                {
+                    _isBroken = value;
+
+                    Dirty();
+                }
+            }
+        }
+
+        public string StartCuffSound { get; set; }
+        public string EndCuffSound { get; set; }
+        public string StartBreakoutSound { get; set; }
+        public string StartUncuffSound { get; set; }
+        public string EndUncuffSound { get; set; }
+        public Color Color { get; set; }
+
+        // Non-exposed data fields
+        private bool _isBroken = false;
+        private float _interactRange;
+        private DoAfterSystem _doAfterSystem;
+        private AudioSystem _audioSystem;
+        
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            _audioSystem = EntitySystem.Get<AudioSystem>();
+            _doAfterSystem = EntitySystem.Get<DoAfterSystem>();
+            _interactRange = SharedInteractionSystem.InteractionRange / 2;
+        }
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+            serializer.DataField(this, x => x.CuffTime, "cuffTime", 5.0f);
+            serializer.DataField(this, x => x.BreakoutTime, "breakoutTime", 30.0f);
+            serializer.DataField(this, x => x.UncuffTime, "uncuffTime", 5.0f);
+            serializer.DataField(this, x => x.StunBonus, "stunBonus", 2.0f);
+            serializer.DataField(this, x => x.StartCuffSound, "startCuffSound", "/Audio/Items/Handcuffs/cuff_start.ogg");
+            serializer.DataField(this, x => x.EndCuffSound, "endCuffSound", "/Audio/Items/Handcuffs/cuff_end.ogg");
+            serializer.DataField(this, x => x.StartUncuffSound, "startUncuffSound", "/Audio/Items/Handcuffs/cuff_takeoff_start.ogg");
+            serializer.DataField(this, x => x.EndUncuffSound, "endUncuffSound", "/Audio/Items/Handcuffs/cuff_takeoff_end.ogg");
+            serializer.DataField(this, x => x.StartBreakoutSound, "startBreakoutSound", "/Audio/Items/Handcuffs/cuff_breakout_start.ogg");
+            serializer.DataField(this, x => x.CuffedRSI, "cuffedRSI", "Objects/Misc/handcuffs.rsi");
+            serializer.DataField(this, x => x.OverlayIconState, "bodyIconState", "body-overlay");
+            serializer.DataField(this, x => x.Color, "color", Color.White);
+            serializer.DataField(this, x => x.BreakOnRemove, "breakOnRemove", false);
+            serializer.DataField(this, x => x.BrokenState, "brokenIconState", string.Empty);
+            serializer.DataField(this, x => x.BrokenName, "brokenName", string.Empty);
+            serializer.DataField(this, x => x.BrokenDesc, "brokenDesc", string.Empty);
+        }
+
+        public override ComponentState GetComponentState()
+        {
+            return new HandcuffedComponentState(Broken ? BrokenState : string.Empty);
+        }
+
+        void IAfterInteract.AfterInteract(AfterInteractEventArgs eventArgs)
+        {
+            if (eventArgs.Target == null || !ActionBlockerSystem.CanUse(eventArgs.User) || !eventArgs.Target.TryGetComponent<CuffableComponent>(out var cuffed))
+            {
+                return;
+            }
+
+            if (eventArgs.Target == eventArgs.User)
+            {
+                _notifyManager.PopupMessage(eventArgs.User, eventArgs.User, Loc.GetString("You can't cuff yourself!"));
+                return;
+            }
+
+            if (Broken)
+            {
+                _notifyManager.PopupMessage(eventArgs.User, eventArgs.User, Loc.GetString("The cuffs are broken!"));
+                return;
+            }
+
+            if (!eventArgs.Target.TryGetComponent<HandsComponent>(out var hands))
+            {
+                _notifyManager.PopupMessage(eventArgs.User, eventArgs.User, Loc.GetString("{0:theName} has no hands!", eventArgs.Target));
+                return;
+            }
+
+            if (cuffed.CuffedHandCount == hands.Count)
+            {
+                _notifyManager.PopupMessage(eventArgs.User, eventArgs.User, Loc.GetString("{0:theName} has no free hands to handcuff!", eventArgs.Target));
+                return;
+            }
+
+            if (!EntitySystem.Get<SharedInteractionSystem>().InRangeUnobstructed(
+                    eventArgs.User.Transform.MapPosition,
+                    eventArgs.Target.Transform.MapPosition,
+                    _interactRange,
+                    ignoredEnt: Owner))
+            {
+                _notifyManager.PopupMessage(eventArgs.User, eventArgs.User, Loc.GetString("You are too far away to use the cuffs!"));
+                return;
+            }
+
+            _notifyManager.PopupMessage(eventArgs.User, eventArgs.User, Loc.GetString("You start cuffing {0:theName}.", eventArgs.Target));
+            _notifyManager.PopupMessage(eventArgs.User, eventArgs.Target, Loc.GetString("{0:theName} starts cuffing you!", eventArgs.User));
+            _audioSystem.PlayFromEntity(StartCuffSound, Owner);
+
+            TryUpdateCuff(eventArgs.User, eventArgs.Target, cuffed); 
+        }
+
+        /// <summary>
+        /// Update the cuffed state of an entity
+        /// </summary>
+        private async void TryUpdateCuff(IEntity user, IEntity target, CuffableComponent cuffs)
+        {
+            var cuffTime = CuffTime;
+
+            if (target.TryGetComponent<StunnableComponent>(out var stun) && stun.Stunned)
+            {
+                cuffTime = MathF.Max(0.1f, cuffTime - StunBonus);
+            }
+
+            var doAfterEventArgs = new DoAfterEventArgs(user, cuffTime, default, target)
+            {
+                BreakOnTargetMove = true,
+                BreakOnUserMove = true,
+                BreakOnDamage = true,
+                BreakOnStun = true,
+                NeedHand = true
+            };
+
+            var result = await _doAfterSystem.DoAfter(doAfterEventArgs);
+
+            if (result != DoAfterStatus.Cancelled)
+            {
+                _audioSystem.PlayFromEntity(EndCuffSound, Owner);
+                _notifyManager.PopupMessage(user, user, Loc.GetString("You successfully cuff {0:theName}.", target));
+                _notifyManager.PopupMessage(target, target, Loc.GetString("You have been cuffed by {0:theName}!", user));
+
+                if (user.TryGetComponent<HandsComponent>(out var hands))
+                {
+                    hands.Drop(Owner);
+                    cuffs.AddNewCuffs(Owner);
+                }
+                else
+                {
+                    Logger.Warning("Unable to remove handcuffs from player's hands! This should not happen!");
+                }
+            }
+            else
+            {
+                user.PopupMessage(user, Loc.GetString("You were interrupted while cuffing {0:theName}!", target));
+                target.PopupMessage(target, Loc.GetString("You interrupt {0:theName} while they are cuffing you!", user));
+            }
+        }
+    }
+}

Content.Server/GameObjects/Components/Atmos/AirtightComponent.cs

@@ -1,9 +1,12 @@
-using System;
+#nullable enable
 using Content.Server.GameObjects.EntitySystems;
 using Robust.Server.Interfaces.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameObjects.Components.Transform;
 using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Interfaces.Map;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
@@ -13,7 +16,8 @@ namespace Content.Server.GameObjects.Components.Atmos
     [RegisterComponent]
     public class AirtightComponent : Component, IMapInit
     {
-        private SnapGridComponent _snapGrid;
+        [Dependency] private readonly IMapManager _mapManager = default!;
+
         private (GridId, MapIndices) _lastPosition;
 
         public override string Name => "Airtight";
@@ -28,7 +32,11 @@ namespace Content.Server.GameObjects.Components.Atmos
             set
             {
                 _airBlocked = value;
-                EntitySystem.Get<AtmosphereSystem>().GetGridAtmosphere(Owner.Transform.GridID)?.Revalidate(_snapGrid.Position);
+
+                if (Owner.TryGetComponent(out SnapGridComponent? snapGrid))
+                {
+                    EntitySystem.Get<AtmosphereSystem>().GetGridAtmosphere(Owner.Transform.GridID)?.Invalidate(snapGrid.Position);
+                }
             }
         }
 
@@ -48,19 +56,23 @@ namespace Content.Server.GameObjects.Components.Atmos
             base.Initialize();
 
             // Using the SnapGrid is critical for the performance of the room builder, and thus if
-            // it is absent the component will not be airtight. An exception is much easier to track
-            // down than the object magically not being airtight, so throw one if the SnapGrid component
+            // it is absent the component will not be airtight. A warning is much easier to track
+            // down than the object magically not being airtight, so log one if the SnapGrid component
             // is missing.
-            if (!Owner.TryGetComponent(out _snapGrid))
-                throw new Exception("Airtight entities must have a SnapGrid component");
+            if (!Owner.EnsureComponent(out SnapGridComponent _))
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition.ToString()} didn't have a {nameof(SnapGridComponent)}");
 
             UpdatePosition();
         }
 
         public void MapInit()
         {
-            _snapGrid.OnPositionChanged += OnTransformMove;
-            _lastPosition = (Owner.Transform.GridID, _snapGrid.Position);
+            if (Owner.TryGetComponent(out SnapGridComponent? snapGrid))
+            {
+                snapGrid.OnPositionChanged += OnTransformMove;
+                _lastPosition = (Owner.Transform.GridID, snapGrid.Position);
+            }
+
             UpdatePosition();
         }
 
@@ -70,11 +82,16 @@ namespace Content.Server.GameObjects.Components.Atmos
 
             _airBlocked = false;
 
-            _snapGrid.OnPositionChanged -= OnTransformMove;
+            if (Owner.TryGetComponent(out SnapGridComponent? snapGrid))
+            {
+                snapGrid.OnPositionChanged -= OnTransformMove;
+            }
 
-            if(_fixVacuum)
-                EntitySystem.Get<AtmosphereSystem>().GetGridAtmosphere(Owner.Transform.GridID)?
-                    .FixVacuum(_snapGrid.Position);
+            if (_fixVacuum)
+            {
+                var mapIndices = Owner.Transform.GridPosition.ToMapIndices(_mapManager);
+                EntitySystem.Get<AtmosphereSystem>().GetGridAtmosphere(Owner.Transform.GridID)?.FixVacuum(mapIndices);
+            }
 
             UpdatePosition();
         }
@@ -83,15 +100,22 @@ namespace Content.Server.GameObjects.Components.Atmos
         {
             UpdatePosition(_lastPosition.Item1, _lastPosition.Item2);
             UpdatePosition();
-            _lastPosition = (Owner.Transform.GridID, _snapGrid.Position);
+
+            if (Owner.TryGetComponent(out SnapGridComponent? snapGrid))
+            {
+                _lastPosition = (Owner.Transform.GridID, snapGrid.Position);
+            }
         }
 
-        private void UpdatePosition() => UpdatePosition(Owner.Transform.GridID, _snapGrid.Position);
+        private void UpdatePosition()
+        {
+            var mapIndices = Owner.Transform.GridPosition.ToMapIndices(_mapManager);
+            UpdatePosition(Owner.Transform.GridID, mapIndices);
+        }
 
         private void UpdatePosition(GridId gridId, MapIndices pos)
         {
             EntitySystem.Get<AtmosphereSystem>().GetGridAtmosphere(gridId)?.Invalidate(pos);
         }
-
     }
 }

Content.Server/GameObjects/Components/Atmos/GasAnalyzerComponent.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using Content.Server.GameObjects.EntitySystems;
 using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Server.Utility;
 using Content.Shared.Atmos;
 using Content.Shared.GameObjects.Components;
 using Content.Shared.GameObjects.EntitySystems;
@@ -16,30 +17,32 @@ using Robust.Shared.Interfaces.Map;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Map;
+using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Atmos
 {
     [RegisterComponent]
     public class GasAnalyzerComponent : SharedGasAnalyzerComponent, IAfterInteract, IDropped, IUse
     {
-#pragma warning disable 649
-        [Dependency] private IServerNotifyManager _notifyManager = default!;
-        [Dependency] private IMapManager _mapManager = default!;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
+        [Dependency] private readonly IMapManager _mapManager = default!;
 
-        private BoundUserInterface _userInterface = default!;
         private GasAnalyzerDanger _pressureDanger;
         private float _timeSinceSync;
         private const float TimeBetweenSyncs = 2f;
         private bool _checkPlayer = false; // Check at the player pos or at some other tile?
         private GridCoordinates? _position; // The tile that we scanned
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(GasAnalyzerUiKey.Key);
+
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(GasAnalyzerUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnReceiveMessage;
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnReceiveMessage;
+            }
         }
 
         public override ComponentState GetComponentState()
@@ -56,7 +59,7 @@ namespace Content.Server.GameObjects.Components.Atmos
         {
             _checkPlayer = true;
             _position = null;
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
             UpdateUserInterface();
             Resync();
         }
@@ -71,7 +74,7 @@ namespace Content.Server.GameObjects.Components.Atmos
         {
             _checkPlayer = false;
             _position = pos;
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
             UpdateUserInterface();
             Resync();
         }
@@ -79,7 +82,7 @@ namespace Content.Server.GameObjects.Components.Atmos
         public void CloseInterface(IPlayerSession session)
         {
             _position = null;
-            _userInterface.Close(session);
+            UserInterface?.Close(session);
             Resync();
         }
 
@@ -123,10 +126,15 @@ namespace Content.Server.GameObjects.Components.Atmos
 
         private void UpdateUserInterface()
         {
+            if (UserInterface == null)
+            {
+                return;
+            }
+
             string? error = null;
 
             // Check if the player is still holding the gas analyzer => if not, don't update
-            foreach (var session in _userInterface.SubscribedSessions)
+            foreach (var session in UserInterface.SubscribedSessions)
             {
                 if (session.AttachedEntity == null)
                     return;
@@ -151,12 +159,13 @@ namespace Content.Server.GameObjects.Components.Atmos
                 pos = _position.Value;
             }
 
-            var gam = EntitySystem.Get<AtmosphereSystem>().GetGridAtmosphere(pos.GridID);
+            var atmosSystem = EntitySystem.Get<AtmosphereSystem>();
+            var gam = atmosSystem.GetGridAtmosphere(pos.GridID);
             var tile = gam?.GetTile(pos).Air;
             if (tile == null)
             {
                 error = "No Atmosphere!";
-                _userInterface.SetState(
+                UserInterface.SetState(
                 new GasAnalyzerBoundUserInterfaceState(
                     0,
                     0,
@@ -166,16 +175,17 @@ namespace Content.Server.GameObjects.Components.Atmos
             }
 
             var gases = new List<GasEntry>();
-            for (int i = 0; i < Atmospherics.TotalNumberOfGases; i++)
+
+            for (var i = 0; i < Atmospherics.TotalNumberOfGases; i++)
             {
-                var gas = Atmospherics.GetGas(i);
+                var gas = atmosSystem.GetGas(i);
 
                 if (tile.Gases[i] <= Atmospherics.GasMinMoles) continue;
 
                 gases.Add(new GasEntry(gas.Name, tile.Gases[i], gas.Color));
             }
 
-            _userInterface.SetState(
+            UserInterface.SetState(
                 new GasAnalyzerBoundUserInterfaceState(
                     tile.Pressure,
                     tile.Temperature,

Content.Server/GameObjects/Components/Atmos/GasMixtureHolderComponent.cs

@@ -6,16 +6,23 @@ using Robust.Shared.ViewVariables;
 namespace Content.Server.GameObjects.Components.Atmos
 {
     [RegisterComponent]
-    public class GasMixtureComponent : Component
+    public class GasMixtureHolderComponent : Component
     {
-        public override string Name => "GasMixture";
+        public override string Name => "GasMixtureHolder";
 
-        [ViewVariables] public GasMixture GasMixture { get; set; } = new GasMixture();
+        [ViewVariables] public GasMixture GasMixture { get; set; }
 
         public override void ExposeData(ObjectSerializer serializer)
         {
             base.ExposeData(serializer);
-            serializer.DataField(this, x => GasMixture.Volume, "volume", 0f);
+
+            GasMixture = new GasMixture();
+
+            serializer.DataReadWriteFunction(
+                "volume",
+                0f,
+                vol => GasMixture.Volume = vol,
+                () => GasMixture.Volume);
         }
     }
 }

Content.Server/GameObjects/Components/Atmos/GridAtmosphereComponent.cs

@@ -1,9 +1,12 @@
-using System;
+#nullable enable
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using Content.Server.Atmos;
+using Content.Server.GameObjects.Components.Atmos.Piping;
+using Content.Server.GameObjects.Components.NodeContainer.NodeGroups;
 using Content.Shared.Atmos;
 using Content.Shared.Maps;
 using Robust.Server.Interfaces.GameObjects;
@@ -33,7 +36,7 @@ namespace Content.Server.GameObjects.Components.Atmos
         /// <summary>
         ///     Check current execution time every n instances processed.
         /// </summary>
-        private const int LagCheckIterations = 15;
+        private const int LagCheckIterations = 30;
 
         /// <summary>
         ///     Max milliseconds allowed for atmos updates.
@@ -47,32 +50,94 @@ namespace Content.Server.GameObjects.Components.Atmos
 
         public override string Name => "GridAtmosphere";
 
+        private bool _paused = false;
         private float _timer = 0f;
         private Stopwatch _stopwatch = new Stopwatch();
+
+        [ViewVariables]
         public int UpdateCounter { get; private set; } = 0;
-        private IMapGrid _grid;
+
+        [ViewVariables]
+        private double _tileEqualizeLastProcess;
 
         [ViewVariables]
         private readonly HashSet<ExcitedGroup> _excitedGroups = new HashSet<ExcitedGroup>(1000);
 
+        [ViewVariables]
+        private int ExcitedGroupCount => _excitedGroups.Count;
+
+        [ViewVariables]
+        private double _excitedGroupLastProcess;
+
         [ViewVariables]
         private readonly Dictionary<MapIndices, TileAtmosphere> _tiles = new Dictionary<MapIndices, TileAtmosphere>(1000);
 
         [ViewVariables]
         private readonly HashSet<TileAtmosphere> _activeTiles = new HashSet<TileAtmosphere>(1000);
 
+        [ViewVariables]
+        private int ActiveTilesCount => _activeTiles.Count;
+
+        [ViewVariables]
+        private double _activeTilesLastProcess;
+
         [ViewVariables]
         private readonly HashSet<TileAtmosphere> _hotspotTiles = new HashSet<TileAtmosphere>(1000);
 
+        [ViewVariables]
+        private int HotspotTilesCount => _hotspotTiles.Count;
+
+        [ViewVariables]
+        private double _hotspotsLastProcess;
+
         [ViewVariables]
         private readonly HashSet<TileAtmosphere> _superconductivityTiles = new HashSet<TileAtmosphere>(1000);
 
+        [ViewVariables]
+        private int SuperconductivityTilesCount => _superconductivityTiles.Count;
+
+        [ViewVariables]
+        private double _superconductivityLastProcess;
+
         [ViewVariables]
         private readonly HashSet<MapIndices> _invalidatedCoords = new HashSet<MapIndices>(1000);
 
+        [ViewVariables]
+        private int InvalidatedCoordsCount => _invalidatedCoords.Count;
+
         [ViewVariables]
         private HashSet<TileAtmosphere> _highPressureDelta = new HashSet<TileAtmosphere>(1000);
 
+        [ViewVariables]
+        private int HighPressureDeltaCount => _highPressureDelta.Count;
+
+        [ViewVariables]
+        private double _highPressureDeltaLastProcess;
+
+        [ViewVariables]
+        private readonly HashSet<IPipeNet> _pipeNets = new HashSet<IPipeNet>();
+
+        [ViewVariables]
+        private double _pipeNetLastProcess;
+
+        [ViewVariables]
+        private readonly HashSet<PipeNetDeviceComponent> _pipeNetDevices = new HashSet<PipeNetDeviceComponent>();
+
+        [ViewVariables]
+        private double _pipeNetDevicesLastProcess;
+
+        [ViewVariables]
+        private Queue<TileAtmosphere> _currentRunTiles = new Queue<TileAtmosphere>();
+
+        [ViewVariables]
+        private Queue<ExcitedGroup> _currentRunExcitedGroups = new Queue<ExcitedGroup>();
+
+        [ViewVariables]
+        private Queue<IPipeNet> _currentRunPipeNet = new Queue<IPipeNet>();
+
+        [ViewVariables]
+        private Queue<PipeNetDeviceComponent> _currentRunPipeNetDevice = new Queue<PipeNetDeviceComponent>();
+
         [ViewVariables]
         private ProcessState _state = ProcessState.TileEqualize;
 
@@ -84,47 +149,47 @@ namespace Content.Server.GameObjects.Components.Atmos
             HighPressureDelta,
             Hotspots,
             Superconductivity,
+            PipeNet,
+            PipeNetDevices,
         }
 
         /// <inheritdoc />
         public void PryTile(MapIndices indices)
         {
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGridComponent)) return;
             if (IsSpace(indices) || IsAirBlocked(indices)) return;
 
-            var tile = _grid.GetTileRef(indices).Tile;
+            var mapGrid = mapGridComponent.Grid;
+            var tile = mapGrid.GetTileRef(indices).Tile;
 
             var tileDefinitionManager = IoCManager.Resolve<ITileDefinitionManager>();
             var tileDef = (ContentTileDefinition)tileDefinitionManager[tile.TypeId];
 
             var underplating = tileDefinitionManager["underplating"];
-            _grid.SetTile(indices, new Tile(underplating.TileId));
+            mapGrid.SetTile(indices, new Tile(underplating.TileId));
 
             //Actually spawn the relevant tile item at the right position and give it some offset to the corner.
-            var tileItem = IoCManager.Resolve<IServerEntityManager>().SpawnEntity(tileDef.ItemDropPrototypeName, new GridCoordinates(indices.X, indices.Y, _grid));
+            var tileItem = IoCManager.Resolve<IServerEntityManager>().SpawnEntity(tileDef.ItemDropPrototypeName, new GridCoordinates(indices.X, indices.Y, mapGrid));
             tileItem.Transform.WorldPosition += (0.2f, 0.2f);
         }
 
         public override void Initialize()
         {
             base.Initialize();
-
-            _grid = Owner.GetComponent<IMapGridComponent>().Grid;
-
             RepopulateTiles();
         }
 
         public override void OnAdd()
         {
             base.OnAdd();
-
-            _grid = Owner.GetComponent<IMapGridComponent>().Grid;
-
             RepopulateTiles();
         }
 
         public void RepopulateTiles()
         {
-            foreach (var tile in _grid.GetAllTiles())
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
+
+            foreach (var tile in mapGrid.Grid.GetAllTiles())
             {
                 if(!_tiles.ContainsKey(tile.GridIndices))
                     _tiles.Add(tile.GridIndices, new TileAtmosphere(this, tile.GridIndex, tile.GridIndices, new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.T20C}));
@@ -145,69 +210,66 @@ namespace Content.Server.GameObjects.Components.Atmos
 
         private void Revalidate()
         {
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
+
             foreach (var indices in _invalidatedCoords.ToArray())
             {
-                Revalidate(indices);
+                var tile = GetTile(indices);
+                AddActiveTile(tile);
+
+                if (tile == null)
+                {
+                    tile = new TileAtmosphere(this, mapGrid.Grid.Index, indices, new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.T20C});
+                    _tiles[indices] = tile;
+                }
+
+                if (IsSpace(indices))
+                {
+                    tile.Air = new GasMixture(GetVolumeForCells(1));
+                    tile.Air.MarkImmutable();
+                    _tiles[indices] = tile;
+
+                } else if (IsAirBlocked(indices))
+                {
+                    tile.Air = null;
+                }
+                else
+                {
+                    var obs = GetObstructingComponent(indices);
+
+                    if (obs != null)
+                    {
+                        if (tile.Air == null && obs.FixVacuum)
+                        {
+                            FixVacuum(tile.GridIndices);
+                        }
+                    }
+
+                    tile.Air ??= new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.T20C};
+                }
+
+                tile.UpdateAdjacent();
+                tile.UpdateVisuals();
+
+                for (var i = 0; i < Atmospherics.Directions; i++)
+                {
+                    var direction = (AtmosDirection) (1 << i);
+                    var otherIndices = indices.Offset(direction.ToDirection());
+                    var otherTile = GetTile(otherIndices);
+                    AddActiveTile(otherTile);
+                    otherTile?.UpdateAdjacent(direction.GetOpposite());
+                }
             }
 
             _invalidatedCoords.Clear();
         }
 
-        /// <inheritdoc />
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Revalidate(MapIndices indices)
-        {
-            var tile = GetTile(indices);
-            AddActiveTile(tile);
-
-            if (tile == null)
-            {
-                tile = new TileAtmosphere(this, _grid.Index, indices, new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.T20C});
-                _tiles[indices] = tile;
-            }
-
-            if (IsSpace(indices))
-            {
-                tile.Air = new GasMixture(GetVolumeForCells(1));
-                tile.Air.MarkImmutable();
-                _tiles[indices] = tile;
-
-            } else if (IsAirBlocked(indices))
-            {
-                tile.Air = null;
-            }
-            else
-            {
-                var obs = GetObstructingComponent(indices);
-
-                if (obs != null)
-                {
-                    if (tile.Air == null && obs.FixVacuum)
-                    {
-                        FixVacuum(tile.GridIndices);
-                    }
-                }
-
-                tile.Air ??= new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.T20C};
-            }
-
-            tile.UpdateAdjacent();
-            tile.UpdateVisuals();
-
-            foreach (var direction in Cardinal)
-            {
-                var otherIndices = indices.Offset(direction);
-                var otherTile = GetTile(otherIndices);
-                AddActiveTile(otherTile);
-                otherTile?.UpdateAdjacent(direction.GetOpposite());
-            }
-        }
-
         /// <inheritdoc />
         public void FixVacuum(MapIndices indices)
         {
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
             var tile = GetTile(indices);
-            if (tile?.GridIndex != _grid.Index) return;
+            if (tile?.GridIndex != mapGrid.Grid.Index) return;
             var adjacent = GetAdjacentTiles(indices);
             tile.Air = new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.T20C};
             _tiles[indices] = tile;
@@ -224,16 +286,17 @@ namespace Content.Server.GameObjects.Components.Atmos
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void AddActiveTile(TileAtmosphere tile)
+        public void AddActiveTile(TileAtmosphere? tile)
         {
-            if (tile?.GridIndex != _grid.Index || tile?.Air == null) return;
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
+            if (tile?.GridIndex != mapGrid.Grid.Index || tile?.Air == null) return;
             tile.Excited = true;
             _activeTiles.Add(tile);
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void RemoveActiveTile(TileAtmosphere tile)
+        public void RemoveActiveTile(TileAtmosphere? tile)
         {
             if (tile == null) return;
             _activeTiles.Remove(tile);
@@ -243,27 +306,29 @@ namespace Content.Server.GameObjects.Components.Atmos
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void AddHotspotTile(TileAtmosphere tile)
+        public void AddHotspotTile(TileAtmosphere? tile)
         {
-            if (tile?.GridIndex != _grid.Index || tile?.Air == null) return;
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
+            if (tile?.GridIndex != mapGrid.Grid.Index || tile?.Air == null) return;
             _hotspotTiles.Add(tile);
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void RemoveHotspotTile(TileAtmosphere tile)
+        public void RemoveHotspotTile(TileAtmosphere? tile)
         {
             if (tile == null) return;
             _hotspotTiles.Remove(tile);
         }
 
-        public void AddSuperconductivityTile(TileAtmosphere tile)
+        public void AddSuperconductivityTile(TileAtmosphere? tile)
         {
-            if (tile?.GridIndex != _grid.Index) return;
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
+            if (tile?.GridIndex != mapGrid.Grid.Index) return;
             _superconductivityTiles.Add(tile);
         }
 
-        public void RemoveSuperconductivityTile(TileAtmosphere tile)
+        public void RemoveSuperconductivityTile(TileAtmosphere? tile)
         {
             if (tile == null) return;
             _superconductivityTiles.Remove(tile);
@@ -271,9 +336,10 @@ namespace Content.Server.GameObjects.Components.Atmos
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void AddHighPressureDelta(TileAtmosphere tile)
+        public void AddHighPressureDelta(TileAtmosphere? tile)
         {
-            if (tile?.GridIndex != _grid.Index) return;
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return;
+            if (tile?.GridIndex != mapGrid.Grid.Index) return;
             _highPressureDelta.Add(tile);
         }
 
@@ -298,23 +364,43 @@ namespace Content.Server.GameObjects.Components.Atmos
             _excitedGroups.Remove(excitedGroup);
         }
 
-        /// <inheritdoc />
-        public TileAtmosphere GetTile(GridCoordinates coordinates)
+        public void AddPipeNet(IPipeNet pipeNet)
         {
-            return GetTile(coordinates.ToMapIndices(_mapManager));
+            _pipeNets.Add(pipeNet);
+        }
+
+        public void RemovePipeNet(IPipeNet pipeNet)
+        {
+            _pipeNets.Remove(pipeNet);
+        }
+
+        public void AddPipeNetDevice(PipeNetDeviceComponent pipeNetDevice)
+        {
+            _pipeNetDevices.Add(pipeNetDevice);
+        }
+
+        public void RemovePipeNetDevice(PipeNetDeviceComponent pipeNetDevice)
+        {
+            _pipeNetDevices.Remove(pipeNetDevice);
         }
 
         /// <inheritdoc />
-        public TileAtmosphere GetTile(MapIndices indices)
+        public TileAtmosphere? GetTile(GridCoordinates coordinates, bool createSpace = true)
         {
+            return GetTile(coordinates.ToMapIndices(_mapManager), createSpace);
+        }
+
+        /// <inheritdoc />
+        public TileAtmosphere? GetTile(MapIndices indices, bool createSpace = true)
+        {
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return null;
+
             if (_tiles.TryGetValue(indices, out var tile)) return tile;
 
             // We don't have that tile!
-            if (IsSpace(indices))
+            if (IsSpace(indices) && createSpace)
             {
-                var space = new TileAtmosphere(this, _grid.Index, indices, new GasMixture(int.MaxValue){Temperature = Atmospherics.TCMB});
-                space.Air.MarkImmutable();
-                return space;
+                return new TileAtmosphere(this, mapGrid.Grid.Index, indices, new GasMixture(GetVolumeForCells(1)){Temperature = Atmospherics.TCMB}, true);
             }
 
             return null;
@@ -331,32 +417,34 @@ namespace Content.Server.GameObjects.Components.Atmos
         public bool IsSpace(MapIndices indices)
         {
             // TODO ATMOS use ContentTileDefinition to define in YAML whether or not a tile is considered space
-            return _grid.GetTileRef(indices).Tile.IsEmpty;
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return default;
+
+            return mapGrid.Grid.GetTileRef(indices).Tile.IsEmpty;
         }
 
-        public Dictionary<Direction, TileAtmosphere> GetAdjacentTiles(MapIndices indices, bool includeAirBlocked = false)
+        public Dictionary<AtmosDirection, TileAtmosphere> GetAdjacentTiles(MapIndices indices, bool includeAirBlocked = false)
         {
-            var sides = new Dictionary<Direction, TileAtmosphere>();
-            foreach (var dir in Cardinal)
+            var sides = new Dictionary<AtmosDirection, TileAtmosphere>();
+            for (var i = 0; i < Atmospherics.Directions; i++)
             {
-                var side = indices.Offset(dir);
+                var direction = (AtmosDirection) (1 << i);
+                var side = indices.Offset(direction.ToDirection());
                 var tile = GetTile(side);
-                if(tile?.Air != null || includeAirBlocked)
-                    sides[dir] = tile;
+                if (tile != null && (tile.Air != null || includeAirBlocked))
+                    sides[direction] = tile;
             }
 
             return sides;
         }
 
-        /// <inheritdoc />
-        public int HighPressureDeltaCount => _highPressureDelta.Count;
-
         public long EqualizationQueueCycleControl { get; set; }
 
         /// <inheritdoc />
         public float GetVolumeForCells(int cellCount)
         {
-            return _grid.TileSize * cellCount * Atmospherics.CellVolume;
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return default;
+
+            return mapGrid.Grid.TileSize * cellCount * Atmospherics.CellVolume;
         }
 
         /// <inheritdoc />
@@ -376,27 +464,83 @@ namespace Content.Server.GameObjects.Components.Atmos
             switch (_state)
             {
                 case ProcessState.TileEqualize:
-                    ProcessTileEqualize();
+                    if (!ProcessTileEqualize(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
                     _state = ProcessState.ActiveTiles;
                     return;
                 case ProcessState.ActiveTiles:
-                    ProcessActiveTiles();
+                    if (!ProcessActiveTiles(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
                     _state = ProcessState.ExcitedGroups;
                     return;
                 case ProcessState.ExcitedGroups:
-                    ProcessExcitedGroups();
+                    if (!ProcessExcitedGroups(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
                     _state = ProcessState.HighPressureDelta;
                     return;
                 case ProcessState.HighPressureDelta:
-                    ProcessHighPressureDelta();
+                    if (!ProcessHighPressureDelta(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
                     _state = ProcessState.Hotspots;
                     break;
                 case ProcessState.Hotspots:
-                    ProcessHotspots();
+                    if (!ProcessHotspots(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
                     _state = ProcessState.Superconductivity;
                     break;
                 case ProcessState.Superconductivity:
-                    ProcessSuperconductivity();
+                    if (!ProcessSuperconductivity(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
+                    _state = ProcessState.PipeNet;
+                    break;
+                case ProcessState.PipeNet:
+                    if (!ProcessPipeNets(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
+                    _state = ProcessState.PipeNetDevices;
+                    break;
+                case ProcessState.PipeNetDevices:
+                    if (!ProcessPipeNetDevices(_paused))
+                    {
+                        _paused = true;
+                        return;
+                    }
+
+                    _paused = false;
                     _state = ProcessState.TileEqualize;
                     break;
             }
@@ -404,47 +548,71 @@ namespace Content.Server.GameObjects.Components.Atmos
             UpdateCounter++;
         }
 
-        public void ProcessTileEqualize()
+        public bool ProcessTileEqualize(bool resumed = false)
         {
             _stopwatch.Restart();
 
+            if(!resumed)
+                _currentRunTiles = new Queue<TileAtmosphere>(_activeTiles);
+
             var number = 0;
-            foreach (var tile in _activeTiles.ToArray())
+            while (_currentRunTiles.Count > 0)
             {
+                var tile = _currentRunTiles.Dequeue();
                 tile.EqualizePressureInZone(UpdateCounter);
 
                 if (number++ < LagCheckIterations) continue;
                 number = 0;
                 // Process the rest next time.
                 if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
-                    return;
+                {
+                    _tileEqualizeLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
             }
+
+            _tileEqualizeLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
         }
 
-        public void ProcessActiveTiles()
+        public bool ProcessActiveTiles(bool resumed = false)
         {
             _stopwatch.Restart();
 
+            if(!resumed)
+                _currentRunTiles = new Queue<TileAtmosphere>(_activeTiles);
+
             var number = 0;
-            foreach (var tile in _activeTiles.ToArray())
+            while (_currentRunTiles.Count > 0)
             {
+                var tile = _currentRunTiles.Dequeue();
                 tile.ProcessCell(UpdateCounter);
 
                 if (number++ < LagCheckIterations) continue;
                 number = 0;
                 // Process the rest next time.
                 if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
-                    return;
+                {
+                    _activeTilesLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
             }
+
+            _activeTilesLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
         }
 
-        public void ProcessExcitedGroups()
+        public bool ProcessExcitedGroups(bool resumed = false)
         {
             _stopwatch.Restart();
 
+            if(!resumed)
+                _currentRunExcitedGroups = new Queue<ExcitedGroup>(_excitedGroups);
+
             var number = 0;
-            foreach (var excitedGroup in _excitedGroups.ToArray())
+            while (_currentRunExcitedGroups.Count > 0)
             {
+                var excitedGroup = _currentRunExcitedGroups.Dequeue();
                 excitedGroup.BreakdownCooldown++;
                 excitedGroup.DismantleCooldown++;
 
@@ -458,17 +626,27 @@ namespace Content.Server.GameObjects.Components.Atmos
                 number = 0;
                 // Process the rest next time.
                 if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
-                    return;
+                {
+                    _excitedGroupLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
             }
+
+            _excitedGroupLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
         }
 
-        public void ProcessHighPressureDelta()
+        public bool ProcessHighPressureDelta(bool resumed = false)
         {
             _stopwatch.Restart();
 
+            if(!resumed)
+                _currentRunTiles = new Queue<TileAtmosphere>(_highPressureDelta);
+
             var number = 0;
-            foreach (var tile in _highPressureDelta.ToArray())
+            while (_currentRunTiles.Count > 0)
             {
+                var tile = _currentRunTiles.Dequeue();
                 tile.HighPressureMovements();
                 tile.PressureDifference = 0f;
                 tile.PressureSpecificTarget = null;
@@ -478,47 +656,129 @@ namespace Content.Server.GameObjects.Components.Atmos
                 number = 0;
                 // Process the rest next time.
                 if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
-                    return;
+                {
+                    _highPressureDeltaLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
             }
+
+            _highPressureDeltaLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
         }
 
-        private void ProcessHotspots()
+        private bool ProcessHotspots(bool resumed = false)
         {
             _stopwatch.Restart();
 
+            if(!resumed)
+                _currentRunTiles = new Queue<TileAtmosphere>(_hotspotTiles);
+
             var number = 0;
-            foreach (var hotspot in _hotspotTiles.ToArray())
+            while (_currentRunTiles.Count > 0)
             {
+                var hotspot = _currentRunTiles.Dequeue();
                 hotspot.ProcessHotspot();
 
                 if (number++ < LagCheckIterations) continue;
                 number = 0;
                 // Process the rest next time.
                 if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
-                    return;
+                {
+                    _hotspotsLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
             }
+
+            _hotspotsLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
         }
 
-        private void ProcessSuperconductivity()
+        private bool ProcessSuperconductivity(bool resumed = false)
         {
             _stopwatch.Restart();
 
+            if(!resumed)
+                _currentRunTiles = new Queue<TileAtmosphere>(_superconductivityTiles);
+
             var number = 0;
-            foreach (var superconductivity in _superconductivityTiles.ToArray())
+            while (_currentRunTiles.Count > 0)
             {
+                var superconductivity = _currentRunTiles.Dequeue();
                 superconductivity.Superconduct();
 
                 if (number++ < LagCheckIterations) continue;
                 number = 0;
                 // Process the rest next time.
                 if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
-                    return;
+                {
+                    _superconductivityLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
             }
+
+            _superconductivityLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
         }
 
-        private AirtightComponent GetObstructingComponent(MapIndices indices)
+        private bool ProcessPipeNets(bool resumed = false)
         {
-            foreach (var v in _grid.GetSnapGridCell(indices, SnapGridOffset.Center))
+            _stopwatch.Restart();
+
+            if(!resumed)
+                _currentRunPipeNet = new Queue<IPipeNet>(_pipeNets);
+
+            var number = 0;
+            while (_currentRunPipeNet.Count > 0)
+            {
+                var pipenet = _currentRunPipeNet.Dequeue();
+                pipenet.Update();
+
+                if (number++ < LagCheckIterations) continue;
+                number = 0;
+                // Process the rest next time.
+                if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
+                {
+                    _pipeNetLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
+            }
+
+            _pipeNetLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
+        }
+
+        private bool ProcessPipeNetDevices(bool resumed = false)
+        {
+            _stopwatch.Restart();
+
+            if(!resumed)
+                _currentRunPipeNetDevice = new Queue<PipeNetDeviceComponent>(_pipeNetDevices);
+
+            var number = 0;
+            while (_currentRunPipeNet.Count > 0)
+            {
+                var device = _currentRunPipeNetDevice.Dequeue();
+                device.Update();
+
+                if (number++ < LagCheckIterations) continue;
+                number = 0;
+                // Process the rest next time.
+                if (_stopwatch.Elapsed.TotalMilliseconds >= LagCheckMaxMilliseconds)
+                {
+                    _pipeNetDevicesLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+                    return false;
+                }
+            }
+
+            _pipeNetDevicesLastProcess = _stopwatch.Elapsed.TotalMilliseconds;
+            return true;
+        }
+
+        private AirtightComponent? GetObstructingComponent(MapIndices indices)
+        {
+            if (!Owner.TryGetComponent(out IMapGridComponent? mapGrid)) return default;
+
+            foreach (var v in mapGrid.Grid.GetSnapGridCell(indices, SnapGridOffset.Center))
             {
                 if (v.Owner.TryGetComponent<AirtightComponent>(out var ac))
                     return ac;
@@ -527,12 +787,6 @@ namespace Content.Server.GameObjects.Components.Atmos
             return null;
         }
 
-        private static readonly Direction[] Cardinal =
-            new []
-            {
-                Direction.North, Direction.East, Direction.South, Direction.West
-            };
-
         public void Dispose()
         {
 
@@ -541,22 +795,24 @@ namespace Content.Server.GameObjects.Components.Atmos
         public override void ExposeData(ObjectSerializer serializer)
         {
             base.ExposeData(serializer);
-            if (serializer.Reading)
+            if (serializer.Reading &&
+                Owner.TryGetComponent(out IMapGridComponent? mapGrid))
             {
-                var gridId = Owner.GetComponent<IMapGridComponent>().Grid.Index;
+                var gridId = mapGrid.Grid.Index;
 
-                if (!serializer.TryReadDataField("uniqueMixes", out List<GasMixture> uniqueMixes) ||
-                    !serializer.TryReadDataField("tiles", out Dictionary<MapIndices, int> tiles))
+                if (!serializer.TryReadDataField("uniqueMixes", out List<GasMixture>? uniqueMixes) ||
+                    !serializer.TryReadDataField("tiles", out Dictionary<MapIndices, int>? tiles))
                     return;
 
                 _tiles.Clear();
 
-                foreach (var (indices, mix) in tiles)
+                foreach (var (indices, mix) in tiles!)
                 {
-                    _tiles.Add(indices, new TileAtmosphere(this, gridId, indices, (GasMixture)uniqueMixes[mix].Clone()));
+                    _tiles.Add(indices, new TileAtmosphere(this, gridId, indices, (GasMixture)uniqueMixes![mix].Clone()));
                     Invalidate(indices);
                 }
-            } else if (serializer.Writing)
+            }
+            else if (serializer.Writing)
             {
                 var uniqueMixes = new List<GasMixture>();
                 var uniqueMixHash = new Dictionary<GasMixture, int>();

Content.Server/GameObjects/Components/Atmos/Piping/PipeNetDeviceComponent.cs

@@ -0,0 +1,50 @@
+using Content.Server.Atmos;
+using Content.Server.GameObjects.EntitySystems;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Log;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///     Adds itself to a <see cref="IGridAtmosphereComponent"/> to be updated by.
+    ///     TODO: Make compatible with unanchoring/anchoring. Currently assumes that the Owner does not move.
+    /// </summary>
+    public abstract class PipeNetDeviceComponent : Component
+    {
+        public abstract void Update();
+
+        protected IGridAtmosphereComponent JoinedGridAtmos { get; private set; }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            JoinGridAtmos();
+        }
+
+        public override void OnRemove()
+        {
+            base.OnRemove();
+            LeaveGridAtmos();
+        }
+
+        private void JoinGridAtmos()
+        {
+            var gridAtmos = EntitySystem.Get<AtmosphereSystem>()
+                .GetGridAtmosphere(Owner.Transform.GridID);
+            if (gridAtmos == null)
+            {
+                Logger.Error($"{nameof(PipeNetDeviceComponent)} on entity {Owner.Uid} could not find an {nameof(IGridAtmosphereComponent)}.");
+                return;
+            }
+            JoinedGridAtmos = gridAtmos;
+            JoinedGridAtmos.AddPipeNetDevice(this);
+        }
+
+        private void LeaveGridAtmos()
+        {
+            JoinedGridAtmos?.RemovePipeNetDevice(this);
+            JoinedGridAtmos = null;
+        }
+    }
+}

Content.Server/GameObjects/Components/Atmos/Piping/Pumps/BasePumpComponent.cs

@@ -0,0 +1,68 @@
+using Content.Server.Atmos;
+using Content.Server.GameObjects.Components.NodeContainer;
+using Content.Server.GameObjects.Components.NodeContainer.Nodes;
+using Robust.Shared.Log;
+using Robust.Shared.Serialization;
+using Robust.Shared.ViewVariables;
+using System.Linq;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///     Transfer gas from one <see cref="PipeNode"/> to another.
+    /// </summary>
+    public abstract class BasePumpComponent : PipeNetDeviceComponent
+    {
+        /// <summary>
+        ///     Needs to be same <see cref="PipeDirection"/> as that of a <see cref="Pipe"/> on this entity.
+        /// </summary>
+        [ViewVariables]
+        private PipeDirection _inletDirection;
+
+        /// <summary>
+        ///     Needs to be same <see cref="PipeDirection"/> as that of a <see cref="Pipe"/> on this entity.
+        /// </summary>
+        [ViewVariables]
+        private PipeDirection _outletDirection;
+
+        [ViewVariables]
+        private PipeNode _inletPipe;
+
+        [ViewVariables]
+        private PipeNode _outletPipe;
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+            serializer.DataField(ref _inletDirection, "inletDirection", PipeDirection.None);
+            serializer.DataField(ref _outletDirection, "outletDirection", PipeDirection.None);
+        }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            if (!Owner.TryGetComponent<NodeContainerComponent>(out var container))
+            {
+                JoinedGridAtmos?.RemovePipeNetDevice(this);
+                Logger.Error($"{typeof(BasePumpComponent)} on entity {Owner.Uid} did not have a {nameof(NodeContainerComponent)}.");
+                return;
+            }
+            var pipeNodes = container.Nodes.OfType<PipeNode>();
+            _inletPipe = pipeNodes.Where(pipe => pipe.PipeDirection == _inletDirection).FirstOrDefault();
+            _outletPipe = pipeNodes.Where(pipe => pipe.PipeDirection == _outletDirection).FirstOrDefault();
+            if (_inletPipe == null | _outletPipe == null)
+            {
+                JoinedGridAtmos?.RemovePipeNetDevice(this);
+                Logger.Error($"{typeof(BasePumpComponent)} on entity {Owner.Uid} could not find compatible {nameof(PipeNode)}s on its {nameof(NodeContainerComponent)}.");
+                return;
+            }
+        }
+
+        public override void Update()
+        {
+            PumpGas(_inletPipe.Air, _outletPipe.Air);
+        }
+
+        protected abstract void PumpGas(GasMixture inletGas, GasMixture outletGas);
+    }
+}

Content.Server/GameObjects/Components/Atmos/Piping/Pumps/DebugPumpComponent.cs

@@ -0,0 +1,21 @@
+using Content.Server.Atmos;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///  Placeholder example of pump functionality.
+    /// </summary>
+    [RegisterComponent]
+    [ComponentReference(typeof(BasePumpComponent))]
+    public class DebugPumpComponent : BasePumpComponent
+    {
+        public override string Name => "DebugPump";
+
+        protected override void PumpGas(GasMixture inletGas, GasMixture outletGas)
+        {
+            outletGas.Merge(inletGas);
+            inletGas.Clear();
+        }
+    }
+}

Content.Server/GameObjects/Components/Atmos/Piping/Scrubbers/BaseSiphonComponent.cs

@@ -0,0 +1,52 @@
+using Content.Server.Atmos;
+using Content.Server.GameObjects.Components.NodeContainer;
+using Content.Server.GameObjects.Components.NodeContainer.Nodes;
+using Content.Server.GameObjects.EntitySystems;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Log;
+using Robust.Shared.ViewVariables;
+using System.Linq;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///     Transfers gas from the tile it is on to a <see cref="PipeNode"/>.
+    /// </summary>
+    public abstract class BaseSiphonComponent : PipeNetDeviceComponent
+    {
+        [ViewVariables]
+        private PipeNode _scrubberOutlet;
+
+        private AtmosphereSystem _atmosSystem;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            _atmosSystem = EntitySystem.Get<AtmosphereSystem>();
+            if (!Owner.TryGetComponent<NodeContainerComponent>(out var container))
+            {
+                JoinedGridAtmos?.RemovePipeNetDevice(this);
+                Logger.Error($"{typeof(BaseSiphonComponent)} on entity {Owner.Uid} did not have a {nameof(NodeContainerComponent)}.");
+                return;
+            }
+            _scrubberOutlet = container.Nodes.OfType<PipeNode>().FirstOrDefault();
+            if (_scrubberOutlet == null)
+            {
+                JoinedGridAtmos?.RemovePipeNetDevice(this);
+                Logger.Error($"{typeof(BaseSiphonComponent)} on entity {Owner.Uid} could not find compatible {nameof(PipeNode)}s on its {nameof(NodeContainerComponent)}.");
+                return;
+            }
+        }
+
+        public override void Update()
+        {
+            var tileAtmos = AtmosHelpers.GetTileAtmosphere(Owner.Transform.GridPosition);
+            if (tileAtmos == null)
+                return;
+            ScrubGas(tileAtmos.Air, _scrubberOutlet.Air);
+            _atmosSystem.GetGridAtmosphere(Owner.Transform.GridID).Invalidate(tileAtmos.GridIndices);
+        }
+
+        protected abstract void ScrubGas(GasMixture inletGas, GasMixture outletGas);
+    }
+}

Content.Server/GameObjects/Components/Atmos/Piping/Scrubbers/DebugSiphonComponent.cs

@@ -0,0 +1,21 @@
+using Content.Server.Atmos;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///     Placeholder example of scrubber functionality.
+    /// </summary>
+    [RegisterComponent]
+    [ComponentReference(typeof(BaseSiphonComponent))]
+    public class DebugSiphonComponent : BaseSiphonComponent
+    {
+        public override string Name => "DebugSiphon";
+
+        protected override void ScrubGas(GasMixture inletGas, GasMixture outletGas)
+        {
+            outletGas.Merge(inletGas);
+            inletGas.Clear();
+        }
+    }
+}

Content.Server/GameObjects/Components/Atmos/Piping/Vents/BaseVentComponent.cs

@@ -0,0 +1,54 @@
+using Content.Server.Atmos;
+using Content.Server.GameObjects.Components.NodeContainer;
+using Content.Server.GameObjects.Components.NodeContainer.Nodes;
+using Content.Server.GameObjects.EntitySystems;
+using Robust.Shared.GameObjects.Systems;
+using Robust.Shared.Log;
+using Robust.Shared.ViewVariables;
+using System.Linq;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///     Transfers gas from a <see cref="PipeNode"/> to the tile it is on.
+    /// </summary>
+    public abstract class BaseVentComponent : PipeNetDeviceComponent
+    {
+        [ViewVariables]
+        private PipeNode _ventInlet;
+
+        private AtmosphereSystem _atmosSystem;
+
+
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            _atmosSystem = EntitySystem.Get<AtmosphereSystem>();
+            if (!Owner.TryGetComponent<NodeContainerComponent>(out var container))
+            {
+                JoinedGridAtmos?.RemovePipeNetDevice(this);
+                Logger.Error($"{typeof(BaseVentComponent)} on entity {Owner.Uid} did not have a {nameof(NodeContainerComponent)}.");
+                return;
+            }
+            _ventInlet = container.Nodes.OfType<PipeNode>().FirstOrDefault();
+            if (_ventInlet == null)
+            {
+                JoinedGridAtmos?.RemovePipeNetDevice(this);
+                Logger.Error($"{typeof(BaseVentComponent)} on entity {Owner.Uid} could not find compatible {nameof(PipeNode)}s on its {nameof(NodeContainerComponent)}.");
+                return;
+            }
+        }
+
+        public override void Update()
+        {
+            var tileAtmos = AtmosHelpers.GetTileAtmosphere(Owner.Transform.GridPosition);
+            if (tileAtmos == null)
+                return;
+            VentGas(_ventInlet.Air, tileAtmos.Air);
+            _atmosSystem.GetGridAtmosphere(Owner.Transform.GridID).Invalidate(tileAtmos.GridIndices);
+        }
+
+        protected abstract void VentGas(GasMixture inletGas, GasMixture outletGas);
+    }
+}

Content.Server/GameObjects/Components/Atmos/Piping/Vents/DebugVentComponent.cs

@@ -0,0 +1,21 @@
+using Content.Server.Atmos;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.GameObjects.Components.Atmos.Piping
+{
+    /// <summary>
+    ///     Placeholder example of vent functionality.
+    /// </summary>
+    [RegisterComponent]
+    [ComponentReference(typeof(BaseVentComponent))]
+    public class DebugVentComponent : BaseVentComponent
+    {
+        public override string Name => "DebugVent";
+
+        protected override void VentGas(GasMixture inletGas, GasMixture outletGas)
+        {
+            outletGas.Merge(inletGas);
+            inletGas.Clear();
+        }
+    }
+}

Content.Server/GameObjects/Components/BarSign/BarSignComponent.cs

@@ -1,4 +1,5 @@
-using System.Linq;
+#nullable enable
+using System.Linq;
 using Content.Server.GameObjects.Components.Power.ApcNetComponents;
 using Robust.Server.GameObjects;
 using Robust.Server.Interfaces.GameObjects;
@@ -19,18 +20,13 @@ namespace Content.Server.GameObjects.Components.BarSign
     {
         public override string Name => "BarSign";
 
-#pragma warning disable 649
-        [Dependency] private readonly IPrototypeManager _prototypeManager;
-        [Dependency] private readonly IRobustRandom _robustRandom;
-#pragma warning restore 649
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+        [Dependency] private readonly IRobustRandom _robustRandom = default!;
 
-        private string _currentSign;
-
-        private PowerReceiverComponent _power;
-        private SpriteComponent _sprite;
+        private string? _currentSign;
 
         [ViewVariables(VVAccess.ReadWrite)]
-        public string CurrentSign
+        public string? CurrentSign
         {
             get => _currentSign;
             set
@@ -40,6 +36,8 @@ namespace Content.Server.GameObjects.Components.BarSign
             }
         }
 
+        private bool Powered => !Owner.TryGetComponent(out PowerReceiverComponent? receiver) || receiver.Powered;
+
         private void UpdateSignInfo()
         {
             if (_currentSign == null)
@@ -53,15 +51,18 @@ namespace Content.Server.GameObjects.Components.BarSign
                 return;
             }
 
-            if (!_power.Powered)
+            if (Owner.TryGetComponent(out SpriteComponent? sprite))
             {
-                _sprite.LayerSetState(0, "empty");
-                _sprite.LayerSetShader(0, "shaded");
-            }
-            else
-            {
-                _sprite.LayerSetState(0, prototype.Icon);
-                _sprite.LayerSetShader(0, "unshaded");
+                if (!Powered)
+                {
+                    sprite.LayerSetState(0, "empty");
+                    sprite.LayerSetShader(0, "shaded");
+                }
+                else
+                {
+                    sprite.LayerSetState(0, prototype.Icon);
+                    sprite.LayerSetShader(0, "unshaded");
+                }
             }
 
             if (!string.IsNullOrEmpty(prototype.Name))
@@ -80,21 +81,25 @@ namespace Content.Server.GameObjects.Components.BarSign
         {
             base.Initialize();
 
-            _power = Owner.GetComponent<PowerReceiverComponent>();
-            _sprite = Owner.GetComponent<SpriteComponent>();
-
-            _power.OnPowerStateChanged += PowerOnOnPowerStateChanged;
+            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            {
+                receiver.OnPowerStateChanged += PowerOnOnPowerStateChanged;
+            }
 
             UpdateSignInfo();
         }
 
         public override void OnRemove()
         {
-            _power.OnPowerStateChanged -= PowerOnOnPowerStateChanged;
+            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            {
+                receiver.OnPowerStateChanged -= PowerOnOnPowerStateChanged;
+            }
+
             base.OnRemove();
         }
 
-        private void PowerOnOnPowerStateChanged(object sender, PowerStateEventArgs e)
+        private void PowerOnOnPowerStateChanged(object? sender, PowerStateEventArgs e)
         {
             UpdateSignInfo();
         }

Content.Server/GameObjects/Components/Body/BodyManagerComponent.cs

@@ -18,14 +18,12 @@ using Content.Shared.Body.Template;
 using Content.Shared.GameObjects.Components.Body;
 using Content.Shared.GameObjects.Components.Damage;
 using Content.Shared.GameObjects.Components.Movement;
-using Robust.Server.GameObjects;
 using Robust.Server.Interfaces.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Reflection;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
-using Robust.Shared.Maths;
 using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
@@ -43,11 +41,9 @@ namespace Content.Server.GameObjects.Components.Body
     [ComponentReference(typeof(IBodyManagerComponent))]
     public class BodyManagerComponent : SharedBodyManagerComponent, IBodyPartContainer, IRelayMoveInput
     {
-#pragma warning disable CS0649
         [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
         [Dependency] private readonly IBodyNetworkFactory _bodyNetworkFactory = default!;
         [Dependency] private readonly IReflectionManager _reflectionManager = default!;
-#pragma warning restore
 
         [ViewVariables] private string _presetName = default!;
 
@@ -138,11 +134,6 @@ namespace Content.Server.GameObjects.Components.Body
             base.Initialize();
 
             LoadBodyPreset(Preset);
-
-            foreach (var behavior in Owner.GetAllComponents<IOnHealthChangedBehavior>())
-            {
-                HealthChangedEvent += behavior.OnHealthChanged;
-            }
         }
 
         protected override void Startup()

Content.Server/GameObjects/Components/Body/BodyScannerComponent.cs

@@ -1,10 +1,14 @@
-using System.Collections.Generic;
+#nullable enable
+using System.Collections.Generic;
 using Content.Server.Body;
+using Content.Server.Utility;
 using Content.Shared.Body.Scanner;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects.Components.UserInterface;
 using Robust.Server.Interfaces.GameObjects;
 using Robust.Shared.GameObjects;
+using Robust.Shared.Log;
+using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Body
 {
@@ -12,32 +16,39 @@ namespace Content.Server.GameObjects.Components.Body
     [ComponentReference(typeof(IActivate))]
     public class BodyScannerComponent : Component, IActivate
     {
-        private BoundUserInterface _userInterface;
         public sealed override string Name => "BodyScanner";
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(BodyScannerUiKey.Key);
+
         void IActivate.Activate(ActivateEventArgs eventArgs)
         {
-            if (!eventArgs.User.TryGetComponent(out IActorComponent actor) ||
+            if (!eventArgs.User.TryGetComponent(out IActorComponent? actor) ||
                 actor.playerSession.AttachedEntity == null)
             {
                 return;
             }
 
-            if (actor.playerSession.AttachedEntity.TryGetComponent(out BodyManagerComponent attempt))
+            if (actor.playerSession.AttachedEntity.TryGetComponent(out BodyManagerComponent? attempt))
             {
                 var state = InterfaceState(attempt.Template, attempt.Parts);
-                _userInterface.SetState(state);
+                UserInterface?.SetState(state);
             }
 
-            _userInterface.Open(actor.playerSession);
+            UserInterface?.Open(actor.playerSession);
         }
 
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(BodyScannerUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+
+            if (UserInterface == null)
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} doesn't have a {nameof(ServerUserInterfaceComponent)}");
+            }
+            else
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
         }
 
         private void UserInterfaceOnOnReceiveMessage(ServerBoundUserInterfaceMessage serverMsg) { }

Content.Server/GameObjects/Components/Body/Circulatory/BloodstreamComponent.cs

@@ -29,7 +29,7 @@ namespace Content.Server.GameObjects.Components.Body.Circulatory
         /// </summary>
         [ViewVariables] public ReagentUnit EmptyVolume => _internalSolution.EmptyVolume;
 
-        [ViewVariables] public GasMixture Air { get; set; } = new GasMixture(6);
+        [ViewVariables] public GasMixture Air { get; set; }
 
         [ViewVariables] public SolutionComponent Solution => _internalSolution;
 
@@ -45,6 +45,8 @@ namespace Content.Server.GameObjects.Components.Body.Circulatory
         {
             base.ExposeData(serializer);
 
+            Air = new GasMixture(6);
+
             serializer.DataField(ref _initialMaxVolume, "maxVolume", ReagentUnit.New(250));
         }
 

Content.Server/GameObjects/Components/Body/Digestive/StomachComponent.cs

@@ -1,12 +1,11 @@
-using System.Collections.Generic;
+#nullable enable
+using System.Collections.Generic;
 using System.Linq;
 using Content.Server.GameObjects.Components.Body.Circulatory;
 using Content.Server.GameObjects.Components.Chemistry;
 using Content.Shared.Chemistry;
 using Content.Shared.GameObjects.Components.Nutrition;
 using Robust.Shared.GameObjects;
-using Robust.Shared.IoC;
-using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
@@ -20,25 +19,21 @@ namespace Content.Server.GameObjects.Components.Body.Digestive
     [RegisterComponent]
     public class StomachComponent : SharedStomachComponent
     {
-#pragma warning disable 649
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
-
         /// <summary>
         ///     Max volume of internal solution storage
         /// </summary>
         public ReagentUnit MaxVolume
         {
-            get => _stomachContents.MaxVolume;
-            set => _stomachContents.MaxVolume = value;
+            get => Owner.TryGetComponent(out SolutionComponent? solution) ? solution.MaxVolume : ReagentUnit.Zero;
+            set
+            {
+                if (Owner.TryGetComponent(out SolutionComponent? solution))
+                {
+                    solution.MaxVolume = value;
+                }
+            }
         }
 
-        /// <summary>
-        ///     Internal solution storage
-        /// </summary>
-        [ViewVariables]
-        private SolutionComponent _stomachContents;
-
         /// <summary>
         ///     Initial internal solution storage volume
         /// </summary>
@@ -68,20 +63,29 @@ namespace Content.Server.GameObjects.Components.Body.Digestive
         {
             base.Startup();
 
-            _stomachContents = Owner.GetComponent<SolutionComponent>();
-            _stomachContents.MaxVolume = _initialMaxVolume;
+            if (!Owner.EnsureComponent(out SolutionComponent solution))
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionComponent)}");
+            }
+
+            solution.MaxVolume = _initialMaxVolume;
         }
 
         public bool TryTransferSolution(Solution solution)
         {
+            if (!Owner.TryGetComponent(out SolutionComponent? solutionComponent))
+            {
+                return false;
+            }
+
             // TODO: For now no partial transfers. Potentially change by design
-            if (solution.TotalVolume + _stomachContents.CurrentVolume > _stomachContents.MaxVolume)
+            if (solution.TotalVolume + solutionComponent.CurrentVolume > solutionComponent.MaxVolume)
             {
                 return false;
             }
 
             // Add solution to _stomachContents
-            _stomachContents.TryAddSolution(solution, false, true);
+            solutionComponent.TryAddSolution(solution, false, true);
             // Add each reagent to _reagentDeltas. Used to track how long each reagent has been in the stomach
             foreach (var reagent in solution.Contents)
             {
@@ -99,7 +103,8 @@ namespace Content.Server.GameObjects.Components.Body.Digestive
         /// <param name="frameTime">The time since the last update in seconds.</param>
         public void Update(float frameTime)
         {
-            if (!Owner.TryGetComponent(out BloodstreamComponent bloodstream))
+            if (!Owner.TryGetComponent(out SolutionComponent? solutionComponent) ||
+                !Owner.TryGetComponent(out BloodstreamComponent? bloodstream))
             {
                 return;
             }
@@ -114,7 +119,7 @@ namespace Content.Server.GameObjects.Components.Body.Digestive
                 delta.Increment(frameTime);
                 if (delta.Lifetime > _digestionDelay)
                 {
-                    _stomachContents.TryRemoveReagent(delta.ReagentId, delta.Quantity);
+                    solutionComponent.TryRemoveReagent(delta.ReagentId, delta.Quantity);
                     transferSolution.AddReagent(delta.ReagentId, delta.Quantity);
                     _reagentDeltas.Remove(delta);
                 }

Content.Server/GameObjects/Components/Body/DroppedBodyPartComponent.cs

@@ -1,11 +1,14 @@
-using System.Collections.Generic;
+#nullable enable
+using System.Collections.Generic;
 using System.Linq;
 using Content.Shared.Interfaces;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Content.Server.Body;
+using Content.Server.Utility;
 using Content.Shared.Body.Surgery;
 using Robust.Server.GameObjects;
 using Robust.Server.GameObjects.Components.UserInterface;
+using Robust.Server.Interfaces.GameObjects;
 using Robust.Server.Interfaces.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
@@ -21,20 +24,18 @@ namespace Content.Server.GameObjects.Components.Body
     [RegisterComponent]
     public class DroppedBodyPartComponent : Component, IAfterInteract, IBodyPartContainer
     {
-#pragma warning disable 649
-        [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager = default!;
 
         private readonly Dictionary<int, object> _optionsCache = new Dictionary<int, object>();
-        private BodyManagerComponent _bodyManagerComponentCache;
+        private BodyManagerComponent? _bodyManagerComponentCache;
         private int _idHash;
-        private IEntity _performerCache;
-
-        private BoundUserInterface _userInterface;
+        private IEntity? _performerCache;
 
         public sealed override string Name => "DroppedBodyPart";
 
-        [ViewVariables] public BodyPart ContainedBodyPart { get; private set; }
+        [ViewVariables] public BodyPart ContainedBodyPart { get; private set; } = default!;
+
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(GenericSurgeryUiKey.Key);
 
         void IAfterInteract.AfterInteract(AfterInteractEventArgs eventArgs)
         {
@@ -48,7 +49,7 @@ namespace Content.Server.GameObjects.Components.Body
             _performerCache = null;
             _bodyManagerComponentCache = null;
 
-            if (eventArgs.Target.TryGetComponent(out BodyManagerComponent bodyManager))
+            if (eventArgs.Target.TryGetComponent(out BodyManagerComponent? bodyManager))
             {
                 SendBodySlotListToUser(eventArgs, bodyManager);
             }
@@ -58,9 +59,10 @@ namespace Content.Server.GameObjects.Components.Body
         {
             base.Initialize();
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(GenericSurgeryUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
         }
 
         public void TransferBodyPartData(BodyPart data)
@@ -68,7 +70,7 @@ namespace Content.Server.GameObjects.Components.Body
             ContainedBodyPart = data;
             Owner.Name = Loc.GetString(ContainedBodyPart.Name);
 
-            if (Owner.TryGetComponent(out SpriteComponent component))
+            if (Owner.TryGetComponent(out SpriteComponent? component))
             {
                 component.LayerSetRSI(0, data.RSIPath);
                 component.LayerSetState(0, data.RSIState);
@@ -91,7 +93,7 @@ namespace Content.Server.GameObjects.Components.Body
             foreach (var slot in unoccupiedSlots)
             {
                 if (!bodyManager.TryGetSlotType(slot, out var typeResult) ||
-                    typeResult != ContainedBodyPart.PartType ||
+                    typeResult != ContainedBodyPart?.PartType ||
                     !bodyManager.TryGetBodyPartConnections(slot, out var parts))
                 {
                     continue;
@@ -129,7 +131,18 @@ namespace Content.Server.GameObjects.Components.Body
         /// </summary>
         private void HandleReceiveBodyPartSlot(int key)
         {
-            CloseSurgeryUI(_performerCache.GetComponent<BasicActorComponent>().playerSession);
+            if (_performerCache == null ||
+                !_performerCache.TryGetComponent(out IActorComponent? actor))
+            {
+                return;
+            }
+
+            CloseSurgeryUI(actor.playerSession);
+
+            if (_bodyManagerComponentCache == null)
+            {
+                return;
+            }
 
             // TODO: sanity checks to see whether user is in range, user is still able-bodied, target is still the same, etc etc
             if (!_optionsCache.TryGetValue(key, out var targetObject))
@@ -138,34 +151,42 @@ namespace Content.Server.GameObjects.Components.Body
                     Loc.GetString("You see no useful way to attach {0:theName} anymore.", Owner));
             }
 
-            var target = targetObject as string;
+            var target = (string) targetObject!;
+            string message;
+
+            if (_bodyManagerComponentCache.InstallDroppedBodyPart(this, target))
+            {
+                message = Loc.GetString("You attach {0:theName}.", ContainedBodyPart);
+            }
+            else
+            {
+                message = Loc.GetString("You can't attach it!");
+            }
 
             _sharedNotifyManager.PopupMessage(
                 _bodyManagerComponentCache.Owner,
                 _performerCache,
-                !_bodyManagerComponentCache.InstallDroppedBodyPart(this, target)
-                    ? Loc.GetString("You can't attach it!")
-                    : Loc.GetString("You attach {0:theName}.", ContainedBodyPart));
+                message);
         }
 
         private void OpenSurgeryUI(IPlayerSession session)
         {
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
         }
 
         private void UpdateSurgeryUIBodyPartSlotRequest(IPlayerSession session, Dictionary<string, int> options)
         {
-            _userInterface.SendMessage(new RequestBodyPartSlotSurgeryUIMessage(options), session);
+            UserInterface?.SendMessage(new RequestBodyPartSlotSurgeryUIMessage(options), session);
         }
 
         private void CloseSurgeryUI(IPlayerSession session)
         {
-            _userInterface.Close(session);
+            UserInterface?.Close(session);
         }
 
         private void CloseAllSurgeryUIs()
         {
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
 
         private void UserInterfaceOnOnReceiveMessage(ServerBoundUserInterfaceMessage message)

Content.Server/GameObjects/Components/Body/DroppedMechanismComponent.cs

@@ -1,21 +1,23 @@
-using System;
+#nullable enable
 using System.Collections.Generic;
 using Content.Server.Body;
 using Content.Server.Body.Mechanisms;
+using Content.Server.Utility;
 using Content.Shared.Body.Mechanism;
 using Content.Shared.Body.Surgery;
 using Content.Shared.Interfaces;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects;
 using Robust.Server.GameObjects.Components.UserInterface;
+using Robust.Server.Interfaces.GameObjects;
 using Robust.Server.Interfaces.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
-using Robust.Shared.Log;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
+using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Body
@@ -26,24 +28,22 @@ namespace Content.Server.GameObjects.Components.Body
     [RegisterComponent]
     public class DroppedMechanismComponent : Component, IAfterInteract
     {
-#pragma warning disable 649
-        [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager;
-        [Dependency] private IPrototypeManager _prototypeManager;
-#pragma warning restore 649
+        [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager = default!;
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
 
         public sealed override string Name => "DroppedMechanism";
 
         private readonly Dictionary<int, object> _optionsCache = new Dictionary<int, object>();
 
-        private BodyManagerComponent _bodyManagerComponentCache;
+        private BodyManagerComponent? _bodyManagerComponentCache;
 
         private int _idHash;
 
-        private IEntity _performerCache;
+        private IEntity? _performerCache;
 
-        private BoundUserInterface _userInterface;
+        [ViewVariables] public Mechanism ContainedMechanism { get; private set; } = default!;
 
-        [ViewVariables] public Mechanism ContainedMechanism { get; private set; }
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(GenericSurgeryUiKey.Key);
 
         void IAfterInteract.AfterInteract(AfterInteractEventArgs eventArgs)
         {
@@ -63,12 +63,7 @@ namespace Content.Server.GameObjects.Components.Body
             }
             else if (eventArgs.Target.TryGetComponent<DroppedBodyPartComponent>(out var droppedBodyPart))
             {
-                if (droppedBodyPart.ContainedBodyPart == null)
-                {
-                    Logger.Debug(
-                        "Installing a mechanism was attempted on an IEntity with a DroppedBodyPartComponent that doesn't have a BodyPart in it!");
-                    throw new InvalidOperationException("A DroppedBodyPartComponent exists without a BodyPart in it!");
-                }
+                DebugTools.AssertNotNull(droppedBodyPart.ContainedBodyPart);
 
                 if (!droppedBodyPart.ContainedBodyPart.TryInstallDroppedMechanism(this))
                 {
@@ -82,9 +77,10 @@ namespace Content.Server.GameObjects.Components.Body
         {
             base.Initialize();
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(GenericSurgeryUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
         }
 
         public void InitializeDroppedMechanism(Mechanism data)
@@ -92,7 +88,7 @@ namespace Content.Server.GameObjects.Components.Body
             ContainedMechanism = data;
             Owner.Name = Loc.GetString(ContainedMechanism.Name);
 
-            if (Owner.TryGetComponent(out SpriteComponent component))
+            if (Owner.TryGetComponent(out SpriteComponent? component))
             {
                 component.LayerSetRSI(0, data.RSIPath);
                 component.LayerSetState(0, data.RSIState);
@@ -111,7 +107,7 @@ namespace Content.Server.GameObjects.Components.Body
 
             if (serializer.Reading && debugLoadMechanismData != "")
             {
-                _prototypeManager.TryIndex(debugLoadMechanismData, out MechanismPrototype data);
+                _prototypeManager.TryIndex(debugLoadMechanismData!, out MechanismPrototype data);
 
                 var mechanism = new Mechanism(data);
                 mechanism.EnsureInitialize();
@@ -155,7 +151,18 @@ namespace Content.Server.GameObjects.Components.Body
         /// </summary>
         private void HandleReceiveBodyPart(int key)
         {
-            CloseSurgeryUI(_performerCache.GetComponent<BasicActorComponent>().playerSession);
+            if (_performerCache == null ||
+                !_performerCache.TryGetComponent(out IActorComponent? actor))
+            {
+                return;
+            }
+
+            CloseSurgeryUI(actor.playerSession);
+
+            if (_bodyManagerComponentCache == null)
+            {
+                return;
+            }
 
             // TODO: sanity checks to see whether user is in range, user is still able-bodied, target is still the same, etc etc
             if (!_optionsCache.TryGetValue(key, out var targetObject))
@@ -165,36 +172,37 @@ namespace Content.Server.GameObjects.Components.Body
                 return;
             }
 
-            var target = targetObject as BodyPart;
+            var target = (BodyPart) targetObject;
+            var message = target.TryInstallDroppedMechanism(this)
+                ? Loc.GetString("You jam the {0} inside {1:them}.", ContainedMechanism.Name, _performerCache)
+                : Loc.GetString("You can't fit it in!");
 
             _sharedNotifyManager.PopupMessage(
                 _bodyManagerComponentCache.Owner,
                 _performerCache,
-                !target.TryInstallDroppedMechanism(this)
-                    ? Loc.GetString("You can't fit it in!")
-                    : Loc.GetString("You jam the {1} inside {0:them}.", _performerCache, ContainedMechanism.Name));
+                message);
 
             // TODO: {1:theName}
         }
 
         private void OpenSurgeryUI(IPlayerSession session)
         {
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
         }
 
         private void UpdateSurgeryUIBodyPartRequest(IPlayerSession session, Dictionary<string, int> options)
         {
-            _userInterface.SendMessage(new RequestBodyPartSurgeryUIMessage(options), session);
+            UserInterface?.SendMessage(new RequestBodyPartSurgeryUIMessage(options), session);
         }
 
         private void CloseSurgeryUI(IPlayerSession session)
         {
-            _userInterface.Close(session);
+            UserInterface?.Close(session);
         }
 
         private void CloseAllSurgeryUIs()
         {
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
 
         private void UserInterfaceOnOnReceiveMessage(ServerBoundUserInterfaceMessage message)

Content.Server/GameObjects/Components/Body/Respiratory/LungComponent.cs

@@ -21,7 +21,7 @@ namespace Content.Server.GameObjects.Components.Body.Respiratory
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)] private float Pressure { get; set; }
 
-        [ViewVariables] public GasMixture Air { get; set; } = new GasMixture();
+        [ViewVariables] public GasMixture Air { get; set; }
 
         [ViewVariables] public LungStatus Status { get; set; }
 
@@ -29,6 +29,8 @@ namespace Content.Server.GameObjects.Components.Body.Respiratory
         {
             base.ExposeData(serializer);
 
+            Air = new GasMixture();
+
             serializer.DataReadWriteFunction(
                 "volume",
                 6,

Content.Server/GameObjects/Components/Body/SurgeryToolComponent.cs

@@ -1,8 +1,10 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using Content.Server.Body;
 using Content.Server.Body.Mechanisms;
 using Content.Server.Body.Surgery;
+using Content.Server.Utility;
 using Content.Shared.Body.Surgery;
 using Content.Shared.GameObjects;
 using Content.Shared.GameObjects.Components.Body;
@@ -18,6 +20,8 @@ using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Serialization;
+using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Body
 {
@@ -30,9 +34,7 @@ namespace Content.Server.GameObjects.Components.Body
     [RegisterComponent]
     public class SurgeryToolComponent : Component, ISurgeon, IAfterInteract
     {
-#pragma warning disable 649
-        [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly ISharedNotifyManager _sharedNotifyManager = default!;
 
         public override string Name => "SurgeryTool";
         public override uint? NetID => ContentNetIDs.SURGERY;
@@ -41,17 +43,17 @@ namespace Content.Server.GameObjects.Components.Body
 
         private float _baseOperateTime;
 
-        private BodyManagerComponent _bodyManagerComponentCache;
+        private BodyManagerComponent? _bodyManagerComponentCache;
 
-        private ISurgeon.MechanismRequestCallback _callbackCache;
+        private ISurgeon.MechanismRequestCallback? _callbackCache;
 
         private int _idHash;
 
-        private IEntity _performerCache;
+        private IEntity? _performerCache;
 
         private SurgeryType _surgeryType;
 
-        private BoundUserInterface _userInterface;
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(GenericSurgeryUiKey.Key);
 
         void IAfterInteract.AfterInteract(AfterInteractEventArgs eventArgs)
         {
@@ -60,7 +62,7 @@ namespace Content.Server.GameObjects.Components.Body
                 return;
             }
 
-            if (!eventArgs.User.TryGetComponent(out IActorComponent actor))
+            if (!eventArgs.User.TryGetComponent(out IActorComponent? actor))
             {
                 return;
             }
@@ -73,7 +75,7 @@ namespace Content.Server.GameObjects.Components.Body
             _callbackCache = null;
 
             // Attempt surgery on a BodyManagerComponent by sending a list of operable BodyParts to the client to choose from
-            if (eventArgs.Target.TryGetComponent(out BodyManagerComponent body))
+            if (eventArgs.Target.TryGetComponent(out BodyManagerComponent? body))
             {
                 // Create dictionary to send to client (text to be shown : data sent back if selected)
                 var toSend = new Dictionary<string, int>();
@@ -105,13 +107,7 @@ namespace Content.Server.GameObjects.Components.Body
                 // Attempt surgery on a DroppedBodyPart - there's only one possible target so no need for selection UI
                 _performerCache = eventArgs.User;
 
-                if (droppedBodyPart.ContainedBodyPart == null)
-                {
-                    // Throw error if the DroppedBodyPart has no data in it.
-                    Logger.Debug(
-                        "Surgery was attempted on an IEntity with a DroppedBodyPartComponent that doesn't have a BodyPart in it!");
-                    throw new InvalidOperationException("A DroppedBodyPartComponent exists without a BodyPart in it!");
-                }
+                DebugTools.AssertNotNull(droppedBodyPart.ContainedBodyPart);
 
                 // If surgery can be performed...
                 if (!droppedBodyPart.ContainedBodyPart.SurgeryCheck(_surgeryType))
@@ -144,7 +140,7 @@ namespace Content.Server.GameObjects.Components.Body
                 toSend.Add(mechanism.Name, _idHash++);
             }
 
-            if (_optionsCache.Count > 0)
+            if (_optionsCache.Count > 0 && _performerCache != null)
             {
                 OpenSurgeryUI(_performerCache.GetComponent<BasicActorComponent>().playerSession);
                 UpdateSurgeryUIMechanismRequest(_performerCache.GetComponent<BasicActorComponent>().playerSession,
@@ -162,34 +158,35 @@ namespace Content.Server.GameObjects.Components.Body
         {
             base.Initialize();
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(GenericSurgeryUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
         }
 
         private void OpenSurgeryUI(IPlayerSession session)
         {
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
         }
 
         private void UpdateSurgeryUIBodyPartRequest(IPlayerSession session, Dictionary<string, int> options)
         {
-            _userInterface.SendMessage(new RequestBodyPartSurgeryUIMessage(options), session);
+            UserInterface?.SendMessage(new RequestBodyPartSurgeryUIMessage(options), session);
         }
 
         private void UpdateSurgeryUIMechanismRequest(IPlayerSession session, Dictionary<string, int> options)
         {
-            _userInterface.SendMessage(new RequestMechanismSurgeryUIMessage(options), session);
+            UserInterface?.SendMessage(new RequestMechanismSurgeryUIMessage(options), session);
         }
 
         private void CloseSurgeryUI(IPlayerSession session)
         {
-            _userInterface.Close(session);
+            UserInterface?.Close(session);
         }
 
         private void CloseAllSurgeryUIs()
         {
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
 
         private void UserInterfaceOnOnReceiveMessage(ServerBoundUserInterfaceMessage message)
@@ -211,14 +208,22 @@ namespace Content.Server.GameObjects.Components.Body
         /// </summary>
         private void HandleReceiveBodyPart(int key)
         {
-            CloseSurgeryUI(_performerCache.GetComponent<BasicActorComponent>().playerSession);
-            // TODO: sanity checks to see whether user is in range, user is still able-bodied, target is still the same, etc etc
-            if (!_optionsCache.TryGetValue(key, out var targetObject))
+            if (_performerCache == null ||
+                !_performerCache.TryGetComponent(out IActorComponent? actor))
             {
-                SendNoUsefulWayToUseAnymorePopup();
+                return;
             }
 
-            var target = targetObject as BodyPart;
+            CloseSurgeryUI(actor.playerSession);
+            // TODO: sanity checks to see whether user is in range, user is still able-bodied, target is still the same, etc etc
+            if (!_optionsCache.TryGetValue(key, out var targetObject) ||
+                _bodyManagerComponentCache == null)
+            {
+                SendNoUsefulWayToUseAnymorePopup();
+                return;
+            }
+
+            var target = (BodyPart) targetObject!;
 
             if (!target.AttemptSurgery(_surgeryType, _bodyManagerComponentCache, this, _performerCache))
             {
@@ -233,19 +238,27 @@ namespace Content.Server.GameObjects.Components.Body
         private void HandleReceiveMechanism(int key)
         {
             // TODO: sanity checks to see whether user is in range, user is still able-bodied, target is still the same, etc etc
-            if (!_optionsCache.TryGetValue(key, out var targetObject))
+            if (!_optionsCache.TryGetValue(key, out var targetObject) ||
+                _performerCache == null ||
+                !_performerCache.TryGetComponent(out IActorComponent? actor))
             {
                 SendNoUsefulWayToUseAnymorePopup();
+                return;
             }
 
             var target = targetObject as Mechanism;
 
-            CloseSurgeryUI(_performerCache.GetComponent<BasicActorComponent>().playerSession);
-            _callbackCache(target, _bodyManagerComponentCache, this, _performerCache);
+            CloseSurgeryUI(actor.playerSession);
+            _callbackCache?.Invoke(target, _bodyManagerComponentCache, this, _performerCache);
         }
 
         private void SendNoUsefulWayToUsePopup()
         {
+            if (_bodyManagerComponentCache == null)
+            {
+                return;
+            }
+
             _sharedNotifyManager.PopupMessage(
                 _bodyManagerComponentCache.Owner,
                 _performerCache,
@@ -254,6 +267,11 @@ namespace Content.Server.GameObjects.Components.Body
 
         private void SendNoUsefulWayToUseAnymorePopup()
         {
+            if (_bodyManagerComponentCache == null)
+            {
+                return;
+            }
+
             _sharedNotifyManager.PopupMessage(
                 _bodyManagerComponentCache.Owner,
                 _performerCache,

Content.Server/GameObjects/Components/Buckle/BuckleComponent.cs

@@ -34,13 +34,11 @@ namespace Content.Server.GameObjects.Components.Buckle
     [RegisterComponent]
     public class BuckleComponent : SharedBuckleComponent, IInteractHand, IDragDrop
     {
-#pragma warning disable 649
         [Dependency] private readonly IEntityManager _entityManager = default!;
         [Dependency] private readonly IEntitySystemManager _entitySystem = default!;
         [Dependency] private readonly IGameTiming _gameTiming = default!;
         [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
-#pragma warning restore 649
 
         private int _size;
 

Content.Server/GameObjects/Components/Cargo/CargoConsoleComponent.cs

@@ -2,6 +2,7 @@
 using Content.Server.Cargo;
 using Content.Server.GameObjects.Components.Power.ApcNetComponents;
 using Content.Server.GameObjects.EntitySystems;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.Components.Cargo;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Content.Shared.Prototypes.Cargo;
@@ -10,6 +11,7 @@ using Robust.Server.Interfaces.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -19,21 +21,11 @@ namespace Content.Server.GameObjects.Components.Cargo
     [ComponentReference(typeof(IActivate))]
     public class CargoConsoleComponent : SharedCargoConsoleComponent, IActivate
     {
-#pragma warning disable 649
         [Dependency] private readonly ICargoOrderDataManager _cargoOrderDataManager = default!;
-#pragma warning restore 649
 
         [ViewVariables]
         public int Points = 1000;
 
-        private BoundUserInterface _userInterface  = default!;
-
-        [ViewVariables]
-        public GalacticMarketComponent Market { get; private set; } = default!;
-
-        [ViewVariables]
-        public CargoOrderDatabaseComponent Orders { get; private set; } = default!;
-
         private CargoBankAccount? _bankAccount;
 
         [ViewVariables]
@@ -65,22 +57,44 @@ namespace Content.Server.GameObjects.Components.Cargo
 
         private bool _requestOnly = false;
 
-        private PowerReceiverComponent _powerReceiver = default!;
-        private bool Powered => _powerReceiver.Powered;
+        private bool Powered => !Owner.TryGetComponent(out PowerReceiverComponent? receiver) || receiver.Powered;
         private CargoConsoleSystem _cargoConsoleSystem = default!;
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(CargoConsoleUiKey.Key);
+
         public override void Initialize()
         {
             base.Initialize();
-            Market = Owner.GetComponent<GalacticMarketComponent>();
-            Orders = Owner.GetComponent<CargoOrderDatabaseComponent>();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>().GetBoundUserInterface(CargoConsoleUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
-            _powerReceiver = Owner.GetComponent<PowerReceiverComponent>();
+
+            if (!Owner.EnsureComponent(out GalacticMarketComponent _))
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} had no {nameof(GalacticMarketComponent)}");
+            }
+
+            if (!Owner.EnsureComponent(out CargoOrderDatabaseComponent _))
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} had no {nameof(GalacticMarketComponent)}");
+            }
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
+
             _cargoConsoleSystem = EntitySystem.Get<CargoConsoleSystem>();
             BankAccount = _cargoConsoleSystem.StationAccount;
         }
 
+        public override void OnRemove()
+        {
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
+
+            base.OnRemove();
+        }
+
         /// <summary>
         ///    Reads data from YAML
         /// </summary>
@@ -93,8 +107,13 @@ namespace Content.Server.GameObjects.Components.Cargo
 
         private void UserInterfaceOnOnReceiveMessage(ServerBoundUserInterfaceMessage serverMsg)
         {
+            if (!Owner.TryGetComponent(out CargoOrderDatabaseComponent? orders))
+            {
+                return;
+            }
+
             var message = serverMsg.Message;
-            if (!Orders.ConnectedToDatabase)
+            if (!orders.ConnectedToDatabase)
                 return;
             if (!Powered)
                 return;
@@ -107,45 +126,45 @@ namespace Content.Server.GameObjects.Components.Cargo
                         break;
                     }
 
-                    _cargoOrderDataManager.AddOrder(Orders.Database.Id, msg.Requester, msg.Reason, msg.ProductId, msg.Amount, _bankAccount.Id);
+                    _cargoOrderDataManager.AddOrder(orders.Database.Id, msg.Requester, msg.Reason, msg.ProductId, msg.Amount, _bankAccount.Id);
                     break;
                 }
                 case CargoConsoleRemoveOrderMessage msg:
                 {
-                    _cargoOrderDataManager.RemoveOrder(Orders.Database.Id, msg.OrderNumber);
+                    _cargoOrderDataManager.RemoveOrder(orders.Database.Id, msg.OrderNumber);
                     break;
                 }
                 case CargoConsoleApproveOrderMessage msg:
                 {
                     if (_requestOnly ||
-                        !Orders.Database.TryGetOrder(msg.OrderNumber, out var order) ||
+                        !orders.Database.TryGetOrder(msg.OrderNumber, out var order) ||
                         _bankAccount == null)
                     {
                         break;
                     }
 
-                    _prototypeManager.TryIndex(order.ProductId, out CargoProductPrototype product);
-                    if (product == null)
+                    PrototypeManager.TryIndex(order.ProductId, out CargoProductPrototype product);
+                    if (product == null!)
                         break;
-                    var capacity = _cargoOrderDataManager.GetCapacity(Orders.Database.Id);
+                    var capacity = _cargoOrderDataManager.GetCapacity(orders.Database.Id);
                     if (capacity.CurrentCapacity == capacity.MaxCapacity)
                         break;
                     if (!_cargoConsoleSystem.ChangeBalance(_bankAccount.Id, (-product.PointCost) * order.Amount))
                         break;
-                    _cargoOrderDataManager.ApproveOrder(Orders.Database.Id, msg.OrderNumber);
+                    _cargoOrderDataManager.ApproveOrder(orders.Database.Id, msg.OrderNumber);
                     UpdateUIState();
                     break;
                 }
                 case CargoConsoleShuttleMessage _:
                 {
-                    var approvedOrders = _cargoOrderDataManager.RemoveAndGetApprovedFrom(Orders.Database);
-                    Orders.Database.ClearOrderCapacity();
+                    var approvedOrders = _cargoOrderDataManager.RemoveAndGetApprovedFrom(orders.Database);
+                    orders.Database.ClearOrderCapacity();
                     // TODO replace with shuttle code
 
                     // TEMPORARY loop for spawning stuff on top of console
                     foreach (var order in approvedOrders)
                     {
-                        if (!_prototypeManager.TryIndex(order.ProductId, out CargoProductPrototype product))
+                        if (!PrototypeManager.TryIndex(order.ProductId, out CargoProductPrototype product))
                             continue;
                         for (var i = 0; i < order.Amount; i++)
                         {
@@ -166,12 +185,12 @@ namespace Content.Server.GameObjects.Components.Cargo
             if (!Powered)
                 return;
 
-            _userInterface.Open(actor.playerSession);
+            UserInterface?.Open(actor.playerSession);
         }
 
         private void UpdateUIState()
         {
-            if (_bankAccount == null)
+            if (_bankAccount == null || !Owner.IsValid())
             {
                 return;
             }
@@ -180,7 +199,7 @@ namespace Content.Server.GameObjects.Components.Cargo
             var name = _bankAccount.Name;
             var balance = _bankAccount.Balance;
             var capacity = _cargoOrderDataManager.GetCapacity(id);
-            _userInterface.SetState(new CargoConsoleInterfaceState(_requestOnly, id, name, balance, capacity));
+            UserInterface?.SetState(new CargoConsoleInterfaceState(_requestOnly, id, name, balance, capacity));
         }
     }
 }

Content.Server/GameObjects/Components/Cargo/CargoOrderDatabaseComponent.cs

@@ -8,9 +8,7 @@ namespace Content.Server.GameObjects.Components.Cargo
     [RegisterComponent]
     public class CargoOrderDatabaseComponent : SharedCargoOrderDatabaseComponent
     {
-#pragma warning disable 649
-        [Dependency] private readonly ICargoOrderDataManager _cargoOrderDataManager;
-#pragma warning restore 649
+        [Dependency] private readonly ICargoOrderDataManager _cargoOrderDataManager = default!;
 
         public CargoOrderDatabase Database { get; set; }
         public bool ConnectedToDatabase => Database != null;

Content.Server/GameObjects/Components/Chemistry/ChemMasterComponent.cs

@@ -1,4 +1,6 @@
-using System;
+#nullable enable
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.GUI;
@@ -7,6 +9,7 @@ using Content.Server.GameObjects.Components.Power.ApcNetComponents;
 using Content.Server.GameObjects.EntitySystems;
 using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Server.Utility;
 using Content.Shared.Chemistry;
 using Content.Shared.GameObjects.Components.Chemistry.ChemMaster;
 using Content.Shared.GameObjects.EntitySystems;
@@ -40,24 +43,20 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [ComponentReference(typeof(IInteractUsing))]
     public class ChemMasterComponent : SharedChemMasterComponent, IActivate, IInteractUsing, ISolutionChange
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
 
-        [ViewVariables] private BoundUserInterface _userInterface;
-        [ViewVariables] private ContainerSlot _beakerContainer;
-        [ViewVariables] private string _packPrototypeId;
+        [ViewVariables] private ContainerSlot _beakerContainer = default!;
+        [ViewVariables] private string _packPrototypeId = "";
 
         [ViewVariables] private bool HasBeaker => _beakerContainer.ContainedEntity != null;
 
-        [ViewVariables] private bool BufferModeTransfer = true;
+        [ViewVariables] private bool _bufferModeTransfer = true;
 
-        private PowerReceiverComponent _powerReceiver;
-        private bool Powered => _powerReceiver.Powered;
+        private bool Powered => !Owner.TryGetComponent(out PowerReceiverComponent? receiver) || receiver.Powered;
 
         private readonly SolutionComponent BufferSolution = new SolutionComponent();
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(ChemMasterUiKey.Key);
 
         /// <summary>
         /// Shows the serializer how to save/load this components yaml prototype.
@@ -77,14 +76,19 @@ namespace Content.Server.GameObjects.Components.Chemistry
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(ChemMasterUiKey.Key);
-            _userInterface.OnReceiveMessage += OnUiReceiveMessage;
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += OnUiReceiveMessage;
+            }
 
             _beakerContainer =
                 ContainerManagerComponent.Ensure<ContainerSlot>($"{Name}-reagentContainerContainer", Owner);
-            _powerReceiver = Owner.GetComponent<PowerReceiverComponent>();
-            _powerReceiver.OnPowerStateChanged += OnPowerChanged;
+
+            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            {
+                receiver.OnPowerStateChanged += OnPowerChanged;
+            }
 
             //BufferSolution = Owner.BufferSolution
             BufferSolution.Solution = new Solution();
@@ -93,7 +97,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             UpdateUserInterface();
         }
 
-        private void OnPowerChanged(object sender, PowerStateEventArgs e)
+        private void OnPowerChanged(object? sender, PowerStateEventArgs e)
         {
             UpdateUserInterface();
         }
@@ -105,6 +109,11 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// <param name="obj">A user interface message from the client.</param>
         private void OnUiReceiveMessage(ServerBoundUserInterfaceMessage obj)
         {
+            if (obj.Session.AttachedEntity == null)
+            {
+                return;
+            }
+
             var msg = (UiActionMessage) obj.Message;
             var needsPower = msg.action switch
             {
@@ -124,11 +133,11 @@ namespace Content.Server.GameObjects.Components.Chemistry
                     TransferReagent(msg.id, msg.amount, msg.isBuffer);
                     break;
                 case UiAction.Transfer:
-                    BufferModeTransfer = true;
+                    _bufferModeTransfer = true;
                     UpdateUserInterface();
                     break;
                 case UiAction.Discard:
-                    BufferModeTransfer = false;
+                    _bufferModeTransfer = false;
                     UpdateUserInterface();
                     break;
                 case UiAction.CreatePills:
@@ -147,7 +156,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// </summary>
         /// <param name="playerEntity">The player entity.</param>
         /// <returns>Returns true if the entity can use the chem master, and false if it cannot.</returns>
-        private bool PlayerCanUseChemMaster(IEntity playerEntity, bool needsPower = true)
+        private bool PlayerCanUseChemMaster(IEntity? playerEntity, bool needsPower = true)
         {
             //Need player entity to check if they are still able to use the chem master
             if (playerEntity == null)
@@ -172,18 +181,18 @@ namespace Content.Server.GameObjects.Components.Chemistry
             if (beaker == null)
             {
                 return new ChemMasterBoundUserInterfaceState(Powered, false, ReagentUnit.New(0), ReagentUnit.New(0),
-                    "", Owner.Name, null, BufferSolution.ReagentList.ToList(), BufferModeTransfer, BufferSolution.CurrentVolume, BufferSolution.MaxVolume);
+                    "", Owner.Name, new List<Solution.ReagentQuantity>(), BufferSolution.ReagentList.ToList(), _bufferModeTransfer, BufferSolution.CurrentVolume, BufferSolution.MaxVolume);
             }
 
             var solution = beaker.GetComponent<SolutionComponent>();
             return new ChemMasterBoundUserInterfaceState(Powered, true, solution.CurrentVolume, solution.MaxVolume,
-                beaker.Name, Owner.Name, solution.ReagentList.ToList(), BufferSolution.ReagentList.ToList(), BufferModeTransfer, BufferSolution.CurrentVolume, BufferSolution.MaxVolume);
+                beaker.Name, Owner.Name, solution.ReagentList.ToList(), BufferSolution.ReagentList.ToList(), _bufferModeTransfer, BufferSolution.CurrentVolume, BufferSolution.MaxVolume);
         }
 
         private void UpdateUserInterface()
         {
             var state = GetUserInterfaceState();
-            _userInterface.SetState(state);
+            UserInterface?.SetState(state);
         }
 
         /// <summary>
@@ -207,7 +216,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
         private void TransferReagent(string id, ReagentUnit amount, bool isBuffer)
         {
-            if (!HasBeaker && BufferModeTransfer) return;
+            if (!HasBeaker && _bufferModeTransfer) return;
             var beaker = _beakerContainer.ContainedEntity;
             var beakerSolution = beaker.GetComponent<SolutionComponent>();
             if (isBuffer)
@@ -227,7 +236,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
                         }
 
                         BufferSolution.Solution.RemoveReagent(id, actualAmount);
-                        if (BufferModeTransfer)
+                        if (_bufferModeTransfer)
                         {
                             beakerSolution.Solution.AddReagent(id, actualAmount);
                         }
@@ -351,22 +360,22 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// <param name="args">Data relevant to the event such as the actor which triggered it.</param>
         void IActivate.Activate(ActivateEventArgs args)
         {
-            if (!args.User.TryGetComponent(out IActorComponent actor))
+            if (!args.User.TryGetComponent(out IActorComponent? actor))
             {
                 return;
             }
 
-            if (!args.User.TryGetComponent(out IHandsComponent hands))
+            if (!args.User.TryGetComponent(out IHandsComponent? hands))
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                    _localizationManager.GetString("You have no hands."));
+                    Loc.GetString("You have no hands."));
                 return;
             }
 
             var activeHandEntity = hands.GetActiveHand?.Owner;
             if (activeHandEntity == null)
             {
-                _userInterface.Open(actor.playerSession);
+                UserInterface?.Open(actor.playerSession);
             }
         }
 
@@ -379,26 +388,33 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// <returns></returns>
         async Task<bool> IInteractUsing.InteractUsing(InteractUsingEventArgs args)
         {
-            if (!args.User.TryGetComponent(out IHandsComponent hands))
+            if (!args.User.TryGetComponent(out IHandsComponent? hands))
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                    _localizationManager.GetString("You have no hands."));
+                    Loc.GetString("You have no hands."));
                 return true;
             }
 
+            if (hands.GetActiveHand == null)
+            {
+                _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
+                    Loc.GetString("You have nothing on your hand."));
+                return false;
+            }
+
             var activeHandEntity = hands.GetActiveHand.Owner;
             if (activeHandEntity.TryGetComponent<SolutionComponent>(out var solution))
             {
                 if (HasBeaker)
                 {
                     _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                        _localizationManager.GetString("This ChemMaster already has a container in it."));
+                        Loc.GetString("This ChemMaster already has a container in it."));
                 }
                 else if ((solution.Capabilities & SolutionCaps.FitsInDispenser) == 0) //Close enough to a chem master...
                 {
                     //If it can't fit in the chem master, don't put it in. For example, buckets and mop buckets can't fit.
                     _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                        _localizationManager.GetString("That can't fit in the ChemMaster."));
+                        Loc.GetString("That can't fit in the ChemMaster."));
                 }
                 else
                 {
@@ -409,7 +425,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             else
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                    _localizationManager.GetString("You can't put this in the ChemMaster."));
+                    Loc.GetString("You can't put this in the ChemMaster."));
             }
 
             return true;

Content.Server/GameObjects/Components/Chemistry/InjectorComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using Content.Server.GameObjects.Components.Body.Circulatory;
 using Content.Server.Interfaces;
 using Content.Server.Utility;
@@ -22,9 +23,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [RegisterComponent]
     public class InjectorComponent : SharedInjectorComponent, IAfterInteract, IUse
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
 
         /// <summary>
         /// Whether or not the injector is able to draw from containers or if it's a single use
@@ -53,11 +52,6 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// </summary>
         [ViewVariables(VVAccess.ReadWrite)]
         private InjectorToggleMode _toggleState;
-        /// <summary>
-        /// Internal solution container
-        /// </summary>
-        [ViewVariables]
-        private SolutionComponent _internalContents;
 
         public override void ExposeData(ObjectSerializer serializer)
         {
@@ -69,9 +63,15 @@ namespace Content.Server.GameObjects.Components.Chemistry
         protected override void Startup()
         {
             base.Startup();
-            _internalContents = Owner.GetComponent<SolutionComponent>();
-            _internalContents.Capabilities |= SolutionCaps.Injector;
-            //Set _toggleState based on prototype
+
+            Owner.EnsureComponent<SolutionComponent>();
+
+            if (Owner.TryGetComponent(out SolutionComponent? solution))
+            {
+                solution.Capabilities |= SolutionCaps.Injector;
+            }
+
+            // Set _toggleState based on prototype
             _toggleState = _injectOnly ? InjectorToggleMode.Inject : InjectorToggleMode.Draw;
         }
 
@@ -114,7 +114,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             if (!InteractionChecks.InRangeUnobstructed(eventArgs)) return;
 
             //Make sure we have the attacking entity
-            if (eventArgs.Target == null || !_internalContents.Injector)
+            if (eventArgs.Target == null || !Owner.TryGetComponent(out SolutionComponent? solution) || !solution.Injector)
             {
                 return;
             }
@@ -134,7 +134,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             }
             else //Handle injecting into bloodstream
             {
-                if (targetEntity.TryGetComponent(out BloodstreamComponent bloodstream) &&
+                if (targetEntity.TryGetComponent(out BloodstreamComponent? bloodstream) &&
                     _toggleState == InjectorToggleMode.Inject)
                 {
                     TryInjectIntoBloodstream(bloodstream, eventArgs.User);
@@ -155,7 +155,8 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
         private void TryInjectIntoBloodstream(BloodstreamComponent targetBloodstream, IEntity user)
         {
-            if (_internalContents.CurrentVolume == 0)
+            if (!Owner.TryGetComponent(out SolutionComponent? solution) ||
+                solution.CurrentVolume == 0)
             {
                 return;
             }
@@ -170,7 +171,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             }
 
             //Move units from attackSolution to targetSolution
-            var removedSolution = _internalContents.SplitSolution(realTransferAmount);
+            var removedSolution = solution.SplitSolution(realTransferAmount);
             if (!targetBloodstream.TryTransferSolution(removedSolution))
             {
                 return;
@@ -183,7 +184,8 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
         private void TryInject(SolutionComponent targetSolution, IEntity user)
         {
-            if (_internalContents.CurrentVolume == 0)
+            if (!Owner.TryGetComponent(out SolutionComponent? solution) ||
+                solution.CurrentVolume == 0)
             {
                 return;
             }
@@ -198,7 +200,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             }
 
             //Move units from attackSolution to targetSolution
-            var removedSolution = _internalContents.SplitSolution(realTransferAmount);
+            var removedSolution = solution.SplitSolution(realTransferAmount);
             if (!targetSolution.TryAddSolution(removedSolution))
             {
                 return;
@@ -211,7 +213,8 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
         private void TryDraw(SolutionComponent targetSolution, IEntity user)
         {
-            if (_internalContents.EmptyVolume == 0)
+            if (!Owner.TryGetComponent(out SolutionComponent? solution) ||
+                solution.EmptyVolume == 0)
             {
                 return;
             }
@@ -227,7 +230,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
             //Move units from attackSolution to targetSolution
             var removedSolution = targetSolution.SplitSolution(realTransferAmount);
-            if (!_internalContents.TryAddSolution(removedSolution))
+            if (!solution.TryAddSolution(removedSolution))
             {
                 return;
             }
@@ -239,7 +242,12 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
         public override ComponentState GetComponentState()
         {
-            return new InjectorComponentState(_internalContents.CurrentVolume, _internalContents.MaxVolume, _toggleState);
+            Owner.TryGetComponent(out SolutionComponent? solution);
+
+            var currentVolume = solution?.CurrentVolume ?? ReagentUnit.Zero;
+            var maxVolume = solution?.MaxVolume ?? ReagentUnit.Zero;
+
+            return new InjectorComponentState(currentVolume, maxVolume, _toggleState);
         }
     }
 }

Content.Server/GameObjects/Components/Chemistry/PillComponent.cs

@@ -20,9 +20,8 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [ComponentReference(typeof(IAfterInteract))]
     public class PillComponent : FoodComponent, IUse, IAfterInteract
     {
-#pragma warning disable 649
-        [Dependency] private readonly IEntitySystemManager _entitySystem;
-#pragma warning restore 649
+        [Dependency] private readonly IEntitySystemManager _entitySystem = default!;
+
         public override string Name => "Pill";
 
         [ViewVariables]

Content.Server/GameObjects/Components/Chemistry/PourableComponent.cs

@@ -19,10 +19,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [RegisterComponent]
     class PourableComponent : Component, IInteractUsing
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
 
         public override string Name => "Pourable";
 
@@ -91,7 +88,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             if (realTransferAmount <= 0) //Special message if container is full
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, eventArgs.User,
-                    _localizationManager.GetString("Container is full"));
+                    Loc.GetString("Container is full"));
                 return false;
             }
 
@@ -101,7 +98,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
                 return false;
 
             _notifyManager.PopupMessage(Owner.Transform.GridPosition, eventArgs.User,
-                _localizationManager.GetString("Transferred {0}u", removedSolution.TotalVolume));
+                Loc.GetString("Transferred {0}u", removedSolution.TotalVolume));
 
             return true;
         }

Content.Server/GameObjects/Components/Chemistry/ReagentDispenserComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Linq;
 using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.GUI;
@@ -7,6 +8,7 @@ using Content.Server.GameObjects.Components.Power.ApcNetComponents;
 using Content.Server.GameObjects.EntitySystems;
 using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Server.Utility;
 using Content.Shared.Chemistry;
 using Content.Shared.GameObjects.Components.Chemistry.ReagentDispenser;
 using Content.Shared.GameObjects.EntitySystems;
@@ -38,14 +40,10 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [ComponentReference(typeof(IInteractUsing))]
     public class ReagentDispenserComponent : SharedReagentDispenserComponent, IActivate, IInteractUsing, ISolutionChange
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
 
-        [ViewVariables] private BoundUserInterface _userInterface;
-        [ViewVariables] private ContainerSlot _beakerContainer;
-        [ViewVariables] private string _packPrototypeId;
+        [ViewVariables] private ContainerSlot _beakerContainer = default!;
+        [ViewVariables] private string _packPrototypeId = "";
 
         [ViewVariables] private bool HasBeaker => _beakerContainer.ContainedEntity != null;
         [ViewVariables] private ReagentUnit _dispenseAmount = ReagentUnit.New(10);
@@ -53,9 +51,9 @@ namespace Content.Server.GameObjects.Components.Chemistry
         [ViewVariables]
         private SolutionComponent Solution => _beakerContainer.ContainedEntity.GetComponent<SolutionComponent>();
 
-        private PowerReceiverComponent _powerReceiver;
-        private bool Powered => _powerReceiver.Powered;
+        private bool Powered => !Owner.TryGetComponent(out PowerReceiverComponent? receiver) || receiver.Powered;
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(ReagentDispenserUiKey.Key);
 
         /// <summary>
         /// Shows the serializer how to save/load this components yaml prototype.
@@ -75,14 +73,19 @@ namespace Content.Server.GameObjects.Components.Chemistry
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(ReagentDispenserUiKey.Key);
-            _userInterface.OnReceiveMessage += OnUiReceiveMessage;
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += OnUiReceiveMessage;
+            }
 
             _beakerContainer =
                 ContainerManagerComponent.Ensure<ContainerSlot>($"{Name}-reagentContainerContainer", Owner);
-            _powerReceiver = Owner.GetComponent<PowerReceiverComponent>();
-            _powerReceiver.OnPowerStateChanged += OnPowerChanged;
+
+            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            {
+                receiver.OnPowerStateChanged += OnPowerChanged;
+            }
 
             InitializeFromPrototype();
             UpdateUserInterface();
@@ -108,7 +111,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             }
         }
 
-        private void OnPowerChanged(object sender, PowerStateEventArgs e)
+        private void OnPowerChanged(object? sender, PowerStateEventArgs e)
         {
             UpdateUserInterface();
         }
@@ -120,6 +123,11 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// <param name="obj">A user interface message from the client.</param>
         private void OnUiReceiveMessage(ServerBoundUserInterfaceMessage obj)
         {
+            if (obj.Session.AttachedEntity == null)
+            {
+                return;
+            }
+
             var msg = (UiButtonPressedMessage) obj.Message;
             var needsPower = msg.Button switch
             {
@@ -175,7 +183,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// </summary>
         /// <param name="playerEntity">The player entity.</param>
         /// <returns>Returns true if the entity can use the dispenser, and false if it cannot.</returns>
-        private bool PlayerCanUseDispenser(IEntity playerEntity, bool needsPower = true)
+        private bool PlayerCanUseDispenser(IEntity? playerEntity, bool needsPower = true)
         {
             //Need player entity to check if they are still able to use the dispenser
             if (playerEntity == null)
@@ -211,7 +219,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
         private void UpdateUserInterface()
         {
             var state = GetUserInterfaceState();
-            _userInterface.SetState(state);
+            UserInterface?.SetState(state);
         }
 
         /// <summary>
@@ -265,22 +273,22 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// <param name="args">Data relevant to the event such as the actor which triggered it.</param>
         void IActivate.Activate(ActivateEventArgs args)
         {
-            if (!args.User.TryGetComponent(out IActorComponent actor))
+            if (!args.User.TryGetComponent(out IActorComponent? actor))
             {
                 return;
             }
 
-            if (!args.User.TryGetComponent(out IHandsComponent hands))
+            if (!args.User.TryGetComponent(out IHandsComponent? hands))
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                    _localizationManager.GetString("You have no hands."));
+                    Loc.GetString("You have no hands."));
                 return;
             }
 
             var activeHandEntity = hands.GetActiveHand?.Owner;
             if (activeHandEntity == null)
             {
-                _userInterface.Open(actor.playerSession);
+                UserInterface?.Open(actor.playerSession);
             }
         }
 
@@ -293,26 +301,33 @@ namespace Content.Server.GameObjects.Components.Chemistry
         /// <returns></returns>
         async Task<bool> IInteractUsing.InteractUsing(InteractUsingEventArgs args)
         {
-            if (!args.User.TryGetComponent(out IHandsComponent hands))
+            if (!args.User.TryGetComponent(out IHandsComponent? hands))
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                    _localizationManager.GetString("You have no hands."));
+                    Loc.GetString("You have no hands."));
                 return true;
             }
 
+            if (hands.GetActiveHand == null)
+            {
+                _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
+                    Loc.GetString("You have nothing on your hand."));
+                return false;
+            }
+
             var activeHandEntity = hands.GetActiveHand.Owner;
             if (activeHandEntity.TryGetComponent<SolutionComponent>(out var solution))
             {
                 if (HasBeaker)
                 {
                     _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                        _localizationManager.GetString("This dispenser already has a container in it."));
+                        Loc.GetString("This dispenser already has a container in it."));
                 }
                 else if ((solution.Capabilities & SolutionCaps.FitsInDispenser) == 0)
                 {
                     //If it can't fit in the dispenser, don't put it in. For example, buckets and mop buckets can't fit.
                     _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                        _localizationManager.GetString("That can't fit in the dispenser."));
+                        Loc.GetString("That can't fit in the dispenser."));
                 }
                 else
                 {
@@ -323,7 +338,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             else
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
-                    _localizationManager.GetString("You can't put this in the dispenser."));
+                    Loc.GetString("You can't put this in the dispenser."));
             }
 
             return true;

Content.Server/GameObjects/Components/Chemistry/SolutionComponent.cs

@@ -29,11 +29,8 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [RegisterComponent]
     public class SolutionComponent : SharedSolutionComponent, IExamine
     {
-#pragma warning disable 649
-        [Dependency] private readonly IPrototypeManager _prototypeManager;
-        [Dependency] private readonly ILocalizationManager _loc;
-        [Dependency] private readonly IEntitySystemManager _entitySystemManager;
-#pragma warning restore 649
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
 
         private IEnumerable<ReactionPrototype> _reactions;
         private AudioSystem _audioSystem;
@@ -276,7 +273,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
                 return;
             }
 
-            message.AddText(_loc.GetString("Contains:\n"));
+            message.AddText(Loc.GetString("Contains:\n"));
             if (ReagentList.Count == 0)
             {
                 message.AddText("Nothing.\n");
@@ -303,12 +300,12 @@ namespace Content.Server.GameObjects.Components.Chemistry
                             colorIsh = "Blue";
                         }
 
-                        message.AddText(_loc.GetString("A {0} liquid\n", colorIsh));
+                        message.AddText(Loc.GetString("A {0} liquid\n", colorIsh));
                     }
                 }
                 else
                 {
-                    message.AddText(_loc.GetString("Unknown reagent: {0}u\n", reagent.Quantity));
+                    message.AddText(Loc.GetString("Unknown reagent: {0}u\n", reagent.Quantity));
                 }
             }
         }

Content.Server/GameObjects/Components/Chemistry/TransformableContainerComponent.cs

@@ -1,8 +1,10 @@
-using Content.Server.GameObjects.EntitySystems;
+#nullable enable
+using Content.Server.GameObjects.EntitySystems;
 using Content.Shared.Chemistry;
 using Robust.Server.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Utility;
 
@@ -11,28 +13,27 @@ namespace Content.Server.GameObjects.Components.Chemistry
     [RegisterComponent]
     public class TransformableContainerComponent : Component, ISolutionChange
     {
-#pragma warning disable 649
-        [Dependency] private readonly IPrototypeManager _prototypeManager;
-#pragma warning restore 649
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
 
         public override string Name => "TransformableContainer";
 
-        private bool _transformed = false;
-        public bool Transformed { get => _transformed; }
+        private SpriteSpecifier? _initialSprite;
+        private string _initialName = default!;
+        private string _initialDescription = default!;
+        private ReagentPrototype? _currentReagent;
 
-        private SpriteSpecifier _initialSprite;
-        private string _initialName;
-        private string _initialDescription;
-        private SpriteComponent _sprite;
-
-        private ReagentPrototype _currentReagent;
+        public bool Transformed { get; private set; }
 
         public override void Initialize()
         {
             base.Initialize();
 
-            _sprite = Owner.GetComponent<SpriteComponent>();
-            _initialSprite = new SpriteSpecifier.Rsi(new ResourcePath(_sprite.BaseRSIPath), "icon");
+            if (Owner.TryGetComponent(out SpriteComponent? sprite) &&
+                sprite.BaseRSIPath != null)
+            {
+                _initialSprite = new SpriteSpecifier.Rsi(new ResourcePath(sprite.BaseRSIPath), "icon");
+            }
+
             _initialName = Owner.Name;
             _initialDescription = Owner.Description;
         }
@@ -40,14 +41,27 @@ namespace Content.Server.GameObjects.Components.Chemistry
         protected override void Startup()
         {
             base.Startup();
-            Owner.GetComponent<SolutionComponent>().Capabilities |= SolutionCaps.FitsInDispenser;;
+
+            if (!Owner.EnsureComponent(out SolutionComponent solution))
+            {
+                Logger.Warning(
+                    $"Entity {Owner.Name} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionComponent)}");
+            }
+
+            solution.Capabilities |= SolutionCaps.FitsInDispenser;
         }
 
         public void CancelTransformation()
         {
             _currentReagent = null;
-            _transformed = false;
-            _sprite.LayerSetSprite(0, _initialSprite);
+            Transformed = false;
+
+            if (Owner.TryGetComponent(out SpriteComponent? sprite) &&
+                _initialSprite != null)
+            {
+                sprite.LayerSetSprite(0, _initialSprite);
+            }
+
             Owner.Name = _initialName;
             Owner.Description = _initialDescription;
         }
@@ -76,11 +90,16 @@ namespace Content.Server.GameObjects.Components.Chemistry
                 !string.IsNullOrWhiteSpace(proto.SpriteReplacementPath))
             {
                 var spriteSpec = new SpriteSpecifier.Rsi(new ResourcePath("Objects/Drinks/" + proto.SpriteReplacementPath),"icon");
-                _sprite.LayerSetSprite(0, spriteSpec);
+
+                if (Owner.TryGetComponent(out SpriteComponent? sprite))
+                {
+                    sprite?.LayerSetSprite(0, spriteSpec);
+                }
+
                 Owner.Name = proto.Name + " glass";
                 Owner.Description = proto.Description;
                 _currentReagent = proto;
-                _transformed = true;
+                Transformed = true;
             }
         }
     }

Content.Server/GameObjects/Components/Chemistry/VaporComponent.cs

@@ -7,6 +7,7 @@ using Robust.Shared.GameObjects.Components;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Map;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
@@ -19,8 +20,6 @@ namespace Content.Server.GameObjects.Components.Chemistry
         [Dependency] private readonly IMapManager _mapManager = default!;
         public override string Name => "Vapor";
 
-        [ViewVariables]
-        private SolutionComponent _contents;
         [ViewVariables]
         private ReagentUnit _transferAmount;
 
@@ -28,11 +27,15 @@ namespace Content.Server.GameObjects.Components.Chemistry
         private Vector2 _direction;
         private float _velocity;
 
-
         public override void Initialize()
         {
             base.Initialize();
-            _contents = Owner.GetComponent<SolutionComponent>();
+
+            if (!Owner.EnsureComponent(out SolutionComponent _))
+            {
+                Logger.Warning(
+                    $"Entity {Owner.Name} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionComponent)}");
+            }
         }
 
         public void Start(Vector2 dir, float velocity)
@@ -56,6 +59,9 @@ namespace Content.Server.GameObjects.Components.Chemistry
 
         public void Update()
         {
+            if (!Owner.TryGetComponent(out SolutionComponent contents))
+                return;
+
             if (!_running)
                 return;
 
@@ -70,11 +76,11 @@ namespace Content.Server.GameObjects.Components.Chemistry
                 foreach (var tile in tiles)
                 {
                     var pos = tile.GridIndices.ToGridCoordinates(_mapManager, tile.GridIndex);
-                    SpillHelper.SpillAt(pos, _contents.SplitSolution(amount), "PuddleSmear", false); //make non PuddleSmear?
+                    SpillHelper.SpillAt(pos, contents.SplitSolution(amount), "PuddleSmear", false); //make non PuddleSmear?
                 }
             }
 
-            if (_contents.CurrentVolume == 0)
+            if (contents.CurrentVolume == 0)
             {
                 // Delete this
                 Owner.Delete();
@@ -87,7 +93,14 @@ namespace Content.Server.GameObjects.Components.Chemistry
             {
                 return false;
             }
-            var result = _contents.TryAddSolution(solution);
+
+            if (!Owner.TryGetComponent(out SolutionComponent contents))
+            {
+                return false;
+            }
+
+            var result = contents.TryAddSolution(solution);
+
             if (!result)
             {
                 return false;

Content.Server/GameObjects/Components/Command/CommunicationsConsoleComponent.cs

@@ -1,5 +1,7 @@
-using Content.Server.GameObjects.Components.Power.ApcNetComponents;
+#nullable enable
+using Content.Server.GameObjects.Components.Power.ApcNetComponents;
 using Content.Server.GameObjects.EntitySystems;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.Components.Command;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects.Components.UserInterface;
@@ -8,6 +10,7 @@ using Robust.Server.Interfaces.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Command
 {
@@ -15,22 +18,22 @@ namespace Content.Server.GameObjects.Components.Command
     [ComponentReference(typeof(IActivate))]
     public class CommunicationsConsoleComponent : SharedCommunicationsConsoleComponent, IActivate
     {
-#pragma warning disable 649
-        [Dependency] private IEntitySystemManager _entitySystemManager;
-#pragma warning restore 649
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
+
+        private bool Powered => !Owner.TryGetComponent(out PowerReceiverComponent? receiver) || receiver.Powered;
 
-        private BoundUserInterface _userInterface;
-        private PowerReceiverComponent _powerReceiver;
-        private bool Powered => _powerReceiver.Powered;
         private RoundEndSystem RoundEndSystem => _entitySystemManager.GetEntitySystem<RoundEndSystem>();
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(CommunicationsConsoleUiKey.Key);
+
         public override void Initialize()
         {
             base.Initialize();
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>().GetBoundUserInterface(CommunicationsConsoleUiKey.Key);
-            _userInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
-            _powerReceiver = Owner.GetComponent<PowerReceiverComponent>();
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += UserInterfaceOnOnReceiveMessage;
+            }
 
             RoundEndSystem.OnRoundEndCountdownStarted += UpdateBoundInterface;
             RoundEndSystem.OnRoundEndCountdownCancelled += UpdateBoundInterface;
@@ -39,7 +42,7 @@ namespace Content.Server.GameObjects.Components.Command
 
         private void UpdateBoundInterface()
         {
-            _userInterface.SetState(new CommunicationsConsoleInterfaceState(RoundEndSystem.ExpectedCountdownEnd));
+            UserInterface?.SetState(new CommunicationsConsoleInterfaceState(RoundEndSystem.ExpectedCountdownEnd));
         }
 
         private void UserInterfaceOnOnReceiveMessage(ServerBoundUserInterfaceMessage obj)
@@ -58,12 +61,12 @@ namespace Content.Server.GameObjects.Components.Command
 
         public void OpenUserInterface(IPlayerSession session)
         {
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
         }
 
         void IActivate.Activate(ActivateEventArgs eventArgs)
         {
-            if (!eventArgs.User.TryGetComponent(out IActorComponent actor))
+            if (!eventArgs.User.TryGetComponent(out IActorComponent? actor))
                 return;
 
             if (!Powered)

Content.Server/GameObjects/Components/Conveyor/ConveyorComponent.cs

@@ -28,10 +28,8 @@ namespace Content.Server.GameObjects.Components.Conveyor
     [RegisterComponent]
     public class ConveyorComponent : Component, IInteractUsing
     {
-#pragma warning disable 649
         [Dependency] private readonly IEntityManager _entityManager = default!;
         [Dependency] private readonly IRobustRandom _random = default!;
-#pragma warning restore 649
 
         public override string Name => "Conveyor";
 

Content.Server/GameObjects/Components/Damage/BreakableComponent.cs

@@ -21,10 +21,8 @@ namespace Content.Server.GameObjects.Components.Damage
     [ComponentReference(typeof(IDamageableComponent))]
     public class BreakableComponent : RuinableComponent, IExAct
     {
-#pragma warning disable 649
-        [Dependency] private readonly IEntitySystemManager _entitySystemManager;
-        [Dependency] private readonly IRobustRandom _random;
-#pragma warning restore 649
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
+        [Dependency] private readonly IRobustRandom _random = default!;
 
         public override string Name => "Breakable";
 
@@ -41,8 +39,6 @@ namespace Content.Server.GameObjects.Components.Damage
             switch (eventArgs.Severity)
             {
                 case ExplosionSeverity.Destruction:
-                    PerformDestruction();
-                    break;
                 case ExplosionSeverity.Heavy:
                     PerformDestruction();
                     break;

Content.Server/GameObjects/Components/Damage/DamageOnToolInteractComponent.cs

@@ -2,6 +2,7 @@
 using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.Interactable;
 using Content.Shared.Damage;
+using Content.Shared.GameObjects.Components.Damage;
 using Content.Shared.GameObjects.Components.Interactable;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Shared.GameObjects;
@@ -27,12 +28,6 @@ namespace Content.Server.GameObjects.Components.Damage
             serializer.DataField(ref _tools, "tools", new List<ToolQuality>());
         }
 
-        public override void Initialize()
-        {
-            base.Initialize();
-            Owner.EnsureComponent<DestructibleComponent>();
-        }
-
         public async Task<bool> InteractUsing(InteractUsingEventArgs eventArgs)
         {
             if (eventArgs.Using.TryGetComponent<ToolComponent>(out var tool))
@@ -56,7 +51,7 @@ namespace Content.Server.GameObjects.Components.Damage
 
         protected bool CallDamage(InteractUsingEventArgs eventArgs, ToolComponent tool)
         {
-            if (eventArgs.Target.TryGetComponent<DestructibleComponent>(out var damageable))
+            if (eventArgs.Target.TryGetComponent<IDamageableComponent>(out var damageable))
             {
                 damageable.ChangeDamage(tool.HasQuality(ToolQuality.Welding)
                         ? DamageType.Heat

Content.Server/GameObjects/Components/Damage/DestructibleComponent.cs

@@ -16,9 +16,7 @@ namespace Content.Server.GameObjects.Components.Damage
     [ComponentReference(typeof(IDamageableComponent))]
     public class DestructibleComponent : RuinableComponent, IDestroyAct
     {
-#pragma warning disable 649
-        [Dependency] private readonly IEntitySystemManager _entitySystemManager;
-#pragma warning restore 649
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
 
         protected ActSystem ActSystem;
 

Content.Server/GameObjects/Components/Damage/RuinableComponent.cs

@@ -5,7 +5,6 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Serialization;
-using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Damage
 {
@@ -18,13 +17,6 @@ namespace Content.Server.GameObjects.Components.Damage
     {
         private DamageState _currentDamageState;
 
-        /// <summary>
-        ///     How much HP this component can sustain before triggering
-        ///     <see cref="PerformDestruction"/>.
-        /// </summary>
-        [ViewVariables(VVAccess.ReadWrite)]
-        public int MaxHp { get; private set; }
-
         /// <summary>
         ///     Sound played upon destruction.
         /// </summary>
@@ -35,29 +27,24 @@ namespace Content.Server.GameObjects.Components.Damage
 
         public override DamageState CurrentDamageState => _currentDamageState;
 
-        public override void Initialize()
-        {
-            base.Initialize();
-            HealthChangedEvent += OnHealthChanged;
-        }
-
         public override void ExposeData(ObjectSerializer serializer)
         {
             base.ExposeData(serializer);
 
-            serializer.DataField(this, ruinable => ruinable.MaxHp, "maxHP", 100);
+            serializer.DataReadWriteFunction(
+                "deadThreshold",
+                100,
+                t => DeadThreshold = t ,
+                () => DeadThreshold ?? -1);
+
             serializer.DataField(this, ruinable => ruinable.DestroySound, "destroySound", string.Empty);
         }
 
-        public override void OnRemove()
+        protected override void EnterState(DamageState state)
         {
-            base.OnRemove();
-            HealthChangedEvent -= OnHealthChanged;
-        }
+            base.EnterState(state);
 
-        private void OnHealthChanged(HealthChangedEventArgs e)
-        {
-            if (CurrentDamageState != DamageState.Dead && TotalDamage >= MaxHp)
+            if (state == DamageState.Dead)
             {
                 PerformDestruction();
             }

Content.Server/GameObjects/Components/Disposal/DisposalEntryComponent.cs

@@ -1,7 +1,11 @@
 using System.Collections.Generic;
+using System.Linq;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Random;
+using Robust.Shared.IoC;
 using Robust.Shared.Maths;
+using Robust.Shared.Random;
 
 namespace Content.Server.GameObjects.Components.Disposal
 {
@@ -9,6 +13,8 @@ namespace Content.Server.GameObjects.Components.Disposal
     [ComponentReference(typeof(IDisposalTubeComponent))]
     public class DisposalEntryComponent : DisposalTubeComponent
     {
+        [Dependency] private readonly IRobustRandom _random = default!;
+
         private const string HolderPrototypeId = "DisposalHolder";
 
         public override string Name => "DisposalEntry";
@@ -43,8 +49,19 @@ namespace Content.Server.GameObjects.Components.Disposal
             return new[] {Owner.Transform.LocalRotation.GetDir()};
         }
 
+        /// <summary>
+        ///     Ejects contents when they come from the same direction the entry is facing.
+        /// </summary>
         public override Direction NextDirection(DisposalHolderComponent holder)
         {
+            if (holder.PreviousTube != null && DirectionTo(holder.PreviousTube) == ConnectableDirections()[0])
+            {
+                var invalidDirections = new Direction[] { ConnectableDirections()[0], Direction.Invalid };
+                var directions = System.Enum.GetValues(typeof(Direction))
+                    .Cast<Direction>().Except(invalidDirections).ToList();
+                return _random.Pick<Direction>(directions);
+            }
+
             return ConnectableDirections()[0];
         }
     }

Content.Server/GameObjects/Components/Disposal/DisposalJunctionComponent.cs

@@ -14,9 +14,7 @@ namespace Content.Server.GameObjects.Components.Disposal
     [ComponentReference(typeof(IDisposalTubeComponent))]
     public class DisposalJunctionComponent : DisposalTubeComponent
     {
-#pragma warning disable 649
-        [Dependency] private readonly IRobustRandom _random;
-#pragma warning restore 649
+        [Dependency] private readonly IRobustRandom _random = default!;
 
         /// <summary>
         ///     The angles to connect to.

Content.Server/GameObjects/Components/Disposal/DisposalRouterComponent.cs

@@ -1,4 +1,5 @@
-using Content.Server.Interfaces;
+#nullable enable
+using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
 using Content.Shared.GameObjects.EntitySystems;
 using Content.Shared.Interfaces.GameObjects.Components;
@@ -16,6 +17,7 @@ using Robust.Shared.Maths;
 using Robust.Shared.ViewVariables;
 using System;
 using System.Collections.Generic;
+using Content.Server.Utility;
 using static Content.Shared.GameObjects.Components.Disposal.SharedDisposalRouterComponent;
 
 namespace Content.Server.GameObjects.Components.Disposal
@@ -25,22 +27,19 @@ namespace Content.Server.GameObjects.Components.Disposal
     [ComponentReference(typeof(IDisposalTubeComponent))]
     public class DisposalRouterComponent : DisposalJunctionComponent, IActivate
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
         public override string Name => "DisposalRouter";
 
         [ViewVariables]
-        private BoundUserInterface _userInterface;
-
-        [ViewVariables]
-        private HashSet<string> _tags;
+        private readonly HashSet<string> _tags = new HashSet<string>();
 
         [ViewVariables]
         public bool Anchored =>
-            !Owner.TryGetComponent(out CollidableComponent collidable) ||
+            !Owner.TryGetComponent(out ICollidableComponent? collidable) ||
             collidable.Anchored;
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(DisposalRouterUiKey.Key);
+
         public override Direction NextDirection(DisposalHolderComponent holder)
         {
             var directions = ConnectableDirections();
@@ -53,15 +52,14 @@ namespace Content.Server.GameObjects.Components.Disposal
             return Owner.Transform.LocalRotation.GetDir();
         }
 
-
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(DisposalRouterUiKey.Key);
-            _userInterface.OnReceiveMessage += OnUiReceiveMessage;
 
-            _tags = new HashSet<string>();
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += OnUiReceiveMessage;
+            }
 
             UpdateUserInterface();
         }
@@ -73,6 +71,11 @@ namespace Content.Server.GameObjects.Components.Disposal
         /// <param name="obj">A user interface message from the client.</param>
         private void OnUiReceiveMessage(ServerBoundUserInterfaceMessage obj)
         {
+            if (obj.Session.AttachedEntity == null)
+            {
+                return;
+            }
+
             var msg = (UiActionMessage) obj.Message;
 
             if (!PlayerCanUseDisposalTagger(obj.Session.AttachedEntity))
@@ -112,10 +115,10 @@ namespace Content.Server.GameObjects.Components.Disposal
         /// <summary>
         /// Gets component data to be used to update the user interface client-side.
         /// </summary>
-        /// <returns>Returns a <see cref="SharedDisposalRouterComponent.DisposalRouterBoundUserInterfaceState"/></returns>
+        /// <returns>Returns a <see cref="DisposalRouterUserInterfaceState"/></returns>
         private DisposalRouterUserInterfaceState GetUserInterfaceState()
         {
-            if(_tags == null || _tags.Count <= 0)
+            if(_tags.Count <= 0)
             {
                 return new DisposalRouterUserInterfaceState("");
             }
@@ -136,7 +139,7 @@ namespace Content.Server.GameObjects.Components.Disposal
         private void UpdateUserInterface()
         {
             var state = GetUserInterfaceState();
-            _userInterface.SetState(state);
+            UserInterface?.SetState(state);
         }
 
         private void ClickSound()
@@ -150,12 +153,12 @@ namespace Content.Server.GameObjects.Components.Disposal
         /// <param name="args">Data relevant to the event such as the actor which triggered it.</param>
         void IActivate.Activate(ActivateEventArgs args)
         {
-            if (!args.User.TryGetComponent(out IActorComponent actor))
+            if (!args.User.TryGetComponent(out IActorComponent? actor))
             {
                 return;
             }
 
-            if (!args.User.TryGetComponent(out IHandsComponent hands))
+            if (!args.User.TryGetComponent(out IHandsComponent? hands))
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
                     Loc.GetString("You have no hands."));
@@ -166,13 +169,13 @@ namespace Content.Server.GameObjects.Components.Disposal
             if (activeHandEntity == null)
             {
                 UpdateUserInterface();
-                _userInterface.Open(actor.playerSession);
+                UserInterface?.Open(actor.playerSession);
             }
         }
 
         public override void OnRemove()
         {
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
             base.OnRemove();
         }
     }

Content.Server/GameObjects/Components/Disposal/DisposalTaggerComponent.cs

@@ -1,5 +1,7 @@
-using Content.Server.Interfaces;
+#nullable enable
+using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.EntitySystems;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects.Components.UserInterface;
@@ -23,35 +25,33 @@ namespace Content.Server.GameObjects.Components.Disposal
     [ComponentReference(typeof(IDisposalTubeComponent))]
     public class DisposalTaggerComponent : DisposalTransitComponent, IActivate
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
         public override string Name => "DisposalTagger";
 
-        [ViewVariables]
-        private BoundUserInterface _userInterface;
-
         [ViewVariables(VVAccess.ReadWrite)]
         private string _tag = "";
 
         [ViewVariables]
         public bool Anchored =>
-            !Owner.TryGetComponent(out CollidableComponent collidable) ||
+            !Owner.TryGetComponent(out CollidableComponent? collidable) ||
             collidable.Anchored;
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(DisposalTaggerUiKey.Key);
+
         public override Direction NextDirection(DisposalHolderComponent holder)
         {
             holder.Tags.Add(_tag);
             return base.NextDirection(holder);
         }
 
-
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(DisposalTaggerUiKey.Key);
-            _userInterface.OnReceiveMessage += OnUiReceiveMessage;
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += OnUiReceiveMessage;
+            }
 
             UpdateUserInterface();
         }
@@ -70,7 +70,7 @@ namespace Content.Server.GameObjects.Components.Disposal
 
             //Check for correct message and ignore maleformed strings
             if (msg.Action == UiAction.Ok && TagRegex.IsMatch(msg.Tag))
-            {   
+            {
                     _tag = msg.Tag;
                     ClickSound();
             }
@@ -81,7 +81,7 @@ namespace Content.Server.GameObjects.Components.Disposal
         /// </summary>
         /// <param name="playerEntity">The player entity.</param>
         /// <returns>Returns true if the entity can use the configuration interface, and false if it cannot.</returns>
-        private bool PlayerCanUseDisposalTagger(IEntity playerEntity)
+        private bool PlayerCanUseDisposalTagger(IEntity? playerEntity)
         {
             //Need player entity to check if they are still able to use the configuration interface
             if (playerEntity == null)
@@ -98,7 +98,7 @@ namespace Content.Server.GameObjects.Components.Disposal
         /// <summary>
         /// Gets component data to be used to update the user interface client-side.
         /// </summary>
-        /// <returns>Returns a <see cref="SharedDisposalTaggerComponent.DisposalTaggerBoundUserInterfaceState"/></returns>
+        /// <returns>Returns a <see cref="DisposalTaggerUserInterfaceState"/></returns>
         private DisposalTaggerUserInterfaceState GetUserInterfaceState()
         {
             return new DisposalTaggerUserInterfaceState(_tag);
@@ -107,7 +107,7 @@ namespace Content.Server.GameObjects.Components.Disposal
         private void UpdateUserInterface()
         {
             var state = GetUserInterfaceState();
-            _userInterface.SetState(state);
+            UserInterface?.SetState(state);
         }
 
         private void ClickSound()
@@ -121,12 +121,12 @@ namespace Content.Server.GameObjects.Components.Disposal
         /// <param name="args">Data relevant to the event such as the actor which triggered it.</param>
         void IActivate.Activate(ActivateEventArgs args)
         {
-            if (!args.User.TryGetComponent(out IActorComponent actor))
+            if (!args.User.TryGetComponent(out IActorComponent? actor))
             {
                 return;
             }
 
-            if (!args.User.TryGetComponent(out IHandsComponent hands))
+            if (!args.User.TryGetComponent(out IHandsComponent? hands))
             {
                 _notifyManager.PopupMessage(Owner.Transform.GridPosition, args.User,
                     Loc.GetString("You have no hands."));
@@ -137,14 +137,14 @@ namespace Content.Server.GameObjects.Components.Disposal
             if (activeHandEntity == null)
             {
                 UpdateUserInterface();
-                _userInterface.Open(actor.playerSession);
+                UserInterface?.Open(actor.playerSession);
             }
         }
 
         public override void OnRemove()
         {
             base.OnRemove();
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
     }
 }

Content.Server/GameObjects/Components/Disposal/DisposalTubeComponent.cs

@@ -24,7 +24,6 @@ using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Disposal
 {
-    // TODO: Make unanchored pipes pullable
     public abstract class DisposalTubeComponent : Component, IDisposalTubeComponent, IBreakAct
     {
         [Dependency] private readonly IGameTiming _gameTiming = default!;
@@ -69,21 +68,11 @@ namespace Content.Server.GameObjects.Components.Disposal
         {
             var nextDirection = NextDirection(holder);
             var snapGrid = Owner.GetComponent<SnapGridComponent>();
+            var oppositeDirection = new Angle(nextDirection.ToAngle().Theta + Math.PI).GetDir();
             var tube = snapGrid
                 .GetInDir(nextDirection)
                 .Select(x => x.TryGetComponent(out IDisposalTubeComponent? c) ? c : null)
-                .FirstOrDefault(x => x != null && x != this);
-
-            if (tube == null)
-            {
-                return null;
-            }
-
-            var oppositeDirection = new Angle(nextDirection.ToAngle().Theta + Math.PI).GetDir();
-            if (!tube.CanConnect(oppositeDirection, this))
-            {
-                return null;
-            }
+                .FirstOrDefault(x => x != null && x != this && x.CanConnect(oppositeDirection, this));
 
             return tube;
         }
@@ -192,6 +181,8 @@ namespace Content.Server.GameObjects.Components.Disposal
                 return;
             }
 
+            collidable.CanCollide = !collidable.Anchored;
+
             if (collidable.Anchored)
             {
                 OnAnchor();
@@ -230,6 +221,8 @@ namespace Content.Server.GameObjects.Components.Disposal
             var collidable = Owner.EnsureComponent<CollidableComponent>();
 
             collidable.AnchoredChanged += AnchoredChanged;
+
+            collidable.CanCollide = !collidable.Anchored;
         }
 
         protected override void Startup()

Content.Server/GameObjects/Components/Disposal/DisposalUnitComponent.cs

@@ -7,8 +7,10 @@ using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.GUI;
 using Content.Server.GameObjects.Components.Items.Storage;
 using Content.Server.GameObjects.Components.Power.ApcNetComponents;
+using Content.Server.GameObjects.EntitySystems.DoAfter;
 using Content.Server.Interfaces;
 using Content.Server.Interfaces.GameObjects.Components.Items;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.Components.Body;
 using Content.Shared.GameObjects.Components.Disposal;
 using Content.Shared.GameObjects.EntitySystems;
@@ -29,6 +31,7 @@ using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Timing;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 using Timer = Robust.Shared.Timers.Timer;
@@ -36,13 +39,12 @@ using Timer = Robust.Shared.Timers.Timer;
 namespace Content.Server.GameObjects.Components.Disposal
 {
     [RegisterComponent]
+    [ComponentReference(typeof(SharedDisposalUnitComponent))]
     [ComponentReference(typeof(IInteractUsing))]
     public class DisposalUnitComponent : SharedDisposalUnitComponent, IInteractHand, IInteractUsing, IDragDropOn
     {
-#pragma warning disable 649
         [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
         [Dependency] private readonly IGameTiming _gameTiming = default!;
-#pragma warning restore 649
 
         public override string Name => "DisposalUnit";
 
@@ -67,6 +69,12 @@ namespace Content.Server.GameObjects.Components.Disposal
         [ViewVariables]
         private TimeSpan _automaticEngageTime;
 
+        [ViewVariables]
+        private TimeSpan _flushDelay;
+
+        [ViewVariables]
+        private float _entryDelay;
+
         /// <summary>
         ///     Token used to cancel the automatic engage of a disposal unit
         ///     after an entity enters it.
@@ -81,9 +89,6 @@ namespace Content.Server.GameObjects.Components.Disposal
 
         [ViewVariables] public IReadOnlyList<IEntity> ContainedEntities => _container.ContainedEntities;
 
-        [ViewVariables]
-        private BoundUserInterface _userInterface = default!;
-
         [ViewVariables]
         public bool Powered =>
             !Owner.TryGetComponent(out PowerReceiverComponent? receiver) ||
@@ -115,6 +120,15 @@ namespace Content.Server.GameObjects.Components.Disposal
             }
         }
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(DisposalUnitUiKey.Key);
+
+        private DisposalUnitBoundUserInterfaceState? _lastUiState;
+
+        /// <summary>
+        ///     Store the translated state.
+        /// </summary>
+        private (PressureState State, string Localized) _locState;
+
         public bool CanInsert(IEntity entity)
         {
             if (!Anchored)
@@ -161,19 +175,40 @@ namespace Content.Server.GameObjects.Components.Disposal
 
             if (entity.TryGetComponent(out IActorComponent? actor))
             {
-                _userInterface.Close(actor.playerSession);
+                UserInterface?.Close(actor.playerSession);
             }
 
             UpdateVisualState();
         }
 
-        public bool TryInsert(IEntity entity)
+        public async Task<bool> TryInsert(IEntity entity, IEntity? user = default)
         {
-            if (!CanInsert(entity) || !_container.Insert(entity))
-            {
+            if (!CanInsert(entity))
                 return false;
+
+            if (user != null && _entryDelay > 0f)
+            {
+                var doAfterSystem = EntitySystem.Get<DoAfterSystem>();
+
+                var doAfterArgs = new DoAfterEventArgs(user, _entryDelay, default, Owner)
+                {
+                    BreakOnDamage = true,
+                    BreakOnStun = true,
+                    BreakOnTargetMove = true,
+                    BreakOnUserMove = true,
+                    NeedHand = false,
+                };
+
+                var result = await doAfterSystem.DoAfter(doAfterArgs);
+
+                if (result == DoAfterStatus.Cancelled)
+                    return false;
+
             }
 
+            if (!_container.Insert(entity))
+                return false;
+
             AfterInsert(entity);
 
             return true;
@@ -218,9 +253,9 @@ namespace Content.Server.GameObjects.Components.Disposal
         {
             Engaged ^= true;
 
-            if (Engaged)
+            if (Engaged && CanFlush())
             {
-                TryFlush();
+                Timer.Spawn(_flushDelay, () => TryFlush());
             }
         }
 
@@ -284,17 +319,35 @@ namespace Content.Server.GameObjects.Components.Disposal
 
         private DisposalUnitBoundUserInterfaceState GetInterfaceState()
         {
-            var state = Loc.GetString($"{State}");
-            return new DisposalUnitBoundUserInterfaceState(Owner.Name, state, _pressure, Powered, Engaged);
+            string stateString;
+
+            if (_locState.State != State)
+            {
+                stateString = Loc.GetString($"{State}");
+                _locState = (State, stateString);
+            }
+            else
+            {
+                stateString = _locState.Localized;
+            }
+
+            return new DisposalUnitBoundUserInterfaceState(Owner.Name, stateString, _pressure, Powered, Engaged);
         }
 
         private void UpdateInterface()
         {
             var state = GetInterfaceState();
-            _userInterface.SetState(state);
+
+            if (_lastUiState != null && _lastUiState.Equals(state))
+            {
+                return;
+            }
+
+            _lastUiState = state;
+            UserInterface?.SetState(state);
         }
 
-        private bool PlayerCanUse(IEntity player)
+        private bool PlayerCanUse(IEntity? player)
         {
             if (player == null)
             {
@@ -402,8 +455,9 @@ namespace Content.Server.GameObjects.Components.Disposal
                 : LightState.Ready);
         }
 
-        public void Update(float frameTime)
+        public override void Update(float frameTime)
         {
+            base.Update(frameTime);
             if (!Powered)
             {
                 return;
@@ -461,10 +515,16 @@ namespace Content.Server.GameObjects.Components.Disposal
                 () => (int) _automaticEngageTime.TotalSeconds);
 
             serializer.DataReadWriteFunction(
-                "automaticEngageTime",
-                30,
-                seconds => _automaticEngageTime = TimeSpan.FromSeconds(seconds),
-                () => (int) _automaticEngageTime.TotalSeconds);
+                "flushDelay",
+                3,
+                seconds => _flushDelay = TimeSpan.FromSeconds(seconds),
+                () => (int) _flushDelay.TotalSeconds);
+
+            serializer.DataReadWriteFunction(
+                "entryDelay",
+                0.5f,
+                seconds => _entryDelay = seconds,
+                () => (int) _entryDelay);
         }
 
         public override void Initialize()
@@ -472,9 +532,11 @@ namespace Content.Server.GameObjects.Components.Disposal
             base.Initialize();
 
             _container = ContainerManagerComponent.Ensure<Container>(Name, Owner);
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(DisposalUnitUiKey.Key);
-            _userInterface.OnReceiveMessage += OnUiReceiveMessage;
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += OnUiReceiveMessage;
+            }
 
             UpdateInterface();
         }
@@ -483,10 +545,15 @@ namespace Content.Server.GameObjects.Components.Disposal
         {
             base.Startup();
 
-            Owner.EnsureComponent<AnchorableComponent>();
+            if(!Owner.HasComponent<AnchorableComponent>())
+            {
+                Logger.WarningS("VitalComponentMissing", $"Disposal unit {Owner.Uid} is missing an anchorable component");
+            }
 
-            var collidable = Owner.EnsureComponent<CollidableComponent>();
-            collidable.AnchoredChanged += UpdateVisualState;
+            if (Owner.TryGetComponent(out CollidableComponent? collidable))
+            {
+                collidable.AnchoredChanged += UpdateVisualState;
+            }
 
             if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
             {
@@ -513,7 +580,7 @@ namespace Content.Server.GameObjects.Components.Disposal
                 _container.ForceRemove(entity);
             }
 
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
 
             _automaticEngageToken?.Cancel();
             _automaticEngageToken = null;
@@ -571,7 +638,7 @@ namespace Content.Server.GameObjects.Components.Disposal
                 return false;
             }
 
-            _userInterface.Open(actor.playerSession);
+            UserInterface?.Open(actor.playerSession);
             return true;
         }
 
@@ -587,7 +654,8 @@ namespace Content.Server.GameObjects.Components.Disposal
 
         bool IDragDropOn.DragDropOn(DragDropEventArgs eventArgs)
         {
-            return TryInsert(eventArgs.Dropped);
+            _ = TryInsert(eventArgs.Dropped, eventArgs.User);
+            return true;
         }
 
         [Verb]
@@ -609,7 +677,7 @@ namespace Content.Server.GameObjects.Components.Disposal
 
             protected override void Activate(IEntity user, DisposalUnitComponent component)
             {
-                component.TryInsert(user);
+                _ = component.TryInsert(user, user);
             }
         }
 

Content.Server/GameObjects/Components/Doors/AirlockComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Threading;
 using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.Interactable;
@@ -34,10 +35,7 @@ namespace Content.Server.GameObjects.Components.Doors
         /// </summary>
         private static readonly TimeSpan PowerWiresTimeout = TimeSpan.FromSeconds(5.0);
 
-        private PowerReceiverComponent _powerReceiver;
-        private WiresComponent _wires;
-
-        private CancellationTokenSource _powerWiresPulsedTimerCancel;
+        private CancellationTokenSource _powerWiresPulsedTimerCancel = new CancellationTokenSource();
 
         private bool _powerWiresPulsed;
 
@@ -89,13 +87,15 @@ namespace Content.Server.GameObjects.Components.Doors
 
         private void UpdateWiresStatus()
         {
+            WiresComponent? wires;
             var powerLight = new StatusLightData(Color.Yellow, StatusLightState.On, "POWR");
             if (PowerWiresPulsed)
             {
                 powerLight = new StatusLightData(Color.Yellow, StatusLightState.BlinkingFast, "POWR");
             }
-            else if (_wires.IsWireCut(Wires.MainPower) &&
-                     _wires.IsWireCut(Wires.BackupPower))
+            else if (Owner.TryGetComponent(out wires) &&
+                     wires.IsWireCut(Wires.MainPower) &&
+                     wires.IsWireCut(Wires.BackupPower))
             {
                 powerLight = new StatusLightData(Color.Red, StatusLightState.On, "POWR");
             }
@@ -114,12 +114,17 @@ namespace Content.Server.GameObjects.Components.Doors
             var safetyStatus =
                 new StatusLightData(Color.Red, Safety ? StatusLightState.On : StatusLightState.Off, "SAFE");
 
-            _wires.SetStatus(AirlockWireStatus.PowerIndicator, powerLight);
-            _wires.SetStatus(AirlockWireStatus.BoltIndicator, boltStatus);
-            _wires.SetStatus(AirlockWireStatus.BoltLightIndicator, boltLightsStatus);
-            _wires.SetStatus(AirlockWireStatus.AIControlIndicator, new StatusLightData(Color.Purple, StatusLightState.BlinkingSlow, "AICT"));
-            _wires.SetStatus(AirlockWireStatus.TimingIndicator, timingStatus);
-            _wires.SetStatus(AirlockWireStatus.SafetyIndicator, safetyStatus);
+            if (!Owner.TryGetComponent(out wires))
+            {
+                return;
+            }
+
+            wires.SetStatus(AirlockWireStatus.PowerIndicator, powerLight);
+            wires.SetStatus(AirlockWireStatus.BoltIndicator, boltStatus);
+            wires.SetStatus(AirlockWireStatus.BoltLightIndicator, boltLightsStatus);
+            wires.SetStatus(AirlockWireStatus.AIControlIndicator, new StatusLightData(Color.Purple, StatusLightState.BlinkingSlow, "AICT"));
+            wires.SetStatus(AirlockWireStatus.TimingIndicator, timingStatus);
+            wires.SetStatus(AirlockWireStatus.SafetyIndicator, safetyStatus);
             /*
             _wires.SetStatus(6, powerLight);
             _wires.SetStatus(7, powerLight);
@@ -131,26 +136,45 @@ namespace Content.Server.GameObjects.Components.Doors
 
         private void UpdatePowerCutStatus()
         {
-            _powerReceiver.PowerDisabled = PowerWiresPulsed ||
-                                           _wires.IsWireCut(Wires.MainPower) ||
-                                           _wires.IsWireCut(Wires.BackupPower);
+            if (!Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            {
+                return;
+            }
+
+            if (PowerWiresPulsed)
+            {
+                receiver.PowerDisabled = true;
+                return;
+            }
+
+            if (!Owner.TryGetComponent(out WiresComponent? wires))
+            {
+                return;
+            }
+
+            receiver.PowerDisabled =
+                wires.IsWireCut(Wires.MainPower) ||
+                wires.IsWireCut(Wires.BackupPower);
         }
 
         private void UpdateBoltLightStatus()
         {
-            if (Owner.TryGetComponent(out AppearanceComponent appearance))
+            if (Owner.TryGetComponent(out AppearanceComponent? appearance))
             {
                 appearance.SetData(DoorVisuals.BoltLights, BoltLightsVisible);
             }
         }
 
-        protected override DoorState State
+        public override DoorState State
         {
-            set
+            protected set
             {
                 base.State = value;
                 // Only show the maintenance panel if the airlock is closed
-                _wires.IsPanelVisible = value != DoorState.Open;
+                if (Owner.TryGetComponent(out WiresComponent? wires))
+                {
+                    wires.IsPanelVisible = value != DoorState.Open;
+                }
                 // If the door is closed, we should look if the bolt was locked while closing
                 UpdateBoltLightStatus();
             }
@@ -159,25 +183,32 @@ namespace Content.Server.GameObjects.Components.Doors
         public override void Initialize()
         {
             base.Initialize();
-            _powerReceiver = Owner.GetComponent<PowerReceiverComponent>();
-            _wires = Owner.GetComponent<WiresComponent>();
 
-            _powerReceiver.OnPowerStateChanged += PowerDeviceOnOnPowerStateChanged;
-            if (Owner.TryGetComponent(out AppearanceComponent appearance))
+            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
             {
-                appearance.SetData(DoorVisuals.Powered, _powerReceiver.Powered);
+                receiver.OnPowerStateChanged += PowerDeviceOnOnPowerStateChanged;
+
+                if (Owner.TryGetComponent(out AppearanceComponent? appearance))
+                {
+
+                    appearance.SetData(DoorVisuals.Powered, receiver.Powered);
+                }
             }
         }
 
         public override void OnRemove()
         {
-            _powerReceiver.OnPowerStateChanged -= PowerDeviceOnOnPowerStateChanged;
+            if (Owner.TryGetComponent(out PowerReceiverComponent? receiver))
+            {
+                receiver.OnPowerStateChanged -= PowerDeviceOnOnPowerStateChanged;
+            }
+
             base.OnRemove();
         }
 
-        private void PowerDeviceOnOnPowerStateChanged(object sender, PowerStateEventArgs e)
+        private void PowerDeviceOnOnPowerStateChanged(object? sender, PowerStateEventArgs e)
         {
-            if (Owner.TryGetComponent(out AppearanceComponent appearance))
+            if (Owner.TryGetComponent(out AppearanceComponent? appearance))
             {
                 appearance.SetData(DoorVisuals.Powered, e.Powered);
             }
@@ -188,11 +219,12 @@ namespace Content.Server.GameObjects.Components.Doors
 
         protected override void ActivateImpl(ActivateEventArgs args)
         {
-            if (_wires.IsPanelOpen)
+            if (Owner.TryGetComponent(out WiresComponent? wires) &&
+                wires.IsPanelOpen)
             {
-                if (args.User.TryGetComponent(out IActorComponent actor))
+                if (args.User.TryGetComponent(out IActorComponent? actor))
                 {
-                    _wires.OpenInterface(actor.playerSession);
+                    wires.OpenInterface(actor.playerSession);
                 }
             }
             else
@@ -272,8 +304,7 @@ namespace Content.Server.GameObjects.Components.Doors
                     case Wires.MainPower:
                     case Wires.BackupPower:
                         PowerWiresPulsed = true;
-                        _powerWiresPulsedTimerCancel?.Cancel();
-                        _powerWiresPulsedTimerCancel = new CancellationTokenSource();
+                        _powerWiresPulsedTimerCancel.Cancel();
                         Timer.Spawn(PowerWiresTimeout,
                             () => PowerWiresPulsed = false,
                             _powerWiresPulsedTimerCancel.Token);
@@ -377,7 +408,8 @@ namespace Content.Server.GameObjects.Components.Doors
 
         private bool IsPowered()
         {
-            return _powerReceiver.Powered;
+            return !Owner.TryGetComponent(out PowerReceiverComponent? receiver)
+                   || receiver.Powered;
         }
 
         public async Task<bool> InteractUsing(InteractUsingEventArgs eventArgs)
@@ -388,11 +420,12 @@ namespace Content.Server.GameObjects.Components.Doors
             if (tool.HasQuality(ToolQuality.Cutting)
                 || tool.HasQuality(ToolQuality.Multitool))
             {
-                if (_wires.IsPanelOpen)
+                if (Owner.TryGetComponent(out WiresComponent? wires)
+                    && wires.IsPanelOpen)
                 {
-                    if (eventArgs.User.TryGetComponent(out IActorComponent actor))
+                    if (eventArgs.User.TryGetComponent(out IActorComponent? actor))
                     {
-                        _wires.OpenInterface(actor.playerSession);
+                        wires.OpenInterface(actor.playerSession);
                         return true;
                     }
                 }

Content.Server/GameObjects/Components/Doors/ServerDoorComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Linq;
 using System.Threading;
 using Content.Server.Atmos;
@@ -35,10 +36,10 @@ namespace Content.Server.GameObjects.Components.Doors
 
         private DoorState _state = DoorState.Closed;
 
-        protected virtual DoorState State
+        public virtual DoorState State
         {
             get => _state;
-            set => _state = value;
+            protected set => _state = value;
         }
 
         protected float OpenTimeCounter;
@@ -46,10 +47,7 @@ namespace Content.Server.GameObjects.Components.Doors
         protected const float AutoCloseDelay = 5;
         protected float CloseSpeed = AutoCloseDelay;
 
-        private AirtightComponent airtightComponent;
-        private ICollidableComponent _collidableComponent;
-        private AppearanceComponent _appearance;
-        private CancellationTokenSource _cancellationTokenSource;
+        private CancellationTokenSource _cancellationTokenSource = new CancellationTokenSource();
 
         protected virtual TimeSpan CloseTimeOne => TimeSpan.FromSeconds(0.3f);
         protected virtual TimeSpan CloseTimeTwo => TimeSpan.FromSeconds(0.9f);
@@ -72,21 +70,9 @@ namespace Content.Server.GameObjects.Components.Doors
             serializer.DataField(ref _occludes, "occludes", true);
         }
 
-        public override void Initialize()
-        {
-            base.Initialize();
-
-            airtightComponent = Owner.GetComponent<AirtightComponent>();
-            _collidableComponent = Owner.GetComponent<ICollidableComponent>();
-            _appearance = Owner.GetComponent<AppearanceComponent>();
-            _cancellationTokenSource = new CancellationTokenSource();
-        }
-
         public override void OnRemove()
         {
-            _cancellationTokenSource.Cancel();
-            _collidableComponent = null;
-            _appearance = null;
+            _cancellationTokenSource?.Cancel();
 
             base.OnRemove();
         }
@@ -108,7 +94,6 @@ namespace Content.Server.GameObjects.Components.Doors
             ActivateImpl(eventArgs);
         }
 
-
         void ICollideBehavior.CollideWith(IEntity entity)
         {
             if (State != DoorState.Closed)
@@ -139,8 +124,10 @@ namespace Content.Server.GameObjects.Components.Doors
 
         protected void SetAppearance(DoorVisualState state)
         {
-            if (_appearance != null || Owner.TryGetComponent(out _appearance))
-                _appearance.SetData(DoorVisuals.VisualState, state);
+            if (Owner.TryGetComponent(out AppearanceComponent? appearance))
+            {
+                appearance.SetData(DoorVisuals.VisualState, state);
+            }
         }
 
         public virtual bool CanOpen()
@@ -151,28 +138,53 @@ namespace Content.Server.GameObjects.Components.Doors
         public virtual bool CanOpen(IEntity user)
         {
             if (!CanOpen()) return false;
-            if (!Owner.TryGetComponent(out AccessReader accessReader))
+
+            if (!Owner.TryGetComponent<AccessReader>(out var accessReader))
             {
                 return true;
             }
 
-            return accessReader.IsAllowed(user);
+            var doorSystem = EntitySystem.Get<DoorSystem>();
+            var isAirlockExternal = HasAccessType("External");
+
+            return doorSystem.AccessType switch
+            {
+                DoorSystem.AccessTypes.AllowAll => true,
+                DoorSystem.AccessTypes.AllowAllIdExternal => isAirlockExternal ? accessReader.IsAllowed(user) : true,
+                DoorSystem.AccessTypes.AllowAllNoExternal => !isAirlockExternal,
+                _ => accessReader.IsAllowed(user)
+            };
+        }
+
+        /// <summary>
+        /// Returns whether a door has a certain access type. For example, maintenance doors will have access type
+        /// "Maintenance" in their AccessReader.
+        /// </summary>
+        private bool HasAccessType(string accesType)
+        {
+            if(Owner.TryGetComponent<AccessReader>(out var accessReader))
+            {
+                return accessReader.AccessLists.Any(list => list.Contains(accesType));
+            }
+
+            return true;
         }
 
         public void TryOpen(IEntity user)
         {
-            if (!CanOpen(user))
+            if (CanOpen(user))
+            {
+                Open();
+
+                if (user.TryGetComponent(out HandsComponent? hands) && hands.Count == 0)
+                {
+                    EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Effects/bang.ogg", Owner,
+                                                                   AudioParams.Default.WithVolume(-2));
+                }
+            }
+            else
             {
                 Deny();
-                return;
-            }
-
-            Open();
-
-            if (user.TryGetComponent(out HandsComponent hands) && hands.Count == 0)
-            {
-                EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Effects/bang.ogg", Owner,
-                    AudioParams.Default.WithVolume(-2));
             }
         }
 
@@ -185,15 +197,22 @@ namespace Content.Server.GameObjects.Components.Doors
 
             State = DoorState.Opening;
             SetAppearance(DoorVisualState.Opening);
-            if (_occludes && Owner.TryGetComponent(out OccluderComponent occluder))
+            if (_occludes && Owner.TryGetComponent(out OccluderComponent? occluder))
             {
                 occluder.Enabled = false;
             }
 
             Timer.Spawn(OpenTimeOne, async () =>
             {
-                airtightComponent.AirBlocked = false;
-                _collidableComponent.Hard = false;
+                if (Owner.TryGetComponent(out AirtightComponent? airtight))
+                {
+                    airtight.AirBlocked = false;
+                }
+
+                if (Owner.TryGetComponent(out ICollidableComponent? collidable))
+                {
+                    collidable.Hard = false;
+                }
 
                 await Timer.Delay(OpenTimeTwo, _cancellationTokenSource.Token);
 
@@ -212,7 +231,7 @@ namespace Content.Server.GameObjects.Components.Doors
         public virtual bool CanClose(IEntity user)
         {
             if (!CanClose()) return false;
-            if (!Owner.TryGetComponent(out AccessReader accessReader))
+            if (!Owner.TryGetComponent(out AccessReader? accessReader))
             {
                 return true;
             }
@@ -233,18 +252,22 @@ namespace Content.Server.GameObjects.Components.Doors
 
         private void CheckCrush()
         {
+            if (!Owner.TryGetComponent(out ICollidableComponent? body))
+            {
+                return;
+            }
+
             // Check if collides with something
-            var collidesWith = _collidableComponent.GetCollidingEntities(Vector2.Zero, false);
+            var collidesWith = body.GetCollidingEntities(Vector2.Zero, false);
             if (collidesWith.Count() != 0)
             {
                 // Crush
                 bool hitSomeone = false;
                 foreach (var e in collidesWith)
                 {
-                    if (!e.TryGetComponent(out StunnableComponent stun)
-                        || !e.TryGetComponent(out IDamageableComponent damage)
-                        || !e.TryGetComponent(out ICollidableComponent otherBody)
-                        || !Owner.TryGetComponent(out ICollidableComponent body))
+                    if (!e.TryGetComponent(out StunnableComponent? stun)
+                        || !e.TryGetComponent(out IDamageableComponent? damage)
+                        || !e.TryGetComponent(out ICollidableComponent? otherBody))
                         continue;
 
                     var percentage = otherBody.WorldAABB.IntersectPercentage(body.WorldAABB);
@@ -319,7 +342,8 @@ namespace Content.Server.GameObjects.Components.Doors
         public bool Close()
         {
             bool shouldCheckCrush = false;
-            if (_collidableComponent.IsColliding(Vector2.Zero, false))
+
+            if (Owner.TryGetComponent(out ICollidableComponent? collidable) && collidable.IsColliding(Vector2.Zero, false))
             {
                 if (Safety)
                     return false;
@@ -331,7 +355,7 @@ namespace Content.Server.GameObjects.Components.Doors
             State = DoorState.Closing;
             OpenTimeCounter = 0;
             SetAppearance(DoorVisualState.Closing);
-            if (_occludes && Owner.TryGetComponent(out OccluderComponent occluder))
+            if (_occludes && Owner.TryGetComponent(out OccluderComponent? occluder))
             {
                 occluder.Enabled = true;
             }
@@ -343,8 +367,15 @@ namespace Content.Server.GameObjects.Components.Doors
                     CheckCrush();
                 }
 
-                airtightComponent.AirBlocked = true;
-                _collidableComponent.Hard = true;
+                if (Owner.TryGetComponent(out AirtightComponent? airtight))
+                {
+                    airtight.AirBlocked = true;
+                }
+
+                if (Owner.TryGetComponent(out ICollidableComponent? body))
+                {
+                    body.Hard = true;
+                }
 
                 await Timer.Delay(CloseTimeTwo, _cancellationTokenSource.Token);
 
@@ -391,7 +422,7 @@ namespace Content.Server.GameObjects.Components.Doors
             }
         }
 
-        protected enum DoorState
+        public enum DoorState
         {
             Closed,
             Open,

Content.Server/GameObjects/Components/Fluids/BucketComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.Chemistry;
 using Content.Shared.Chemistry;
@@ -19,23 +20,25 @@ namespace Content.Server.GameObjects.Components.Fluids
     [RegisterComponent]
     public class BucketComponent : Component, IInteractUsing
     {
-#pragma warning disable 649
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
-
         public override string Name => "Bucket";
 
         public ReagentUnit MaxVolume
         {
-            get => _contents.MaxVolume;
-            set => _contents.MaxVolume = value;
+            get => Owner.TryGetComponent(out SolutionComponent? solution) ? solution.MaxVolume : ReagentUnit.Zero;
+            set
+            {
+                if (Owner.TryGetComponent(out SolutionComponent? solution))
+                {
+                    solution.MaxVolume = value;
+                }
+            }
         }
 
-        public ReagentUnit CurrentVolume => _contents.CurrentVolume;
+        public ReagentUnit CurrentVolume => Owner.TryGetComponent(out SolutionComponent? solution)
+            ? solution.CurrentVolume
+            : ReagentUnit.Zero;
 
-        private SolutionComponent _contents;
-
-        private string _sound;
+        private string? _sound;
 
         /// <inheritdoc />
         public override void ExposeData(ObjectSerializer serializer)
@@ -47,16 +50,28 @@ namespace Content.Server.GameObjects.Components.Fluids
         public override void Initialize()
         {
             base.Initialize();
-            _contents = Owner.GetComponent<SolutionComponent>();
+            Owner.EnsureComponent<SolutionComponent>();
         }
 
         private bool TryGiveToMop(MopComponent mopComponent)
         {
+            if (!Owner.TryGetComponent(out SolutionComponent? contents))
+            {
+                return false;
+            }
+
+            var mopContents = mopComponent.Contents;
+
+            if (mopContents == null)
+            {
+                return false;
+            }
+
             // Let's fill 'er up
             // If this is called the mop should be empty but just in case we'll do Max - Current
             var transferAmount = ReagentUnit.Min(mopComponent.MaxVolume - mopComponent.CurrentVolume, CurrentVolume);
-            var solution = _contents.SplitSolution(transferAmount);
-            if (!mopComponent.Contents.TryAddSolution(solution) || mopComponent.CurrentVolume == 0)
+            var solution = contents.SplitSolution(transferAmount);
+            if (!mopContents.TryAddSolution(solution) || mopComponent.CurrentVolume == 0)
             {
                 return false;
             }
@@ -73,7 +88,12 @@ namespace Content.Server.GameObjects.Components.Fluids
 
         public async Task<bool> InteractUsing(InteractUsingEventArgs eventArgs)
         {
-            if (!eventArgs.Using.TryGetComponent(out MopComponent mopComponent))
+            if (!Owner.TryGetComponent(out SolutionComponent? contents))
+            {
+                return false;
+            }
+
+            if (!eventArgs.Using.TryGetComponent(out MopComponent? mopComponent))
             {
                 return false;
             }
@@ -86,7 +106,7 @@ namespace Content.Server.GameObjects.Components.Fluids
                     return false;
                 }
 
-                Owner.PopupMessage(eventArgs.User, _localizationManager.GetString("Splish"));
+                Owner.PopupMessage(eventArgs.User, Loc.GetString("Splish"));
                 return true;
             }
 
@@ -96,15 +116,22 @@ namespace Content.Server.GameObjects.Components.Fluids
                 return false;
             }
 
-            var solution = mopComponent.Contents.SplitSolution(transferAmount);
-            if (!_contents.TryAddSolution(solution))
+            var mopContents = mopComponent.Contents;
+
+            if (mopContents == null)
+            {
+                return false;
+            }
+
+            var solution = mopContents.SplitSolution(transferAmount);
+            if (!contents.TryAddSolution(solution))
             {
                 //This really shouldn't happen
                 throw new InvalidOperationException();
             }
 
             // Give some visual feedback shit's happening (for anyone who can't hear sound)
-            Owner.PopupMessage(eventArgs.User, _localizationManager.GetString("Sploosh"));
+            Owner.PopupMessage(eventArgs.User, Loc.GetString("Sploosh"));
 
             if (_sound == null)
             {
@@ -114,7 +141,6 @@ namespace Content.Server.GameObjects.Components.Fluids
             EntitySystem.Get<AudioSystem>().PlayFromEntity(_sound, Owner);
 
             return true;
-
         }
     }
 }

Content.Server/GameObjects/Components/Fluids/MopComponent.cs

@@ -1,4 +1,5 @@
-using Content.Server.GameObjects.Components.Chemistry;
+#nullable enable
+using Content.Server.GameObjects.Components.Chemistry;
 using Content.Server.Utility;
 using Content.Shared.Chemistry;
 using Content.Shared.Interfaces;
@@ -6,8 +7,8 @@ using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects.EntitySystems;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameObjects.Systems;
-using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 
 namespace Content.Server.GameObjects.Components.Fluids
@@ -18,21 +19,24 @@ namespace Content.Server.GameObjects.Components.Fluids
     [RegisterComponent]
     public class MopComponent : Component, IAfterInteract
     {
-#pragma warning disable 649
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
-
         public override string Name => "Mop";
-        internal SolutionComponent Contents => _contents;
-        private SolutionComponent _contents;
+
+        public SolutionComponent? Contents => Owner.GetComponentOrNull<SolutionComponent>();
 
         public ReagentUnit MaxVolume
         {
-            get => _contents.MaxVolume;
-            set => _contents.MaxVolume = value;
+            get => Owner.GetComponentOrNull<SolutionComponent>()?.MaxVolume ?? ReagentUnit.Zero;
+            set
+            {
+                if (Owner.TryGetComponent(out SolutionComponent? solution))
+                {
+                    solution.MaxVolume = value;
+                }
+            }
         }
 
-        public ReagentUnit CurrentVolume => _contents.CurrentVolume;
+        public ReagentUnit CurrentVolume =>
+            Owner.GetComponentOrNull<SolutionComponent>()?.CurrentVolume ?? ReagentUnit.Zero;
 
         // Currently there's a separate amount for pickup and dropoff so
         // Picking up a puddle requires multiple clicks
@@ -41,7 +45,7 @@ namespace Content.Server.GameObjects.Components.Fluids
         public ReagentUnit PickupAmount => _pickupAmount;
         private ReagentUnit _pickupAmount;
 
-        private string _pickupSound;
+        private string _pickupSound = "";
 
         /// <inheritdoc />
         public override void ExposeData(ObjectSerializer serializer)
@@ -54,12 +58,16 @@ namespace Content.Server.GameObjects.Components.Fluids
         public override void Initialize()
         {
             base.Initialize();
-            _contents = Owner.GetComponent<SolutionComponent>();
 
+            if (!Owner.EnsureComponent(out SolutionComponent _))
+            {
+                Logger.Warning($"Entity {Owner.Name} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionComponent)}");
+            }
         }
 
         void IAfterInteract.AfterInteract(AfterInteractEventArgs eventArgs)
         {
+            if (!Owner.TryGetComponent(out SolutionComponent? contents)) return;
             if (!InteractionChecks.InRangeUnobstructed(eventArgs)) return;
 
             if (CurrentVolume <= 0)
@@ -71,12 +79,12 @@ namespace Content.Server.GameObjects.Components.Fluids
             if (eventArgs.Target == null)
             {
                 // Drop the liquid on the mop on to the ground
-                SpillHelper.SpillAt(eventArgs.ClickLocation, _contents.SplitSolution(CurrentVolume), "PuddleSmear");
+                SpillHelper.SpillAt(eventArgs.ClickLocation, contents.SplitSolution(CurrentVolume), "PuddleSmear");
 
                 return;
             }
 
-            if (!eventArgs.Target.TryGetComponent(out PuddleComponent puddleComponent))
+            if (!eventArgs.Target.TryGetComponent(out PuddleComponent? puddleComponent))
             {
                 return;
             }
@@ -107,23 +115,22 @@ namespace Content.Server.GameObjects.Components.Fluids
 
             if (puddleCleaned) //After cleaning the puddle, make a new puddle with solution from the mop as a "wet floor". Then evaporate it slowly.
             {
-                SpillHelper.SpillAt(eventArgs.ClickLocation, _contents.SplitSolution(transferAmount), "PuddleSmear");
+                SpillHelper.SpillAt(eventArgs.ClickLocation, contents.SplitSolution(transferAmount), "PuddleSmear");
             }
             else
             {
-                _contents.SplitSolution(transferAmount);
+                contents.SplitSolution(transferAmount);
             }
 
             // Give some visual feedback shit's happening (for anyone who can't hear sound)
-            Owner.PopupMessage(eventArgs.User, _localizationManager.GetString("Swish"));
+            Owner.PopupMessage(eventArgs.User, Loc.GetString("Swish"));
 
-            if (_pickupSound == null)
+            if (string.IsNullOrWhiteSpace(_pickupSound))
             {
                 return;
             }
 
             EntitySystem.Get<AudioSystem>().PlayFromEntity(_pickupSound, Owner);
-
         }
     }
 }

Content.Server/GameObjects/Components/Fluids/PuddleComponent.cs

@@ -46,10 +46,7 @@ namespace Content.Server.GameObjects.Components.Fluids
         // based on behaviour (e.g. someone being punched vs slashed with a sword would have different blood sprite)
         // to check for low volumes for evaporation or whatever
 
-#pragma warning disable 649
-        [Dependency] private readonly IMapManager _mapManager;
-        [Dependency] private readonly ILocalizationManager _loc;
-#pragma warning restore 649
+        [Dependency] private readonly IMapManager _mapManager = default!;
 
         public override string Name => "Puddle";
 
@@ -116,6 +113,7 @@ namespace Content.Server.GameObjects.Components.Fluids
         public override void Initialize()
         {
             base.Initialize();
+
             if (Owner.TryGetComponent(out SolutionComponent solutionComponent))
             {
                 _contents = solutionComponent;
@@ -123,21 +121,27 @@ namespace Content.Server.GameObjects.Components.Fluids
             else
             {
                 _contents = Owner.AddComponent<SolutionComponent>();
-                _contents.Initialize();
             }
 
-            _snapGrid = Owner.GetComponent<SnapGridComponent>();
+            _snapGrid = Owner.EnsureComponent<SnapGridComponent>();
 
             // Smaller than 1m^3 for now but realistically this shouldn't be hit
             MaxVolume = ReagentUnit.New(1000);
 
             // Random sprite state set server-side so it's consistent across all clients
-            _spriteComponent = Owner.GetComponent<SpriteComponent>();
+            _spriteComponent = Owner.EnsureComponent<SpriteComponent>();
+
             var robustRandom = IoCManager.Resolve<IRobustRandom>();
             var randomVariant = robustRandom.Next(0, _spriteVariants - 1);
-            var baseName = new ResourcePath(_spriteComponent.BaseRSIPath).FilenameWithoutExtension;
 
-            _spriteComponent.LayerSetState(0, $"{baseName}-{randomVariant}"); // TODO: Remove hardcode
+            if (_spriteComponent.BaseRSIPath != null)
+            {
+                var baseName = new ResourcePath(_spriteComponent.BaseRSIPath).FilenameWithoutExtension;
+
+                _spriteComponent.LayerSetState(0, $"{baseName}-{randomVariant}"); // TODO: Remove hardcode
+
+            }
+
             // UpdateAppearance should get called soon after this so shouldn't need to call Dirty() here
 
             UpdateStatus();
@@ -153,7 +157,7 @@ namespace Content.Server.GameObjects.Components.Fluids
         {
             if(_slippery)
             {
-                message.AddText(_loc.GetString("It looks slippery."));
+                message.AddText(Loc.GetString("It looks slippery."));
             }
         }
 

Content.Server/GameObjects/Components/Fluids/SprayComponent.cs

@@ -8,6 +8,7 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
@@ -16,10 +17,9 @@ namespace Content.Server.GameObjects.Components.Fluids
     [RegisterComponent]
     class SprayComponent : Component, IAfterInteract
     {
-#pragma warning disable 649
         [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
         [Dependency] private readonly IServerEntityManager _serverEntityManager = default!;
-#pragma warning restore 649
+
         public override string Name => "Spray";
 
         private ReagentUnit _transferAmount;
@@ -46,13 +46,17 @@ namespace Content.Server.GameObjects.Components.Fluids
             set => _sprayVelocity = value;
         }
 
-        private SolutionComponent _contents;
-        public ReagentUnit CurrentVolume => _contents.CurrentVolume;
+        public ReagentUnit CurrentVolume => Owner.GetComponentOrNull<SolutionComponent>()?.CurrentVolume ?? ReagentUnit.Zero;
 
         public override void Initialize()
         {
             base.Initialize();
-            _contents = Owner.GetComponent<SolutionComponent>();
+
+            if (!Owner.EnsureComponent(out SolutionComponent _))
+            {
+                Logger.Warning(
+                    $"Entity {Owner.Name} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionComponent)}");
+            }
         }
 
         public override void ExposeData(ObjectSerializer serializer)
@@ -75,8 +79,11 @@ namespace Content.Server.GameObjects.Components.Fluids
             if (eventArgs.ClickLocation.GridID != playerPos.GridID)
                 return;
 
+            if (!Owner.TryGetComponent(out SolutionComponent contents))
+                return;
+
             var direction = (eventArgs.ClickLocation.Position - playerPos.Position).Normalized;
-            var solution = _contents.SplitSolution(_transferAmount);
+            var solution = contents.SplitSolution(_transferAmount);
 
             playerPos = playerPos.Offset(direction); // Move a bit so we don't hit the player
             //TODO: check for wall?

Content.Server/GameObjects/Components/GUI/HandsComponent.cs

@@ -29,6 +29,7 @@ using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Players;
 using Robust.Shared.ViewVariables;
+using Content.Server.GameObjects.Components.ActionBlocking;
 
 namespace Content.Server.GameObjects.Components.GUI
 {
@@ -37,9 +38,7 @@ namespace Content.Server.GameObjects.Components.GUI
     [ComponentReference(typeof(ISharedHandsComponent))]
     public class HandsComponent : SharedHandsComponent, IHandsComponent, IBodyPartAdded, IBodyPartRemoved
     {
-#pragma warning disable 649
         [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
-#pragma warning restore 649
 
         private string? _activeHand;
         private uint _nextHand;
@@ -446,6 +445,7 @@ namespace Content.Server.GameObjects.Components.GUI
             ActiveHand ??= name;
 
             OnItemChanged?.Invoke();
+            Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new HandCountChangedEvent(Owner));
 
             Dirty();
         }
@@ -468,6 +468,7 @@ namespace Content.Server.GameObjects.Components.GUI
             }
 
             OnItemChanged?.Invoke();
+            Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new HandCountChangedEvent(Owner));
 
             Dirty();
         }
@@ -793,4 +794,14 @@ namespace Content.Server.GameObjects.Components.GUI
             return new SharedHand(index, Name, Entity?.Uid, location);
         }
     }
+
+    public class HandCountChangedEvent : EntitySystemMessage
+    {
+        public HandCountChangedEvent(IEntity sender)
+        {
+            Sender = sender;
+        }
+
+        public IEntity Sender { get; }
+    }
 }

Content.Server/GameObjects/Components/GUI/HumanInventoryControllerComponent.cs

@@ -21,7 +21,7 @@ namespace Content.Server.GameObjects.Components.GUI
         {
             base.Initialize();
 
-            _inventory = Owner.GetComponent<InventoryComponent>();
+            _inventory = Owner.EnsureComponent<InventoryComponent>();
         }
 
         bool IInventoryController.CanEquip(Slots slot, IEntity entity, bool flagsCheck, out string reason)

Content.Server/GameObjects/Components/GUI/InventoryComponent.cs

@@ -28,10 +28,8 @@ namespace Content.Server.GameObjects.Components.GUI
     [RegisterComponent]
     public class InventoryComponent : SharedInventoryComponent, IExAct, IEffectBlocker, IPressureProtection
     {
-#pragma warning disable 649
-        [Dependency] private readonly IEntitySystemManager _entitySystemManager;
-        [Dependency] private readonly IServerNotifyManager _serverNotifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
+        [Dependency] private readonly IServerNotifyManager _serverNotifyManager = default!;
 
         [ViewVariables]
         private readonly Dictionary<Slots, ContainerSlot> _slotContainers = new Dictionary<Slots, ContainerSlot>();

Content.Server/GameObjects/Components/GUI/StrippableComponent.cs

@@ -1,12 +1,15 @@
-using System;
+#nullable enable
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading;
+using Content.Server.GameObjects.Components.ActionBlocking;
 using Content.Server.GameObjects.Components.Items.Storage;
 using Content.Server.GameObjects.EntitySystems.DoAfter;
 using Content.Server.Interfaces;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.Components.GUI;
-using Content.Shared.GameObjects.Components.Inventory;
 using Content.Shared.GameObjects.EntitySystems;
+using Content.Shared.GameObjects.Verbs;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Server.GameObjects.Components.UserInterface;
 using Robust.Server.Interfaces.GameObjects;
@@ -16,7 +19,6 @@ using Robust.Shared.GameObjects.Systems;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
-using Robust.Shared.Log;
 using Robust.Shared.ViewVariables;
 using static Content.Shared.GameObjects.Components.Inventory.EquipmentSlotDefines;
 
@@ -25,27 +27,39 @@ namespace Content.Server.GameObjects.Components.GUI
     [RegisterComponent]
     public sealed class StrippableComponent : SharedStrippableComponent, IDragDrop
     {
-        [Dependency] private IServerNotifyManager _notifyManager = default!;
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
 
         public const float StripDelay = 2f;
 
-        [ViewVariables]
-        private BoundUserInterface _userInterface;
-
-        private InventoryComponent _inventoryComponent;
-        private HandsComponent _handsComponent;
+        [ViewVariables] 
+		private BoundUserInterface? UserInterface => Owner.GetUIOrNull(StrippingUiKey.Key);
 
         public override void Initialize()
         {
             base.Initialize();
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>().GetBoundUserInterface(StrippingUiKey.Key);
-            _userInterface.OnReceiveMessage += HandleUserInterfaceMessage;
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += HandleUserInterfaceMessage;
+            }
 
-            _inventoryComponent = Owner.GetComponent<InventoryComponent>();
-            _handsComponent = Owner.GetComponent<HandsComponent>();
+            Owner.EnsureComponent<InventoryComponent>();
+            Owner.EnsureComponent<HandsComponent>();
+            Owner.EnsureComponent<CuffableComponent>();
+            
+            if (Owner.TryGetComponent(out CuffableComponent? cuffed))
+            {
+                cuffed.OnCuffedStateChanged += UpdateSubscribed;
+            }
+            if (Owner.TryGetComponent(out InventoryComponent? inventory))
+            {
+                inventory.OnItemChanged += UpdateSubscribed;
+            }
 
-            _inventoryComponent.OnItemChanged += UpdateSubscribed;
+            if (Owner.TryGetComponent(out HandsComponent? hands))
+            {
+                hands.OnItemChanged += UpdateSubscribed;
+            }
 
             // Initial update.
             UpdateSubscribed();
@@ -53,33 +67,69 @@ namespace Content.Server.GameObjects.Components.GUI
 
         private void UpdateSubscribed()
         {
+            if (UserInterface == null)
+            {
+                return;
+            }
+
             var inventory = GetInventorySlots();
             var hands = GetHandSlots();
+            var cuffs = GetHandcuffs();
 
-            _userInterface.SetState(new StrippingBoundUserInterfaceState(inventory, hands));
+            UserInterface.SetState(new StrippingBoundUserInterfaceState(inventory, hands, cuffs));
+        }
+
+        public bool CanBeStripped(IEntity by)
+        {
+            return by != Owner
+                   && by.HasComponent<HandsComponent>()
+                   && ActionBlockerSystem.CanInteract(by);
         }
 
         public bool CanDragDrop(DragDropEventArgs eventArgs)
         {
-            return eventArgs.User.HasComponent<HandsComponent>()
-                   && eventArgs.Target != eventArgs.Dropped && eventArgs.Target == eventArgs.User;
+            return eventArgs.Target != eventArgs.Dropped
+                   && eventArgs.Target == eventArgs.User
+                   && CanBeStripped(eventArgs.User);
         }
 
         public bool DragDrop(DragDropEventArgs eventArgs)
         {
-            if (!eventArgs.User.TryGetComponent(out IActorComponent actor)) return false;
+            if (!eventArgs.User.TryGetComponent(out IActorComponent? actor)) return false;
 
             OpenUserInterface(actor.playerSession);
             return true;
         }
 
+        private Dictionary<EntityUid, string> GetHandcuffs()
+        {
+            var dictionary = new Dictionary<EntityUid, string>();
+            
+            if (!Owner.TryGetComponent(out CuffableComponent? cuffed))
+            {
+                return dictionary;
+            }
+
+            foreach (IEntity entity in cuffed.StoredEntities)
+            {
+                dictionary.Add(entity.Uid, entity.Name);
+            }
+
+            return dictionary;
+        }
+
         private Dictionary<Slots, string> GetInventorySlots()
         {
             var dictionary = new Dictionary<Slots, string>();
 
-            foreach (var slot in _inventoryComponent.Slots)
+            if (!Owner.TryGetComponent(out InventoryComponent? inventory))
             {
-                dictionary[slot] = _inventoryComponent.GetSlotItem(slot)?.Owner.Name ?? "None";
+                return dictionary;
+            }
+
+            foreach (var slot in inventory.Slots)
+            {
+                dictionary[slot] = inventory.GetSlotItem(slot)?.Owner.Name ?? "None";
             }
 
             return dictionary;
@@ -89,9 +139,14 @@ namespace Content.Server.GameObjects.Components.GUI
         {
             var dictionary = new Dictionary<string, string>();
 
-            foreach (var hand in _handsComponent.Hands)
+            if (!Owner.TryGetComponent(out HandsComponent? hands))
             {
-                dictionary[hand] = _handsComponent.GetItem(hand)?.Owner.Name ?? "None";
+                return dictionary;
+            }
+
+            foreach (var hand in hands.Hands)
+            {
+                dictionary[hand] = hands.GetItem(hand)?.Owner.Name ?? "None";
             }
 
             return dictionary;
@@ -99,7 +154,7 @@ namespace Content.Server.GameObjects.Components.GUI
 
         private void OpenUserInterface(IPlayerSession session)
         {
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
         }
 
         /// <summary>
@@ -336,34 +391,80 @@ namespace Content.Server.GameObjects.Components.GUI
         private void HandleUserInterfaceMessage(ServerBoundUserInterfaceMessage obj)
         {
             var user = obj.Session.AttachedEntity;
-            if (user == null || !(user.TryGetComponent(out HandsComponent userHands))) return;
+            if (user == null || !(user.TryGetComponent(out HandsComponent? userHands))) return;
 
             var placingItem = userHands.GetActiveHand != null;
 
             switch (obj.Message)
             {
                 case StrippingInventoryButtonPressed inventoryMessage:
-                    var inventory = Owner.GetComponent<InventoryComponent>();
 
-                    if (inventory.TryGetSlotItem(inventoryMessage.Slot, out ItemComponent _))
-                        placingItem = false;
+                    if (Owner.TryGetComponent<InventoryComponent>(out var inventory))
+                    {
+                        if (inventory.TryGetSlotItem(inventoryMessage.Slot, out ItemComponent _))
+                            placingItem = false;
 
-                    if(placingItem)
-                        PlaceActiveHandItemInInventory(user, inventoryMessage.Slot);
-                    else
-                        TakeItemFromInventory(user, inventoryMessage.Slot);
+                        if (placingItem)
+                            PlaceActiveHandItemInInventory(user, inventoryMessage.Slot);
+                        else
+                            TakeItemFromInventory(user, inventoryMessage.Slot);
+                    }
                     break;
+
                 case StrippingHandButtonPressed handMessage:
-                    var hands = Owner.GetComponent<HandsComponent>();
 
-                    if (hands.TryGetItem(handMessage.Hand, out _))
-                        placingItem = false;
+                    if (Owner.TryGetComponent<HandsComponent>(out var hands))
+                    {
+                        if (hands.TryGetItem(handMessage.Hand, out _))
+                            placingItem = false;
 
-                    if(placingItem)
-                        PlaceActiveHandItemInHands(user, handMessage.Hand);
-                    else
-                        TakeItemFromHands(user, handMessage.Hand);
+                        if (placingItem)
+                            PlaceActiveHandItemInHands(user, handMessage.Hand);
+                        else
+                            TakeItemFromHands(user, handMessage.Hand);
+                    }
                     break;
+
+                case StrippingHandcuffButtonPressed handcuffMessage:
+
+                    if (Owner.TryGetComponent<CuffableComponent>(out var cuffed))
+                    {
+                        foreach (var entity in cuffed.StoredEntities)
+                        {
+                            if (entity.Uid == handcuffMessage.Handcuff)
+                            {
+                                cuffed.TryUncuff(user, entity);
+                                return;
+                            }
+                        }
+                    }
+                    break;
+            }
+        }
+
+        [Verb]
+        private sealed class StripVerb : Verb<StrippableComponent>
+        {
+            protected override void GetData(IEntity user, StrippableComponent component, VerbData data)
+            {
+                if (!component.CanBeStripped(user))
+                {
+                    data.Visibility = VerbVisibility.Invisible;
+                    return;
+                }
+
+                data.Visibility = VerbVisibility.Visible;
+                data.Text = Loc.GetString("Strip");
+            }
+
+            protected override void Activate(IEntity user, StrippableComponent component)
+            {
+                if (!user.TryGetComponent(out IActorComponent? actor))
+                {
+                    return;
+                }
+
+                component.OpenUserInterface(actor.playerSession);
             }
         }
     }

Content.Server/GameObjects/Components/Gravity/GravityGeneratorComponent.cs

@@ -1,9 +1,10 @@
-using System.Threading.Tasks;
+#nullable enable
+using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.Damage;
 using Content.Server.GameObjects.Components.Interactable;
 using Content.Server.GameObjects.Components.Power.ApcNetComponents;
-using Content.Server.GameObjects.EntitySystems;
 using Content.Server.Interfaces;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.Components.Gravity;
 using Content.Shared.GameObjects.Components.Interactable;
 using Content.Shared.GameObjects.EntitySystems;
@@ -16,17 +17,13 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Serialization;
+using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Gravity
 {
     [RegisterComponent]
     public class GravityGeneratorComponent : SharedGravityGeneratorComponent, IInteractUsing, IBreakAct, IInteractHand
     {
-        private BoundUserInterface _userInterface;
-
-        private PowerReceiverComponent _powerReceiver;
-
-        private SpriteComponent _sprite;
 
         private bool _switchedOn;
 
@@ -34,7 +31,7 @@ namespace Content.Server.GameObjects.Components.Gravity
 
         private GravityGeneratorStatus _status;
 
-        public bool Powered => _powerReceiver.Powered;
+        public bool Powered => !Owner.TryGetComponent(out PowerReceiverComponent? receiver) || receiver.Powered;
 
         public bool SwitchedOn => _switchedOn;
 
@@ -64,15 +61,17 @@ namespace Content.Server.GameObjects.Components.Gravity
 
         public override string Name => "GravityGenerator";
 
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(GravityGeneratorUiKey.Key);
+
         public override void Initialize()
         {
             base.Initialize();
 
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>()
-                .GetBoundUserInterface(GravityGeneratorUiKey.Key);
-            _userInterface.OnReceiveMessage += HandleUIMessage;
-            _powerReceiver = Owner.GetComponent<PowerReceiverComponent>();
-            _sprite = Owner.GetComponent<SpriteComponent>();
+            if (UserInterface != null)
+            {
+                UserInterface.OnReceiveMessage += HandleUIMessage;
+            }
+
             _switchedOn = true;
             _intact = true;
             _status = GravityGeneratorStatus.On;
@@ -101,7 +100,7 @@ namespace Content.Server.GameObjects.Components.Gravity
 
         public async Task<bool> InteractUsing(InteractUsingEventArgs eventArgs)
         {
-            if (!eventArgs.Using.TryGetComponent(out WelderComponent tool))
+            if (!eventArgs.Using.TryGetComponent(out WelderComponent? tool))
                 return false;
 
             if (!await tool.UseTool(eventArgs.User, Owner, 2f, ToolQuality.Welding, 5f))
@@ -150,7 +149,7 @@ namespace Content.Server.GameObjects.Components.Gravity
             switch (message.Message)
             {
                 case GeneratorStatusRequestMessage _:
-                    _userInterface.SetState(new GeneratorState(Status == GravityGeneratorStatus.On));
+                    UserInterface?.SetState(new GeneratorState(Status == GravityGeneratorStatus.On));
                     break;
                 case SwitchGeneratorMessage msg:
                     _switchedOn = msg.On;
@@ -163,35 +162,51 @@ namespace Content.Server.GameObjects.Components.Gravity
 
         private void OpenUserInterface(IPlayerSession playerSession)
         {
-            _userInterface.Open(playerSession);
+            UserInterface?.Open(playerSession);
         }
 
         private void MakeBroken()
         {
             _status = GravityGeneratorStatus.Broken;
-            _sprite.LayerSetState(0, "broken");
-            _sprite.LayerSetVisible(1, false);
+
+            if (Owner.TryGetComponent(out SpriteComponent? sprite))
+            {
+                sprite.LayerSetState(0, "broken");
+                sprite.LayerSetVisible(1, false);
+            }
         }
 
         private void MakeUnpowered()
         {
             _status = GravityGeneratorStatus.Unpowered;
-            _sprite.LayerSetState(0, "off");
-            _sprite.LayerSetVisible(1, false);
+
+            if (Owner.TryGetComponent(out SpriteComponent? sprite))
+            {
+                sprite.LayerSetState(0, "off");
+                sprite.LayerSetVisible(1, false);
+            }
         }
 
         private void MakeOff()
         {
             _status = GravityGeneratorStatus.Off;
-            _sprite.LayerSetState(0, "off");
-            _sprite.LayerSetVisible(1, false);
+
+            if (Owner.TryGetComponent(out SpriteComponent? sprite))
+            {
+                sprite.LayerSetState(0, "off");
+                sprite.LayerSetVisible(1, false);
+            }
         }
 
         private void MakeOn()
         {
             _status = GravityGeneratorStatus.On;
-            _sprite.LayerSetState(0, "on");
-            _sprite.LayerSetVisible(1, true);
+
+            if (Owner.TryGetComponent(out SpriteComponent? sprite))
+            {
+                sprite.LayerSetState(0, "on");
+                sprite.LayerSetVisible(1, true);
+            }
         }
     }
 

Content.Server/GameObjects/Components/Instruments/InstrumentComponent.cs

@@ -1,8 +1,10 @@
-using System;
+#nullable enable
+using System;
 using System.Linq;
 using Content.Server.GameObjects.Components.Mobs;
 using Content.Server.Interfaces;
 using Content.Server.Mobs;
+using Content.Server.Utility;
 using Content.Shared.GameObjects.Components.Instruments;
 using Content.Shared.GameObjects.EntitySystems;
 using Content.Shared.Interfaces.GameObjects.Components;
@@ -34,12 +36,8 @@ namespace Content.Server.GameObjects.Components.Instruments
             IUse,
             IThrown
     {
-
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _notifyManager;
-
-        [Dependency] private readonly IGameTiming _gameTiming;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
+        [Dependency] private readonly IGameTiming _gameTiming = default!;
 
         private static readonly TimeSpan OneSecAgo = TimeSpan.FromSeconds(-1);
 
@@ -47,7 +45,7 @@ namespace Content.Server.GameObjects.Components.Instruments
         ///     The client channel currently playing the instrument, or null if there's none.
         /// </summary>
         [ViewVariables]
-        private IPlayerSession _instrumentPlayer;
+        private IPlayerSession? _instrumentPlayer;
 
         private bool _handheld;
 
@@ -72,9 +70,6 @@ namespace Content.Server.GameObjects.Components.Instruments
         [ViewVariables]
         private int _midiEventCount = 0;
 
-        [ViewVariables]
-        private BoundUserInterface _userInterface;
-
         /// <summary>
         ///     Whether the instrument is an item which can be held or not.
         /// </summary>
@@ -95,7 +90,7 @@ namespace Content.Server.GameObjects.Components.Instruments
             }
         }
 
-        public IPlayerSession InstrumentPlayer
+        public IPlayerSession? InstrumentPlayer
         {
             get => _instrumentPlayer;
             private set
@@ -108,11 +103,13 @@ namespace Content.Server.GameObjects.Components.Instruments
                 _instrumentPlayer = value;
 
                 if (value != null)
-                    _instrumentPlayer.PlayerStatusChanged += OnPlayerStatusChanged;
+                    _instrumentPlayer!.PlayerStatusChanged += OnPlayerStatusChanged;
             }
         }
 
-        private void OnPlayerStatusChanged(object sender, SessionStatusEventArgs e)
+        [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(InstrumentUiKey.Key);
+
+        private void OnPlayerStatusChanged(object? sender, SessionStatusEventArgs e)
         {
             if (e.Session != _instrumentPlayer || e.NewStatus != SessionStatus.Disconnected) return;
             InstrumentPlayer = null;
@@ -122,8 +119,11 @@ namespace Content.Server.GameObjects.Components.Instruments
         public override void Initialize()
         {
             base.Initialize();
-            _userInterface = Owner.GetComponent<ServerUserInterfaceComponent>().GetBoundUserInterface(InstrumentUiKey.Key);
-            _userInterface.OnClosed += UserInterfaceOnClosed;
+
+            if (UserInterface != null)
+            {
+                UserInterface.OnClosed += UserInterfaceOnClosed;
+            }
         }
 
         public override void ExposeData(ObjectSerializer serializer)
@@ -137,14 +137,14 @@ namespace Content.Server.GameObjects.Components.Instruments
             return new InstrumentState(Playing, _lastSequencerTick);
         }
 
-        public override void HandleNetworkMessage(ComponentMessage message, INetChannel channel, ICommonSession session = null)
+        public override void HandleNetworkMessage(ComponentMessage message, INetChannel channel, ICommonSession? session = null)
         {
             base.HandleNetworkMessage(message, channel, session);
 
             switch (message)
             {
                 case InstrumentMidiEventMessage midiEventMsg:
-                    if (!Playing || session != _instrumentPlayer) return;
+                    if (!Playing || session != _instrumentPlayer || InstrumentPlayer == null) return;
 
                     var send = true;
 
@@ -231,7 +231,7 @@ namespace Content.Server.GameObjects.Components.Instruments
             Clean();
             SendNetworkMessage(new InstrumentStopMidiMessage());
             InstrumentPlayer = null;
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
 
         public void Thrown(ThrownEventArgs eventArgs)
@@ -239,7 +239,7 @@ namespace Content.Server.GameObjects.Components.Instruments
             Clean();
             SendNetworkMessage(new InstrumentStopMidiMessage());
             InstrumentPlayer = null;
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
 
         public void HandSelected(HandSelectedEventArgs eventArgs)
@@ -255,12 +255,12 @@ namespace Content.Server.GameObjects.Components.Instruments
         {
             Clean();
             SendNetworkMessage(new InstrumentStopMidiMessage());
-            _userInterface.CloseAll();
+            UserInterface?.CloseAll();
         }
 
         public void Activate(ActivateEventArgs eventArgs)
         {
-            if (Handheld || !eventArgs.User.TryGetComponent(out IActorComponent actor)) return;
+            if (Handheld || !eventArgs.User.TryGetComponent(out IActorComponent? actor)) return;
 
             if (InstrumentPlayer != null) return;
 
@@ -270,7 +270,7 @@ namespace Content.Server.GameObjects.Components.Instruments
 
         public bool UseEntity(UseEntityEventArgs eventArgs)
         {
-            if (!eventArgs.User.TryGetComponent(out IActorComponent actor)) return false;
+            if (!eventArgs.User.TryGetComponent(out IActorComponent? actor)) return false;
 
             if (InstrumentPlayer == actor.playerSession)
             {
@@ -291,7 +291,7 @@ namespace Content.Server.GameObjects.Components.Instruments
 
         private void OpenUserInterface(IPlayerSession session)
         {
-            _userInterface.Open(session);
+            UserInterface?.Open(session);
         }
 
         public override void Update(float delta)
@@ -302,7 +302,7 @@ namespace Content.Server.GameObjects.Components.Instruments
             {
                 InstrumentPlayer = null;
                 Clean();
-                _userInterface.CloseAll();
+                UserInterface?.CloseAll();
             }
 
             if ((_batchesDropped >= MaxMidiBatchDropped
@@ -314,9 +314,9 @@ namespace Content.Server.GameObjects.Components.Instruments
                 SendNetworkMessage(new InstrumentStopMidiMessage());
                 Playing = false;
 
-                _userInterface.CloseAll();
+                UserInterface?.CloseAll();
 
-                if (mob.TryGetComponent(out StunnableComponent stun))
+                if (mob != null && mob.TryGetComponent(out StunnableComponent? stun))
                 {
                     stun.Stun(1);
                     Clean();

Content.Server/GameObjects/Components/Interactable/HandheldLightComponent.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+#nullable enable
+using System.Threading.Tasks;
 using Content.Server.GameObjects.Components.GUI;
 using Content.Server.GameObjects.Components.Items.Clothing;
 using Content.Server.GameObjects.Components.Items.Storage;
@@ -27,28 +28,26 @@ namespace Content.Server.GameObjects.Components.Interactable
     ///     Component that represents a handheld lightsource which can be toggled on and off.
     /// </summary>
     [RegisterComponent]
-    internal sealed class HandheldLightComponent : SharedHandheldLightComponent, IUse, IExamine, IInteractUsing, IMapInit
+    internal sealed class HandheldLightComponent : SharedHandheldLightComponent, IUse, IExamine, IInteractUsing,
+        IMapInit
     {
-#pragma warning disable 649
-        [Dependency] private readonly ISharedNotifyManager _notifyManager;
-        [Dependency] private readonly ILocalizationManager _localizationManager;
-#pragma warning restore 649
+        [Dependency] private readonly ISharedNotifyManager _notifyManager = default!;
 
         [ViewVariables(VVAccess.ReadWrite)] public float Wattage { get; set; } = 10;
-        [ViewVariables] private ContainerSlot _cellContainer;
-        private PointLightComponent _pointLight;
-        private SpriteComponent _spriteComponent;
-        private ClothingComponent _clothingComponent;
+        [ViewVariables] private ContainerSlot _cellContainer = default!;
 
         [ViewVariables]
-        private BatteryComponent Cell
+        private BatteryComponent? Cell
         {
             get
             {
                 if (_cellContainer.ContainedEntity == null) return null;
+                if (_cellContainer.ContainedEntity.TryGetComponent(out BatteryComponent? cell))
+                {
+                    return cell;
+                }
 
-                _cellContainer.ContainedEntity.TryGetComponent(out BatteryComponent cell);
-                return cell;
+                return null;
             }
         }
 
@@ -58,6 +57,8 @@ namespace Content.Server.GameObjects.Components.Interactable
         [ViewVariables]
         public bool Activated { get; private set; }
 
+        [ViewVariables] protected override bool HasCell => Cell != null;
+
         async Task<bool> IInteractUsing.InteractUsing(InteractUsingEventArgs eventArgs)
         {
             if (!eventArgs.Using.HasComponent<BatteryComponent>()) return false;
@@ -81,11 +82,9 @@ namespace Content.Server.GameObjects.Components.Interactable
 
         void IExamine.Examine(FormattedMessage message, bool inDetailsRange)
         {
-            var loc = IoCManager.Resolve<ILocalizationManager>();
-
             if (Activated)
             {
-                message.AddMarkup(loc.GetString("The light is currently [color=darkgreen]on[/color]."));
+                message.AddMarkup(Loc.GetString("The light is currently [color=darkgreen]on[/color]."));
             }
         }
 
@@ -98,11 +97,10 @@ namespace Content.Server.GameObjects.Components.Interactable
         {
             base.Initialize();
 
-            _pointLight = Owner.GetComponent<PointLightComponent>();
-            _spriteComponent = Owner.GetComponent<SpriteComponent>();
-            Owner.TryGetComponent(out _clothingComponent);
+            Owner.EnsureComponent<PointLightComponent>();
             _cellContainer =
                 ContainerManagerComponent.Ensure<ContainerSlot>("flashlight_cell_container", Owner, out _);
+
             Dirty();
         }
 
@@ -140,7 +138,6 @@ namespace Content.Server.GameObjects.Components.Interactable
             Activated = false;
 
             EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Items/flashlight_toggle.ogg", Owner);
-
         }
 
         private void TurnOn(IEntity user)
@@ -153,10 +150,9 @@ namespace Content.Server.GameObjects.Components.Interactable
             var cell = Cell;
             if (cell == null)
             {
-
                 EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Machines/button.ogg", Owner);
 
-                _notifyManager.PopupMessage(Owner, user, _localizationManager.GetString("Cell missing..."));
+                _notifyManager.PopupMessage(Owner, user, Loc.GetString("Cell missing..."));
                 return;
             }
 
@@ -166,7 +162,7 @@ namespace Content.Server.GameObjects.Components.Interactable
             if (Wattage > cell.CurrentCharge)
             {
                 EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Machines/button.ogg", Owner);
-                _notifyManager.PopupMessage(Owner, user, _localizationManager.GetString("Dead cell..."));
+                _notifyManager.PopupMessage(Owner, user, Loc.GetString("Dead cell..."));
                 return;
             }
 
@@ -174,25 +170,46 @@ namespace Content.Server.GameObjects.Components.Interactable
             SetState(true);
 
             EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Items/flashlight_toggle.ogg", Owner);
-
         }
 
         private void SetState(bool on)
         {
-            _spriteComponent.LayerSetVisible(1, on);
-            _pointLight.Enabled = on;
-            if (_clothingComponent != null)
+            if (Owner.TryGetComponent(out SpriteComponent? sprite))
             {
-                _clothingComponent.ClothingEquippedPrefix = on ? "On" : "Off";
+                sprite.LayerSetVisible(1, on);
+            }
+
+            if (Owner.TryGetComponent(out PointLightComponent? light))
+            {
+                light.Enabled = on;
+            }
+
+            if (Owner.TryGetComponent(out ClothingComponent? clothing))
+            {
+                clothing.ClothingEquippedPrefix = on ? "On" : "Off";
             }
         }
 
         public void OnUpdate(float frameTime)
         {
-            if (!Activated) return;
+            if (!Activated || Cell == null) return;
 
-            var cell = Cell;
-            if (cell == null || !cell.TryUseCharge(Wattage * frameTime)) TurnOff();
+            var appearanceComponent = Owner.GetComponent<AppearanceComponent>();
+
+            if (Cell.MaxCharge - Cell.CurrentCharge < Cell.MaxCharge * 0.70)
+            {
+                appearanceComponent.SetData(HandheldLightVisuals.Power, HandheldLightPowerStates.FullPower);
+            }
+            else if (Cell.MaxCharge - Cell.CurrentCharge < Cell.MaxCharge * 0.90)
+            {
+                appearanceComponent.SetData(HandheldLightVisuals.Power, HandheldLightPowerStates.LowPower);
+            }
+            else
+            {
+                appearanceComponent.SetData(HandheldLightVisuals.Power, HandheldLightPowerStates.Dying);
+            }
+
+            if (Cell == null || !Cell.TryUseCharge(Wattage * frameTime)) TurnOff();
 
             Dirty();
         }
@@ -211,7 +228,9 @@ namespace Content.Server.GameObjects.Components.Interactable
                 return;
             }
 
-            if (!user.TryGetComponent(out HandsComponent hands))
+            Dirty();
+
+            if (!user.TryGetComponent(out HandsComponent? hands))
             {
                 return;
             }
@@ -222,24 +241,23 @@ namespace Content.Server.GameObjects.Components.Interactable
             }
 
             EntitySystem.Get<AudioSystem>().PlayFromEntity("/Audio/Items/pistol_magout.ogg", Owner);
-
         }
 
         public override ComponentState GetComponentState()
         {
             if (Cell == null)
             {
-                return new HandheldLightComponentState(null);
+                return new HandheldLightComponentState(null, false);
             }
 
             if (Wattage > Cell.CurrentCharge)
             {
                 // Practically zero.
                 // This is so the item status works correctly.
-                return new HandheldLightComponentState(0);
+                return new HandheldLightComponentState(0, HasCell);
             }
 
-            return new HandheldLightComponentState(Cell.CurrentCharge / Cell.MaxCharge);
+            return new HandheldLightComponentState(Cell.CurrentCharge / Cell.MaxCharge, HasCell);
         }
 
         [Verb]

Content.Server/GameObjects/Components/Interactable/TilePryingComponent.cs

@@ -14,11 +14,9 @@ namespace Content.Server.GameObjects.Components.Interactable
     [RegisterComponent]
     public class TilePryingComponent : Component, IAfterInteract
     {
-#pragma warning disable 649
-        [Dependency] private readonly IEntitySystemManager _entitySystemManager;
-        [Dependency] private readonly ITileDefinitionManager _tileDefinitionManager;
-        [Dependency] private readonly IMapManager _mapManager;
-#pragma warning restore 649
+        [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
+        [Dependency] private readonly ITileDefinitionManager _tileDefinitionManager = default!;
+        [Dependency] private readonly IMapManager _mapManager = default!;
 
         public override string Name => "TilePrying";
         private bool _toolComponentNeeded = true;

Content.Server/GameObjects/Components/Interactable/WelderComponent.cs

@@ -29,10 +29,8 @@ namespace Content.Server.GameObjects.Components.Interactable
     [ComponentReference(typeof(IToolComponent))]
     public class WelderComponent : ToolComponent, IExamine, IUse, ISuicideAct, ISolutionChange
     {
-#pragma warning disable 649
         [Dependency] private readonly IEntitySystemManager _entitySystemManager = default!;
         [Dependency] private readonly IServerNotifyManager _notifyManager = default!;
-#pragma warning restore 649
 
         public override string Name => "Welder";
         public override uint? NetID => ContentNetIDs.WELDER;

Content.Server/GameObjects/Components/Items/Clothing/ClothingComponent.cs

@@ -20,9 +20,7 @@ namespace Content.Server.GameObjects.Components.Items.Clothing
     [ComponentReference(typeof(IItemComponent))]
     public class ClothingComponent : ItemComponent, IUse
     {
-#pragma warning disable 649
-        [Dependency] private readonly IServerNotifyManager _serverNotifyManager;
-#pragma warning restore 649
+        [Dependency] private readonly IServerNotifyManager _serverNotifyManager = default!;
 
         public override string Name => "Clothing";
         public override uint? NetID => ContentNetIDs.CLOTHING;
@@ -63,7 +61,6 @@ namespace Content.Server.GameObjects.Components.Items.Clothing
             });
 
             serializer.DataField(ref _quickEquipEnabled, "QuickEquip", true);
-
             serializer.DataFieldCached(ref _heatResistance, "HeatResistance", 323);
         }
 

Content.Server/GameObjects/Components/Items/DiceComponent.cs

@@ -20,10 +20,8 @@ namespace Content.Server.GameObjects.Components.Items
     [RegisterComponent]
     public class DiceComponent : Component, IActivate, IUse, ILand, IExamine
     {
-#pragma warning disable 649
-        [Dependency] private readonly IPrototypeManager _prototypeManager;
-        [Dependency] private readonly IRobustRandom _random;
-#pragma warning restore 649
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+        [Dependency] private readonly IRobustRandom _random = default!;
 
         public override string Name => "Dice";
 
@@ -85,9 +83,9 @@ namespace Content.Server.GameObjects.Components.Items
         void IExamine.Examine(FormattedMessage message, bool inDetailsRange)
         {
             //No details check, since the sprite updates to show the side.
-            var loc = IoCManager.Resolve<ILocalizationManager>();
-            message.AddMarkup(loc.GetString("A dice with [color=lightgray]{0}[/color] sides.\n" +
-                                            "It has landed on a [color=white]{1}[/color].", _sides, _currentSide));
+            message.AddMarkup(Loc.GetString(
+                "A dice with [color=lightgray]{0}[/color] sides.\n" + "It has landed on a [color=white]{1}[/color].",
+                _sides, _currentSide));
         }
     }
 }