Make mechanism behaviors properly update, fix eating and drinking (#2472)

* Make mechanisms properly update and fix eating and drinking

* Remove outdated component ignores

* Fix nullable error

* Fix mechanism behavior events

* Remove unnecessary code

Content.Client/GameObjects/Components/Body/Mechanism/HeartBehaviorComponent.cs

@@ -1,12 +0,0 @@
-using Content.Shared.GameObjects.Components.Body.Behavior;
-using Robust.Shared.GameObjects;
-
-namespace Content.Client.GameObjects.Components.Body.Mechanism
-{
-    [RegisterComponent]
-    [ComponentReference(typeof(SharedHeartBehaviorComponent))]
-    public class HeartBehaviorComponent : SharedHeartBehaviorComponent
-    {
-        public override void Update(float frameTime) { }
-    }
-}

Content.Client/IgnoredComponents.cs

@@ -58,7 +58,6 @@
             "Drink",
             "Food",
             "FoodContainer",
-            "Stomach",
             "Rotatable",
             "MagicMirror",
             "FloorTile",
@@ -180,10 +179,8 @@
             "BreakableConstruction",
             "GasCanister",
             "GasCanisterPort",
-            "Lung",
             "Cleanable",
             "Configuration",
-            "Brain",
             "PlantHolder",
             "SeedExtractor",
             "Produce",

Content.IntegrationTests/Tests/Body/LungTest.cs

@@ -20,7 +20,7 @@ using Robust.Shared.Maths;
 namespace Content.IntegrationTests.Tests.Body
 {
     [TestFixture]
-    [TestOf(typeof(LungBehaviorComponent))]
+    [TestOf(typeof(LungBehavior))]
     public class LungTest : ContentIntegrationTest
     {
         [Test]
@@ -39,7 +39,7 @@ namespace Content.IntegrationTests.Tests.Body
                 var human = entityManager.SpawnEntity("HumanMob_Content", MapCoordinates.Nullspace);
 
                 Assert.That(human.TryGetComponent(out IBody body));
-                Assert.That(body.TryGetMechanismBehaviors(out List<LungBehaviorComponent> lungs));
+                Assert.That(body.TryGetMechanismBehaviors(out List<LungBehavior> lungs));
                 Assert.That(lungs.Count, Is.EqualTo(1));
                 Assert.That(human.TryGetComponent(out BloodstreamComponent bloodstream));
 
@@ -141,7 +141,7 @@ namespace Content.IntegrationTests.Tests.Body
                 human = entityManager.SpawnEntity("HumanMob_Content", coordinates);
 
                 Assert.True(human.TryGetComponent(out IBody body));
-                Assert.True(body.HasMechanismBehavior<LungBehaviorComponent>());
+                Assert.True(body.HasMechanismBehavior<LungBehavior>());
                 Assert.True(human.TryGetComponent(out metabolism));
                 Assert.False(metabolism.Suffocating);
             });

Content.IntegrationTests/Tests/Body/MechanismBehaviorEventsTest.cs

@@ -1,12 +1,12 @@
 #nullable enable
 using System.Linq;
 using System.Threading.Tasks;
+using Content.Server.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body;
 using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Mechanism;
 using Content.Shared.GameObjects.Components.Body.Part;
 using NUnit.Framework;
-using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
 using Robust.Shared.Interfaces.Map;
 using Robust.Shared.IoC;
@@ -18,14 +18,11 @@ namespace Content.IntegrationTests.Tests.Body
     [TestOf(typeof(SharedBodyComponent))]
     [TestOf(typeof(SharedBodyPartComponent))]
     [TestOf(typeof(SharedMechanismComponent))]
-    [TestOf(typeof(MechanismBehaviorComponent))]
+    [TestOf(typeof(MechanismBehavior))]
     public class MechanismBehaviorEventsTest : ContentIntegrationTest
     {
-        [RegisterComponent]
+        private class TestMechanismBehavior : MechanismBehavior
-        private class TestBehaviorComponent : MechanismBehaviorComponent
         {
-            public override string Name => nameof(MechanismBehaviorEventsTest) + "TestBehavior";
-
             public bool WasAddedToBody;
             public bool WasAddedToPart;
             public bool WasAddedToPartInBody;
@@ -33,8 +30,6 @@ namespace Content.IntegrationTests.Tests.Body
             public bool WasRemovedFromPart;
             public bool WasRemovedFromPartInBody;
 
-            public override void Update(float frameTime) { }
-
             public bool NoAdded()
             {
                 return !WasAddedToBody && !WasAddedToPart && !WasAddedToPartInBody;
@@ -111,13 +106,7 @@ namespace Content.IntegrationTests.Tests.Body
         [Test]
         public async Task EventsTest()
         {
-            var server = StartServerDummyTicker(new ServerContentIntegrationOption
+            var server = StartServerDummyTicker();
-            {
-                ContentBeforeIoC = () =>
-                {
-                    IoCManager.Resolve<IComponentFactory>().Register<TestBehaviorComponent>();
-                }
-            });
 
             await server.WaitAssertion(() =>
             {
@@ -141,68 +130,68 @@ namespace Content.IntegrationTests.Tests.Body
                 var mechanism = centerPart!.Mechanisms.First();
                 Assert.NotNull(mechanism);
 
-                var component = mechanism.Owner.AddComponent<TestBehaviorComponent>();
+                mechanism.EnsureBehavior<TestMechanismBehavior>(out var behavior);
-                Assert.False(component.WasAddedToBody);
+                Assert.False(behavior.WasAddedToBody);
-                Assert.False(component.WasAddedToPart);
+                Assert.False(behavior.WasAddedToPart);
-                Assert.That(component.WasAddedToPartInBody);
+                Assert.That(behavior.WasAddedToPartInBody);
-                Assert.That(component.NoRemoved);
+                Assert.That(behavior.NoRemoved);
 
-                component.ResetAll();
+                behavior.ResetAll();
 
-                Assert.That(component.NoAdded);
+                Assert.That(behavior.NoAdded);
-                Assert.That(component.NoRemoved);
+                Assert.That(behavior.NoRemoved);
 
                 centerPart.RemoveMechanism(mechanism);
 
-                Assert.That(component.NoAdded);
+                Assert.That(behavior.NoAdded);
-                Assert.False(component.WasRemovedFromBody);
+                Assert.False(behavior.WasRemovedFromBody);
-                Assert.False(component.WasRemovedFromPart);
+                Assert.False(behavior.WasRemovedFromPart);
-                Assert.That(component.WasRemovedFromPartInBody);
+                Assert.That(behavior.WasRemovedFromPartInBody);
 
-                component.ResetAll();
+                behavior.ResetAll();
 
                 centerPart.TryAddMechanism(mechanism, true);
 
-                Assert.False(component.WasAddedToBody);
+                Assert.False(behavior.WasAddedToBody);
-                Assert.False(component.WasAddedToPart);
+                Assert.False(behavior.WasAddedToPart);
-                Assert.That(component.WasAddedToPartInBody);
+                Assert.That(behavior.WasAddedToPartInBody);
-                Assert.That(component.NoRemoved());
+                Assert.That(behavior.NoRemoved());
 
-                component.ResetAll();
+                behavior.ResetAll();
 
                 body.RemovePart(centerPart);
 
-                Assert.That(component.NoAdded);
+                Assert.That(behavior.NoAdded);
-                Assert.That(component.WasRemovedFromBody);
+                Assert.That(behavior.WasRemovedFromBody);
-                Assert.False(component.WasRemovedFromPart);
+                Assert.False(behavior.WasRemovedFromPart);
-                Assert.False(component.WasRemovedFromPartInBody);
+                Assert.False(behavior.WasRemovedFromPartInBody);
 
-                component.ResetAll();
+                behavior.ResetAll();
 
                 centerPart.RemoveMechanism(mechanism);
 
-                Assert.That(component.NoAdded);
+                Assert.That(behavior.NoAdded);
-                Assert.False(component.WasRemovedFromBody);
+                Assert.False(behavior.WasRemovedFromBody);
-                Assert.That(component.WasRemovedFromPart);
+                Assert.That(behavior.WasRemovedFromPart);
-                Assert.False(component.WasRemovedFromPartInBody);
+                Assert.False(behavior.WasRemovedFromPartInBody);
 
-                component.ResetAll();
+                behavior.ResetAll();
 
                 centerPart.TryAddMechanism(mechanism, true);
 
-                Assert.False(component.WasAddedToBody);
+                Assert.False(behavior.WasAddedToBody);
-                Assert.That(component.WasAddedToPart);
+                Assert.That(behavior.WasAddedToPart);
-                Assert.False(component.WasAddedToPartInBody);
+                Assert.False(behavior.WasAddedToPartInBody);
-                Assert.That(component.NoRemoved);
+                Assert.That(behavior.NoRemoved);
 
-                component.ResetAll();
+                behavior.ResetAll();
 
                 body.TryAddPart(centerSlot!, centerPart, true);
 
-                Assert.That(component.WasAddedToBody);
+                Assert.That(behavior.WasAddedToBody);
-                Assert.False(component.WasAddedToPart);
+                Assert.False(behavior.WasAddedToPart);
-                Assert.False(component.WasAddedToPartInBody);
+                Assert.False(behavior.WasAddedToPartInBody);
-                Assert.That(component.NoRemoved);
+                Assert.That(behavior.NoRemoved);
             });
         }
     }

Content.Server/Commands/Hungry.cs

@@ -0,0 +1,39 @@
+#nullable enable
+using Content.Server.GameObjects.Components.Nutrition;
+using Content.Shared.GameObjects.Components.Nutrition;
+using Robust.Server.Interfaces.Console;
+using Robust.Server.Interfaces.Player;
+
+namespace Content.Server.Commands
+{
+    public class Hungry : IClientCommand
+    {
+        public string Command => "hungry";
+        public string Description => "Makes you hungry.";
+        public string Help => $"{Command}";
+
+        public void Execute(IConsoleShell shell, IPlayerSession? player, string[] args)
+        {
+            if (player == null)
+            {
+                shell.SendText(player, "You cannot use this command unless you are a player.");
+                return;
+            }
+
+            if (player.AttachedEntity == null)
+            {
+                shell.SendText(player, "You cannot use this command without an entity.");
+                return;
+            }
+
+            if (!player.AttachedEntity.TryGetComponent(out HungerComponent? hunger))
+            {
+                shell.SendText(player, $"Your entity does not have a {nameof(HungerComponent)} component.");
+                return;
+            }
+
+            var hungryThreshold = hunger.HungerThresholds[HungerThreshold.Starving];
+            hunger.CurrentHunger = hungryThreshold;
+        }
+    }
+}

Content.Server/GameObjects/Components/Body/Behavior/BrainBehavior.cs

@@ -1,22 +1,14 @@
 #nullable enable
 using Content.Server.GameObjects.Components.Mobs;
-using Content.Server.Mobs;
 using Content.Shared.GameObjects.Components.Body;
-using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Part;
 using Robust.Shared.GameObjects;
-using Robust.Shared.GameObjects.ComponentDependencies;
 using Robust.Shared.Interfaces.GameObjects;
-using Robust.Shared.Log;
-using Robust.Shared.ViewVariables;
 
 namespace Content.Server.GameObjects.Components.Body.Behavior
 {
-    [RegisterComponent]
+    public class BrainBehavior : MechanismBehavior
-    public class BrainBehaviorComponent : MechanismBehaviorComponent
     {
-        public override string Name => "Brain";
-
         protected override void OnAddedToBody(IBody body)
         {
             base.OnAddedToBody(body);
@@ -66,9 +58,5 @@ namespace Content.Server.GameObjects.Components.Body.Behavior
 
             oldMind.Mind?.TransferTo(newEntity);
         }
-
-        public override void Update(float frameTime)
-        {
-        }
     }
 }

Content.Server/GameObjects/Components/Body/Behavior/HeartBehavior.cs

@@ -1,20 +1,17 @@
 using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Networks;
-using Robust.Shared.GameObjects;
 
 namespace Content.Server.GameObjects.Components.Body.Behavior
 {
-    [RegisterComponent]
+    public class HeartBehavior : MechanismBehavior
-    [ComponentReference(typeof(SharedHeartBehaviorComponent))]
-    public class HeartBehaviorComponent : SharedHeartBehaviorComponent
     {
         private float _accumulatedFrameTime;
 
         public override void Update(float frameTime)
         {
             // TODO BODY do between pre and metabolism
-            if (Mechanism?.Body == null ||
+            if (Parent.Body == null ||
-                !Mechanism.Body.Owner.HasComponent<SharedBloodstreamComponent>())
+                !Parent.Body.Owner.HasComponent<SharedBloodstreamComponent>())
             {
                 return;
             }

Content.Server/GameObjects/Components/Body/Behavior/LungBehavior.cs

@@ -8,19 +8,15 @@ using Content.Server.GameObjects.Components.Body.Respiratory;
 using Content.Server.Utility;
 using Content.Shared.Atmos;
 using Content.Shared.GameObjects.Components.Body.Behavior;
-using Robust.Shared.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;
 
 namespace Content.Server.GameObjects.Components.Body.Behavior
 {
-    [RegisterComponent]
+    public class LungBehavior : MechanismBehavior
-    [ComponentReference(typeof(SharedLungBehaviorComponent))]
-    public class LungBehaviorComponent : SharedLungBehaviorComponent
     {
         [Dependency] private readonly IGameTiming _gameTiming = default!;
 
@@ -30,18 +26,24 @@ namespace Content.Server.GameObjects.Components.Body.Behavior
 
         [ViewVariables] public GasMixture Air { get; set; } = default!;
 
-        [ViewVariables] public override float Temperature => Air.Temperature;
+        [ViewVariables] public float Temperature => Air.Temperature;
 
-        [ViewVariables] public override float Volume => Air.Volume;
+        [ViewVariables] public float Volume => Air.Volume;
 
         [ViewVariables] public TimeSpan GaspPopupCooldown { get; private set; }
 
+        [ViewVariables] public LungStatus Status { get; set; }
+
+        [ViewVariables] public float CycleDelay { get; set; }
+
         public override void ExposeData(ObjectSerializer serializer)
         {
             base.ExposeData(serializer);
 
             Air = new GasMixture {Temperature = Atmospherics.NormalBodyTemperature};
 
+            serializer.DataField(this, l => l.CycleDelay, "cycleDelay", 2);
+
             serializer.DataReadWriteFunction(
                 "volume",
                 6,
@@ -61,7 +63,7 @@ namespace Content.Server.GameObjects.Components.Body.Behavior
                 () => GaspPopupCooldown.TotalSeconds);
         }
 
-        public override void Gasp()
+        public void Gasp()
         {
             if (_gameTiming.CurTime >= _lastGaspPopupTime + GaspPopupCooldown)
             {
@@ -148,7 +150,7 @@ namespace Content.Server.GameObjects.Components.Body.Behavior
             _accumulatedFrameTime = absoluteTime - delay;
         }
 
-        public override void Inhale(float frameTime)
+        public void Inhale(float frameTime)
         {
             if (Body != null && Body.Owner.TryGetComponent(out InternalsComponent? internals)
                              && internals.BreathToolEntity != null && internals.GasTankEntity != null
@@ -176,7 +178,7 @@ namespace Content.Server.GameObjects.Components.Body.Behavior
             ToBloodstream(Air);
         }
 
-        public override void Exhale(float frameTime)
+        public void Exhale(float frameTime)
         {
             if (!Owner.Transform.Coordinates.TryGetTileAir(out var tileAir))
             {
@@ -218,4 +220,11 @@ namespace Content.Server.GameObjects.Components.Body.Behavior
             Air.Merge(lungRemoved);
         }
     }
+
+    public enum LungStatus
+    {
+        None = 0,
+        Inhaling,
+        Exhaling
+    }
 }

Content.Server/GameObjects/Components/Body/Behavior/MechanismBehavior.cs

@@ -1,23 +1,33 @@
 #nullable enable
+using Content.Shared.GameObjects.Components.Body;
+using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Mechanism;
 using Content.Shared.GameObjects.Components.Body.Part;
-using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Serialization;
 using Robust.Shared.Utility;
 
-namespace Content.Shared.GameObjects.Components.Body.Behavior
+namespace Content.Server.GameObjects.Components.Body.Behavior
 {
-    public abstract class MechanismBehaviorComponent : Component, IMechanismBehavior
+    public abstract class MechanismBehavior : IMechanismBehavior
     {
         public IBody? Body => Part?.Body;
 
-        public IBodyPart? Part => Mechanism?.Part;
+        public IBodyPart? Part => Parent.Part;
 
-        public IMechanism? Mechanism => Owner.GetComponentOrNull<IMechanism>();
+        public IMechanism Parent { get; private set; } = default!;
 
-        protected override void Startup()
+        public IEntity Owner => Parent.Owner;
+
+        public virtual void ExposeData(ObjectSerializer serializer) { }
+
+        public virtual void Initialize(IMechanism parent)
         {
-            base.Startup();
+            Parent = parent;
+        }
 
+        public virtual void Startup()
+        {
             if (Part == null)
             {
                 return;
@@ -33,8 +43,6 @@ namespace Content.Shared.GameObjects.Components.Body.Behavior
             }
         }
 
-        public abstract void Update(float frameTime);
-
         public void AddedToBody(IBody body)
         {
             DebugTools.AssertNotNull(Body);
@@ -98,5 +106,7 @@ namespace Content.Shared.GameObjects.Components.Body.Behavior
         protected virtual void OnRemovedFromPart(IBodyPart old) { }
 
         protected virtual void OnRemovedFromPartInBody(IBody oldBody, IBodyPart oldPart) { }
+
+        public virtual void Update(float frameTime) { }
     }
 }

Content.Server/GameObjects/Components/Body/Behavior/MechanismExtensions.cs

@@ -2,33 +2,29 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Content.Shared.GameObjects.Components.Body;
 using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Part;
 
-namespace Content.Shared.GameObjects.Components.Body.Mechanism
+namespace Content.Server.GameObjects.Components.Body.Behavior
 {
     public static class MechanismExtensions
     {
-        public static bool HasMechanismBehavior<T>(this IBody body)
+        public static bool HasMechanismBehavior<T>(this IBody body) where T : IMechanismBehavior
         {
             return body.Parts.Values.Any(p => p.HasMechanismBehavior<T>());
         }
 
-        public static bool HasMechanismBehavior<T>(this IBodyPart part)
+        public static bool HasMechanismBehavior<T>(this IBodyPart part) where T : IMechanismBehavior
         {
-            return part.Mechanisms.Any(m => m.Owner.HasComponent<T>());
+            return part.Mechanisms.Any(m => m.HasBehavior<T>());
-        }
-
-        public static bool HasMechanismBehavior<T>(this IMechanism mechanism)
-        {
-            return mechanism.Owner.HasComponent<T>();
         }
 
         public static IEnumerable<IMechanismBehavior> GetMechanismBehaviors(this IBody body)
         {
             foreach (var part in body.Parts.Values)
             foreach (var mechanism in part.Mechanisms)
-            foreach (var behavior in mechanism.Owner.GetAllComponents<IMechanismBehavior>())
+            foreach (var behavior in mechanism.Behaviors.Values)
             {
                 yield return behavior;
             }
@@ -52,10 +48,11 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
         {
             foreach (var part in body.Parts.Values)
             foreach (var mechanism in part.Mechanisms)
+            foreach (var behavior in mechanism.Behaviors.Values)
             {
-                if (mechanism.Owner.TryGetComponent(out T? behavior))
+                if (behavior is T tBehavior)
                 {
-                    yield return behavior;
+                    yield return tBehavior;
                 }
             }
         }

Content.Server/GameObjects/Components/Body/Behavior/StomachBehavior.cs

@@ -1,23 +1,23 @@
-#nullable enable
+#nullable enable
 using System.Collections.Generic;
 using System.Linq;
+using Content.Server.GameObjects.Components.Chemistry;
 using Content.Shared.Chemistry;
 using Content.Shared.GameObjects.Components.Body.Networks;
 using Content.Shared.GameObjects.Components.Chemistry;
 using Robust.Shared.GameObjects;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 
-namespace Content.Shared.GameObjects.Components.Body.Behavior
+namespace Content.Server.GameObjects.Components.Body.Behavior
 {
     /// <summary>
     /// Where reagents go when ingested. Tracks ingested reagents over time, and
     /// eventually transfers them to <see cref="SharedBloodstreamComponent"/> once digested.
     /// </summary>
-    public abstract class SharedStomachBehaviorComponent : MechanismBehaviorComponent
+    public class StomachBehavior : MechanismBehavior
     {
-        public override string Name => "Stomach";
-
         private float _accumulatedFrameTime;
 
         /// <summary>
@@ -45,7 +45,7 @@ namespace Content.Shared.GameObjects.Components.Body.Behavior
 
             _accumulatedFrameTime -= 1;
 
-            if (!Body.Owner.TryGetComponent(out SharedSolutionContainerComponent? solution) ||
+            if (!Owner.TryGetComponent(out SharedSolutionContainerComponent? solution) ||
                 !Body.Owner.TryGetComponent(out SharedBloodstreamComponent? bloodstream))
             {
                 return;
@@ -58,7 +58,7 @@ namespace Content.Shared.GameObjects.Components.Body.Behavior
             foreach (var delta in _reagentDeltas.ToList())
             {
                 //Increment lifetime of reagents
-                delta.Increment(frameTime);
+                delta.Increment(1);
                 if (delta.Lifetime > _digestionDelay)
                 {
                     solution.TryRemoveReagent(delta.ReagentId, delta.Quantity);
@@ -112,6 +112,18 @@ namespace Content.Shared.GameObjects.Components.Body.Behavior
             serializer.DataField(ref _digestionDelay, "digestionDelay", 20);
         }
 
+        public override void Startup()
+        {
+            base.Startup();
+
+            if (!Owner.EnsureComponent(out SolutionContainerComponent solution))
+            {
+                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionContainerComponent)}");
+            }
+
+            solution.MaxVolume = InitialMaxVolume;
+        }
+
         public bool CanTransferSolution(Solution solution)
         {
             if (!Owner.TryGetComponent(out SharedSolutionContainerComponent? solutionComponent))

Content.Server/GameObjects/Components/Body/Behavior/StomachBehaviorComponent.cs

@@ -1,24 +0,0 @@
-using Content.Server.GameObjects.Components.Chemistry;
-using Content.Shared.GameObjects.Components.Body.Behavior;
-using Robust.Shared.GameObjects;
-using Robust.Shared.Log;
-
-namespace Content.Server.GameObjects.Components.Body.Behavior
-{
-    [RegisterComponent]
-    [ComponentReference(typeof(SharedStomachBehaviorComponent))]
-    public class StomachBehaviorComponent : SharedStomachBehaviorComponent
-    {
-        protected override void Startup()
-        {
-            base.Startup();
-
-            if (!Owner.EnsureComponent(out SolutionContainerComponent solution))
-            {
-                Logger.Warning($"Entity {Owner} at {Owner.Transform.MapPosition} didn't have a {nameof(SolutionContainerComponent)}");
-            }
-
-            solution.MaxVolume = InitialMaxVolume;
-        }
-    }
-}

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

@@ -84,7 +84,7 @@ namespace Content.Server.GameObjects.Components.Chemistry
             var trueTarget = target ?? user;
 
             if (!trueTarget.TryGetComponent(out IBody body) ||
-                !body.TryGetMechanismBehaviors<StomachBehaviorComponent>(out var stomachs))
+                !body.TryGetMechanismBehaviors<StomachBehavior>(out var stomachs))
             {
                 return false;
             }

Content.Server/GameObjects/Components/Metabolism/MetabolismComponent.cs

@@ -192,7 +192,7 @@ namespace Content.Server.GameObjects.Components.Metabolism
                 return;
             }
 
-            var lungs = _body.GetMechanismBehaviors<LungBehaviorComponent>().ToArray();
+            var lungs = _body.GetMechanismBehaviors<LungBehavior>().ToArray();
 
             var needs = NeedsAndDeficit(frameTime);
             var used = 0f;

Content.Server/GameObjects/Components/Nutrition/DrinkComponent.cs

@@ -153,7 +153,7 @@ namespace Content.Server.GameObjects.Components.Nutrition
             }
 
             if (!target.TryGetComponent(out IBody body) ||
-                !body.TryGetMechanismBehaviors<StomachBehaviorComponent>(out var stomachs))
+                !body.TryGetMechanismBehaviors<StomachBehavior>(out var stomachs))
             {
                 return false;
             }

Content.Server/GameObjects/Components/Nutrition/FoodComponent.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Content.Server.GameObjects.Components.Body.Behavior;
 using Content.Server.GameObjects.Components.Chemistry;
 using Content.Server.GameObjects.Components.GUI;
 using Content.Server.GameObjects.Components.Items.Storage;
@@ -133,7 +134,7 @@ namespace Content.Server.GameObjects.Components.Nutrition
             var trueTarget = target ?? user;
 
             if (!trueTarget.TryGetComponent(out IBody? body) ||
-                !body.TryGetMechanismBehaviors<SharedStomachBehaviorComponent>(out var stomachs))
+                !body.TryGetMechanismBehaviors<StomachBehavior>(out var stomachs))
             {
                 return false;
             }

Content.Server/GameObjects/EntitySystems/HeartSystem.cs

@@ -1,28 +0,0 @@
-using Content.Shared.GameObjects.Components.Body.Behavior;
-using Content.Shared.GameObjects.EntitySystems;
-using JetBrains.Annotations;
-using Robust.Shared.GameObjects.Systems;
-
-namespace Content.Server.GameObjects.EntitySystems
-{
-    [UsedImplicitly]
-    public class HeartSystem : EntitySystem
-    {
-        public override void Initialize()
-        {
-            base.Initialize();
-
-            UpdatesBefore.Add(typeof(MetabolismSystem));
-        }
-
-        public override void Update(float frameTime)
-        {
-            base.Update(frameTime);
-
-            foreach (var heart in ComponentManager.EntityQuery<SharedHeartBehaviorComponent>())
-            {
-                heart.Update(frameTime);
-            }
-        }
-    }
-}

Content.Server/GameObjects/EntitySystems/LungSystem.cs

@@ -1,28 +0,0 @@
-using Content.Shared.GameObjects.Components.Body.Behavior;
-using Content.Shared.GameObjects.EntitySystems;
-using JetBrains.Annotations;
-using Robust.Shared.GameObjects.Systems;
-
-namespace Content.Server.GameObjects.EntitySystems
-{
-    [UsedImplicitly]
-    public class LungSystem : EntitySystem
-    {
-        public override void Initialize()
-        {
-            base.Initialize();
-
-            UpdatesBefore.Add(typeof(MetabolismSystem));
-        }
-
-        public override void Update(float frameTime)
-        {
-            base.Update(frameTime);
-
-            foreach (var lung in ComponentManager.EntityQuery<SharedLungBehaviorComponent>())
-            {
-                lung.Update(frameTime);
-            }
-        }
-    }
-}

Content.Shared/GameObjects/Components/Body/Behavior/IMechanismBehavior.cs

@@ -2,10 +2,11 @@
 using Content.Shared.GameObjects.Components.Body.Mechanism;
 using Content.Shared.GameObjects.Components.Body.Part;
 using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Serialization;
 
 namespace Content.Shared.GameObjects.Components.Body.Behavior
 {
-    public interface IMechanismBehavior : IComponent
+    public interface IMechanismBehavior : IExposeData
     {
         IBody? Body { get; }
 
@@ -15,7 +16,20 @@ namespace Content.Shared.GameObjects.Components.Body.Behavior
         ///     Upward reference to the parent <see cref="IMechanism"/> that this
         ///     behavior is attached to.
         /// </summary>
-        IMechanism? Mechanism { get; }
+        IMechanism Parent { get; }
+
+        /// <summary>
+        ///     The entity that owns <see cref="Parent"/>.
+        ///     For the entity owning the body that this mechanism may be in,
+        ///     see <see cref="IBody.Owner"/>
+        /// </summary>
+        IEntity Owner { get; }
+
+        void Initialize(IMechanism parent);
+
+        void Startup();
+
+        void Update(float frameTime);
 
         /// <summary>
         ///     Called when the containing <see cref="IBodyPart"/> is attached to a

Content.Shared/GameObjects/Components/Body/Behavior/SharedHeartBehaviorComponent.cs

@@ -1,8 +0,0 @@
-#nullable enable
-namespace Content.Shared.GameObjects.Components.Body.Behavior
-{
-    public abstract class SharedHeartBehaviorComponent : MechanismBehaviorComponent
-    {
-        public override string Name => "Heart";
-    }
-}

Content.Shared/GameObjects/Components/Body/Behavior/SharedLungBehaviorComponent.cs

@@ -1,39 +0,0 @@
-#nullable enable
-using Robust.Shared.Serialization;
-using Robust.Shared.ViewVariables;
-
-namespace Content.Shared.GameObjects.Components.Body.Behavior
-{
-    public abstract class SharedLungBehaviorComponent : MechanismBehaviorComponent
-    {
-        public override string Name => "Lung";
-
-        [ViewVariables] public abstract float Temperature { get; }
-
-        [ViewVariables] public abstract float Volume { get; }
-
-        [ViewVariables] public LungStatus Status { get; set; }
-
-        [ViewVariables] public float CycleDelay { get; set; }
-
-        public override void ExposeData(ObjectSerializer serializer)
-        {
-            base.ExposeData(serializer);
-
-            serializer.DataField(this, l => l.CycleDelay, "cycleDelay", 2);
-        }
-
-        public abstract void Inhale(float frameTime);
-
-        public abstract void Exhale(float frameTime);
-
-        public abstract void Gasp();
-    }
-
-    public enum LungStatus
-    {
-        None = 0,
-        Inhaling,
-        Exhaling
-    }
-}

Content.Shared/GameObjects/Components/Body/Mechanism/IMechanism.cs

@@ -1,4 +1,7 @@
 #nullable enable
+using System;
+using System.Collections.Generic;
+using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Part;
 using Robust.Shared.Interfaces.GameObjects;
 
@@ -10,6 +13,8 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
 
         IBodyPart? Part { get; set; }
 
+        IReadOnlyDictionary<Type, IMechanismBehavior> Behaviors { get; }
+
         /// <summary>
         ///     Professional description of the <see cref="IMechanism"/>.
         /// </summary>
@@ -55,6 +60,21 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
         /// </summary>
         BodyPartCompatibility Compatibility { get; set; }
 
+        /// <summary>
+        ///    Adds a behavior if it does not exist already.
+        /// </summary>
+        /// <typeparam name="T">The behavior type to add.</typeparam>
+        /// <returns>
+        ///     True if the behavior already existed, false if it had to be created.
+        /// </returns>
+        bool EnsureBehavior<T>(out T behavior) where T : IMechanismBehavior, new();
+
+        bool HasBehavior<T>() where T : IMechanismBehavior;
+
+        bool TryRemoveBehavior<T>() where T : IMechanismBehavior;
+
+        void Update(float frameTime);
+
         // TODO BODY Turn these into event listeners so they dont need to be exposed
         /// <summary>
         ///     Called when the containing <see cref="IBodyPart"/> is attached to a

Content.Shared/GameObjects/Components/Body/Mechanism/SharedMechanismComponent.cs

@@ -1,10 +1,14 @@
 #nullable enable
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Content.Shared.GameObjects.Components.Body.Behavior;
 using Content.Shared.GameObjects.Components.Body.Part;
+using Content.Shared.Interfaces;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 using Robust.Shared.Utility;
 
@@ -14,11 +18,12 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
     {
         public override string Name => "Mechanism";
 
-        private IBodyPart? _part;
         protected readonly Dictionary<int, object> OptionsCache = new Dictionary<int, object>();
         protected IBody? BodyCache;
         protected int IdHash;
         protected IEntity? PerformerCache;
+        private IBodyPart? _part;
+        private readonly Dictionary<Type, IMechanismBehavior> _behaviors = new Dictionary<Type, IMechanismBehavior>();
 
         public IBody? Body => Part?.Body;
 
@@ -61,6 +66,8 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             }
         }
 
+        public IReadOnlyDictionary<Type, IMechanismBehavior> Behaviors => _behaviors;
+
         public string Description { get; set; } = string.Empty;
 
         public string ExamineMessage { get; set; } = string.Empty;
@@ -98,6 +105,91 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             serializer.DataField(this, m => m.Size, "size", 1);
 
             serializer.DataField(this, m => m.Compatibility, "compatibility", BodyPartCompatibility.Universal);
+
+            var moduleManager = IoCManager.Resolve<IModuleManager>();
+
+            if (moduleManager.IsServerModule)
+            {
+                serializer.DataReadWriteFunction(
+                    "behaviors",
+                    null!,
+                    behaviors =>
+                    {
+                        if (behaviors == null)
+                        {
+                            return;
+                        }
+
+                        foreach (var behavior in behaviors)
+                        {
+                            var type = behavior.GetType();
+
+                            if (!_behaviors.TryAdd(type, behavior))
+                            {
+                                Logger.Warning($"Duplicate behavior in {nameof(SharedMechanismComponent)} for entity {Owner.Name}: {type}.");
+                                continue;
+                            }
+
+                            IoCManager.InjectDependencies(behavior);
+                        }
+                    },
+                    () => _behaviors.Values.ToList());
+            }
+        }
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            foreach (var behavior in _behaviors.Values)
+            {
+                behavior.Initialize(this);
+            }
+        }
+
+        protected override void Startup()
+        {
+            base.Startup();
+
+            foreach (var behavior in _behaviors.Values)
+            {
+                behavior.Startup();
+            }
+        }
+
+        public bool EnsureBehavior<T>(out T behavior) where T : IMechanismBehavior, new()
+        {
+            if (_behaviors.TryGetValue(typeof(T), out var rawBehavior))
+            {
+                behavior = (T) rawBehavior;
+                return true;
+            }
+
+            behavior = new T();
+            IoCManager.InjectDependencies(behavior);
+            _behaviors.Add(typeof(T), behavior);
+            behavior.Initialize(this);
+            behavior.Startup();
+
+            return false;
+        }
+
+        public bool HasBehavior<T>() where T : IMechanismBehavior
+        {
+            return _behaviors.ContainsKey(typeof(T));
+        }
+
+        public bool TryRemoveBehavior<T>() where T : IMechanismBehavior
+        {
+            return _behaviors.Remove(typeof(T));
+        }
+
+        public void Update(float frameTime)
+        {
+            foreach (var behavior in _behaviors.Values)
+            {
+                behavior.Update(frameTime);
+            }
         }
 
         public void AddedToBody(IBody body)
@@ -105,9 +197,7 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             DebugTools.AssertNotNull(Body);
             DebugTools.AssertNotNull(body);
 
-            OnAddedToBody(body);
+            foreach (var behavior in _behaviors.Values)
-
-            foreach (var behavior in Owner.GetAllComponents<IMechanismBehavior>())
             {
                 behavior.AddedToBody(body);
             }
@@ -119,9 +209,8 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             DebugTools.AssertNotNull(part);
 
             Owner.Transform.AttachParent(part.Owner);
-            OnAddedToPart(part);
 
-            foreach (var behavior in Owner.GetAllComponents<IMechanismBehavior>().ToArray())
+            foreach (var behavior in _behaviors.Values)
             {
                 behavior.AddedToPart(part);
             }
@@ -135,9 +224,8 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             DebugTools.AssertNotNull(part);
 
             Owner.Transform.AttachParent(part.Owner);
-            OnAddedToPartInBody(body, part);
 
-            foreach (var behavior in Owner.GetAllComponents<IMechanismBehavior>())
+            foreach (var behavior in _behaviors.Values)
             {
                 behavior.AddedToPartInBody(body, part);
             }
@@ -148,9 +236,7 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             DebugTools.AssertNull(Body);
             DebugTools.AssertNotNull(old);
 
-            OnRemovedFromBody(old);
+            foreach (var behavior in _behaviors.Values)
-
-            foreach (var behavior in Owner.GetAllComponents<IMechanismBehavior>())
             {
                 behavior.RemovedFromBody(old);
             }
@@ -162,9 +248,8 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             DebugTools.AssertNotNull(old);
 
             Owner.Transform.AttachToGridOrMap();
-            OnRemovedFromPart(old);
 
-            foreach (var behavior in Owner.GetAllComponents<IMechanismBehavior>())
+            foreach (var behavior in _behaviors.Values)
             {
                 behavior.RemovedFromPart(old);
             }
@@ -178,24 +263,11 @@ namespace Content.Shared.GameObjects.Components.Body.Mechanism
             DebugTools.AssertNotNull(oldPart);
 
             Owner.Transform.AttachToGridOrMap();
-            OnRemovedFromPartInBody(oldBody, oldPart);
 
-            foreach (var behavior in Owner.GetAllComponents<IMechanismBehavior>())
+            foreach (var behavior in _behaviors.Values)
             {
                 behavior.RemovedFromPartInBody(oldBody, oldPart);
             }
         }
-
-        protected virtual void OnAddedToBody(IBody body) { }
-
-        protected virtual void OnAddedToPart(IBodyPart part) { }
-
-        protected virtual void OnAddedToPartInBody(IBody body, IBodyPart part) { }
-
-        protected virtual void OnRemovedFromBody(IBody old) { }
-
-        protected virtual void OnRemovedFromPart(IBodyPart old) { }
-
-        protected virtual void OnRemovedFromPartInBody(IBody oldBody, IBodyPart oldPart) { }
     }
 }

Content.Shared/GameObjects/Components/Nutrition/SharedStomachComponent.cs

@@ -1,12 +0,0 @@
-using Robust.Shared.GameObjects;
-
-namespace Content.Shared.GameObjects.Components.Nutrition
-{
-    /// <summary>
-    /// Shared class for stomach components
-    /// </summary>
-    public class SharedStomachComponent : Component
-    {
-        public override string Name => "Stomach";
-    }
-}

Content.Shared/GameObjects/EntitySystems/MechanismSystem.cs

@@ -0,0 +1,21 @@
+using Content.Shared.GameObjects.Components.Body.Behavior;
+using Content.Shared.GameObjects.Components.Body.Mechanism;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects.Systems;
+
+namespace Content.Shared.GameObjects.EntitySystems
+{
+    [UsedImplicitly]
+    public class MechanismSystem : EntitySystem
+    {
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+
+            foreach (var mechanism in ComponentManager.EntityQuery<IMechanism>())
+            {
+                mechanism.Update(frameTime);
+            }
+        }
+    }
+}

Resources/Groups/groups.yml

@@ -119,6 +119,7 @@
   - attachtogrid
   - attachtograndparent
   - inrangeunoccluded
+  - hungry
   CanViewVar: true
   CanAdminPlace: true
   CanAdminMenu: true
@@ -231,6 +232,7 @@
   - attachtogrid
   - attachtograndparent
   - inrangeunoccluded
+  - hungry
   CanViewVar: true
   CanAdminPlace: true
   CanScript: true

Resources/Prototypes/Body/Mechanisms/basic_human_organs.yml

@@ -11,7 +11,8 @@
     durability: 10
     size: 1
     compatibility: Biological
-  - type: Brain
+    behaviors:
+    - !type:BrainBehavior {}
 
 - type: entity
   id: EyesHuman
@@ -40,7 +41,8 @@
     durability: 10
     size: 1
     compatibility: Biological
-  - type: Heart
+    behaviors:
+    - !type:HeartBehavior {}
 
 - type: entity
   id: LungsHuman
@@ -55,7 +57,8 @@
     durability: 13
     size: 1
     compatibility: Biological
-  - type: Lung
+    behaviors:
+    - !type:LungBehavior {}
 
 - type: entity
   id: StomachHuman
@@ -70,7 +73,10 @@
     durability: 13
     size: 1
     compatibility: Biological
-  - type: Stomach
+    behaviors:
+    - !type:StomachBehavior
+      max_volume: 250
+      digestionDelay: 20
 
 - type: entity
   id: LiverHuman

Resources/Prototypes/Entities/Mobs/Species/human.yml

@@ -23,9 +23,6 @@
     caps: AddTo, RemoveFrom, NoExamine
   - type: Bloodstream
     max_volume: 100
-  - type: Stomach
-    max_volume: 250
-    digestionDelay: 20
   # StatusEffects
   - type: Stunnable
   # Other