Remove IBody, IBodyPart, IMechanism and IMechanismBehavior (#4187)

* Remove IBody, IBodyPart, IMechanism and IMechanismBehavior interfaces

* Summary cleanup

Content.Client/Body/Components/BodyComponent.cs

@@ -5,7 +5,7 @@ using Robust.Shared.GameObjects;
 namespace Content.Client.Body.Components
 {
     [RegisterComponent]
-    [ComponentReference(typeof(IBody))]
+    [ComponentReference(typeof(SharedBodyComponent))]
     public class BodyComponent : SharedBodyComponent, IDraggable
     {
         bool IDraggable.CanStartDrag(StartDragDropEvent args)

Content.Client/Body/Components/BodyPartComponent.cs

@@ -5,7 +5,6 @@ namespace Content.Client.Body.Components
 {
     [RegisterComponent]
     [ComponentReference(typeof(SharedBodyPartComponent))]
-    [ComponentReference(typeof(IBodyPart))]
     public class BodyPartComponent : SharedBodyPartComponent
     {
     }

Content.Client/Body/Components/MechanismComponent.cs

@@ -5,6 +5,7 @@ namespace Content.Client.Body.Components
 {
     [RegisterComponent]
     [ComponentReference(typeof(SharedMechanismComponent))]
-    [ComponentReference(typeof(IMechanism))]
-    public class MechanismComponent : SharedMechanismComponent { }
+    public class MechanismComponent : SharedMechanismComponent
+    {
+    }
 }

Content.Client/Body/UI/BodyScannerDisplay.cs

@@ -15,9 +15,9 @@ namespace Content.Client.Body.UI
     public sealed class BodyScannerDisplay : SS14Window
     {
         private IEntity? _currentEntity;
-        private IBodyPart? _currentBodyPart;
+        private SharedBodyPartComponent? _currentBodyPart;
 
-        private IBody? CurrentBody => _currentEntity?.GetComponentOrNull<IBody>();
+        private SharedBodyComponent? CurrentBody => _currentEntity?.GetComponentOrNull<SharedBodyComponent>();
 
         public BodyScannerDisplay(BodyScannerBoundUserInterface owner)
         {
@@ -137,7 +137,7 @@ namespace Content.Client.Body.UI
             }
         }
 
-        private void UpdateBodyPartBox(IBodyPart part, string slotName)
+        private void UpdateBodyPartBox(SharedBodyPartComponent part, string slotName)
         {
             BodyPartLabel.Text = $"{Loc.GetString(slotName)}: {Loc.GetString(part.Owner.Name)}";
 
@@ -161,7 +161,7 @@ namespace Content.Client.Body.UI
             UpdateMechanismBox(_currentBodyPart?.Mechanisms.ElementAt(args.ItemIndex));
         }
 
-        private void UpdateMechanismBox(IMechanism? mechanism)
+        private void UpdateMechanismBox(SharedMechanismComponent? mechanism)
         {
             // TODO BODY Improve UI
             if (mechanism == null)

Content.Client/CharacterAppearance/HumanoidAppearanceComponent.cs

@@ -52,7 +52,7 @@ namespace Content.Client.CharacterAppearance
                 return;
             }
 
-            if (Owner.TryGetComponent(out IBody? body))
+            if (Owner.TryGetComponent(out SharedBodyComponent? body))
             {
                 foreach (var (part, _) in body.Parts)
                 {
@@ -115,7 +115,7 @@ namespace Content.Client.CharacterAppearance
                 return;
             }
 
-            if (!args.Part.Owner.TryGetComponent(out SpriteComponent? partSprite))
+            if (!args.Part.Owner.HasComponent<SpriteComponent>())
             {
                 return;
             }
@@ -138,7 +138,7 @@ namespace Content.Client.CharacterAppearance
                 return;
             }
 
-            if (!args.Part.Owner.TryGetComponent(out SpriteComponent? partSprite))
+            if (!args.Part.Owner.HasComponent<SpriteComponent>())
             {
                 return;
             }

Content.Client/Commands/HideMechanismsCommand.cs

@@ -17,7 +17,7 @@ namespace Content.Client.Commands
         public void Execute(IConsoleShell shell, string argStr, string[] args)
         {
             var componentManager = IoCManager.Resolve<IComponentManager>();
-            var mechanisms = componentManager.EntityQuery<IMechanism>(true);
+            var mechanisms = componentManager.EntityQuery<SharedMechanismComponent>(true);
 
             foreach (var mechanism in mechanisms)
             {

Content.Client/Commands/ShowMechanismsCommand.cs

@@ -19,7 +19,7 @@ namespace Content.Client.Commands
         public void Execute(IConsoleShell shell, string argStr, string[] args)
         {
             var componentManager = IoCManager.Resolve<IComponentManager>();
-            var mechanisms = componentManager.EntityQuery<IMechanism>(true);
+            var mechanisms = componentManager.EntityQuery<SharedMechanismComponent>(true);
 
             foreach (var mechanism in mechanisms)
             {

Content.IntegrationTests/Tests/Body/LegTest.cs

@@ -46,7 +46,7 @@ namespace Content.IntegrationTests.Tests.Body
                 var entityManager = IoCManager.Resolve<IEntityManager>();
                 var human = entityManager.SpawnEntity("HumanBodyAndAppearanceDummy", new MapCoordinates(Vector2.Zero, mapId));
 
-                Assert.That(human.TryGetComponent(out IBody body));
+                Assert.That(human.TryGetComponent(out SharedBodyComponent body));
                 Assert.That(human.TryGetComponent(out appearance));
 
                 Assert.That(!appearance.TryGetData(RotationVisuals.RotationState, out RotationState _));

Content.IntegrationTests/Tests/Body/LungTest.cs

@@ -63,7 +63,7 @@ namespace Content.IntegrationTests.Tests.Body
 
                 var human = entityManager.SpawnEntity("HumanBodyAndBloodstreamDummy", new MapCoordinates(Vector2.Zero, mapId));
 
-                Assert.That(human.TryGetComponent(out IBody body));
+                Assert.That(human.TryGetComponent(out SharedBodyComponent body));
                 Assert.That(body.TryGetMechanismBehaviors(out List<LungBehavior> lungs));
                 Assert.That(lungs.Count, Is.EqualTo(1));
                 Assert.That(human.TryGetComponent(out BloodstreamComponent bloodstream));
@@ -167,7 +167,7 @@ namespace Content.IntegrationTests.Tests.Body
                 var coordinates = new EntityCoordinates(grid.GridEntityId, center);
                 human = entityManager.SpawnEntity("HumanBodyAndBloodstreamDummy", coordinates);
 
-                Assert.True(human.TryGetComponent(out IBody body));
+                Assert.True(human.TryGetComponent(out SharedBodyComponent body));
                 Assert.True(body.HasMechanismBehavior<LungBehavior>());
                 Assert.True(human.TryGetComponent(out metabolism));
                 Assert.False(metabolism.Suffocating);

Content.IntegrationTests/Tests/Body/MechanismBehaviorEventsTest.cs

@@ -59,42 +59,42 @@ namespace Content.IntegrationTests.Tests.Body
                 ResetRemoved();
             }
 
-            protected override void OnAddedToBody(IBody body)
+            protected override void OnAddedToBody(SharedBodyComponent body)
             {
                 base.OnAddedToBody(body);
 
                 WasAddedToBody = true;
             }
 
-            protected override void OnAddedToPart(IBodyPart part)
+            protected override void OnAddedToPart(SharedBodyPartComponent part)
             {
                 base.OnAddedToPart(part);
 
                 WasAddedToPart = true;
             }
 
-            protected override void OnAddedToPartInBody(IBody body, IBodyPart part)
+            protected override void OnAddedToPartInBody(SharedBodyComponent body, SharedBodyPartComponent part)
             {
                 base.OnAddedToPartInBody(body, part);
 
                 WasAddedToPartInBody = true;
             }
 
-            protected override void OnRemovedFromBody(IBody old)
+            protected override void OnRemovedFromBody(SharedBodyComponent old)
             {
                 base.OnRemovedFromBody(old);
 
                 WasRemovedFromBody = true;
             }
 
-            protected override void OnRemovedFromPart(IBodyPart old)
+            protected override void OnRemovedFromPart(SharedBodyPartComponent old)
             {
                 base.OnRemovedFromPart(old);
 
                 WasRemovedFromPart = true;
             }
 
-            protected override void OnRemovedFromPartInBody(IBody oldBody, IBodyPart oldPart)
+            protected override void OnRemovedFromPartInBody(SharedBodyComponent oldBody, SharedBodyPartComponent oldPart)
             {
                 base.OnRemovedFromPartInBody(oldBody, oldPart);
 
@@ -128,7 +128,7 @@ namespace Content.IntegrationTests.Tests.Body
                 var entityManager = IoCManager.Resolve<IEntityManager>();
                 var human = entityManager.SpawnEntity("HumanBodyDummy", new MapCoordinates(Vector2.Zero, mapId));
 
-                Assert.That(human.TryGetComponent(out IBody? body));
+                Assert.That(human.TryGetComponent(out SharedBodyComponent? body));
                 Assert.NotNull(body);
 
                 var centerPart = body!.CenterPart;

Content.IntegrationTests/Tests/Buckle/BuckleTest.cs

@@ -213,7 +213,7 @@ namespace Content.IntegrationTests.Tests.Buckle
             IEntity human = null;
             BuckleComponent buckle = null;
             HandsComponent hands = null;
-            IBody body = null;
+            SharedBodyComponent body = null;
 
             await server.WaitIdleAsync();
 

Content.IntegrationTests/Tests/GameObjects/Components/ActionBlocking/HandCuffTest.cs

@@ -69,7 +69,7 @@ namespace Content.IntegrationTests.Tests.GameObjects.Components.ActionBlocking
                 // Test for components existing
                 Assert.True(human.TryGetComponent(out cuffed!), $"Human has no {nameof(CuffableComponent)}");
                 Assert.True(human.TryGetComponent(out hands!), $"Human has no {nameof(HandsComponent)}");
-                Assert.True(human.TryGetComponent(out IBody _), $"Human has no {nameof(IBody)}");
+                Assert.True(human.TryGetComponent(out SharedBodyComponent _), $"Human has no {nameof(SharedBodyComponent)}");
                 Assert.True(cuffs.TryGetComponent(out HandcuffComponent _), $"Handcuff has no {nameof(HandcuffComponent)}");
                 Assert.True(secondCuffs.TryGetComponent(out HandcuffComponent _), $"Second handcuffs has no {nameof(HandcuffComponent)}");
 

Content.Server/AI/WorldState/States/Mobs/NearbyBodiesState.cs

@@ -21,7 +21,7 @@ namespace Content.Server.AI.WorldState.States.Mobs
                 return result;
             }
 
-            foreach (var entity in Visibility.GetEntitiesInRange(Owner.Transform.Coordinates, typeof(IBody), controller.VisionRadius))
+            foreach (var entity in Visibility.GetEntitiesInRange(Owner.Transform.Coordinates, typeof(SharedBodyComponent), controller.VisionRadius))
             {
                 if (entity == Owner) continue;
                 result.Add(entity);

Content.Server/Body/Behavior/BrainBehavior.cs

@@ -11,42 +11,42 @@ namespace Content.Server.Body.Behavior
 {
     public class BrainBehavior : MechanismBehavior
     {
-        protected override void OnAddedToBody(IBody body)
+        protected override void OnAddedToBody(SharedBodyComponent body)
         {
             base.OnAddedToBody(body);
 
             HandleMind(body.Owner, Owner);
         }
 
-        protected override void OnAddedToPart(IBodyPart part)
+        protected override void OnAddedToPart(SharedBodyPartComponent part)
         {
             base.OnAddedToPart(part);
 
             HandleMind(part.Owner, Owner);
         }
 
-        protected override void OnAddedToPartInBody(IBody body, IBodyPart part)
+        protected override void OnAddedToPartInBody(SharedBodyComponent body, SharedBodyPartComponent part)
         {
             base.OnAddedToPartInBody(body, part);
 
             HandleMind(body.Owner, Owner);
         }
 
-        protected override void OnRemovedFromBody(IBody old)
+        protected override void OnRemovedFromBody(SharedBodyComponent old)
         {
             base.OnRemovedFromBody(old);
 
             HandleMind(Part!.Owner, old.Owner);
         }
 
-        protected override void OnRemovedFromPart(IBodyPart old)
+        protected override void OnRemovedFromPart(SharedBodyPartComponent old)
         {
             base.OnRemovedFromPart(old);
 
             HandleMind(Owner, old.Owner);
         }
 
-        protected override void OnRemovedFromPartInBody(IBody oldBody, IBodyPart oldPart)
+        protected override void OnRemovedFromPartInBody(SharedBodyComponent oldBody, SharedBodyPartComponent oldPart)
         {
             base.OnRemovedFromPartInBody(oldBody, oldPart);
 

Content.Server/Body/Behavior/LungBehavior.cs

@@ -48,7 +48,7 @@ namespace Content.Server.Body.Behavior
             IoCManager.InjectDependencies(this);
         }
 
-        protected override void OnAddedToBody(IBody body)
+        protected override void OnAddedToBody(SharedBodyComponent body)
         {
             base.OnAddedToBody(body);
             Inhale(CycleDelay);

Content.Server/Body/Behavior/MechanismBehavior.cs

@@ -8,22 +8,24 @@ using Robust.Shared.Utility;
 
 namespace Content.Server.Body.Behavior
 {
-    public abstract class MechanismBehavior : IMechanismBehavior
+    public abstract class MechanismBehavior : SharedMechanismBehavior
     {
-        public IBody? Body => Part?.Body;
+        private SharedMechanismComponent _parent = default!;
 
-        public IBodyPart? Part => Parent.Part;
+        public override SharedBodyComponent? Body => Part?.Body;
 
-        public IMechanism Parent { get; private set; } = default!;
+        public override SharedBodyPartComponent? Part => Parent.Part;
 
-        public IEntity Owner => Parent.Owner;
+        public override SharedMechanismComponent Parent => _parent;
 
-        public virtual void Initialize(IMechanism parent)
+        public override IEntity Owner => Parent.Owner;
+
+        public override void Initialize(SharedMechanismComponent parent)
         {
-            Parent = parent;
+            _parent = parent;
         }
 
-        public virtual void Startup()
+        public override void Startup()
         {
             if (Part == null)
             {
@@ -40,7 +42,9 @@ namespace Content.Server.Body.Behavior
             }
         }
 
-        public void AddedToBody(IBody body)
+        public override void Update(float frameTime) { }
+
+        public override void AddedToBody(SharedBodyComponent body)
         {
             DebugTools.AssertNotNull(Body);
             DebugTools.AssertNotNull(body);
@@ -48,7 +52,7 @@ namespace Content.Server.Body.Behavior
             OnAddedToBody(body);
         }
 
-        public void AddedToPart(IBodyPart part)
+        public override void AddedToPart(SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(Part);
             DebugTools.AssertNotNull(part);
@@ -56,7 +60,7 @@ namespace Content.Server.Body.Behavior
             OnAddedToPart(part);
         }
 
-        public void AddedToPartInBody(IBody body, IBodyPart part)
+        public override void AddedToPartInBody(SharedBodyComponent body, SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(Body);
             DebugTools.AssertNotNull(body);
@@ -66,7 +70,7 @@ namespace Content.Server.Body.Behavior
             OnAddedToPartInBody(body, part);
         }
 
-        public void RemovedFromBody(IBody old)
+        public override void RemovedFromBody(SharedBodyComponent old)
         {
             DebugTools.AssertNull(Body);
             DebugTools.AssertNotNull(old);
@@ -74,7 +78,7 @@ namespace Content.Server.Body.Behavior
             OnRemovedFromBody(old);
         }
 
-        public void RemovedFromPart(IBodyPart old)
+        public override void RemovedFromPart(SharedBodyPartComponent old)
         {
             DebugTools.AssertNull(Part);
             DebugTools.AssertNotNull(old);
@@ -82,7 +86,7 @@ namespace Content.Server.Body.Behavior
             OnRemovedFromPart(old);
         }
 
-        public void RemovedFromPartInBody(IBody oldBody, IBodyPart oldPart)
+        public override void RemovedFromPartInBody(SharedBodyComponent oldBody, SharedBodyPartComponent oldPart)
         {
             DebugTools.AssertNull(Body);
             DebugTools.AssertNull(Part);
@@ -92,18 +96,16 @@ namespace Content.Server.Body.Behavior
             OnRemovedFromPartInBody(oldBody, oldPart);
         }
 
-        protected virtual void OnAddedToBody(IBody body) { }
+        protected virtual void OnAddedToBody(SharedBodyComponent body) { }
 
-        protected virtual void OnAddedToPart(IBodyPart part) { }
+        protected virtual void OnAddedToPart(SharedBodyPartComponent part) { }
 
-        protected virtual void OnAddedToPartInBody(IBody body, IBodyPart part) { }
+        protected virtual void OnAddedToPartInBody(SharedBodyComponent body, SharedBodyPartComponent part) { }
 
-        protected virtual void OnRemovedFromBody(IBody old) { }
+        protected virtual void OnRemovedFromBody(SharedBodyComponent old) { }
 
-        protected virtual void OnRemovedFromPart(IBodyPart old) { }
+        protected virtual void OnRemovedFromPart(SharedBodyPartComponent old) { }
 
-        protected virtual void OnRemovedFromPartInBody(IBody oldBody, IBodyPart oldPart) { }
-
-        public virtual void Update(float frameTime) { }
+        protected virtual void OnRemovedFromPartInBody(SharedBodyComponent oldBody, SharedBodyPartComponent oldPart) { }
     }
 }

Content.Server/Body/Behavior/MechanismExtensions.cs

@@ -1,74 +0,0 @@
-#nullable enable
-using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
-using System.Linq;
-using Content.Shared.Body.Behavior;
-using Content.Shared.Body.Components;
-using Content.Shared.Body.Part;
-
-namespace Content.Server.Body.Behavior
-{
-    public static class MechanismExtensions
-    {
-        public static bool HasMechanismBehavior<T>(this IBody body) where T : IMechanismBehavior
-        {
-            return body.Parts.Any(p => p.Key.HasMechanismBehavior<T>());
-        }
-
-        public static bool HasMechanismBehavior<T>(this IBodyPart part) where T : IMechanismBehavior
-        {
-            return part.Mechanisms.Any(m => m.HasBehavior<T>());
-        }
-
-        public static IEnumerable<IMechanismBehavior> GetMechanismBehaviors(this IBody body)
-        {
-            foreach (var (part, _) in body.Parts)
-            foreach (var mechanism in part.Mechanisms)
-            foreach (var behavior in mechanism.Behaviors.Values)
-            {
-                yield return behavior;
-            }
-        }
-
-        public static bool TryGetMechanismBehaviors(this IBody body,
-            [NotNullWhen(true)] out List<IMechanismBehavior>? behaviors)
-        {
-            behaviors = body.GetMechanismBehaviors().ToList();
-
-            if (behaviors.Count == 0)
-            {
-                behaviors = null;
-                return false;
-            }
-
-            return true;
-        }
-
-        public static IEnumerable<T> GetMechanismBehaviors<T>(this IBody body) where T : class, IMechanismBehavior
-        {
-            foreach (var (part, _) in body.Parts)
-            foreach (var mechanism in part.Mechanisms)
-            foreach (var behavior in mechanism.Behaviors.Values)
-            {
-                if (behavior is T tBehavior)
-                {
-                    yield return tBehavior;
-                }
-            }
-        }
-
-        public static bool TryGetMechanismBehaviors<T>(this IBody entity, [NotNullWhen(true)] out List<T>? behaviors)
-            where T : class, IMechanismBehavior
-        {
-            behaviors = entity.GetMechanismBehaviors<T>().ToList();
-
-            if (behaviors.Count == 0)
-            {
-                behaviors = null;
-                return false;
-            }
-
-            return true;
-        }
-    }
-}

Content.Server/Body/BodyComponent.cs

@@ -21,27 +21,26 @@ namespace Content.Server.Body
 {
     [RegisterComponent]
     [ComponentReference(typeof(SharedBodyComponent))]
-    [ComponentReference(typeof(IBody))]
     [ComponentReference(typeof(IGhostOnMove))]
     public class BodyComponent : SharedBodyComponent, IRelayMoveInput, IGhostOnMove
     {
         private Container _partContainer = default!;
         [Dependency] private readonly IGameTicker _gameTicker = default!;
 
-        protected override bool CanAddPart(string slotId, IBodyPart part)
+        protected override bool CanAddPart(string slotId, SharedBodyPartComponent part)
         {
             return base.CanAddPart(slotId, part) &&
                    _partContainer.CanInsert(part.Owner);
         }
 
-        protected override void OnAddPart(BodyPartSlot slot, IBodyPart part)
+        protected override void OnAddPart(BodyPartSlot slot, SharedBodyPartComponent part)
         {
             base.OnAddPart(slot, part);
 
             _partContainer.Insert(part.Owner);
         }
 
-        protected override void OnRemovePart(BodyPartSlot slot, IBodyPart part)
+        protected override void OnRemovePart(BodyPartSlot slot, SharedBodyPartComponent part)
         {
             base.OnRemovePart(slot, part);
 
@@ -64,9 +63,9 @@ namespace Content.Server.Body
                     // a crash within the character preview menu in the lobby
                     var entity = Owner.EntityManager.SpawnEntity(preset.PartIDs[slot.Id], Owner.Transform.MapPosition);
 
-                    if (!entity.TryGetComponent(out IBodyPart? part))
+                    if (!entity.TryGetComponent(out SharedBodyPartComponent? part))
                     {
-                        Logger.Error($"Entity {slot.Id} does not have a {nameof(IBodyPart)} component.");
+                        Logger.Error($"Entity {slot.Id} does not have a {nameof(SharedBodyPartComponent)} component.");
                         continue;
                     }
 

Content.Server/Body/BodyManagerHealthChangeParams.cs

@@ -3,11 +3,13 @@ using Content.Shared.Damage;
 
 namespace Content.Server.Body
 {
+    // TODO BODY: Remove and pretend it never existed
     public interface IBodyHealthChangeParams
     {
         BodyPartType Part { get; }
     }
 
+    // TODO BODY: Remove and pretend it never existed
     public class BodyDamageChangeParams : DamageChangeParams, IBodyHealthChangeParams
     {
         public BodyDamageChangeParams(BodyPartType part)

Content.Server/Body/Commands/AddHandCommand.cs

@@ -122,7 +122,7 @@ namespace Content.Server.Body.Commands
                 }
             }
 
-            if (!entity.TryGetComponent(out IBody? body))
+            if (!entity.TryGetComponent(out SharedBodyComponent? body))
             {
                 var random = IoCManager.Resolve<IRobustRandom>();
                 var text = $"You have no body{(random.Prob(0.2f) ? " and you must scream." : ".")}";
@@ -131,9 +131,9 @@ namespace Content.Server.Body.Commands
                 return;
             }
 
-            if (!hand.TryGetComponent(out IBodyPart? part))
+            if (!hand.TryGetComponent(out SharedBodyPartComponent? part))
             {
-                shell.WriteLine($"Hand entity {hand} does not have a {nameof(IBodyPart)} component.");
+                shell.WriteLine($"Hand entity {hand} does not have a {nameof(SharedBodyPartComponent)} component.");
                 return;
             }
 

Content.Server/Body/Commands/AttachBodyPartCommand.cs

@@ -76,9 +76,9 @@ namespace Content.Server.Body.Commands
                     return;
             }
 
-            if (!entity.TryGetComponent(out IBody? body))
+            if (!entity.TryGetComponent(out SharedBodyComponent? body))
             {
-                shell.WriteLine($"Entity {entity.Name} with uid {entity.Uid} does not have a {nameof(IBody)} component.");
+                shell.WriteLine($"Entity {entity.Name} with uid {entity.Uid} does not have a {nameof(SharedBodyComponent)} component.");
                 return;
             }
 
@@ -88,9 +88,9 @@ namespace Content.Server.Body.Commands
                 return;
             }
 
-            if (!partEntity.TryGetComponent(out IBodyPart? part))
+            if (!partEntity.TryGetComponent(out SharedBodyPartComponent? part))
             {
-                shell.WriteLine($"Entity {partEntity.Name} with uid {args[0]} does not have a {nameof(IBodyPart)} component.");
+                shell.WriteLine($"Entity {partEntity.Name} with uid {args[0]} does not have a {nameof(SharedBodyPartComponent)} component.");
                 return;
             }
 

Content.Server/Body/Commands/DestroyMechanismCommand.cs

@@ -37,7 +37,7 @@ namespace Content.Server.Body.Commands
                 return;
             }
 
-            if (!player.AttachedEntity.TryGetComponent(out IBody? body))
+            if (!player.AttachedEntity.TryGetComponent(out SharedBodyComponent? body))
             {
                 var random = IoCManager.Resolve<IRobustRandom>();
                 var text = $"You have no body{(random.Prob(0.2f) ? " and you must scream." : ".")}";

Content.Server/Body/Commands/RemoveHandCommand.cs

@@ -33,7 +33,7 @@ namespace Content.Server.Body.Commands
                 return;
             }
 
-            if (!player.AttachedEntity.TryGetComponent(out IBody? body))
+            if (!player.AttachedEntity.TryGetComponent(out SharedBodyComponent? body))
             {
                 var random = IoCManager.Resolve<IRobustRandom>();
                 var text = $"You have no body{(random.Prob(0.2f) ? " and you must scream." : ".")}";

Content.Server/Body/Mechanism/MechanismComponent.cs

@@ -20,7 +20,6 @@ namespace Content.Server.Body.Mechanism
 {
     [RegisterComponent]
     [ComponentReference(typeof(SharedMechanismComponent))]
-    [ComponentReference(typeof(IMechanism))]
     public class MechanismComponent : SharedMechanismComponent, IAfterInteract
     {
         [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(SurgeryUIKey.Key);
@@ -47,11 +46,11 @@ namespace Content.Server.Body.Mechanism
             PerformerCache = null;
             BodyCache = null;
 
-            if (eventArgs.Target.TryGetComponent(out IBody? body))
+            if (eventArgs.Target.TryGetComponent(out SharedBodyComponent? body))
             {
                 SendBodyPartListToUser(eventArgs, body);
             }
-            else if (eventArgs.Target.TryGetComponent<IBodyPart>(out var part))
+            else if (eventArgs.Target.TryGetComponent<SharedBodyPartComponent>(out var part))
             {
                 DebugTools.AssertNotNull(part);
 
@@ -64,7 +63,7 @@ namespace Content.Server.Body.Mechanism
             return true;
         }
 
-        private void SendBodyPartListToUser(AfterInteractEventArgs eventArgs, IBody body)
+        private void SendBodyPartListToUser(AfterInteractEventArgs eventArgs, SharedBodyComponent body)
         {
             // Create dictionary to send to client (text to be shown : data sent back if selected)
             var toSend = new Dictionary<string, int>();
@@ -120,7 +119,7 @@ namespace Content.Server.Body.Mechanism
                 return;
             }
 
-            var target = (IBodyPart) targetObject;
+            var target = (SharedBodyPartComponent) targetObject;
             var message = target.TryAddMechanism(this)
                 ? Loc.GetString("You jam {0:theName} inside {1:them}.", Owner, PerformerCache)
                 : Loc.GetString("You can't fit it in!");

Content.Server/Body/Part/BodyPartComponent.cs

@@ -25,31 +25,30 @@ namespace Content.Server.Body.Part
 {
     [RegisterComponent]
     [ComponentReference(typeof(SharedBodyPartComponent))]
-    [ComponentReference(typeof(IBodyPart))]
     public class BodyPartComponent : SharedBodyPartComponent, IAfterInteract
     {
         private readonly Dictionary<int, object> _optionsCache = new();
-        private IBody? _owningBodyCache;
+        private SharedBodyComponent? _owningBodyCache;
         private int _idHash;
         private IEntity? _surgeonCache;
         private Container _mechanismContainer = default!;
 
         [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(SurgeryUIKey.Key);
 
-        public override bool CanAddMechanism(IMechanism mechanism)
+        public override bool CanAddMechanism(SharedMechanismComponent mechanism)
         {
             return base.CanAddMechanism(mechanism) &&
                    _mechanismContainer.CanInsert(mechanism.Owner);
         }
 
-        protected override void OnAddMechanism(IMechanism mechanism)
+        protected override void OnAddMechanism(SharedMechanismComponent mechanism)
         {
             base.OnAddMechanism(mechanism);
 
             _mechanismContainer.Insert(mechanism.Owner);
         }
 
-        protected override void OnRemoveMechanism(IMechanism mechanism)
+        protected override void OnRemoveMechanism(SharedMechanismComponent mechanism)
         {
             base.OnRemoveMechanism(mechanism);
 
@@ -70,9 +69,9 @@ namespace Content.Server.Body.Part
             {
                 var entity = Owner.EntityManager.SpawnEntity(mechanismId, Owner.Transform.MapPosition);
 
-                if (!entity.TryGetComponent(out IMechanism? mechanism))
+                if (!entity.TryGetComponent(out SharedMechanismComponent? mechanism))
                 {
-                    Logger.Error($"Entity {mechanismId} does not have a {nameof(IMechanism)} component.");
+                    Logger.Error($"Entity {mechanismId} does not have a {nameof(SharedMechanismComponent)} component.");
                     continue;
                 }
 
@@ -108,7 +107,7 @@ namespace Content.Server.Body.Part
             _surgeonCache = null;
             _owningBodyCache = null;
 
-            if (eventArgs.Target.TryGetComponent(out IBody? body))
+            if (eventArgs.Target.TryGetComponent(out SharedBodyComponent? body))
             {
                 SendSlots(eventArgs, body);
             }
@@ -116,7 +115,7 @@ namespace Content.Server.Body.Part
             return true;
         }
 
-        private void SendSlots(AfterInteractEventArgs eventArgs, IBody body)
+        private void SendSlots(AfterInteractEventArgs eventArgs, SharedBodyComponent body)
         {
             // Create dictionary to send to client (text to be shown : data sent back if selected)
             var toSend = new Dictionary<string, int>();
@@ -246,7 +245,7 @@ namespace Content.Server.Body.Part
                     return;
                 }
 
-                if (!user.TryGetComponent(out IBody? body))
+                if (!user.TryGetComponent(out SharedBodyComponent? body))
                 {
                     return;
                 }
@@ -262,7 +261,7 @@ namespace Content.Server.Body.Part
 
             protected override void Activate(IEntity user, BodyPartComponent component)
             {
-                if (!user.TryGetComponent(out IBody? body))
+                if (!user.TryGetComponent(out SharedBodyComponent? body))
                 {
                     return;
                 }

Content.Server/Body/Scanner/BodyScannerComponent.cs

@@ -30,7 +30,7 @@ namespace Content.Server.Body.Scanner
                 return;
             }
 
-            if (session.AttachedEntity.TryGetComponent(out IBody? body))
+            if (session.AttachedEntity.TryGetComponent(out SharedBodyComponent? body))
             {
                 var state = InterfaceState(body);
                 UserInterface?.SetState(state);
@@ -56,7 +56,7 @@ namespace Content.Server.Body.Scanner
         /// <summary>
         ///     Copy BodyTemplate and BodyPart data into a common data class that the client can read.
         /// </summary>
-        private BodyScannerUIState InterfaceState(IBody body)
+        private BodyScannerUIState InterfaceState(SharedBodyComponent body)
         {
             return new(body.Owner.Uid);
         }

Content.Server/Body/Surgery/BiologicalSurgeryDataComponent.cs

@@ -25,7 +25,7 @@ namespace Content.Server.Body.Surgery
     {
         public override string Name => "BiologicalSurgeryData";
 
-        private readonly HashSet<IMechanism> _disconnectedOrgans = new();
+        private readonly HashSet<SharedMechanismComponent> _disconnectedOrgans = new();
 
         private bool SkinOpened { get; set; }
 
@@ -33,11 +33,11 @@ namespace Content.Server.Body.Surgery
 
         private bool VesselsClamped { get; set; }
 
-        public IBodyPart? Parent => Owner.GetComponentOrNull<IBodyPart>();
+        public SharedBodyPartComponent? Parent => Owner.GetComponentOrNull<SharedBodyPartComponent>();
 
         public BodyPartType? ParentType => Parent?.PartType;
 
-        private void AddDisconnectedOrgan(IMechanism mechanism)
+        private void AddDisconnectedOrgan(SharedMechanismComponent mechanism)
         {
             if (_disconnectedOrgans.Add(mechanism))
             {
@@ -45,7 +45,7 @@ namespace Content.Server.Body.Surgery
             }
         }
 
-        private void RemoveDisconnectedOrgan(IMechanism mechanism)
+        private void RemoveDisconnectedOrgan(SharedMechanismComponent mechanism)
         {
             if (_disconnectedOrgans.Remove(mechanism))
             {
@@ -117,7 +117,7 @@ namespace Content.Server.Body.Surgery
             return toReturn.ToString();
         }
 
-        public bool CanAddMechanism(IMechanism mechanism)
+        public bool CanAddMechanism(SharedMechanismComponent mechanism)
         {
             return Parent != null &&
                    SkinOpened &&
@@ -125,7 +125,7 @@ namespace Content.Server.Body.Surgery
                    SkinRetracted;
         }
 
-        public bool CanAttachBodyPart(IBodyPart part)
+        public bool CanAttachBodyPart(SharedBodyPartComponent part)
         {
             return Parent != null;
             // TODO BODY if a part is disconnected, you should have to do some surgery to allow another body part to be attached.
@@ -276,7 +276,7 @@ namespace Content.Server.Body.Surgery
             if (Parent == null) return;
             if (Parent.Mechanisms.Count <= 0) return;
 
-            var toSend = new List<IMechanism>();
+            var toSend = new List<SharedMechanismComponent>();
             foreach (var mechanism in Parent.Mechanisms)
             {
                 if (!_disconnectedOrgans.Contains(mechanism))
@@ -291,7 +291,7 @@ namespace Content.Server.Body.Surgery
             }
         }
 
-        private async void LoosenOrganSurgeryCallback(IMechanism? target, IBodyPartContainer container, ISurgeon surgeon,
+        private async void LoosenOrganSurgeryCallback(SharedMechanismComponent? target, IBodyPartContainer container, ISurgeon surgeon,
             IEntity performer)
         {
             if (Parent == null || target == null || !Parent.Mechanisms.Contains(target))
@@ -332,7 +332,7 @@ namespace Content.Server.Body.Surgery
             }
         }
 
-        private async void RemoveOrganSurgeryCallback(IMechanism? target, IBodyPartContainer container, ISurgeon surgeon,
+        private async void RemoveOrganSurgeryCallback(SharedMechanismComponent? target, IBodyPartContainer container, ISurgeon surgeon,
             IEntity performer)
         {
             if (Parent == null || target == null || !Parent.Mechanisms.Contains(target))
@@ -359,7 +359,7 @@ namespace Content.Server.Body.Surgery
         private async void RemoveBodyPartSurgery(IBodyPartContainer container, ISurgeon surgeon, IEntity performer)
         {
             if (Parent == null) return;
-            if (container is not IBody body) return;
+            if (container is not SharedBodyComponent body) return;
 
             performer.PopupMessage(Loc.GetString("Sawing off the limb!"));
 

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

@@ -47,7 +47,7 @@ namespace Content.Server.Body.Surgery.Components
 
         [ViewVariables] private BoundUserInterface? UserInterface => Owner.GetUIOrNull(SurgeryUIKey.Key);
 
-        public IBody? BodyCache { get; private set; }
+        public SharedBodyComponent? BodyCache { get; private set; }
 
         public IEntity? PerformerCache { get; private set; }
 
@@ -66,7 +66,7 @@ namespace Content.Server.Body.Surgery.Components
             CloseAllSurgeryUIs();
 
             // Attempt surgery on a body by sending a list of operable parts for the client to choose from
-            if (eventArgs.Target.TryGetComponent(out IBody? body))
+            if (eventArgs.Target.TryGetComponent(out SharedBodyComponent? body))
             {
                 // Create dictionary to send to client (text to be shown : data sent back if selected)
                 var toSend = new Dictionary<string, int>();
@@ -93,7 +93,7 @@ namespace Content.Server.Body.Surgery.Components
                     NotUsefulPopup();
                 }
             }
-            else if (eventArgs.Target.TryGetComponent<IBodyPart>(out var part))
+            else if (eventArgs.Target.TryGetComponent<SharedBodyPartComponent>(out var part))
             {
                 // Attempt surgery on a DroppedBodyPart - there's only one possible target so no need for selection UI
                 PerformerCache = eventArgs.User;
@@ -113,7 +113,7 @@ namespace Content.Server.Body.Surgery.Components
                 }
 
                 // Log error if the surgery fails somehow.
-                Logger.Debug($"Error when trying to perform surgery on ${nameof(IBodyPart)} {eventArgs.User.Name}");
+                Logger.Debug($"Error when trying to perform surgery on ${nameof(SharedBodyPartComponent)} {eventArgs.User.Name}");
                 throw new InvalidOperationException();
             }
 
@@ -122,7 +122,7 @@ namespace Content.Server.Body.Surgery.Components
 
         public float BaseOperationTime { get => _baseOperateTime; set => _baseOperateTime = value; }
 
-        public void RequestMechanism(IEnumerable<IMechanism> options, ISurgeon.MechanismRequestCallback callback)
+        public void RequestMechanism(IEnumerable<SharedMechanismComponent> options, ISurgeon.MechanismRequestCallback callback)
         {
             var toSend = new Dictionary<string, int>();
             foreach (var mechanism in options)
@@ -211,7 +211,7 @@ namespace Content.Server.Body.Surgery.Components
 
         /// <summary>
         ///     Called after the client chooses from a list of possible
-        ///     <see cref="IBodyPart"/> that can be operated on.
+        ///     <see cref="SharedBodyPartComponent"/> that can be operated on.
         /// </summary>
         private void HandleReceiveBodyPart(int key)
         {
@@ -230,7 +230,7 @@ namespace Content.Server.Body.Surgery.Components
                 return;
             }
 
-            var target = (IBodyPart) targetObject!;
+            var target = (SharedBodyPartComponent) targetObject!;
 
             // TODO BODY Reconsider
             if (!target.AttemptSurgery(_surgeryType, BodyCache, this, PerformerCache))
@@ -241,7 +241,7 @@ namespace Content.Server.Body.Surgery.Components
 
         /// <summary>
         ///     Called after the client chooses from a list of possible
-        ///     <see cref="IMechanism"/> to choose from.
+        ///     <see cref="SharedMechanismComponent"/> to choose from.
         /// </summary>
         private void HandleReceiveMechanism(int key)
         {

Content.Server/CharacterAppearance/Components/HumanoidAppearanceComponent.cs

@@ -16,7 +16,7 @@ namespace Content.Server.CharacterAppearance.Components
             {
                 base.Appearance = value;
 
-                if (Owner.TryGetComponent(out IBody? body))
+                if (Owner.TryGetComponent(out SharedBodyComponent? body))
                 {
                     foreach (var (part, _) in body.Parts)
                     {
@@ -35,7 +35,7 @@ namespace Content.Server.CharacterAppearance.Components
         {
             base.Startup();
 
-            if (Appearance != null! && Owner.TryGetComponent(out IBody? body))
+            if (Appearance != null! && Owner.TryGetComponent(out SharedBodyComponent? body))
             {
                 foreach (var (part, _) in body.Parts)
                 {

Content.Server/Chemistry/Components/PillComponent.cs

@@ -70,7 +70,7 @@ namespace Content.Server.Chemistry.Components
 
             var trueTarget = target ?? user;
 
-            if (!trueTarget.TryGetComponent(out IBody? body) ||
+            if (!trueTarget.TryGetComponent(out SharedBodyComponent? body) ||
                 !body.TryGetMechanismBehaviors<StomachBehavior>(out var stomachs))
             {
                 return false;

Content.Server/Climbing/Components/ClimbableComponent.cs

@@ -75,7 +75,7 @@ namespace Content.Server.Climbing.Components
             }
 
             if (!user.HasComponent<ClimbingComponent>() ||
-                !user.TryGetComponent(out IBody? body))
+                !user.TryGetComponent(out SharedBodyComponent? body))
             {
                 reason = Loc.GetString("comp-climbable-cant-climb");
                 return false;

Content.Server/Destructible/Thresholds/Behaviors/GibBehavior.cs

@@ -13,7 +13,7 @@ namespace Content.Server.Destructible.Thresholds.Behaviors
 
         public void Execute(IEntity owner, DestructibleSystem system)
         {
-            if (owner.TryGetComponent(out IBody? body))
+            if (owner.TryGetComponent(out SharedBodyComponent? body))
             {
                 body.Gib(_recursive);
             }

Content.Server/Disposal/Mailing/DisposalMailingUnitComponent.cs

@@ -161,7 +161,7 @@ namespace Content.Server.Disposal.Mailing
             }
 
             if (!entity.HasComponent<ItemComponent>() &&
-                !entity.HasComponent<IBody>())
+                !entity.HasComponent<SharedBodyComponent>())
             {
                 return false;
             }

Content.Server/Disposal/Unit/Components/DisposalHolderComponent.cs

@@ -79,7 +79,7 @@ namespace Content.Server.Disposal.Unit.Components
             }
 
             return entity.HasComponent<ItemComponent>() ||
-                   entity.HasComponent<IBody>();
+                   entity.HasComponent<SharedBodyComponent>();
         }
 
         public bool TryInsert(IEntity entity)

Content.Server/Kitchen/Components/MicrowaveComponent.cs

@@ -470,7 +470,7 @@ namespace Content.Server.Kitchen.Components
         {
             var headCount = 0;
 
-            if (victim.TryGetComponent<IBody>(out var body))
+            if (victim.TryGetComponent<SharedBodyComponent>(out var body))
             {
                 var headSlots = body.GetSlotsOfType(BodyPartType.Head);
 

Content.Server/Metabolism/MetabolismComponent.cs

@@ -26,7 +26,7 @@ namespace Content.Server.Metabolism
     [RegisterComponent]
     public class MetabolismComponent : Component
     {
-        [ComponentDependency] private readonly IBody? _body = default!;
+        [ComponentDependency] private readonly SharedBodyComponent? _body = default!;
 
         public override string Name => "Metabolism";
 

Content.Server/Morgue/Components/BodyBagEntityStorageComponent.cs

@@ -44,7 +44,7 @@ namespace Content.Server.Morgue.Components
 
         protected override bool AddToContents(IEntity entity)
         {
-            if (entity.HasComponent<IBody>() && !EntitySystem.Get<StandingStateSystem>().IsDown(entity)) return false;
+            if (entity.HasComponent<SharedBodyComponent>() && !EntitySystem.Get<StandingStateSystem>().IsDown(entity)) return false;
             return base.AddToContents(entity);
         }
 

Content.Server/Morgue/Components/MorgueEntityStorageComponent.cs

@@ -64,7 +64,7 @@ namespace Content.Server.Morgue.Components
 
         protected override bool AddToContents(IEntity entity)
         {
-            if (entity.HasComponent<IBody>() && !EntitySystem.Get<StandingStateSystem>().IsDown(entity)) return false;
+            if (entity.HasComponent<SharedBodyComponent>() && !EntitySystem.Get<StandingStateSystem>().IsDown(entity)) return false;
             return base.AddToContents(entity);
         }
 
@@ -115,7 +115,7 @@ namespace Content.Server.Morgue.Components
             foreach (var entity in Contents.ContainedEntities)
             {
                 count++;
-                if (!hasMob && entity.HasComponent<IBody>()) hasMob = true;
+                if (!hasMob && entity.HasComponent<SharedBodyComponent>()) hasMob = true;
                 if (!hasSoul && entity.TryGetComponent<ActorComponent>(out var actor) && actor.PlayerSession != null) hasSoul = true;
             }
             Appearance?.SetData(MorgueVisuals.HasContents, count > 0);

Content.Server/Nutrition/Components/DrinkComponent.cs

@@ -187,7 +187,7 @@ namespace Content.Server.Nutrition.Components
                 return false;
             }
 
-            if (!target.TryGetComponent(out IBody? body) ||
+            if (!target.TryGetComponent(out SharedBodyComponent? body) ||
                 !body.TryGetMechanismBehaviors<StomachBehavior>(out var stomachs))
             {
                 target.PopupMessage(Loc.GetString("You can't drink {0:theName}!", Owner));

Content.Server/Nutrition/Components/FoodComponent.cs

@@ -103,7 +103,7 @@ namespace Content.Server.Nutrition.Components
 
             var trueTarget = target ?? user;
 
-            if (!trueTarget.TryGetComponent(out IBody? body) ||
+            if (!trueTarget.TryGetComponent(out SharedBodyComponent? body) ||
                 !body.TryGetMechanismBehaviors<StomachBehavior>(out var stomachs))
             {
                 return false;

Content.Server/Recycling/Components/RecyclerComponent.cs

@@ -69,7 +69,7 @@ namespace Content.Server.Recycling.Components
         private bool CanGib(IEntity entity)
         {
             // We suppose this entity has a Recyclable component.
-            return entity.HasComponent<IBody>() && !_safe && Powered;
+            return entity.HasComponent<SharedBodyComponent>() && !_safe && Powered;
         }
 
         private void Recycle(IEntity entity)
@@ -87,7 +87,7 @@ namespace Content.Server.Recycling.Components
             // Mobs are a special case!
             if (CanGib(entity))
             {
-                entity.GetComponent<IBody>().Gib(true);
+                entity.GetComponent<SharedBodyComponent>().Gib(true);
                 Bloodstain();
                 return;
             }
@@ -159,7 +159,7 @@ namespace Content.Server.Recycling.Components
 
             victim.PopupMessageOtherClients(Loc.GetString("{0:theName} tries to recycle {0:themself}!", victim));
 
-            if (victim.TryGetComponent<IBody>(out var body))
+            if (victim.TryGetComponent<SharedBodyComponent>(out var body))
             {
                 body.Gib(true);
             }

Content.Server/Storage/Components/EntityStorageComponent.cs

@@ -208,7 +208,7 @@ namespace Content.Server.Storage.Components
 
                 // only items that can be stored in an inventory, or a mob, can be eaten by a locker
                 if (!entity.HasComponent<SharedItemComponent>() &&
-                    !entity.HasComponent<IBody>())
+                    !entity.HasComponent<SharedBodyComponent>())
                     continue;
 
                 if (!AddToContents(entity))

Content.Server/Toilet/ToiletComponent.cs

@@ -144,7 +144,7 @@ namespace Content.Server.Toilet
         SuicideKind ISuicideAct.Suicide(IEntity victim, IChatManager chat)
         {
             // check that victim even have head
-            if (victim.TryGetComponent<IBody>(out var body) &&
+            if (victim.TryGetComponent<SharedBodyComponent>(out var body) &&
                 body.HasPartOfType(BodyPartType.Head))
             {
                 var othersMessage = Loc.GetString("{0:theName} sticks their head into {1:theName} and flushes it!", victim, Owner);

Content.Shared/Body/Behavior/IMechanismBehavior.cs

@@ -1,142 +0,0 @@
-#nullable enable
-using Content.Shared.Body.Components;
-using Content.Shared.Body.Mechanism;
-using Content.Shared.Body.Part;
-using Robust.Shared.GameObjects;
-using Robust.Shared.Serialization.Manager.Attributes;
-
-namespace Content.Shared.Body.Behavior
-{
-    /// <summary>
-    ///     Gives functionality to a <see cref="IMechanism"/> when added to it.
-    /// </summary>
-    [ImplicitDataDefinitionForInheritors]
-    public interface IMechanismBehavior
-    {
-        /// <summary>
-        ///     The body that owns the <see cref="IBodyPart"/> in which the
-        ///     <see cref="IMechanism"/> that owns this
-        ///     <see cref="IMechanismBehavior"/> is in.
-        /// </summary>
-        IBody? Body { get; }
-
-        /// <summary>
-        ///     The part in which the <see cref="IMechanism"/> that owns this
-        ///     <see cref="IMechanismBehavior"/> is in.
-        /// </summary>
-        IBodyPart? Part { get; }
-
-        /// <summary>
-        ///     Upward reference to the parent <see cref="IMechanism"/> that this
-        ///     behavior is attached to.
-        /// </summary>
-        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="Body"/>'s <see cref="IBody.Owner"/>.
-        /// </summary>
-        IEntity Owner { get; }
-
-        /// <summary>
-        ///     Called when this <see cref="IMechanismBehavior"/> is added to a
-        ///     <see cref="IMechanism"/>, during <see cref="IComponent.Initialize"/>.
-        ///     If it is added after component initialization,
-        ///     it is called immediately.
-        /// </summary>
-        /// <param name="parent">
-        ///     The mechanism that owns this <see cref="IMechanismBehavior"/>.
-        /// </param>
-        void Initialize(IMechanism parent);
-
-        /// <summary>
-        ///     Called when this <see cref="IMechanismBehavior"/> is added to a
-        ///     <see cref="IMechanism"/>, during <see cref="IComponent.Startup"/>.
-        ///     If it is added after component startup, it is called immediately.
-        /// </summary>
-        void Startup();
-
-        /// <summary>
-        ///     Runs an update cycle on this <see cref="IMechanismBehavior"/>.
-        /// </summary>
-        /// <param name="frameTime">
-        ///     The amount of seconds that passed since the last update.
-        /// </param>
-        void Update(float frameTime);
-
-        /// <summary>
-        ///     Called when the containing <see cref="IBodyPart"/> is attached to a
-        ///     <see cref="IBody"/>.
-        ///     For instance, attaching a head with a brain inside to a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="body">
-        ///     The body that the containing <see cref="IMechanism"/> was added to.
-        /// </param>
-        void AddedToBody(IBody body);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is
-        ///     added into a <see cref="IBodyPart"/> that is not attached to a
-        ///     <see cref="IBody"/>.
-        ///     For instance, adding a brain to a dismembered head.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="part">
-        ///     The part that the containing <see cref="IMechanism"/> was added to.
-        /// </param>
-        void AddedToPart(IBodyPart part);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is added to a
-        ///     <see cref="IBodyPart"/> that is attached to a <see cref="IBody"/>.
-        ///     For instance, adding a brain to a head that is attached to a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="body">
-        ///     The body that the containing <see cref="IMechanism"/> was added to.
-        /// </param>
-        /// <param name="part">
-        ///     The part that the containing <see cref="IMechanism"/> was added to.
-        /// </param>
-        void AddedToPartInBody(IBody body, IBodyPart part);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IBodyPart"/> is removed from a
-        ///     <see cref="IBody"/>.
-        ///     For instance, removing a head with a brain inside from a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="old">
-        ///     The body that the containing <see cref="IMechanism"/> was removed from.
-        /// </param>
-        void RemovedFromBody(IBody old);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is
-        ///     removed from a <see cref="IBodyPart"/> that is not attached to a
-        ///     <see cref="IBody"/>.
-        ///     For instance, removing a brain from a dismembered head.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="old">
-        ///     The part that the containing <see cref="IMechanism"/> was removed from.
-        /// </param>
-        void RemovedFromPart(IBodyPart old);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is removed from a
-        ///     <see cref="IBodyPart"/> that is attached to a <see cref="IBody"/>.
-        ///     For instance, removing a brain from a head that is attached to a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="oldBody">
-        ///     The body that the containing <see cref="IMechanism"/> was removed from.
-        /// </param>
-        /// <param name="oldPart">
-        ///     The part that the containing <see cref="IMechanism"/> was removed from.
-        /// </param>
-        void RemovedFromPartInBody(IBody oldBody, IBodyPart oldPart);
-    }
-}

Content.Shared/Body/Behavior/SharedMechanismBehavior.cs

@@ -0,0 +1,119 @@
+#nullable enable
+using Content.Shared.Body.Components;
+using Content.Shared.Body.Mechanism;
+using Content.Shared.Body.Part;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization.Manager.Attributes;
+
+namespace Content.Shared.Body.Behavior
+{
+    /// <summary>
+    ///     Gives functionality to a mechanism when added to it.
+    /// </summary>
+    [ImplicitDataDefinitionForInheritors]
+    public abstract class SharedMechanismBehavior
+    {
+        public abstract SharedBodyComponent? Body { get; }
+
+        public abstract SharedBodyPartComponent? Part { get; }
+
+        public abstract SharedMechanismComponent 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="Body"/>'s <see cref="SharedBodyComponent.Owner"/>.
+        /// </summary>
+        public abstract IEntity Owner { get; }
+
+        /// <summary>
+        ///     Called when this behavior is added to a mechanism, during <see cref="IComponent.Initialize"/>.
+        ///     If it is added after component initialization,
+        ///     it is called immediately.
+        /// </summary>
+        /// <param name="parent">
+        ///     The mechanism that owns this behavior.
+        /// </param>
+        public abstract void Initialize(SharedMechanismComponent parent);
+
+        /// <summary>
+        ///     Called when this behavior is added to a mechanism, during <see cref="Component.Startup"/>.
+        ///     If it is added after component startup, it is called immediately.
+        /// </summary>
+        public abstract void Startup();
+
+        /// <summary>
+        ///     Runs an update cycle on this behavior.
+        /// </summary>
+        /// <param name="frameTime">
+        ///     The amount of seconds that passed since the last update.
+        /// </param>
+        public abstract void Update(float frameTime);
+
+        /// <summary>
+        ///     Called when the containing part is attached to a body.
+        ///     For instance, attaching a head with a brain inside to a body.
+        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
+        /// </summary>
+        /// <param name="body">
+        ///     The body that the containing mechanism was added to.
+        /// </param>
+        public abstract void AddedToBody(SharedBodyComponent body);
+
+        /// <summary>
+        ///     Called when the parent mechanism is added into a part that is not attached to a body.
+        ///     For instance, adding a brain to a dismembered head.
+        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
+        /// </summary>
+        /// <param name="part">
+        ///     The part that the containing mechanism was added to.
+        /// </param>
+        public abstract void AddedToPart(SharedBodyPartComponent part);
+
+        /// <summary>
+        ///     Called when the parent mechanism is added to a part that is attached to a body.
+        ///     For instance, adding a brain to a head that is attached to a body.
+        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
+        /// </summary>
+        /// <param name="body">
+        ///     The body that the containing mechanism was added to.
+        /// </param>
+        /// <param name="part">
+        ///     The part that the containing mechanism was added to.
+        /// </param>
+        public abstract void AddedToPartInBody(SharedBodyComponent body, SharedBodyPartComponent part);
+
+        /// <summary>
+        ///     Called when the parent part is removed from a body.
+        ///     For instance, removing a head with a brain inside from a body.
+        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
+        /// </summary>
+        /// <param name="old">
+        ///     The body that the containing mechanism was removed from.
+        /// </param>
+        public abstract void RemovedFromBody(SharedBodyComponent old);
+
+        /// <summary>
+        ///     Called when the parent mechanism is removed from a part that is not attached to a body.
+        ///     For instance, removing a brain from a dismembered head.
+        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
+        /// </summary>
+        /// <param name="old">
+        ///     The part that the containing mechanism was removed from.
+        /// </param>
+        public abstract void RemovedFromPart(SharedBodyPartComponent old);
+
+        /// <summary>
+        ///     Called when the parent mechanism is removed from a part that is attached to a body.
+        ///     For instance, removing a brain from a head that is attached to a body.
+        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
+        /// </summary>
+        /// <param name="oldBody">
+        ///     The body that the containing mechanism was removed from.
+        /// </param>
+        /// <param name="oldPart">
+        ///     The part that the containing mechanism was removed from.
+        /// </param>
+        public abstract void RemovedFromPartInBody(SharedBodyComponent oldBody, SharedBodyPartComponent oldPart);
+    }
+}

Content.Shared/Body/Components/IBody.cs

@@ -1,256 +0,0 @@
-#nullable enable
-using System;
-using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
-using Content.Shared.Body.Part;
-using Content.Shared.Body.Part.Property;
-using Content.Shared.Body.Preset;
-using Content.Shared.Body.Slot;
-using Content.Shared.Body.Template;
-using Robust.Shared.GameObjects;
-
-namespace Content.Shared.Body.Components
-{
-    /// <summary>
-    ///     Component representing a collection of <see cref="IBodyPart"/>s
-    ///     attached to each other.
-    /// </summary>
-    public interface IBody : IComponent, IBodyPartContainer
-    {
-        /// <summary>
-        ///     The <see cref="BodyTemplatePrototype"/> used to create this
-        ///     <see cref="IBody"/>.
-        /// </summary>
-        public BodyTemplatePrototype? Template { get; }
-
-        /// <summary>
-        ///     The <see cref="BodyPresetPrototype"/> used to create this
-        ///     <see cref="IBody"/>.
-        /// </summary>
-        public BodyPresetPrototype? Preset { get; }
-
-        /// <summary>
-        ///     An enumeration of the slots that make up this body, regardless
-        ///     of if they contain a part or not.
-        /// </summary>
-        IEnumerable<BodyPartSlot> Slots { get; }
-
-        /// <summary>
-        ///     An enumeration of the parts on this body paired with the slots
-        ///     that they are in.
-        /// </summary>
-        IEnumerable<KeyValuePair<IBodyPart, BodyPartSlot>> Parts { get; }
-
-        /// <summary>
-        ///     An enumeration of the slots on this body without a part in them.
-        /// </summary>
-        IEnumerable<BodyPartSlot> EmptySlots { get; }
-
-        /// <summary>
-        ///     Finds the central <see cref="BodyPartSlot"/>, if any,
-        ///     of this body.
-        /// </summary>
-        /// <returns>
-        ///     The central <see cref="BodyPartSlot"/> if one exists,
-        ///     null otherwise.
-        /// </returns>
-        BodyPartSlot? CenterSlot { get; }
-
-        /// <summary>
-        ///     Finds the central <see cref="IBodyPart"/>, if any,
-        ///     of this body.
-        /// </summary>
-        /// <returns>
-        ///     The central <see cref="IBodyPart"/> if one exists,
-        ///     null otherwise.
-        /// </returns>
-        IBodyPart? CenterPart { get; }
-
-        // TODO BODY Sensible templates
-
-        /// <summary>
-        ///     Attempts to add a part to the given slot.
-        /// </summary>
-        /// <param name="slotId">The slot to add this part to.</param>
-        /// <param name="part">The part to add.</param>
-        /// <param name="checkSlotExists">
-        ///     Whether to check if the slot exists, or create one otherwise.
-        /// </param>
-        /// <returns>
-        ///     true if the part was added, false otherwise even if it was
-        ///     already added.
-        /// </returns>
-        bool TryAddPart(string slotId, IBodyPart part);
-
-        void SetPart(string slotId, IBodyPart part);
-
-        /// <summary>
-        ///     Checks if there is a <see cref="IBodyPart"/> in the given slot.
-        /// </summary>
-        /// <param name="slotId">The slot to look in.</param>
-        /// <returns>
-        ///     true if there is a part in the given <see cref="slotId"/>,
-        ///     false otherwise.
-        /// </returns>
-        bool HasPart(string slotId);
-
-        /// <summary>
-        ///     Checks if this <see cref="IBody"/> contains the given <see cref="part"/>.
-        /// </summary>
-        /// <param name="part">The part to look for.</param>
-        /// <returns>
-        ///     true if the given <see cref="part"/> is attached to the body,
-        ///     false otherwise.
-        /// </returns>
-        bool HasPart(IBodyPart part);
-
-        /// <summary>
-        ///     Removes the given <see cref="IBodyPart"/> from this body,
-        ///     dropping other <see cref="IBodyPart"/> if they were hanging
-        ///     off of it.
-        /// <param name="part">The part to remove.</param>
-        /// <returns>
-        ///     true if the part was removed, false otherwise
-        ///     even if the part was already removed previously.
-        /// </returns>
-        /// </summary>
-        bool RemovePart(IBodyPart part);
-
-        /// <summary>
-        ///     Removes the body part in slot <see cref="slotId"/> from this body,
-        ///     if one exists.
-        /// </summary>
-        /// <param name="slotId">The slot to remove it from.</param>
-        /// <returns>true if the part was removed, false otherwise.</returns>
-        bool RemovePart(string slotId);
-
-        /// <summary>
-        ///     Removes the body part from this body, if one exists.
-        /// </summary>
-        /// <param name="part">The part to remove from this body.</param>
-        /// <param name="slotId">The slot that the part was in, if any.</param>
-        /// <returns>
-        ///     true if <see cref="part"/> was removed, false otherwise.
-        /// </returns>
-        bool RemovePart(IBodyPart part, [NotNullWhen(true)] out BodyPartSlot? slotId);
-
-        /// <summary>
-        ///     Disconnects the given <see cref="IBodyPart"/> reference, potentially
-        ///     dropping other <see cref="IBodyPart">BodyParts</see> if they
-        ///     were hanging off of it.
-        /// </summary>
-        /// <param name="slot">The part to drop.</param>
-        /// <param name="dropped">
-        ///     All of the parts that were dropped, including the one in
-        ///     <see cref="slot"/>.
-        /// </param>
-        /// <returns>
-        ///     true if the part was dropped, false otherwise.
-        /// </returns>
-        bool TryDropPart(BodyPartSlot slot, [NotNullWhen(true)] out Dictionary<BodyPartSlot, IBodyPart>? dropped);
-
-        /// <summary>
-        ///     Recursively searches for if <see cref="part"/> is connected to
-        ///     the center.
-        /// </summary>
-        /// <param name="part">The body part to find the center for.</param>
-        /// <returns>
-        ///     true if it is connected to the center, false otherwise.
-        /// </returns>
-        bool ConnectedToCenter(IBodyPart part);
-
-        /// <summary>
-        ///     Returns whether the given part slot exists in this body.
-        /// </summary>
-        /// <param name="slot">The slot to check for.</param>
-        /// <returns>true if the slot exists in this body, false otherwise.</returns>
-        bool HasSlot(string slot);
-
-        BodyPartSlot? GetSlot(IBodyPart part);
-
-        /// <summary>
-        ///     Finds the slot that the given <see cref="IBodyPart"/> resides in.
-        /// </summary>
-        /// <param name="part">
-        ///     The <see cref="IBodyPart"/> to find the slot for.
-        /// </param>
-        /// <param name="slot">The slot found, if any.</param>
-        /// <returns>true if a slot was found, false otherwise</returns>
-        bool TryGetSlot(IBodyPart part, [NotNullWhen(true)] out BodyPartSlot? slot);
-
-        /// <summary>
-        ///     Finds the <see cref="IBodyPart"/> in the given
-        ///     <see cref="slotId"/> if one exists.
-        /// </summary>
-        /// <param name="slotId">The part slot to search in.</param>
-        /// <param name="result">The body part in that slot, if any.</param>
-        /// <returns>true if found, false otherwise.</returns>
-        bool TryGetPart(string slotId, [NotNullWhen(true)] out IBodyPart? result);
-
-        /// <summary>
-        ///     Checks if a slot of the specified type exists on this body.
-        /// </summary>
-        /// <param name="type">The type to check for.</param>
-        /// <returns>true if present, false otherwise.</returns>
-        bool HasSlotOfType(BodyPartType type);
-
-        /// <summary>
-        ///     Gets all slots of the specified type on this body.
-        /// </summary>
-        /// <param name="type">The type to check for.</param>
-        /// <returns>An enumerable of the found slots.</returns>
-        IEnumerable<BodyPartSlot> GetSlotsOfType(BodyPartType type);
-
-        /// <summary>
-        ///     Checks if a part of the specified type exists on this body.
-        /// </summary>
-        /// <param name="type">The type to check for.</param>
-        /// <returns>true if present, false otherwise.</returns>
-        bool HasPartOfType(BodyPartType type);
-
-        /// <summary>
-        ///     Gets all slots of the specified type on this body.
-        /// </summary>
-        /// <param name="type">The type to check for.</param>
-        /// <returns>An enumerable of the found slots.</returns>
-        IEnumerable<IBodyPart> GetPartsOfType(BodyPartType type);
-
-        /// <summary>
-        ///     Finds all <see cref="IBodyPart"/>s with the given property in
-        ///     this body.
-        /// </summary>
-        /// <type name="type">The property type to look for.</type>
-        /// <returns>A list of parts with that property.</returns>
-        IEnumerable<(IBodyPart part, IBodyPartProperty property)> GetPartsWithProperty(Type type);
-
-        /// <summary>
-        ///     Finds all <see cref="IBodyPart"/>s with the given property in this body.
-        /// </summary>
-        /// <typeparam name="T">The property type to look for.</typeparam>
-        /// <returns>A list of parts with that property.</returns>
-        IEnumerable<(IBodyPart part, T property)> GetPartsWithProperty<T>() where T : class, IBodyPartProperty;
-
-        // TODO BODY Make a slot object that makes sense to the human mind, and make it serializable. Imagine the possibilities!
-        /// <summary>
-        ///     Retrieves the slot at the given index.
-        /// </summary>
-        /// <param name="index">The index to look in.</param>
-        /// <returns>A pair of the slot name and part type occupying it.</returns>
-        BodyPartSlot SlotAt(int index);
-
-        /// <summary>
-        ///     Retrieves the part at the given index.
-        /// </summary>
-        /// <param name="index">The index to look in.</param>
-        /// <returns>A pair of the part name and body part occupying it.</returns>
-        KeyValuePair<IBodyPart, BodyPartSlot> PartAt(int index);
-
-        /// <summary>
-        ///     Gibs this body.
-        /// </summary>
-        /// <param name="gibParts">
-        ///     Whether or not to also gib this body's parts.
-        /// </param>
-        void Gib(bool gibParts = false);
-    }
-}

Content.Shared/Body/Components/SharedBodyComponent.cs

@@ -3,6 +3,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Content.Shared.Body.Behavior;
 using Content.Shared.Body.Part;
 using Content.Shared.Body.Part.Property;
 using Content.Shared.Body.Preset;
@@ -25,7 +26,7 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Body.Components
 {
     // TODO BODY Damage methods for collections of IDamageableComponents
-    public abstract class SharedBodyComponent : Component, IBody, ISerializationHooks
+    public abstract class SharedBodyComponent : Component, IBodyPartContainer, ISerializationHooks
     {
         [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
 
@@ -55,13 +56,13 @@ namespace Content.Shared.Body.Components
         private Dictionary<string, BodyPartSlot> SlotIds { get; } = new();
 
         [ViewVariables]
-        private Dictionary<IBodyPart, BodyPartSlot> SlotParts { get; } = new();
+        private Dictionary<SharedBodyPartComponent, BodyPartSlot> SlotParts { get; } = new();
 
         [ViewVariables]
         public IEnumerable<BodyPartSlot> Slots => SlotIds.Values;
 
         [ViewVariables]
-        public IEnumerable<KeyValuePair<IBodyPart, BodyPartSlot>> Parts => SlotParts;
+        public IEnumerable<KeyValuePair<SharedBodyPartComponent, BodyPartSlot>> Parts => SlotParts;
 
         [ViewVariables]
         public IEnumerable<BodyPartSlot> EmptySlots => Slots.Where(slot => slot.Part == null);
@@ -71,7 +72,7 @@ namespace Content.Shared.Body.Components
                 ? SlotIds.GetValueOrDefault(centerSlot)
                 : null;
 
-        public IBodyPart? CenterPart => CenterSlot?.Part;
+        public SharedBodyPartComponent? CenterPart => CenterSlot?.Part;
 
         public override void Initialize()
         {
@@ -119,9 +120,9 @@ namespace Content.Shared.Body.Components
             return slot;
         }
 
-        private Dictionary<BodyPartSlot, IBodyPart> GetHangingParts(BodyPartSlot from)
+        private Dictionary<BodyPartSlot, SharedBodyPartComponent> GetHangingParts(BodyPartSlot from)
         {
-            var hanging = new Dictionary<BodyPartSlot, IBodyPart>();
+            var hanging = new Dictionary<BodyPartSlot, SharedBodyPartComponent>();
 
             foreach (var connection in from.Connections)
             {
@@ -135,7 +136,7 @@ namespace Content.Shared.Body.Components
             return hanging;
         }
 
-        protected virtual bool CanAddPart(string slotId, IBodyPart part)
+        protected virtual bool CanAddPart(string slotId, SharedBodyPartComponent part)
         {
             if (!SlotIds.TryGetValue(slotId, out var slot) ||
                 slot.CanAddPart(part))
@@ -146,7 +147,7 @@ namespace Content.Shared.Body.Components
             return true;
         }
 
-        protected virtual void OnAddPart(BodyPartSlot slot, IBodyPart part)
+        protected virtual void OnAddPart(BodyPartSlot slot, SharedBodyPartComponent part)
         {
             SlotParts[part] = slot;
             part.Body = this;
@@ -162,7 +163,7 @@ namespace Content.Shared.Body.Components
             OnBodyChanged();
         }
 
-        protected virtual void OnRemovePart(BodyPartSlot slot, IBodyPart part)
+        protected virtual void OnRemovePart(BodyPartSlot slot, SharedBodyPartComponent part)
         {
             SlotParts.Remove(part);
 
@@ -203,7 +204,8 @@ namespace Content.Shared.Body.Components
             OnBodyChanged();
         }
 
-        public bool TryAddPart(string slotId, IBodyPart part)
+        // TODO BODY Sensible templates
+        public bool TryAddPart(string slotId, SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(part);
             DebugTools.AssertNotNull(slotId);
@@ -217,7 +219,7 @@ namespace Content.Shared.Body.Components
                    slot.TryAddPart(part);
         }
 
-        public void SetPart(string slotId, IBodyPart part)
+        public void SetPart(string slotId, SharedBodyPartComponent part)
         {
             if (!SlotIds.TryGetValue(slotId, out var slot))
             {
@@ -236,14 +238,14 @@ namespace Content.Shared.Body.Components
                    slot.Part != null;
         }
 
-        public bool HasPart(IBodyPart part)
+        public bool HasPart(SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(part);
 
             return SlotParts.ContainsKey(part);
         }
 
-        public bool RemovePart(IBodyPart part)
+        public bool RemovePart(SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(part);
 
@@ -259,7 +261,7 @@ namespace Content.Shared.Body.Components
                    slot.RemovePart();
         }
 
-        public bool RemovePart(IBodyPart part, [NotNullWhen(true)] out BodyPartSlot? slotId)
+        public bool RemovePart(SharedBodyPartComponent part, [NotNullWhen(true)] out BodyPartSlot? slotId)
         {
             DebugTools.AssertNotNull(part);
 
@@ -279,7 +281,7 @@ namespace Content.Shared.Body.Components
             return true;
         }
 
-        public bool TryDropPart(BodyPartSlot slot, [NotNullWhen(true)] out Dictionary<BodyPartSlot, IBodyPart>? dropped)
+        public bool TryDropPart(BodyPartSlot slot, [NotNullWhen(true)] out Dictionary<BodyPartSlot, SharedBodyPartComponent>? dropped)
         {
             DebugTools.AssertNotNull(slot);
 
@@ -304,7 +306,7 @@ namespace Content.Shared.Body.Components
             return true;
         }
 
-        public bool ConnectedToCenter(IBodyPart part)
+        public bool ConnectedToCenter(SharedBodyPartComponent part)
         {
             return TryGetSlot(part, out var result) &&
                    ConnectedToCenterPartRecursion(result);
@@ -343,7 +345,7 @@ namespace Content.Shared.Body.Components
             return SlotIds.ContainsKey(slot);
         }
 
-        public IEnumerable<IBodyPart> GetParts()
+        public IEnumerable<SharedBodyPartComponent> GetParts()
         {
             foreach (var slot in SlotIds.Values)
             {
@@ -354,7 +356,7 @@ namespace Content.Shared.Body.Components
             }
         }
 
-        public bool TryGetPart(string slotId, [NotNullWhen(true)] out IBodyPart? result)
+        public bool TryGetPart(string slotId, [NotNullWhen(true)] out SharedBodyPartComponent? result)
         {
             result = null;
 
@@ -367,7 +369,7 @@ namespace Content.Shared.Body.Components
             return SlotIds.GetValueOrDefault(id);
         }
 
-        public BodyPartSlot? GetSlot(IBodyPart part)
+        public BodyPartSlot? GetSlot(SharedBodyPartComponent part)
         {
             return SlotParts.GetValueOrDefault(part);
         }
@@ -377,12 +379,12 @@ namespace Content.Shared.Body.Components
             return (slot = GetSlot(slotId)) != null;
         }
 
-        public bool TryGetSlot(IBodyPart part, [NotNullWhen(true)] out BodyPartSlot? slot)
+        public bool TryGetSlot(SharedBodyPartComponent part, [NotNullWhen(true)] out BodyPartSlot? slot)
         {
             return (slot = GetSlot(part)) != null;
         }
 
-        public bool TryGetPartConnections(string slotId, [NotNullWhen(true)] out List<IBodyPart>? connections)
+        public bool TryGetPartConnections(string slotId, [NotNullWhen(true)] out List<SharedBodyPartComponent>? connections)
         {
             if (!SlotIds.TryGetValue(slotId, out var slot))
             {
@@ -390,7 +392,7 @@ namespace Content.Shared.Body.Components
                 return false;
             }
 
-            connections = new List<IBodyPart>();
+            connections = new List<SharedBodyPartComponent>();
             foreach (var connection in slot.Connections)
             {
                 if (connection.Part != null)
@@ -439,7 +441,7 @@ namespace Content.Shared.Body.Components
             return false;
         }
 
-        public IEnumerable<IBodyPart> GetPartsOfType(BodyPartType type)
+        public IEnumerable<SharedBodyPartComponent> GetPartsOfType(BodyPartType type)
         {
             foreach (var slot in GetSlotsOfType(type))
             {
@@ -450,7 +452,8 @@ namespace Content.Shared.Body.Components
             }
         }
 
-        public IEnumerable<(IBodyPart part, IBodyPartProperty property)> GetPartsWithProperty(Type type)
+        /// <returns>A list of parts with that property.</returns>
+        public IEnumerable<(SharedBodyPartComponent part, IBodyPartProperty property)> GetPartsWithProperty(Type type)
         {
             foreach (var slot in SlotIds.Values)
             {
@@ -461,7 +464,7 @@ namespace Content.Shared.Body.Components
             }
         }
 
-        public IEnumerable<(IBodyPart part, T property)> GetPartsWithProperty<T>() where T : class, IBodyPartProperty
+        public IEnumerable<(SharedBodyPartComponent part, T property)> GetPartsWithProperty<T>() where T : class, IBodyPartProperty
         {
             foreach (var part in SlotParts.Keys)
             {
@@ -509,9 +512,6 @@ namespace Content.Shared.Body.Components
             }
         }
 
-        /// <summary>
-        ///     Called when the layout of this body changes.
-        /// </summary>
         private void OnBodyChanged()
         {
             // Calculate move speed based on this body.
@@ -523,19 +523,7 @@ namespace Content.Shared.Body.Components
             Dirty();
         }
 
-        /// <summary>
-        ///     Returns the combined length of the distance to the nearest
-        ///     <see cref="IBodyPart"/> that is a foot.
-        ///     If you consider a <see cref="IBody"/> a node map, then it will
-        ///     look for a foot node from the given node. It can only search
-        ///     through <see cref="IBodyPart"/>s with an
-        ///     <see cref="ExtensionComponent"/>.
-        /// </summary>
-        /// <returns>
-        ///     The distance to the foot if found, <see cref="float.MinValue"/>
-        ///     otherwise.
-        /// </returns>
-        public float DistanceToNearestFoot(IBodyPart source)
+        public float DistanceToNearestFoot(SharedBodyPartComponent source)
         {
             if (source.PartType == BodyPartType.Foot &&
                 source.TryGetProperty<ExtensionComponent>(out var extension))
@@ -546,7 +534,7 @@ namespace Content.Shared.Body.Components
             return LookForFootRecursion(source);
         }
 
-        private float LookForFootRecursion(IBodyPart current, HashSet<BodyPartSlot>? searched = null)
+        private float LookForFootRecursion(SharedBodyPartComponent current, HashSet<BodyPartSlot>? searched = null)
         {
             searched ??= new HashSet<BodyPartSlot>();
 
@@ -555,13 +543,11 @@ namespace Content.Shared.Body.Components
                 return float.MinValue;
             }
 
-            // Get all connected parts if the current part has an extension property
             if (!TryGetSlot(current, out var slot))
             {
                 return float.MinValue;
             }
 
-            // If a connected BodyPart is a foot, return this BodyPart's length.
             foreach (var connection in slot.Connections)
             {
                 if (connection.PartType == BodyPartType.Foot &&
@@ -571,8 +557,6 @@ namespace Content.Shared.Body.Components
                 }
             }
 
-            // Otherwise, get the recursion values of all connected BodyParts and
-            // store them in a list.
             var distances = new List<float>();
             foreach (var connection in slot.Connections)
             {
@@ -589,8 +573,6 @@ namespace Content.Shared.Body.Components
                 }
             }
 
-            // If one or more of the searches found a foot, return the smallest one
-            // and add this ones length.
             if (distances.Count > 0)
             {
                 return distances.Min<float>() + extProperty.Distance;
@@ -605,7 +587,7 @@ namespace Content.Shared.Body.Components
             return SlotIds.Values.ElementAt(index);
         }
 
-        public KeyValuePair<IBodyPart, BodyPartSlot> PartAt(int index)
+        public KeyValuePair<SharedBodyPartComponent, BodyPartSlot> PartAt(int index)
         {
             return SlotParts.ElementAt(index);
         }
@@ -664,12 +646,68 @@ namespace Content.Shared.Body.Components
                     part.Gib();
             }
         }
+
+        public bool TryGetMechanismBehaviors([NotNullWhen(true)] out List<SharedMechanismBehavior>? behaviors)
+        {
+            behaviors = GetMechanismBehaviors().ToList();
+
+            if (behaviors.Count == 0)
+            {
+                behaviors = null;
+                return false;
+            }
+
+            return true;
+        }
+
+        public bool HasMechanismBehavior<T>() where T : SharedMechanismBehavior
+        {
+            return Parts.Any(p => p.Key.HasMechanismBehavior<T>());
+        }
+
+        // TODO cache these 2 methods jesus
+        public IEnumerable<SharedMechanismBehavior> GetMechanismBehaviors()
+        {
+            foreach (var (part, _) in Parts)
+            foreach (var mechanism in part.Mechanisms)
+            foreach (var behavior in mechanism.Behaviors.Values)
+            {
+                yield return behavior;
+            }
+        }
+
+        public IEnumerable<T> GetMechanismBehaviors<T>() where T : SharedMechanismBehavior
+        {
+            foreach (var (part, _) in Parts)
+            foreach (var mechanism in part.Mechanisms)
+            foreach (var behavior in mechanism.Behaviors.Values)
+            {
+                if (behavior is T tBehavior)
+                {
+                    yield return tBehavior;
+                }
+            }
+        }
+
+        public bool TryGetMechanismBehaviors<T>([NotNullWhen(true)] out List<T>? behaviors)
+            where T : SharedMechanismBehavior
+        {
+            behaviors = GetMechanismBehaviors<T>().ToList();
+
+            if (behaviors.Count == 0)
+            {
+                behaviors = null;
+                return false;
+            }
+
+            return true;
+        }
     }
 
     [Serializable, NetSerializable]
     public class BodyComponentState : ComponentState
     {
-        private Dictionary<string, IBodyPart>? _parts;
+        private Dictionary<string, SharedBodyPartComponent>? _parts;
 
         public readonly (string slot, EntityUid partId)[] PartIds;
 
@@ -678,7 +716,7 @@ namespace Content.Shared.Body.Components
             PartIds = partIds;
         }
 
-        public Dictionary<string, IBodyPart> Parts(IEntityManager? entityManager = null)
+        public Dictionary<string, SharedBodyPartComponent> Parts(IEntityManager? entityManager = null)
         {
             if (_parts != null)
             {
@@ -687,7 +725,7 @@ namespace Content.Shared.Body.Components
 
             entityManager ??= IoCManager.Resolve<IEntityManager>();
 
-            var parts = new Dictionary<string, IBodyPart>(PartIds.Length);
+            var parts = new Dictionary<string, SharedBodyPartComponent>(PartIds.Length);
 
             foreach (var (slot, partId) in PartIds)
             {
@@ -696,7 +734,7 @@ namespace Content.Shared.Body.Components
                     continue;
                 }
 
-                if (!entity.TryGetComponent(out IBodyPart? part))
+                if (!entity.TryGetComponent(out SharedBodyPartComponent? part))
                 {
                     continue;
                 }

Content.Shared/Body/Mechanism/IMechanism.cs

@@ -1,178 +0,0 @@
-#nullable enable
-using System;
-using System.Collections.Generic;
-using Content.Shared.Body.Behavior;
-using Content.Shared.Body.Components;
-using Content.Shared.Body.Part;
-using Robust.Shared.GameObjects;
-
-namespace Content.Shared.Body.Mechanism
-{
-    public interface IMechanism : IComponent
-    {
-        /// <summary>
-        ///     The body that owns the <see cref="IBodyPart"/> in which this
-        ///     <see cref="IMechanism"/> is in.
-        /// </summary>
-        IBody? Body { get; }
-
-        /// <summary>
-        ///     The part in which this <see cref="IMechanism"/> is in.
-        /// </summary>
-        IBodyPart? Part { get; set; }
-
-        /// <summary>
-        ///     The behaviors attached to this <see cref="IMechanism"/>
-        ///     mapped by their type.
-        /// </summary>
-        IReadOnlyDictionary<Type, IMechanismBehavior> Behaviors { get; }
-
-        /// <summary>
-        ///     Max HP of this <see cref="IMechanism"/>.
-        /// </summary>
-        int MaxDurability { get; set; }
-
-        /// <summary>
-        ///     Current HP of this <see cref="IMechanism"/>.
-        /// </summary>
-        int CurrentDurability { get; set; }
-
-        /// <summary>
-        ///     At what HP this <see cref="IMechanism"/> is completely destroyed.
-        /// </summary>
-        int DestroyThreshold { get; set; }
-
-        /// <summary>
-        ///     Armor of this <see cref="IMechanism"/> against attacks.
-        /// </summary>
-        int Resistance { get; set; }
-
-        /// <summary>
-        ///     Determines a handful of things - mostly whether this
-        ///     <see cref="IMechanism"/> can fit into a <see cref="IBodyPart"/>.
-        /// </summary>
-        // TODO BODY OnSizeChanged
-        int Size { get; set; }
-
-        /// <summary>
-        ///     What kind of <see cref="IBodyPart"/> this
-        ///     <see cref="IMechanism"/> can be easily installed into.
-        /// </summary>
-        BodyPartCompatibility Compatibility { get; set; }
-
-        /// <summary>
-        ///    Adds a <see cref="IMechanismBehavior"/> if this
-        ///     <see cref="IMechanism"/> does not have it 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();
-
-        /// <summary>
-        ///     Checks if this <see cref="IMechanism"/> has the specified
-        ///     <see cref="IMechanismBehavior"/>.
-        /// </summary>
-        /// <typeparam name="T">
-        ///     The type of <see cref="IMechanismBehavior"/> to check for.
-        /// </typeparam>
-        /// <returns>
-        ///     true if it has the <see cref="IMechanismBehavior"/>, false otherwise.
-        /// </returns>
-        bool HasBehavior<T>() where T : IMechanismBehavior;
-
-        /// <summary>
-        ///     Removes the specified <see cref="IMechanismBehavior"/> from this
-        ///     <see cref="IMechanism"/> if it has it.
-        /// </summary>
-        /// <typeparam name="T">
-        ///     The type of <see cref="IMechanismBehavior"/> to remove.
-        /// </typeparam>
-        /// <returns>true if it was removed, false otherwise.</returns>
-        bool TryRemoveBehavior<T>() where T : IMechanismBehavior;
-
-        /// <summary>
-        ///     Runs an update cycle for this <see cref="IMechanism"/>.
-        /// </summary>
-        /// <param name="frameTime">
-        ///     The amount of seconds that passed since the last update.
-        /// </param>
-        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
-        ///     <see cref="IBody"/>.
-        ///     For instance, attaching a head with a brain inside to a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="body">
-        ///     The body that this <see cref="IMechanism"/> was added to.
-        /// </param>
-        void AddedToBody(IBody body);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is
-        ///     added into a <see cref="IBodyPart"/> that is not attached to a
-        ///     <see cref="IBody"/>.
-        ///     For instance, adding a brain to a dismembered head.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="part">
-        ///     The part that this <see cref="IMechanism"/> was added to.
-        /// </param>
-        void AddedToPart(IBodyPart part);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is added to a
-        ///     <see cref="IBodyPart"/> that is attached to a <see cref="IBody"/>.
-        ///     For instance, adding a brain to a head that is attached to a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="body">
-        ///     The body that this <see cref="IMechanism"/> was added to.
-        /// </param>
-        /// <param name="part">
-        ///     The part that this <see cref="IMechanism"/> was added to.
-        /// </param>
-        void AddedToPartInBody(IBody body, IBodyPart part);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IBodyPart"/> is removed from a
-        ///     <see cref="IBody"/>.
-        ///     For instance, removing a head with a brain inside from a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="old">
-        ///     The body that this <see cref="IMechanism"/> was removed from.
-        /// </param>
-        void RemovedFromBody(IBody old);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is
-        ///     removed from a <see cref="IBodyPart"/> that is not attached to a
-        ///     <see cref="IBody"/>.
-        ///     For instance, removing a brain from a dismembered head.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="old">
-        ///     The part that this <see cref="IMechanism"/> was removed from.
-        /// </param>
-        void RemovedFromPart(IBodyPart old);
-
-        /// <summary>
-        ///     Called when the parent <see cref="IMechanism"/> is removed from a
-        ///     <see cref="IBodyPart"/> that is attached to a <see cref="IBody"/>.
-        ///     For instance, removing a brain from a head that is attached to a body.
-        ///     DO NOT CALL THIS DIRECTLY FROM OUTSIDE BODY SYSTEM CODE!
-        /// </summary>
-        /// <param name="oldBody">
-        ///     The body that this <see cref="IMechanism"/> was removed from.
-        /// </param>
-        /// <param name="oldPart">
-        ///     The part that this <see cref="IMechanism"/> was removed from.
-        /// </param>
-        void RemovedFromPartInBody(IBody oldBody, IBodyPart oldPart);
-    }
-}

Content.Shared/Body/Mechanism/MechanismSystem.cs

@@ -11,7 +11,7 @@ namespace Content.Shared.Body.Mechanism
         {
             base.Update(frameTime);
 
-            foreach (var mechanism in ComponentManager.EntityQuery<IMechanism>(true))
+            foreach (var mechanism in ComponentManager.EntityQuery<SharedMechanismComponent>(true))
             {
                 mechanism.Update(frameTime);
             }

Content.Shared/Body/Mechanism/SharedMechanismComponent.cs

@@ -14,23 +14,23 @@ using Robust.Shared.Utility;
 
 namespace Content.Shared.Body.Mechanism
 {
-    public abstract class SharedMechanismComponent : Component, IMechanism, ISerializationHooks
+    public abstract class SharedMechanismComponent : Component, ISerializationHooks
     {
         public override string Name => "Mechanism";
 
         protected readonly Dictionary<int, object> OptionsCache = new();
-        protected IBody? BodyCache;
+        protected SharedBodyComponent? BodyCache;
         protected int IdHash;
         protected IEntity? PerformerCache;
-        private IBodyPart? _part;
+        private SharedBodyPartComponent? _part;
 
-        [DataField("behaviors", serverOnly: true)] private HashSet<IMechanismBehavior> _behaviorTypes = new();
+        [DataField("behaviors", serverOnly: true)] private HashSet<SharedMechanismBehavior> _behaviorTypes = new();
 
-        private readonly Dictionary<Type, IMechanismBehavior> _behaviors = new();
+        private readonly Dictionary<Type, SharedMechanismBehavior> _behaviors = new();
 
-        public IBody? Body => Part?.Body;
+        public SharedBodyComponent? Body => Part?.Body;
 
-        public IBodyPart? Part
+        public SharedBodyPartComponent? Part
         {
             get => _part;
             set
@@ -69,7 +69,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public IReadOnlyDictionary<Type, IMechanismBehavior> Behaviors => _behaviors;
+        public IReadOnlyDictionary<Type, SharedMechanismBehavior> Behaviors => _behaviors;
 
         [DataField("maxDurability")] public int MaxDurability { get; set; } = 10;
 
@@ -82,8 +82,16 @@ namespace Content.Shared.Body.Mechanism
         [DataField("resistance")] public int Resistance { get; set; } = 0;
 
         // TODO BODY OnSizeChanged
+        /// <summary>
+        ///     Determines whether this
+        ///     <see cref="SharedMechanismComponent"/> can fit into a <see cref="SharedBodyPartComponent"/>.
+        /// </summary>
         [DataField("size")] public int Size { get; set; } = 1;
 
+        /// <summary>
+        ///     What kind of <see cref="SharedBodyPartComponent"/> this
+        ///     <see cref="SharedMechanismComponent"/> can be easily installed into.
+        /// </summary>
         [DataField("compatibility")]
         public BodyPartCompatibility Compatibility { get; set; } = BodyPartCompatibility.Universal;
 
@@ -128,7 +136,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public bool EnsureBehavior<T>(out T behavior) where T : IMechanismBehavior, new()
+        public bool EnsureBehavior<T>(out T behavior) where T : SharedMechanismBehavior, new()
         {
             if (_behaviors.TryGetValue(typeof(T), out var rawBehavior))
             {
@@ -144,12 +152,12 @@ namespace Content.Shared.Body.Mechanism
             return false;
         }
 
-        public bool HasBehavior<T>() where T : IMechanismBehavior
+        public bool HasBehavior<T>() where T : SharedMechanismBehavior
         {
             return _behaviors.ContainsKey(typeof(T));
         }
 
-        public bool TryRemoveBehavior<T>() where T : IMechanismBehavior
+        public bool TryRemoveBehavior<T>() where T : SharedMechanismBehavior
         {
             return _behaviors.Remove(typeof(T));
         }
@@ -162,7 +170,8 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public void AddedToBody(IBody body)
+        // TODO BODY Turn these into event listeners so they dont need to be exposed
+        public void AddedToBody(SharedBodyComponent body)
         {
             DebugTools.AssertNotNull(Body);
             DebugTools.AssertNotNull(body);
@@ -173,7 +182,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public void AddedToPart(IBodyPart part)
+        public void AddedToPart(SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(Part);
             DebugTools.AssertNotNull(part);
@@ -186,7 +195,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public void AddedToPartInBody(IBody body, IBodyPart part)
+        public void AddedToPartInBody(SharedBodyComponent body, SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(Body);
             DebugTools.AssertNotNull(body);
@@ -201,7 +210,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public void RemovedFromBody(IBody old)
+        public void RemovedFromBody(SharedBodyComponent old)
         {
             DebugTools.AssertNull(Body);
             DebugTools.AssertNotNull(old);
@@ -212,7 +221,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public void RemovedFromPart(IBodyPart old)
+        public void RemovedFromPart(SharedBodyPartComponent old)
         {
             DebugTools.AssertNull(Part);
             DebugTools.AssertNotNull(old);
@@ -225,7 +234,7 @@ namespace Content.Shared.Body.Mechanism
             }
         }
 
-        public void RemovedFromPartInBody(IBody oldBody, IBodyPart oldPart)
+        public void RemovedFromPartInBody(SharedBodyComponent oldBody, SharedBodyPartComponent oldPart)
         {
             DebugTools.AssertNull(Body);
             DebugTools.AssertNotNull(oldBody);

Content.Shared/Body/Part/BodyPartCompatibility.cs

@@ -5,7 +5,7 @@ using Robust.Shared.Serialization;
 namespace Content.Shared.Body.Part
 {
     /// <summary>
-    ///     Determines whether two <see cref="IBodyPart"/>s can connect.
+    ///     Determines whether two <see cref="SharedBodyPartComponent"/>s can connect.
     /// </summary>
     [Serializable, NetSerializable]
     public enum BodyPartCompatibility

Content.Shared/Body/Part/BodyPartExtensions.cs

@@ -1,81 +0,0 @@
-#nullable enable
-using System;
-using System.Diagnostics.CodeAnalysis;
-using Content.Shared.Body.Part.Property;
-
-namespace Content.Shared.Body.Part
-{
-    public static class BodyPartExtensions
-    {
-        /// <summary>
-        ///     Checks if the given <see cref="IBodyPart"/> has the specified property.
-        /// </summary>
-        /// <param name="part">The <see cref="IBodyPart"/> to check in.</param>
-        /// <param name="type">
-        ///     The type of <see cref="IBodyPartProperty"/> to check for.
-        /// </param>
-        /// <returns>true if found, false otherwise.</returns>
-        public static bool HasProperty(this IBodyPart part, Type type)
-        {
-            return part.Owner.HasComponent(type);
-        }
-
-        /// <summary>
-        ///     Checks if the given <see cref="IBodyPart"/> has the specified property.
-        /// </summary>
-        /// <param name="part">The <see cref="IBodyPart"/> to check in.</param>
-        /// <typeparam name="T">
-        ///     The type of <see cref="IBodyPartProperty"/> to check for.
-        /// </typeparam>
-        /// <returns>true if found, false otherwise.</returns>
-        public static bool HasProperty<T>(this IBodyPart part) where T : class, IBodyPartProperty
-        {
-            return part.HasProperty(typeof(T));
-        }
-
-        /// <summary>
-        ///     Tries to retrieve the <see cref="IBodyPartProperty"/> with the
-        ///     specified type.
-        /// </summary>
-        /// <param name="part">The <see cref="IBodyPart"/> to search in.</param>
-        /// <param name="type">
-        ///     The type of <see cref="IBodyPartProperty"/> to search for.
-        /// </param>
-        /// <param name="property">
-        ///     The property, if it was found. Null otherwise.
-        /// </param>
-        /// <returns>
-        ///     true if a component with the specified type was found, false otherwise.
-        /// </returns>
-        public static bool TryGetProperty(this IBodyPart part, Type type,
-            [NotNullWhen(true)] out IBodyPartProperty? property)
-        {
-            if (!part.Owner.TryGetComponent(type, out var component))
-            {
-                property = null;
-                return false;
-            }
-
-            return (property = component as IBodyPartProperty) != null;
-        }
-
-        /// <summary>
-        ///     Tries to retrieve the <see cref="IBodyPartProperty"/> with the
-        ///     specified type.
-        /// </summary>
-        /// <param name="part">The <see cref="IBodyPart"/> to search in.</param>
-        /// <typeparam name="T">
-        ///     The type of <see cref="IBodyPartProperty"/> to search for.
-        /// </typeparam>
-        /// <param name="property">
-        ///     The property, if it was found. Null otherwise.
-        /// </param>
-        /// <returns>
-        ///     true if a component with the specified type was found, false otherwise.
-        /// </returns>
-        public static bool TryGetProperty<T>(this IBodyPart part, [NotNullWhen(true)] out T? property) where T : class, IBodyPartProperty
-        {
-            return part.Owner.TryGetComponent(out property);
-        }
-    }
-}

Content.Shared/Body/Part/BodyPartSymmetry.cs

@@ -5,7 +5,7 @@ using Robust.Shared.Serialization;
 namespace Content.Shared.Body.Part
 {
     /// <summary>
-    ///     Defines the symmetry of a <see cref="IBodyPart"/>.
+    ///     Defines the symmetry of a <see cref="SharedBodyPartComponent"/>.
     /// </summary>
     [Serializable, NetSerializable]
     public enum BodyPartSymmetry

Content.Shared/Body/Part/BodyPartType.cs

@@ -5,7 +5,7 @@ using Robust.Shared.Serialization;
 namespace Content.Shared.Body.Part
 {
     /// <summary>
-    ///     Defines the type of a <see cref="IBodyPart"/>.
+    ///     Defines the type of a <see cref="SharedBodyPartComponent"/>.
     /// </summary>
     [Serializable, NetSerializable]
     public enum BodyPartType

Content.Shared/Body/Part/IBodyPart.cs

@@ -1,131 +0,0 @@
-#nullable enable
-using System.Collections.Generic;
-using Content.Shared.Body.Components;
-using Content.Shared.Body.Mechanism;
-using Content.Shared.Body.Surgery;
-using Robust.Shared.GameObjects;
-using Robust.Shared.Map;
-
-namespace Content.Shared.Body.Part
-{
-    public interface IBodyPart : IComponent, IBodyPartContainer
-    {
-        /// <summary>
-        ///     The <see cref="IBody"/> to which this <see cref="IBodyPart"/> is
-        ///     attached to.
-        /// </summary>
-        IBody? Body { get; set; }
-
-        /// <summary>
-        ///     The string to show when displaying this part's name to players.
-        /// </summary>
-        string DisplayName { get; }
-
-        /// <summary>
-        ///     <see cref="BodyPartType"/> that this <see cref="IBodyPart"/> is considered
-        ///     to be.
-        ///     For example, <see cref="BodyPartType.Arm"/>.
-        /// </summary>
-        BodyPartType PartType { get; }
-
-        /// <summary>
-        ///     Determines how many mechanisms can be fit inside this
-        ///     <see cref="IBodyPart"/>.
-        /// </summary>
-        int Size { get; }
-
-        // TODO BODY Mechanisms occupying different parts at the body level
-        /// <summary>
-        ///     Collection of all <see cref="IMechanism"/>s currently inside this
-        ///     <see cref="IBodyPart"/>.
-        ///     To add and remove from this list see <see cref="TryAddMechanism"/> and
-        ///     <see cref="RemoveMechanism"/>
-        /// </summary>
-        IReadOnlyCollection<IMechanism> Mechanisms { get; }
-
-        /// <summary>
-        ///     Whether or not the owning <see cref="Body"/> will die if all
-        ///     <see cref="IBodyPart"/>s of this type are removed from it.
-        /// </summary>
-        public bool IsVital { get; }
-
-        /// <summary>
-        ///     The symmetry of this <see cref="IBodyPart"/>.
-        /// </summary>
-        public BodyPartSymmetry Symmetry { get; }
-
-        /// <summary>
-        ///     Checks if the given <see cref="SurgeryType"/> can be used on
-        ///     the current state of this <see cref="IBodyPart"/>.
-        /// </summary>
-        /// <returns>True if it can be used, false otherwise.</returns>
-        bool SurgeryCheck(SurgeryType surgery);
-
-        /// <summary>
-        ///     Attempts to perform surgery on this <see cref="IBodyPart"/> with the given
-        ///     tool.
-        /// </summary>
-        /// <returns>True if successful, false if there was an error.</returns>
-        public bool AttemptSurgery(SurgeryType toolType, IBodyPartContainer target, ISurgeon surgeon,
-            IEntity performer);
-
-        /// <summary>
-        ///     Checks if another <see cref="IBodyPart"/> can be connected to this one.
-        /// </summary>
-        /// <param name="part">The part to connect.</param>
-        /// <returns>True if it can be connected, false otherwise.</returns>
-        bool CanAttachPart(IBodyPart part);
-
-        /// <summary>
-        ///     Checks if a <see cref="IMechanism"/> can be added on this
-        ///     <see cref="IBodyPart"/>.
-        /// </summary>
-        /// <returns>True if it can be added, false otherwise.</returns>
-        bool CanAddMechanism(IMechanism mechanism);
-
-        /// <summary>
-        ///     Tries to add a <see cref="IMechanism"/> to this body.
-        /// </summary>
-        /// <param name="mechanism">The mechanism to add.</param>
-        /// <param name="force">
-        ///     Whether or not to check if the mechanism is compatible.
-        ///     Passing true does not guarantee it to be added, for example if
-        ///     it was already added before.
-        /// </param>
-        /// <returns>true if added, false otherwise even if it was already added.</returns>
-        bool TryAddMechanism(IMechanism mechanism, bool force = false);
-
-        /// <summary>
-        ///     Tries to remove the given <see cref="mechanism"/> from this
-        ///     <see cref="IBodyPart"/>.
-        /// </summary>
-        /// <param name="mechanism">The mechanism to remove.</param>
-        /// <returns>True if it was removed, false otherwise.</returns>
-        bool RemoveMechanism(IMechanism mechanism);
-
-        /// <summary>
-        ///     Tries to remove the given <see cref="mechanism"/> from this
-        ///     <see cref="IBodyPart"/> and drops it at the specified coordinates.
-        /// </summary>
-        /// <param name="mechanism">The mechanism to remove.</param>
-        /// <param name="dropAt">The coordinates to drop it at.</param>
-        /// <returns>True if it was removed, false otherwise.</returns>
-        bool RemoveMechanism(IMechanism mechanism, EntityCoordinates dropAt);
-
-        /// <summary>
-        ///     Tries to destroy the given <see cref="IMechanism"/> from
-        ///     this <see cref="IBodyPart"/>.
-        ///     The mechanism won't be deleted if it is not in this body part.
-        /// </summary>
-        /// <returns>
-        ///     True if the mechanism was in this body part and destroyed,
-        ///     false otherwise.
-        /// </returns>
-        bool DeleteMechanism(IMechanism mechanism);
-
-        /// <summary>
-        ///     Gibs the body part.
-        /// </summary>
-        void Gib();
-    }
-}

Content.Shared/Body/Part/IBodyPartAdded.cs

@@ -11,7 +11,7 @@ namespace Content.Shared.Body.Part
     public interface IBodyPartAdded : IComponent
     {
         /// <summary>
-        ///     Called when a <see cref="IBodyPart"/> is added to the
+        ///     Called when a <see cref="SharedBodyPartComponent"/> is added to the
         ///     entity owning this component.
         /// </summary>
         /// <param name="args">Information about the part that was added.</param>
@@ -20,7 +20,7 @@ namespace Content.Shared.Body.Part
 
     public class BodyPartAddedEventArgs : EventArgs
     {
-        public BodyPartAddedEventArgs(string slot, IBodyPart part)
+        public BodyPartAddedEventArgs(string slot, SharedBodyPartComponent part)
         {
             Slot = slot;
             Part = part;
@@ -34,6 +34,6 @@ namespace Content.Shared.Body.Part
         /// <summary>
         ///     The part that was added.
         /// </summary>
-        public IBodyPart Part { get; }
+        public SharedBodyPartComponent Part { get; }
     }
 }

Content.Shared/Body/Part/IBodyPartRemoved.cs

@@ -10,7 +10,7 @@ namespace Content.Shared.Body.Part
     public interface IBodyPartRemoved
     {
         /// <summary>
-        ///     Called when a <see cref="IBodyPart"/> is removed from the
+        ///     Called when a <see cref="SharedBodyPartComponent"/> is removed from the
         ///     entity owning this component.
         /// </summary>
         /// <param name="args">Information about the part that was removed.</param>
@@ -19,7 +19,7 @@ namespace Content.Shared.Body.Part
 
     public class BodyPartRemovedEventArgs : EventArgs
     {
-        public BodyPartRemovedEventArgs(string slot, IBodyPart part)
+        public BodyPartRemovedEventArgs(string slot, SharedBodyPartComponent part)
         {
             Slot = slot;
             Part = part;
@@ -33,6 +33,6 @@ namespace Content.Shared.Body.Part
         /// <summary>
         ///     The part that was removed.
         /// </summary>
-        public IBodyPart Part { get; }
+        public SharedBodyPartComponent Part { get; }
     }
 }

Content.Shared/Body/Part/Property/BodyPartPropertyComponent.cs

@@ -5,10 +5,10 @@ using Robust.Shared.Serialization.Manager.Attributes;
 namespace Content.Shared.Body.Part.Property
 {
     /// <summary>
-    ///     Property attachable to a <see cref="IBodyPart"/>.
+    ///     Property attachable to a <see cref="SharedBodyPartComponent"/>.
     ///     For example, this is used to define the speed capabilities of a leg.
     ///     The movement system will look for a <see cref="LegComponent"/> on all
-    ///     <see cref="IBodyPart"/>.
+    ///     <see cref="SharedBodyPartComponent"/>.
     /// </summary>
     public abstract class BodyPartPropertyComponent : Component, IBodyPartProperty
     {

Content.Shared/Body/Part/Property/ExtensionComponent.cs

@@ -5,7 +5,7 @@ using Robust.Shared.Serialization.Manager.Attributes;
 namespace Content.Shared.Body.Part.Property
 {
     /// <summary>
-    ///     Defines the length of a <see cref="IBodyPart"/>.
+    ///     Defines the length of a <see cref="SharedBodyPartComponent"/>.
     /// </summary>
     [RegisterComponent]
     public class ExtensionComponent : BodyPartPropertyComponent

Content.Shared/Body/Part/Property/GraspComponent.cs

@@ -4,7 +4,7 @@ using Robust.Shared.GameObjects;
 namespace Content.Shared.Body.Part.Property
 {
     /// <summary>
-    ///     Defines a <see cref="IBodyPart"/> as being able to grasp around an entity,
+    ///     Defines a <see cref="SharedBodyPartComponent"/> as being able to grasp around an entity,
     ///     for example picking up an item.
     /// </summary>
     // TODO BODY Implement

Content.Shared/Body/Part/Property/IBodyPartProperty.cs

@@ -4,7 +4,7 @@ using Robust.Shared.GameObjects;
 namespace Content.Shared.Body.Part.Property
 {
     /// <summary>
-    ///     Defines a property for a <see cref="IBodyPart"/>.
+    ///     Defines a property for a <see cref="SharedBodyPartComponent"/>.
     /// </summary>
     public interface IBodyPartProperty : IComponent
     {

Content.Shared/Body/Part/Property/LegComponent.cs

@@ -5,7 +5,7 @@ using Robust.Shared.Serialization.Manager.Attributes;
 namespace Content.Shared.Body.Part.Property
 {
     /// <summary>
-    ///     Defines the speed at which a <see cref="IBodyPart"/> can move.
+    ///     Defines the speed at which a <see cref="SharedBodyPartComponent"/> can move.
     /// </summary>
     [RegisterComponent]
     public class LegComponent : BodyPartPropertyComponent

Content.Shared/Body/Part/SharedBodyPartComponent.cs

@@ -1,9 +1,12 @@
 #nullable enable
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Content.Shared.Body.Behavior;
 using Content.Shared.Body.Components;
 using Content.Shared.Body.Mechanism;
+using Content.Shared.Body.Part.Property;
 using Content.Shared.Body.Surgery;
 using Content.Shared.NetIDs;
 using Robust.Shared.GameObjects;
@@ -17,24 +20,24 @@ using Robust.Shared.ViewVariables;
 
 namespace Content.Shared.Body.Part
 {
-    public abstract class SharedBodyPartComponent : Component, IBodyPart
+    public abstract class SharedBodyPartComponent : Component, IBodyPartContainer
     {
         public override string Name => "BodyPart";
 
         public override uint? NetID => ContentNetIDs.BODY_PART;
 
-        private IBody? _body;
+        private SharedBodyComponent? _body;
 
         // TODO BODY Remove
         [DataField("mechanisms")]
-        private List<string> _mechanismIds = new();
+        private readonly List<string> _mechanismIds = new();
         public IReadOnlyList<string> MechanismIds => _mechanismIds;
 
         [ViewVariables]
-        private readonly HashSet<IMechanism> _mechanisms = new();
+        private readonly HashSet<SharedMechanismComponent> _mechanisms = new();
 
         [ViewVariables]
-        public IBody? Body
+        public SharedBodyComponent? Body
         {
             get => _body;
             set
@@ -59,13 +62,25 @@ namespace Content.Shared.Body.Part
             }
         }
 
+        /// <summary>
+        ///     The string to show when displaying this part's name to players.
+        /// </summary>
         [ViewVariables]
         public string DisplayName => Name;
 
+        /// <summary>
+        ///     <see cref="BodyPartType"/> that this <see cref="IBodyPart"/> is considered
+        ///     to be.
+        ///     For example, <see cref="BodyPartType.Arm"/>.
+        /// </summary>
         [ViewVariables]
         [DataField("partType")]
         public BodyPartType PartType { get; private set; } = BodyPartType.Other;
 
+        /// <summary>
+        ///     Determines how many mechanisms can be fit inside this
+        ///     <see cref="SharedBodyPartComponent"/>.
+        /// </summary>
         [ViewVariables] [DataField("size")] public int Size { get; private set; } = 1;
 
         [ViewVariables] public int SizeUsed { get; private set; }
@@ -74,7 +89,7 @@ namespace Content.Shared.Body.Part
         // TODO BODY surgerydata
 
         /// <summary>
-        ///     What types of BodyParts this <see cref="IBodyPart"/> can easily attach to.
+        ///     What types of BodyParts this <see cref="SharedBodyPartComponent"/> can easily attach to.
         ///     For the most part, most limbs aren't universal and require extra work to
         ///     attach between types.
         /// </summary>
@@ -82,17 +97,14 @@ namespace Content.Shared.Body.Part
         [DataField("compatibility")]
         public BodyPartCompatibility Compatibility { get; private set; } = BodyPartCompatibility.Universal;
 
-        /// <summary>
-        ///     Set of all <see cref="IMechanism"/> currently inside this
-        ///     <see cref="IBodyPart"/>.
-        /// </summary>
+        // TODO BODY Mechanisms occupying different parts at the body level
         [ViewVariables]
-        public IReadOnlyCollection<IMechanism> Mechanisms => _mechanisms;
+        public IReadOnlyCollection<SharedMechanismComponent> Mechanisms => _mechanisms;
 
         // TODO BODY Replace with a simulation of organs
         /// <summary>
-        ///     Represents if body part is vital for creature.
-        ///     If the last vital body part is removed creature dies
+        ///     Whether or not the owning <see cref="Body"/> will die if all
+        ///     <see cref="SharedBodyPartComponent"/>s of this type are removed from it.
         /// </summary>
         [ViewVariables]
         [DataField("vital")]
@@ -105,7 +117,7 @@ namespace Content.Shared.Body.Part
         [ViewVariables]
         public ISurgeryData? SurgeryDataComponent => Owner.GetComponentOrNull<ISurgeryData>();
 
-        protected virtual void OnAddMechanism(IMechanism mechanism)
+        protected virtual void OnAddMechanism(SharedMechanismComponent mechanism)
         {
             var prototypeId = mechanism.Owner.Prototype!.ID;
 
@@ -120,7 +132,7 @@ namespace Content.Shared.Body.Part
             Dirty();
         }
 
-        protected virtual void OnRemoveMechanism(IMechanism mechanism)
+        protected virtual void OnRemoveMechanism(SharedMechanismComponent mechanism)
         {
             _mechanismIds.Remove(mechanism.Owner.Prototype!.ID);
             mechanism.Part = null;
@@ -176,11 +188,6 @@ namespace Content.Shared.Body.Part
             return SurgeryDataComponent?.CheckSurgery(surgery) ?? false;
         }
 
-        /// <summary>
-        ///     Attempts to perform surgery on this <see cref="IBodyPart"/> with the given
-        ///     tool.
-        /// </summary>
-        /// <returns>True if successful, false if there was an error.</returns>
         public bool AttemptSurgery(SurgeryType toolType, IBodyPartContainer target, ISurgeon surgeon, IEntity performer)
         {
             DebugTools.AssertNotNull(toolType);
@@ -191,14 +198,14 @@ namespace Content.Shared.Body.Part
             return SurgeryDataComponent?.PerformSurgery(toolType, target, surgeon, performer) ?? false;
         }
 
-        public bool CanAttachPart(IBodyPart part)
+        public bool CanAttachPart(SharedBodyPartComponent part)
         {
             DebugTools.AssertNotNull(part);
 
             return SurgeryDataComponent?.CanAttachBodyPart(part) ?? false;
         }
 
-        public virtual bool CanAddMechanism(IMechanism mechanism)
+        public virtual bool CanAddMechanism(SharedMechanismComponent mechanism)
         {
             DebugTools.AssertNotNull(mechanism);
 
@@ -208,19 +215,16 @@ namespace Content.Shared.Body.Part
         }
 
         /// <summary>
-        ///     Tries to add a mechanism onto this body part.
+        ///     Tries to add a <see cref="SharedMechanismComponent"/> to this part.
         /// </summary>
-        /// <param name="mechanism">The mechanism to try to add.</param>
+        /// <param name="mechanism">The mechanism to add.</param>
         /// <param name="force">
-        ///     Whether or not to check if the mechanism can be added.
+        ///     Whether or not to check if the mechanism is compatible.
+        ///     Passing true does not guarantee it to be added, for example if
+        ///     it was already added before.
         /// </param>
-        /// <returns>
-        ///     True if successful, false if there was an error
-        ///     (e.g. not enough room in <see cref="IBodyPart"/>).
-        ///     Will return false even when forced if the mechanism is already
-        ///     added in this <see cref="IBodyPart"/>.
-        /// </returns>
-        public bool TryAddMechanism(IMechanism mechanism, bool force = false)
+        /// <returns>true if added, false otherwise even if it was already added.</returns>
+        public bool TryAddMechanism(SharedMechanismComponent mechanism, bool force = false)
         {
             DebugTools.AssertNotNull(mechanism);
 
@@ -239,7 +243,12 @@ namespace Content.Shared.Body.Part
             return true;
         }
 
-        public bool RemoveMechanism(IMechanism mechanism)
+        /// <summary>
+        ///     Tries to remove the given <see cref="mechanism"/> from this part.
+        /// </summary>
+        /// <param name="mechanism">The mechanism to remove.</param>
+        /// <returns>True if it was removed, false otherwise.</returns>
+        public bool RemoveMechanism(SharedMechanismComponent mechanism)
         {
             DebugTools.AssertNotNull(mechanism);
 
@@ -253,7 +262,14 @@ namespace Content.Shared.Body.Part
             return true;
         }
 
-        public bool RemoveMechanism(IMechanism mechanism, EntityCoordinates coordinates)
+        /// <summary>
+        ///     Tries to remove the given <see cref="mechanism"/> from this
+        ///     part and drops it at the specified coordinates.
+        /// </summary>
+        /// <param name="mechanism">The mechanism to remove.</param>
+        /// <param name="coordinates">The coordinates to drop it at.</param>
+        /// <returns>True if it was removed, false otherwise.</returns>
+        public bool RemoveMechanism(SharedMechanismComponent mechanism, EntityCoordinates coordinates)
         {
             if (RemoveMechanism(mechanism))
             {
@@ -264,7 +280,16 @@ namespace Content.Shared.Body.Part
             return false;
         }
 
-        public bool DeleteMechanism(IMechanism mechanism)
+        /// <summary>
+        ///     Tries to destroy the given <see cref="SharedMechanismComponent"/> from
+        ///     this part.
+        ///     The mechanism won't be deleted if it is not in this body part.
+        /// </summary>
+        /// <returns>
+        ///     True if the mechanism was in this body part and destroyed,
+        ///     false otherwise.
+        /// </returns>
+        public bool DeleteMechanism(SharedMechanismComponent mechanism)
         {
             DebugTools.AssertNotNull(mechanism);
 
@@ -277,7 +302,7 @@ namespace Content.Shared.Body.Part
             return true;
         }
 
-        private void AddedToBody(IBody body)
+        private void AddedToBody(SharedBodyComponent body)
         {
             Owner.Transform.LocalRotation = 0;
             Owner.Transform.AttachParent(body.Owner);
@@ -289,7 +314,7 @@ namespace Content.Shared.Body.Part
             }
         }
 
-        private void RemovedFromBody(IBody old)
+        private void RemovedFromBody(SharedBodyComponent old)
         {
             if (!Owner.Transform.Deleted)
             {
@@ -304,10 +329,13 @@ namespace Content.Shared.Body.Part
             }
         }
 
-        protected virtual void OnAddedToBody(IBody body) { }
+        protected virtual void OnAddedToBody(SharedBodyComponent body) { }
 
-        protected virtual void OnRemovedFromBody(IBody old) { }
+        protected virtual void OnRemovedFromBody(SharedBodyComponent old) { }
 
+        /// <summary>
+        ///     Gibs the body part.
+        /// </summary>
         public virtual void Gib()
         {
             foreach (var mechanism in _mechanisms)
@@ -315,12 +343,44 @@ namespace Content.Shared.Body.Part
                 RemoveMechanism(mechanism);
             }
         }
+
+        public bool HasProperty(Type type)
+        {
+            return Owner.HasComponent(type);
+        }
+
+        public bool HasProperty<T>() where T : class, IBodyPartProperty
+        {
+            return HasProperty(typeof(T));
+        }
+
+        public bool TryGetProperty(Type type,
+            [NotNullWhen(true)] out IBodyPartProperty? property)
+        {
+            if (!Owner.TryGetComponent(type, out var component))
+            {
+                property = null;
+                return false;
+            }
+
+            return (property = component as IBodyPartProperty) != null;
+        }
+
+        public bool TryGetProperty<T>([NotNullWhen(true)] out T? property) where T : class, IBodyPartProperty
+        {
+            return Owner.TryGetComponent(out property);
+        }
+
+        public bool HasMechanismBehavior<T>() where T : SharedMechanismBehavior
+        {
+            return Mechanisms.Any(m => m.HasBehavior<T>());
+        }
     }
 
     [Serializable, NetSerializable]
     public class BodyPartComponentState : ComponentState
     {
-        [NonSerialized] private List<IMechanism>? _mechanisms;
+        [NonSerialized] private List<SharedMechanismComponent>? _mechanisms;
 
         public readonly EntityUid[] MechanismIds;
 
@@ -329,7 +389,7 @@ namespace Content.Shared.Body.Part
             MechanismIds = mechanismIds;
         }
 
-        public List<IMechanism> Mechanisms(IEntityManager? entityManager = null)
+        public List<SharedMechanismComponent> Mechanisms(IEntityManager? entityManager = null)
         {
             if (_mechanisms != null)
             {
@@ -338,7 +398,7 @@ namespace Content.Shared.Body.Part
 
             entityManager ??= IoCManager.Resolve<IEntityManager>();
 
-            var mechanisms = new List<IMechanism>(MechanismIds.Length);
+            var mechanisms = new List<SharedMechanismComponent>(MechanismIds.Length);
 
             foreach (var id in MechanismIds)
             {
@@ -347,7 +407,7 @@ namespace Content.Shared.Body.Part
                     continue;
                 }
 
-                if (!entity.TryGetComponent(out IMechanism? mechanism))
+                if (!entity.TryGetComponent(out SharedMechanismComponent? mechanism))
                 {
                     continue;
                 }

Content.Shared/Body/Preset/BodyPresetPrototype.cs

@@ -11,7 +11,7 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Body.Preset
 {
     /// <summary>
-    ///     Defines the <see cref="IBodyPart"/>s used in a <see cref="IBody"/>.
+    ///     Defines the parts used in a body.
     /// </summary>
     [Prototype("bodyPreset")]
     [Serializable, NetSerializable]

Content.Shared/Body/Slot/BodyPartSlot.cs

@@ -37,7 +37,7 @@ namespace Content.Shared.Body.Slot
         ///     The part currently in this slot, if any.
         /// </summary>
         [ViewVariables]
-        public IBodyPart? Part { get; private set; }
+        public SharedBodyPartComponent? Part { get; private set; }
 
         /// <summary>
         ///     List of slots that this slot connects to.
@@ -45,21 +45,21 @@ namespace Content.Shared.Body.Slot
         [ViewVariables]
         public HashSet<BodyPartSlot> Connections { get; private set; }
 
-        public event Action<IBodyPart>? PartAdded;
+        public event Action<SharedBodyPartComponent>? PartAdded;
 
-        public event Action<IBodyPart>? PartRemoved;
+        public event Action<SharedBodyPartComponent>? PartRemoved;
 
         internal void SetConnectionsInternal(IEnumerable<BodyPartSlot> connections)
         {
             Connections = new HashSet<BodyPartSlot>(connections);
         }
 
-        public bool CanAddPart(IBodyPart part)
+        public bool CanAddPart(SharedBodyPartComponent part)
         {
             return Part == null && part.PartType == PartType;
         }
 
-        public bool TryAddPart(IBodyPart part)
+        public bool TryAddPart(SharedBodyPartComponent part)
         {
             if (!CanAddPart(part))
             {
@@ -70,7 +70,7 @@ namespace Content.Shared.Body.Slot
             return true;
         }
 
-        public void SetPart(IBodyPart part)
+        public void SetPart(SharedBodyPartComponent part)
         {
             if (Part != null)
             {

Content.Shared/Body/Surgery/ISurgeon.cs

@@ -12,7 +12,7 @@ namespace Content.Shared.Body.Surgery
     public interface ISurgeon
     {
         public delegate void MechanismRequestCallback(
-            IMechanism target,
+            SharedMechanismComponent target,
             IBodyPartContainer container,
             ISurgeon surgeon,
             IEntity performer);
@@ -25,10 +25,10 @@ namespace Content.Shared.Body.Surgery
         /// <summary>
         ///     When performing a surgery, the <see cref="SurgeryDataComponent"/>
         ///     may sometimes require selecting from a set of
-        ///     <see cref="IMechanism"/>s to operate on.
+        ///     <see cref="SharedMechanismComponent"/>s to operate on.
         ///     This function is called in that scenario, and it is expected that you call
-        ///     the callback with one <see cref="IMechanism"/> from the provided list.
+        ///     the callback with one <see cref="SharedMechanismComponent"/> from the provided list.
         /// </summary>
-        public void RequestMechanism(IEnumerable<IMechanism> options, MechanismRequestCallback callback);
+        public void RequestMechanism(IEnumerable<SharedMechanismComponent> options, MechanismRequestCallback callback);
     }
 }

Content.Shared/Body/Surgery/SurgeryDataComponent.cs

@@ -6,21 +6,21 @@ using Robust.Shared.GameObjects;
 namespace Content.Shared.Body.Surgery
 {
     /// <summary>
-    ///     Represents the current surgery state of a <see cref="IBodyPart"/>.
+    ///     Represents the current surgery state of a <see cref="SharedBodyPartComponent"/>.
     /// </summary>
     public interface ISurgeryData : IComponent
     {
         public delegate void SurgeryAction(IBodyPartContainer container, ISurgeon surgeon, IEntity performer);
 
         /// <summary>
-        ///     The <see cref="IBodyPart"/> this
+        ///     The <see cref="SharedBodyPartComponent"/> this
         ///     <see cref="ISurgeryData"/> is attached to.
         /// </summary>
-        public IBodyPart? Parent { get; }
+        public SharedBodyPartComponent? Parent { get; }
 
         /// <summary>
         ///     The <see cref="BodyPartType"/> of the parent
-        ///     <see cref="IBodyPart"/>.
+        ///     <see cref="SharedBodyPartComponent"/>.
         /// </summary>
         public BodyPartType? ParentType { get; }
 
@@ -31,18 +31,18 @@ namespace Content.Shared.Body.Surgery
         public string GetDescription();
 
         /// <summary>
-        ///     Returns whether a <see cref="IMechanism"/> can be added into the
-        ///     <see cref="IBodyPart"/> this <see cref="ISurgeryData"/>
+        ///     Returns whether a <see cref="SharedMechanismComponent"/> can be added into the
+        ///     <see cref="SharedBodyPartComponent"/> this <see cref="ISurgeryData"/>
         ///     represents.
         /// </summary>
-        public bool CanAddMechanism(IMechanism mechanism);
+        public bool CanAddMechanism(SharedMechanismComponent mechanism);
 
         /// <summary>
-        ///     Returns whether the given <see cref="IBodyPart"/> can be connected
-        ///     to the <see cref="IBodyPart"/> this <see cref="ISurgeryData"/>
+        ///     Returns whether the given <see cref="SharedBodyPartComponent"/> can be connected
+        ///     to the <see cref="SharedBodyPartComponent"/> this <see cref="ISurgeryData"/>
         ///     represents.
         /// </summary>
-        public bool CanAttachBodyPart(IBodyPart part);
+        public bool CanAttachBodyPart(SharedBodyPartComponent part);
 
         /// <summary>
         ///     Gets the delegate corresponding to the surgery step using the given
@@ -56,7 +56,7 @@ namespace Content.Shared.Body.Surgery
 
         /// <summary>
         ///     Returns whether the given <see cref="SurgeryType"/> can be used to
-        ///     perform a surgery on the <see cref="IBodyPart"/> this
+        ///     perform a surgery on the <see cref="SharedBodyPartComponent"/> this
         ///     <see cref="ISurgeryData"/> represents.
         /// </summary>
         public bool CheckSurgery(SurgeryType toolType)

Content.Shared/Body/Template/BodyTemplatePrototype.cs

@@ -11,7 +11,7 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Body.Template
 {
     /// <summary>
-    ///     Defines the layout of a <see cref="IBody"/>.
+    ///     Defines the layout of a body.
     /// </summary>
     [Prototype("bodyTemplate")]
     [Serializable, NetSerializable]

Content.Shared/CharacterAppearance/HumanoidVisualLayersExtension.cs

@@ -5,7 +5,7 @@ namespace Content.Shared.CharacterAppearance
 {
     public static class HumanoidVisualLayersExtension
     {
-        public static HumanoidVisualLayers? ToHumanoidLayer(this IBodyPart part)
+        public static HumanoidVisualLayers? ToHumanoidLayer(this SharedBodyPartComponent part)
         {
             return part.PartType switch
             {

Content.Shared/Damage/DamageChangeParams.cs

@@ -12,6 +12,7 @@ namespace Content.Shared.Damage
     ///     <see cref="SharedBodyComponent"/> may require it for extra data
     ///     (such as selecting which limb to target).
     /// </summary>
+    // TODO BODY: Remove and pretend it never existed
     public class DamageChangeParams : EventArgs
     {
     }

Content.Shared/Disposal/Components/SharedDisposalUnitComponent.cs

@@ -131,7 +131,7 @@ namespace Content.Shared.Disposal.Components
 
             // TODO: Probably just need a disposable tag.
             if (!entity.TryGetComponent(out SharedItemComponent? storable) &&
-                !entity.HasComponent<IBody>())
+                !entity.HasComponent<SharedBodyComponent>())
             {
                 return false;
             }

Content.Shared/MedicalScanner/SharedMedicalScannerComponent.cs

@@ -82,7 +82,7 @@ namespace Content.Shared.MedicalScanner
 
         bool IDragDropOn.CanDragDropOn(DragDropEvent eventArgs)
         {
-            return eventArgs.Dragged.HasComponent<IBody>();
+            return eventArgs.Dragged.HasComponent<SharedBodyComponent>();
         }
 
         public abstract bool DragDropOn(DragDropEvent eventArgs);