Refactoring body system to use containers and general body cleanup (#20202)

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

.github/CODEOWNERS

@@ -60,3 +60,6 @@
 /Content.*/Atmos/ @Partmedia
 /Content.*/Botany/ @Partmedia
 
+#Jezi
+/Content.*/Medical @Jezithyr
+/Content.*/Body @Jezithyr

Content.IntegrationTests/Tests/Body/LegTest.cs

@@ -38,6 +38,7 @@ namespace Content.IntegrationTests.Tests.Body
             var entityManager = server.ResolveDependency<IEntityManager>();
             var mapManager = server.ResolveDependency<IMapManager>();
             var appearanceSystem = entityManager.System<SharedAppearanceSystem>();
+            var xformSystem = entityManager.System<SharedTransformSystem>();
 
             await server.WaitAssertion(() =>
             {
@@ -60,7 +61,7 @@ namespace Content.IntegrationTests.Tests.Body
 
                 foreach (var leg in legs)
                 {
-                    bodySystem.DropPart(leg.Id, leg.Component);
+                    xformSystem.DetachParentToNull(leg.Id, entityManager.GetComponent<TransformComponent>(leg.Id));
                 }
             });
 

Content.IntegrationTests/Tests/Body/SaveLoadReparentTest.cs

@@ -3,6 +3,7 @@ using System.Linq;
 using Content.Shared.Body.Components;
 using Content.Shared.Body.Systems;
 using Robust.Server.GameObjects;
+using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
 
@@ -31,6 +32,7 @@ public sealed class SaveLoadReparentTest
         var maps = server.ResolveDependency<IMapManager>();
         var mapLoader = entities.System<MapLoaderSystem>();
         var bodySystem = entities.System<SharedBodySystem>();
+        var containerSystem = entities.System<SharedContainerSystem>();
 
         await server.WaitAssertion(() =>
         {
@@ -40,7 +42,7 @@ public sealed class SaveLoadReparentTest
 
             Assert.That(entities.HasComponent<BodyComponent>(human), Is.True);
 
-            var parts = bodySystem.GetBodyChildren(human).ToArray();
+            var parts = bodySystem.GetBodyChildren(human).Skip(1).ToArray();
             var organs = bodySystem.GetBodyOrgans(human).ToArray();
 
             Assert.Multiple(() =>
@@ -54,9 +56,17 @@ public sealed class SaveLoadReparentTest
                 Assert.Multiple(() =>
                 {
                     Assert.That(component.Body, Is.EqualTo(human));
-                    Assert.That(component.ParentSlot, Is.Not.Null);
+                    Assert.That(component.Body, Is.Not.Null);
-                    Assert.That(component.ParentSlot.Parent, Is.Not.EqualTo(default(EntityUid)));
+                    var parent = bodySystem.GetParentPartOrNull(id);
-                    Assert.That(component.ParentSlot.Child, Is.EqualTo(id));
+                    Assert.That(parent, Is.Not.EqualTo(default(EntityUid)));
+                    if (!bodySystem.IsPartRoot(component.Body.Value, id, null, component))
+                    {
+                        Assert.That(parent, Is.Not.Null);
+                    }
+                    else
+                    {
+                        Assert.That(parent, Is.Null);
+                    }
                 });
 
                 foreach (var (slotId, slot) in component.Children)
@@ -64,19 +74,22 @@ public sealed class SaveLoadReparentTest
                     Assert.Multiple(() =>
                     {
                         Assert.That(slot.Id, Is.EqualTo(slotId));
-                        Assert.That(slot.Parent, Is.Not.EqualTo(default(EntityUid)));
+                        var container =
+                            containerSystem.GetContainer(id, SharedBodySystem.GetPartSlotContainerId(slotId));
+                        Assert.That(container.ContainedEntities, Is.Not.Empty);
                     });
                 }
             }
 
             foreach (var (id, component) in organs)
             {
+                var parent = bodySystem.GetParentPartOrNull(id);
+
                 Assert.Multiple(() =>
                 {
                     Assert.That(component.Body, Is.EqualTo(human));
-                    Assert.That(component.ParentSlot, Is.Not.Null);
+                    Assert.That(parent, Is.Not.Null);
-                    Assert.That(component.ParentSlot.Parent, Is.Not.EqualTo(default(EntityUid)));
+                    Assert.That(parent.Value, Is.Not.EqualTo(default(EntityUid)));
-                    Assert.That(component.ParentSlot.Child, Is.EqualTo(id));
                 });
             }
 
@@ -115,7 +128,7 @@ public sealed class SaveLoadReparentTest
             foreach (var (uid, body) in query)
             {
                 human = uid;
-                parts = bodySystem.GetBodyChildren(human).ToArray();
+                parts = bodySystem.GetBodyChildren(human).Skip(1).ToArray();
                 organs = bodySystem.GetBodyOrgans(human).ToArray();
 
                 Assert.Multiple(() =>
@@ -126,12 +139,13 @@ public sealed class SaveLoadReparentTest
 
                 foreach (var (id, component) in parts)
                 {
+                    var parent = bodySystem.GetParentPartOrNull(id);
+
                     Assert.Multiple(() =>
                     {
                         Assert.That(component.Body, Is.EqualTo(human));
-                        Assert.That(component.ParentSlot, Is.Not.Null);
+                        Assert.That(parent, Is.Not.Null);
-                        Assert.That(component.ParentSlot.Parent, Is.Not.EqualTo(default(EntityUid)));
+                        Assert.That(parent.Value, Is.Not.EqualTo(default(EntityUid)));
-                        Assert.That(component.ParentSlot.Child, Is.EqualTo(id));
                     });
 
                     foreach (var (slotId, slot) in component.Children)
@@ -139,19 +153,22 @@ public sealed class SaveLoadReparentTest
                         Assert.Multiple(() =>
                         {
                             Assert.That(slot.Id, Is.EqualTo(slotId));
-                            Assert.That(slot.Parent, Is.Not.EqualTo(default(EntityUid)));
+                            var container =
+                                containerSystem.GetContainer(id, SharedBodySystem.GetPartSlotContainerId(slotId));
+                            Assert.That(container.ContainedEntities, Is.Not.Empty);
                         });
                     }
                 }
 
                 foreach (var (id, component) in organs)
                 {
+                    var parent = bodySystem.GetParentPartOrNull(id);
+
                     Assert.Multiple(() =>
                     {
                         Assert.That(component.Body, Is.EqualTo(human));
-                        Assert.That(component.ParentSlot, Is.Not.Null);
+                        Assert.That(parent, Is.Not.Null);
-                        Assert.That(component.ParentSlot.Parent, Is.Not.EqualTo(default(EntityUid)));
+                        Assert.That(parent.Value, Is.Not.EqualTo(default(EntityUid)));
-                        Assert.That(component.ParentSlot.Child, Is.EqualTo(id));
                     });
                 }
 

Content.IntegrationTests/Tests/Buckle/BuckleTest.cs

@@ -258,6 +258,7 @@ namespace Content.IntegrationTests.Tests.Buckle
             var entityManager = server.ResolveDependency<IEntityManager>();
             var handsSys = entityManager.EntitySysManager.GetEntitySystem<SharedHandsSystem>();
             var buckleSystem = entityManager.EntitySysManager.GetEntitySystem<SharedBuckleSystem>();
+            var xformSystem = entityManager.System<SharedTransformSystem>();
 
             await server.WaitAssertion(() =>
             {
@@ -309,7 +310,7 @@ namespace Content.IntegrationTests.Tests.Buckle
                 // Break our guy's kneecaps
                 foreach (var leg in legs)
                 {
-                    bodySystem.DropPart(leg.Id, leg.Component);
+                    xformSystem.DetachParentToNull(leg.Id, entityManager.GetComponent<TransformComponent>(leg.Id));
                 }
             });
 

Content.IntegrationTests/Tests/EncryptionKeys/RemoveEncryptionKeys.cs

@@ -30,7 +30,7 @@ public sealed class RemoveEncryptionKeys : InteractionTest
             Assert.That(comp.Channels, Has.Count.EqualTo(0));
         });
 
-        // Checkl that the key was ejected and not just deleted or something.
+        // Check that the key was ejected and not just deleted or something.
         await AssertEntityLookup(("EncryptionKeyCommon", 1));
 
         // Re-insert a key.

Content.IntegrationTests/Tests/Interaction/InteractionTest.cs

@@ -218,12 +218,13 @@ public abstract partial class InteractionTest
         // Ensure that the player only has one hand, so that they do not accidentally pick up deconstruction products
         await Server.WaitPost(() =>
         {
+            // I lost an hour of my life trying to track down how the hell interaction tests were breaking
+            // so greatz to this. Just make your own body prototype!
             var bodySystem = SEntMan.System<BodySystem>();
             var hands = bodySystem.GetBodyChildrenOfType(SEntMan.GetEntity(Player), BodyPartType.Hand).ToArray();
 
             for (var i = 1; i < hands.Length; i++)
             {
-                bodySystem.DropPart(hands[i].Id);
                 SEntMan.DeleteEntity(hands[i].Id);
             }
         });

Content.Server/Administration/Commands/AddBodyPartCommand.cs

@@ -1,5 +1,6 @@
 using Content.Server.Body.Systems;
 using Content.Shared.Administration;
+using Content.Shared.Body.Part;
 using Robust.Shared.Console;
 
 namespace Content.Server.Administration.Commands
@@ -11,7 +12,7 @@ namespace Content.Server.Administration.Commands
 
         public string Command => "addbodypart";
         public string Description => "Adds a given entity to a containing body.";
-        public string Help => "Usage: addbodypart <entity uid> <body uid> <part slot>";
+        public string Help => "Usage: addbodypart <entity uid> <body uid> <part slot> <part type>";
 
         public void Execute(IConsoleShell shell, string argStr, string[] args)
         {
@@ -37,7 +38,10 @@ namespace Content.Server.Administration.Commands
             var parentId = _entManager.GetEntity(parentNetId);
             var bodySystem = _entManager.System<BodySystem>();
 
-            if (bodySystem.TryCreatePartSlotAndAttach(parentId, args[2], childId))
+
+
+            if (Enum.TryParse<BodyPartType>(args[3], out var partType) &&
+                bodySystem.TryCreatePartSlotAndAttach(parentId, args[2], childId, partType))
             {
                 shell.WriteLine($@"Added {childId} to {parentId}.");
             }

Content.Server/Administration/Commands/AddMechanismCommand.cs

@@ -35,7 +35,7 @@ namespace Content.Server.Administration.Commands
 
             var bodySystem = _entManager.System<BodySystem>();
 
-            if (bodySystem.AddOrganToFirstValidSlot(organId, partId))
+            if (bodySystem.AddOrganToFirstValidSlot(partId.Value, organId.Value))
             {
                 shell.WriteLine($@"Added {organId} to {partId}.");
             }

Content.Server/Administration/Commands/RemoveBodyPartCommand.cs

@@ -27,16 +27,10 @@ namespace Content.Server.Administration.Commands
                 return;
             }
 
-            var bodySystem = _entManager.System<BodySystem>();
+            // TODO: THIS IS JUST A MECHANISM COPYPASTE
-
+            var xformSystem = _entManager.System<SharedTransformSystem>();
-            if (bodySystem.DropPart(entityUid))
+            xformSystem.AttachToGridOrMap(entityUid.Value);
-            {
+            shell.WriteLine($"Removed body part {_entManager.ToPrettyString(entityUid.Value)}");
-                shell.WriteLine($"Removed body part {_entManager.ToPrettyString(entityUid.Value)}.");
-            }
-            else
-            {
-                shell.WriteError("Was not a body part, or did not have a parent.");
-            }
         }
     }
 }

Content.Server/Administration/Commands/RemoveMechanismCommand.cs

@@ -27,16 +27,9 @@ namespace Content.Server.Administration.Commands
                 return;
             }
 
-            var bodySystem = _entManager.System<BodySystem>();
+            var xformSystem = _entManager.System<SharedTransformSystem>();
-
+            xformSystem.AttachToGridOrMap(entityUid.Value);
-            if (bodySystem.DropOrgan(entityUid))
+            shell.WriteLine($"Removed organ {_entManager.ToPrettyString(entityUid.Value)}");
-            {
-                shell.WriteLine($"Removed organ {_entManager.ToPrettyString(entityUid.Value)}");
-            }
-            else
-            {
-                shell.WriteError("Was not a mechanism, or did not have a parent.");
-            }
         }
     }
 }

Content.Server/Administration/Systems/AdminVerbSystem.Smites.cs

@@ -76,6 +76,7 @@ public sealed partial class AdminVerbSystem
     [Dependency] private readonly VomitSystem _vomitSystem = default!;
     [Dependency] private readonly WeldableSystem _weldableSystem = default!;
     [Dependency] private readonly SharedContentEyeSystem _eyeSystem = default!;
+    [Dependency] private readonly SharedTransformSystem _transformSystem = default!;
 
     // All smite verbs have names so invokeverb works.
     private void AddSmiteVerbs(GetVerbsEvent<Verb> args)
@@ -293,8 +294,7 @@ public sealed partial class AdminVerbSystem
                         if (HasComp<BrainComponent>(xform.Owner) || HasComp<EyeComponent>(xform.Owner))
                             continue;
 
-                        var coordinates = baseXform.Coordinates.Offset(_random.NextVector2(0.5f, 0.75f));
+                        _transformSystem.AttachToGridOrMap(organ.Owner);
-                        _bodySystem.DropOrganAt(organ.Owner, coordinates, organ);
                     }
 
                     _popupSystem.PopupEntity(Loc.GetString("admin-smite-vomit-organs-self"), args.Target,
@@ -317,7 +317,7 @@ public sealed partial class AdminVerbSystem
                     var baseXform = Transform(args.Target);
                     foreach (var part in _bodySystem.GetBodyChildrenOfType(args.Target, BodyPartType.Hand))
                     {
-                        _bodySystem.DropPartAt(part.Id, baseXform.Coordinates, part.Component);
+                        _transformSystem.AttachToGridOrMap(part.Id);
                     }
                     _popupSystem.PopupEntity(Loc.GetString("admin-smite-remove-hands-self"), args.Target,
                         args.Target, PopupType.LargeCaution);
@@ -339,7 +339,7 @@ public sealed partial class AdminVerbSystem
                     var baseXform = Transform(args.Target);
                     foreach (var part in _bodySystem.GetBodyChildrenOfType(body.Owner, BodyPartType.Hand, body))
                     {
-                        _bodySystem.DropPartAt(part.Id, baseXform.Coordinates, part.Component);
+                        _transformSystem.AttachToGridOrMap(part.Id);
                         break;
                     }
                     _popupSystem.PopupEntity(Loc.GetString("admin-smite-remove-hands-self"), args.Target,

Content.Server/Body/Commands/AddHandCommand.cs

@@ -118,7 +118,7 @@ namespace Content.Server.Body.Commands
                 }
             }
 
-            if (!_entManager.TryGetComponent(entity, out BodyComponent? body) || body.Root == null)
+            if (!_entManager.TryGetComponent(entity, out BodyComponent? body) || body.RootContainer.ContainedEntity == null)
             {
                 var text = $"You have no body{(_random.Prob(0.2f) ? " and you must scream." : ".")}";
 
@@ -140,7 +140,7 @@ namespace Content.Server.Body.Commands
 
             var slotId = part.GetHashCode().ToString();
 
-            if (!bodySystem.TryCreatePartSlotAndAttach(attachAt.Id, slotId, hand, attachAt.Component, part))
+            if (!bodySystem.TryCreatePartSlotAndAttach(attachAt.Id, slotId, hand, BodyPartType.Hand,attachAt.Component, part))
             {
                 shell.WriteError($"Couldn't create a slot with id {slotId} on entity {_entManager.ToPrettyString(entity)}");
                 return;

Content.Server/Body/Commands/AttachBodyPartCommand.cs

@@ -94,7 +94,7 @@ namespace Content.Server.Body.Commands
             }
 
             var bodySystem = _entManager.System<BodySystem>();
-            if (bodySystem.BodyHasChild(bodyId, partUid, body, part))
+            if (bodySystem.BodyHasChild(bodyId, partUid.Value, body, part))
             {
                 shell.WriteLine($"Body part {_entManager.GetComponent<MetaDataComponent>(partUid.Value).EntityName} with uid {partUid} is already attached to entity {_entManager.GetComponent<MetaDataComponent>(bodyId).EntityName} with uid {bodyId}");
                 return;
@@ -103,16 +103,14 @@ namespace Content.Server.Body.Commands
             var slotId = $"AttachBodyPartVerb-{partUid}";
 
             // ReSharper disable once ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
-            if (bodySystem.TryCreateBodyRootSlot(bodyId, slotId, out var rootSlot, body))
+            if (body.RootContainer.ContainedEntity != null)
             {
-                bodySystem.DropPart(partUid, part);
+                bodySystem.AttachPartToRoot(bodyId,partUid.Value, body ,part);
-                bodySystem.AttachPart(partUid, rootSlot, part);
             }
             else
             {
-                var attachAt = bodySystem.GetBodyChildren(bodyId, body).First();
+                var (rootPartId,rootPart) = bodySystem.GetRootPartOrNull(bodyId, body)!.Value;
-
+                if (!bodySystem.TryCreatePartSlotAndAttach(rootPartId, slotId, partUid.Value, part.PartType, rootPart, part))
-                if (!bodySystem.TryCreatePartSlotAndAttach(attachAt.Id, slotId, partUid, attachAt.Component, part))
                 {
                     shell.WriteError($"Could not create slot {slotId} on entity {_entManager.ToPrettyString(bodyId)}");
                     return;

Content.Server/Body/Commands/DestroyMechanismCommand.cs

@@ -55,7 +55,7 @@ namespace Content.Server.Body.Commands
             {
                 if (fac.GetComponentName(organ.Component.GetType()).ToLowerInvariant() == mechanismName)
                 {
-                    bodySystem.DeleteOrgan(organ.Id, organ.Component);
+                    entityManager.QueueDeleteEntity(organ.Id);
                     shell.WriteLine($"Mechanism with name {mechanismName} has been destroyed.");
                     return;
                 }

Content.Server/Body/Commands/RemoveHandCommand.cs

@@ -11,8 +11,11 @@ using Robust.Shared.Random;
 namespace Content.Server.Body.Commands
 {
     [AdminCommand(AdminFlags.Fun)]
-    sealed class RemoveHandCommand : IConsoleCommand
+    public sealed class RemoveHandCommand : IConsoleCommand
     {
+        [Dependency] private readonly IEntityManager _entManager = default!;
+        [Dependency] private readonly IRobustRandom _random = default!;
+
         public string Command => "removehand";
         public string Description => "Removes a hand from your entity.";
         public string Help => $"Usage: {Command}";
@@ -32,18 +35,16 @@ namespace Content.Server.Body.Commands
                 return;
             }
 
-            var entityManager = IoCManager.Resolve<IEntityManager>();
+            if (!_entManager.TryGetComponent(player.AttachedEntity, out BodyComponent? body))
-            if (!entityManager.TryGetComponent(player.AttachedEntity, out BodyComponent? body))
             {
-                var random = IoCManager.Resolve<IRobustRandom>();
+                var text = $"You have no body{(_random.Prob(0.2f) ? " and you must scream." : ".")}";
-                var text = $"You have no body{(random.Prob(0.2f) ? " and you must scream." : ".")}";
 
                 shell.WriteLine(text);
                 return;
             }
 
-            var bodySystem = entityManager.System<BodySystem>();
+            var bodySystem = _entManager.System<BodySystem>();
-            var hand = bodySystem.GetBodyChildrenOfType(player.AttachedEntity, BodyPartType.Hand, body).FirstOrDefault();
+            var hand = bodySystem.GetBodyChildrenOfType(player.AttachedEntity.Value, BodyPartType.Hand, body).FirstOrDefault();
 
             if (hand == default)
             {
@@ -51,7 +52,7 @@ namespace Content.Server.Body.Commands
             }
             else
             {
-                bodySystem.DropPart(hand.Id, hand.Component);
+                _entManager.System<SharedTransformSystem>().AttachToGridOrMap(hand.Id);
             }
         }
     }

Content.Server/Body/Systems/BodySystem.cs

@@ -17,6 +17,7 @@ using Content.Shared.Movement.Events;
 using Content.Shared.Random.Helpers;
 using Robust.Shared.Audio;
 using Robust.Shared.Containers;
+using Robust.Shared.Map;
 using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
@@ -32,80 +33,16 @@ public sealed class BodySystem : SharedBodySystem
     [Dependency] private readonly SharedAudioSystem _audio = default!;
     [Dependency] private readonly SharedAppearanceSystem _appearance = default!;
     [Dependency] private readonly SharedMindSystem _mindSystem = default!;
-    [Dependency] private readonly SharedTransformSystem _transform = default!;
 
     public override void Initialize()
     {
         base.Initialize();
 
-        SubscribeLocalEvent<BodyPartComponent, ComponentStartup>(OnPartStartup);
-        SubscribeLocalEvent<BodyComponent, ComponentStartup>(OnBodyStartup);
         SubscribeLocalEvent<BodyComponent, MoveInputEvent>(OnRelayMoveInput);
         SubscribeLocalEvent<BodyComponent, ApplyMetabolicMultiplierEvent>(OnApplyMetabolicMultiplier);
         SubscribeLocalEvent<BodyComponent, BeingMicrowavedEvent>(OnBeingMicrowaved);
     }
 
-    private void OnPartStartup(EntityUid uid, BodyPartComponent component, ComponentStartup args)
-    {
-        // This inter-entity relationship makes be deeply uncomfortable because its probably going to re-encounter
-        // all of the networking & startup ordering issues that containers and joints have.
-        // TODO just use containers. Please.
-
-        foreach (var slot in component.Children.Values)
-        {
-            DebugTools.Assert(slot.Parent == uid);
-            if (slot.Child == null)
-                continue;
-
-            if (TryComp(slot.Child, out BodyPartComponent? child))
-            {
-                child.ParentSlot = slot;
-                Dirty(slot.Child.Value, child);
-                continue;
-            }
-
-            Log.Error($"Body part encountered missing limbs: {ToPrettyString(uid)}. Slot: {slot.Id}");
-            slot.Child = null;
-        }
-
-        foreach (var slot in component.Organs.Values)
-        {
-            DebugTools.Assert(slot.Parent == uid);
-            if (slot.Child == null)
-                continue;
-
-            if (TryComp(slot.Child, out OrganComponent? child))
-            {
-                child.ParentSlot = slot;
-                Dirty(slot.Child.Value, child);
-                continue;
-            }
-
-            Log.Error($"Body part encountered missing organ: {ToPrettyString(uid)}. Slot: {slot.Id}");
-            slot.Child = null;
-        }
-    }
-
-    private void OnBodyStartup(EntityUid uid, BodyComponent component, ComponentStartup args)
-    {
-        if (component.Root is not { } slot)
-            return;
-
-        DebugTools.Assert(slot.Parent == uid);
-        if (slot.Child == null)
-            return;
-
-        if (!TryComp(slot.Child, out BodyPartComponent? child))
-        {
-            Log.Error($"Body part encountered missing limbs: {ToPrettyString(uid)}. Slot: {slot.Id}");
-            slot.Child = null;
-            return;
-        }
-
-        child.ParentSlot = slot;
-        Dirty(slot.Child.Value, child);
-    }
-
     private void OnRelayMoveInput(EntityUid uid, BodyComponent component, ref MoveInputEvent args)
     {
         if (_mobState.IsDead(uid) && _mindSystem.TryGetMind(uid, out var mindId, out var mind))
@@ -130,98 +67,95 @@ public sealed class BodySystem : SharedBodySystem
             return;
 
         // Don't microwave animals, kids
-        _transform.AttachToGridOrMap(uid);
+        SharedTransform.AttachToGridOrMap(uid);
         _appearance.SetData(args.Microwave, MicrowaveVisualState.Bloody, true);
         GibBody(uid, false, component);
 
         args.Handled = true;
     }
 
-    public override bool AttachPart(
+    protected override void AddPart(
-        EntityUid? partId,
+        EntityUid bodyUid,
-        BodyPartSlot slot,
+        EntityUid partUid,
-        [NotNullWhen(true)] BodyPartComponent? part = null)
+        string slotId,
+        BodyPartComponent component,
+        BodyComponent? bodyComp = null)
     {
-        if (!base.AttachPart(partId, slot, part))
+        // TODO: Predict this probably.
-            return false;
+        base.AddPart(bodyUid, partUid, slotId, component, bodyComp);
 
-        if (part.Body is { } body &&
+        if (TryComp<HumanoidAppearanceComponent>(bodyUid, out var humanoid))
-            TryComp<HumanoidAppearanceComponent>(body, out var humanoid))
         {
-            var layer = part.ToHumanoidLayers();
+            var layer = component.ToHumanoidLayers();
             if (layer != null)
             {
                 var layers = HumanoidVisualLayersExtension.Sublayers(layer.Value);
-                _humanoidSystem.SetLayersVisibility(body, layers, true, true, humanoid);
+                _humanoidSystem.SetLayersVisibility(bodyUid, layers, true, true, humanoid);
             }
         }
-
-        return true;
     }
 
-    public override bool DropPart(EntityUid? partId, BodyPartComponent? part = null)
+    protected override void RemovePart(
+        EntityUid bodyUid,
+        EntityUid partUid,
+        string slotId,
+        BodyPartComponent component,
+        BodyComponent? bodyComp = null)
     {
-        if (partId == null || !Resolve(partId.Value, ref part))
+        base.RemovePart(bodyUid, partUid, slotId, component, bodyComp);
-            return false;
 
-        if (!base.DropPart(partId, part))
+        if (!TryComp<HumanoidAppearanceComponent>(bodyUid, out var humanoid))
-            return false;
+            return;
 
-        var oldBody = part.Body;
+        var layer = component.ToHumanoidLayers();
-        if (oldBody == null || !TryComp<HumanoidAppearanceComponent>(oldBody, out var humanoid))
-            return true;
 
-        var layer = part.ToHumanoidLayers();
         if (layer == null)
-            return true;
+            return;
 
         var layers = HumanoidVisualLayersExtension.Sublayers(layer.Value);
-        _humanoidSystem.SetLayersVisibility(oldBody.Value, layers, false, true, humanoid);
+        _humanoidSystem.SetLayersVisibility(bodyUid, layers, false, true, humanoid);
-        return true;
     }
 
-    public override HashSet<EntityUid> GibBody(EntityUid? bodyId, bool gibOrgans = false, BodyComponent? body = null, bool deleteItems = false)
+    public override HashSet<EntityUid> GibBody(EntityUid bodyId, bool gibOrgans = false, BodyComponent? body = null, bool deleteItems = false)
     {
-        if (bodyId == null || !Resolve(bodyId.Value, ref body, false))
+        if (!Resolve(bodyId, ref body, false))
             return new HashSet<EntityUid>();
 
-        if (LifeStage(bodyId.Value) >= EntityLifeStage.Terminating || EntityManager.IsQueuedForDeletion(bodyId.Value))
+        if (LifeStage(bodyId) >= EntityLifeStage.Terminating || EntityManager.IsQueuedForDeletion(bodyId))
             return new HashSet<EntityUid>();
 
-        var xform = Transform(bodyId.Value);
+        var xform = Transform(bodyId);
         if (xform.MapUid == null)
             return new HashSet<EntityUid>();
 
         var gibs = base.GibBody(bodyId, gibOrgans, body, deleteItems);
 
         var coordinates = xform.Coordinates;
-        var filter = Filter.Pvs(bodyId.Value, entityManager: EntityManager);
+        var filter = Filter.Pvs(bodyId, entityManager: EntityManager);
         var audio = AudioParams.Default.WithVariation(0.025f);
 
         _audio.Play(body.GibSound, filter, coordinates, true, audio);
 
-        if (TryComp(bodyId, out ContainerManagerComponent? container))
+        var containers = GetBodyContainers(bodyId, body: body).ToList();
+
+        foreach (var container in containers)
         {
-            foreach (var cont in container.GetAllContainers().ToArray())
+            foreach (var entity in container.ContainedEntities)
             {
-                foreach (var ent in cont.ContainedEntities.ToArray())
+                if (deleteItems)
                 {
-                    if (deleteItems)
+                    QueueDel(entity);
-                    {
+                }
-                        QueueDel(ent);
+                else
-                    }
+                {
-                    else
+                    container.Remove(entity, EntityManager, force: true);
-                    {
+                    SharedTransform.SetCoordinates(entity,coordinates);
-                        cont.Remove(ent, EntityManager, force: true);
+                    entity.RandomOffset(0.25f);
-                        Transform(ent).Coordinates = coordinates;
-                        ent.RandomOffset(0.25f);
-                    }
                 }
             }
         }
-
+        RaiseLocalEvent(bodyId, new BeingGibbedEvent(gibs));
-        RaiseLocalEvent(bodyId.Value, new BeingGibbedEvent(gibs));
+        QueueDel(bodyId);
-        QueueDel(bodyId.Value);
 
         return gibs;
     }

Content.Server/Body/Systems/BrainSystem.cs

@@ -30,17 +30,18 @@ namespace Content.Server.Body.Systems
         private void OnRemovedFromBody(EntityUid uid, BrainComponent component, RemovedFromBodyEvent args)
         {
             // This one needs to be special, okay?
-            if (!EntityManager.TryGetComponent(uid, out OrganComponent? organ) ||
+            if (!EntityManager.TryGetComponent(uid, out OrganComponent? organ))
-                organ.ParentSlot is not {Parent: var parent})
+            {
                 return;
+            }
 
-            HandleMind(parent, args.Old);
+            HandleMind(uid, args.Old);
         }
 
         private void HandleMind(EntityUid newEntity, EntityUid oldEntity)
         {
             EnsureComp<MindContainerComponent>(newEntity);
-            var oldMind = EnsureComp<MindContainerComponent>(oldEntity);
+            EnsureComp<MindContainerComponent>(oldEntity);
 
             var ghostOnMove = EnsureComp<GhostOnMoveComponent>(newEntity);
             if (HasComp<BodyComponent>(newEntity))

Content.Server/Cargo/Systems/PricingSystem.cs

@@ -94,8 +94,9 @@ public sealed class PricingSystem : EntitySystem
             return;
         }
 
-        var partList = _bodySystem.GetBodyAllSlots(uid, body).ToList();
+        // TODO: Better handling of missing.
-        var totalPartsPresent = partList.Sum(x => x.Child != null ? 1 : 0);
+        var partList = _bodySystem.GetBodyChildren(uid, body).ToList();
+        var totalPartsPresent = partList.Sum(_ => 1);
         var totalParts = partList.Count;
 
         var partRatio = totalPartsPresent / (double) totalParts;

Content.Server/Climbing/ClimbSystem.cs

@@ -300,8 +300,8 @@ public sealed class ClimbSystem : SharedClimbSystem
 
         if (!HasComp<ClimbingComponent>(user)
             || !TryComp(user, out BodyComponent? body)
-            || !_bodySystem.BodyHasChildOfType(user, BodyPartType.Leg, body)
+            || !_bodySystem.BodyHasPartType(user, BodyPartType.Leg, body)
-            || !_bodySystem.BodyHasChildOfType(user, BodyPartType.Foot, body))
+            || !_bodySystem.BodyHasPartType(user, BodyPartType.Foot, body))
         {
             reason = Loc.GetString("comp-climbable-cant-climb");
             return false;

Content.Server/Kitchen/EntitySystems/MicrowaveSystem.cs

@@ -192,11 +192,6 @@ namespace Content.Server.Kitchen.EntitySystems
 
                 foreach (var part in headSlots)
                 {
-                    if (!_bodySystem.OrphanPart(part.Id, part.Component))
-                    {
-                        continue;
-                    }
-
                     component.Storage.Insert(part.Id);
                     headCount++;
                 }

Content.Server/Toilet/ToiletSystem.cs

@@ -53,7 +53,7 @@ namespace Content.Server.Toilet
             // Check that victim has a head
             // FIXME: since suiciding turns you into a ghost immediately, both messages are seen, not sure how this can be fixed
             if (TryComp<BodyComponent>(args.Victim, out var body) &&
-                _body.BodyHasChildOfType(args.Victim, BodyPartType.Head, body))
+                _body.BodyHasPartType(args.Victim, BodyPartType.Head, body))
             {
                 var othersMessage = Loc.GetString("toilet-component-suicide-head-message-others",
                     ("victim", Identity.Entity(args.Victim, EntityManager)), ("owner", uid));

Content.Shared/Body/Components/BodyComponent.cs

@@ -1,9 +1,10 @@
-using Content.Shared.Body.Part;
 using Content.Shared.Body.Prototypes;
 using Content.Shared.Body.Systems;
 using Robust.Shared.Audio;
+using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
-using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization;
 
 namespace Content.Shared.Body.Components;
 
@@ -11,19 +12,52 @@ namespace Content.Shared.Body.Components;
 [Access(typeof(SharedBodySystem))]
 public sealed partial class BodyComponent : Component
 {
-    [DataField("prototype", customTypeSerializer: typeof(PrototypeIdSerializer<BodyPrototype>))]
+    /// <summary>
-    public string? Prototype;
+    /// Relevant template to spawn for this body.
+    /// </summary>
+    [DataField]
+    public ProtoId<BodyPrototype>? Prototype;
 
-    [DataField("root")]
+    /// <summary>
-    public BodyPartSlot? Root;
+    /// Container that holds the root body part.
+    /// </summary>
+    /// <remarks>
+    /// Typically is the torso.
+    /// </remarks>
+    [ViewVariables] public ContainerSlot RootContainer = default!;
 
-    [DataField("gibSound")]
+    [ViewVariables]
-    public SoundSpecifier GibSound = new SoundCollectionSpecifier("gib");
+    public string RootPartSlot => RootContainer.ID;
+
+    [DataField] public SoundSpecifier GibSound = new SoundCollectionSpecifier("gib");
 
     /// <summary>
     /// The amount of legs required to move at full speed.
     /// If 0, then legs do not impact speed.
     /// </summary>
-    [DataField("requiredLegs")]
+    [DataField] public int RequiredLegs;
-    public int RequiredLegs;
+
+    [ViewVariables]
+    [DataField]
+    public HashSet<EntityUid> LegEntities = new();
+}
+
+[Serializable, NetSerializable]
+public sealed class BodyComponentState : ComponentState
+{
+    public string? Prototype;
+    public string? RootPartSlot;
+    public SoundSpecifier GibSound;
+    public int RequiredLegs;
+    public HashSet<NetEntity> LegNetEntities;
+
+    public BodyComponentState(string? prototype, string? rootPartSlot, SoundSpecifier gibSound,
+        int requiredLegs, HashSet<NetEntity> legNetEntities)
+    {
+        Prototype = prototype;
+        RootPartSlot = rootPartSlot;
+        GibSound = gibSound;
+        RequiredLegs = requiredLegs;
+        LegNetEntities = legNetEntities;
+    }
 }

Content.Shared/Body/Components/BodyComponentState.cs

@@ -1,18 +0,0 @@
-using Content.Shared.Body.Part;
-using Robust.Shared.Audio;
-using Robust.Shared.Serialization;
-
-namespace Content.Shared.Body.Components;
-
-[Serializable, NetSerializable]
-public sealed class BodyComponentState : ComponentState
-{
-    public readonly BodyPartSlot? Root;
-    public readonly SoundSpecifier GibSound;
-
-    public BodyComponentState(BodyPartSlot? root, SoundSpecifier gibSound)
-    {
-        Root = root;
-        GibSound = gibSound;
-    }
-}

Content.Shared/Body/Organ/OrganComponent.cs

@@ -1,16 +1,16 @@
 using Content.Shared.Body.Systems;
+using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
 
 namespace Content.Shared.Body.Organ;
 
-[RegisterComponent, NetworkedComponent]
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
 [Access(typeof(SharedBodySystem))]
 public sealed partial class OrganComponent : Component
 {
-    [DataField("body")]
+    /// <summary>
+    /// Relevant body this organ is attached to.
+    /// </summary>
+    [DataField("body"), AutoNetworkedField]
     public EntityUid? Body;
-
-    // TODO use containers. See comments in BodyPartComponent.
-    // Do not rely on this in client-side code.
-    public OrganSlot? ParentSlot;
 }

Content.Shared/Body/Organ/OrganComponentState.cs

@@ -1,16 +0,0 @@
-using Robust.Shared.Serialization;
-
-namespace Content.Shared.Body.Organ;
-
-[Serializable, NetSerializable]
-public sealed class OrganComponentState : ComponentState
-{
-    public readonly NetEntity? Body;
-    public readonly OrganSlot? Parent;
-
-    public OrganComponentState(NetEntity? body, OrganSlot? parent)
-    {
-        Body = body;
-        Parent = parent;
-    }
-}

Content.Shared/Body/Organ/OrganSlot.cs

@@ -1,33 +0,0 @@
-using Content.Shared.Body.Systems;
-using Robust.Shared.Serialization;
-
-namespace Content.Shared.Body.Organ;
-
-[Serializable, NetSerializable]
-[Access(typeof(SharedBodySystem))]
-[DataDefinition]
-public sealed partial record OrganSlot
-{
-    [DataField("id")]
-    public string Id = string.Empty;
-
-    [NonSerialized]
-    [DataField("parent")]
-    public EntityUid Parent;
-
-    public NetEntity NetParent;
-
-    [NonSerialized]
-    [DataField("child")]
-    public EntityUid? Child;
-
-    public NetEntity? NetChild;
-
-    // Rider doesn't suggest explicit properties during deconstruction without this
-    public void Deconstruct(out EntityUid? child, out string id, out EntityUid parent)
-    {
-        child = Child;
-        id = Id;
-        parent = Parent;
-    }
-}

Content.Shared/Body/Part/BodyPartComponent.cs

@@ -1,32 +1,23 @@
 using Content.Shared.Body.Components;
-using Content.Shared.Body.Organ;
 using Content.Shared.Body.Systems;
+using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
+using Robust.Shared.Serialization;
 
 namespace Content.Shared.Body.Part;
 
-[RegisterComponent, NetworkedComponent]
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState]
 [Access(typeof(SharedBodySystem))]
 public sealed partial class BodyPartComponent : Component
 {
-    [DataField("body")]
+    // Need to set this on container changes as it may be several transform parents up the hierarchy.
+    /// <summary>
+    /// Parent body for this part.
+    /// </summary>
+    [DataField, AutoNetworkedField]
     public EntityUid? Body;
 
-    // This inter-entity relationship makes be deeply uncomfortable because its probably going to re-encounter all of the
+    [DataField, AutoNetworkedField]
-    // networking issues that containers and joints have.
-    // TODO just use containers. Please.
-    // Do not use set or get data from this in client-side code.
-    public BodyPartSlot? ParentSlot;
-
-    // Do not use set or get data from this in client-side code.
-    [DataField("children")]
-    public Dictionary<string, BodyPartSlot> Children = new();
-
-    // See all the above ccomments.
-    [DataField("organs")]
-    public Dictionary<string, OrganSlot> Organs = new();
-
-    [DataField("partType")]
     public BodyPartType PartType = BodyPartType.Other;
 
     // TODO BODY Replace with a simulation of organs
@@ -34,9 +25,90 @@ public sealed partial class BodyPartComponent : Component
     ///     Whether or not the owning <see cref="Body"/> will die if all
     ///     <see cref="BodyComponent"/>s of this type are removed from it.
     /// </summary>
-    [DataField("vital")]
+    [DataField("vital"), AutoNetworkedField]
     public bool IsVital;
 
-    [DataField("symmetry")]
+    [DataField, AutoNetworkedField]
     public BodyPartSymmetry Symmetry = BodyPartSymmetry.None;
+
+    /// <summary>
+    /// Child body parts attached to this body part.
+    /// </summary>
+    [DataField, AutoNetworkedField(CloneData = true)]
+    public Dictionary<string, BodyPartSlot> Children = new();
+
+    /// <summary>
+    /// Organs attached to this body part.
+    /// </summary>
+    [DataField, AutoNetworkedField(CloneData = true)]
+    public Dictionary<string, OrganSlot> Organs = new();
+
+    /// <summary>
+    /// These are only for VV/Debug do not use these for gameplay/systems
+    /// </summary>
+    [ViewVariables]
+    private List<ContainerSlot> BodyPartSlotsVV
+    {
+        get
+        {
+            List<ContainerSlot> temp = new();
+            var containerSystem = IoCManager.Resolve<IEntityManager>().System<SharedContainerSystem>();
+
+            foreach (var slotId in Children.Keys)
+            {
+                temp.Add((ContainerSlot) containerSystem.GetContainer(Owner, slotId));
+            }
+
+            return temp;
+        }
+    }
+
+    [ViewVariables]
+    private List<ContainerSlot> OrganSlotsVV
+    {
+        get
+        {
+            List<ContainerSlot> temp = new();
+            var containerSystem = IoCManager.Resolve<IEntityManager>().System<SharedContainerSystem>();
+
+            foreach (var slotId in Organs.Keys)
+            {
+                temp.Add((ContainerSlot) containerSystem.GetContainer(Owner, slotId));
+            }
+
+            return temp;
+        }
+    }
 }
+
+/// <summary>
+/// Contains metadata about a body part in relation to its slot.
+/// </summary>
+[NetSerializable, Serializable]
+[DataRecord]
+public partial struct BodyPartSlot
+{
+    public string Id;
+    public BodyPartType Type;
+
+    public BodyPartSlot(string id, BodyPartType type)
+    {
+        Id = id;
+        Type = type;
+    }
+};
+
+/// <summary>
+/// Contains metadata about an organ part in relation to its slot.
+/// </summary>
+[NetSerializable, Serializable]
+[DataRecord]
+public partial struct OrganSlot
+{
+    public string Id;
+
+    public OrganSlot(string id)
+    {
+        Id = id;
+    }
+};

Content.Shared/Body/Part/BodyPartComponentState.cs

@@ -1,34 +0,0 @@
-using Content.Shared.Body.Organ;
-using Robust.Shared.Serialization;
-
-namespace Content.Shared.Body.Part;
-
-[Serializable, NetSerializable]
-public sealed class BodyPartComponentState : ComponentState
-{
-    public readonly NetEntity? Body;
-    public readonly BodyPartSlot? ParentSlot;
-    public readonly Dictionary<string, BodyPartSlot> Children;
-    public readonly Dictionary<string, OrganSlot> Organs;
-    public readonly BodyPartType PartType;
-    public readonly bool IsVital;
-    public readonly BodyPartSymmetry Symmetry;
-
-    public BodyPartComponentState(
-        NetEntity? body,
-        BodyPartSlot? parentSlot,
-        Dictionary<string, BodyPartSlot> children,
-        Dictionary<string, OrganSlot> organs,
-        BodyPartType partType,
-        bool isVital,
-        BodyPartSymmetry symmetry)
-    {
-        ParentSlot = parentSlot;
-        Children = children;
-        Organs = organs;
-        PartType = partType;
-        IsVital = isVital;
-        Symmetry = symmetry;
-        Body = body;
-    }
-}

Content.Shared/Body/Part/BodyPartSlot.cs

@@ -1,43 +0,0 @@
-using Content.Shared.Body.Systems;
-using Robust.Shared.Serialization;
-
-namespace Content.Shared.Body.Part;
-
-[Serializable, NetSerializable]
-[Access(typeof(SharedBodySystem))]
-[DataDefinition]
-public sealed partial record BodyPartSlot
-{
-    [DataField("id")]
-    public string Id = string.Empty;
-
-    [DataField("type")]
-    public BodyPartType? Type;
-
-    [NonSerialized]
-    [DataField("parent")]
-    public EntityUid Parent;
-
-    public NetEntity NetParent;
-
-    [NonSerialized]
-    [DataField("child")]
-    public EntityUid? Child;
-
-    public NetEntity? NetChild;
-
-    public void SetChild(EntityUid? child, NetEntity? netChild)
-    {
-        Child = child;
-        NetChild = netChild;
-    }
-
-    // Rider doesn't suggest explicit properties during deconstruction without this
-    public void Deconstruct(out EntityUid? child, out string id, out EntityUid parent, out BodyPartType? type)
-    {
-        child = Child;
-        id = Id;
-        parent = Parent;
-        type = Type;
-    }
-}

Content.Shared/Body/Prototypes/BodyPrototype.cs

@@ -27,28 +27,4 @@ public sealed class BodyPrototype : IPrototype
 }
 
 [DataRecord]
-public sealed record BodyPrototypeSlot
+public sealed record BodyPrototypeSlot(EntProtoId? Part, HashSet<string> Connections, Dictionary<string, string> Organs);
-{
-    [DataField("part", customTypeSerializer: typeof(PrototypeIdSerializer<EntityPrototype>))]
-    public string? Part;
-    public readonly HashSet<string> Connections = new();
-    public readonly Dictionary<string, string> Organs = new();
-
-    public BodyPrototypeSlot() : this(null, null, null)
-    {
-    }
-
-    public BodyPrototypeSlot(string? part, HashSet<string>? connections, Dictionary<string, string>? organs)
-    {
-        Part = part;
-        Connections = connections ?? new HashSet<string>();
-        Organs = organs ?? new Dictionary<string, string>();
-    }
-
-    public void Deconstruct(out string? part, out HashSet<string> connections, out Dictionary<string, string> organs)
-    {
-        part = Part;
-        connections = Connections;
-        organs = Organs;
-    }
-}

Content.Shared/Body/Prototypes/BodyPrototypeSerializer.cs

@@ -179,9 +179,10 @@ public sealed class BodyPrototypeSerializer : ITypeReader<BodyPrototype, Mapping
         }
 
         var slots = new Dictionary<string, BodyPrototypeSlot>();
+
         foreach (var (slotId, (part, connections, organs)) in allConnections)
         {
-            var slot = new BodyPrototypeSlot(part, connections, organs);
+            var slot = new BodyPrototypeSlot(part != null ? new EntProtoId(part) : null!, connections ?? new HashSet<string>(), organs ?? new Dictionary<string, string>());
             slots.Add(slotId, slot);
         }
 

Content.Shared/Body/Systems/SharedBodySystem.Body.cs

@@ -1,28 +1,141 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Linq;
-using System.Linq;
+using System.Numerics;
 using Content.Shared.Body.Components;
 using Content.Shared.Body.Organ;
 using Content.Shared.Body.Part;
 using Content.Shared.Body.Prototypes;
-using Content.Shared.Coordinates;
 using Content.Shared.DragDrop;
 using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
-using Robust.Shared.Network;
+using Robust.Shared.Map;
+using MapInitEvent = Robust.Shared.GameObjects.MapInitEvent;
 
 namespace Content.Shared.Body.Systems;
 
 public partial class SharedBodySystem
 {
-    [Dependency] private readonly INetManager _netManager = default!;
+    /*
+     * tl;dr of how bobby works
+     * - BodyComponent uses a BodyPrototype as a template.
+     * - On MapInit we spawn the root entity in the prototype and spawn all connections outwards from here
+     * - Each "connection" is a body part (e.g. arm, hand, etc.) and each part can also contain organs.
+     */
 
-    public void InitializeBody()
+    private void InitializeBody()
     {
-        SubscribeLocalEvent<BodyComponent, ComponentInit>(OnBodyInit);
+        // Body here to handle root body parts.
+        SubscribeLocalEvent<BodyComponent, EntInsertedIntoContainerMessage>(OnBodyInserted);
+        SubscribeLocalEvent<BodyComponent, EntRemovedFromContainerMessage>(OnBodyRemoved);
 
+        SubscribeLocalEvent<BodyComponent, ComponentInit>(OnBodyInit);
+        SubscribeLocalEvent<BodyComponent, MapInitEvent>(OnBodyMapInit);
+        SubscribeLocalEvent<BodyComponent, CanDragEvent>(OnBodyCanDrag);
         SubscribeLocalEvent<BodyComponent, ComponentGetState>(OnBodyGetState);
         SubscribeLocalEvent<BodyComponent, ComponentHandleState>(OnBodyHandleState);
-        SubscribeLocalEvent<BodyComponent, CanDragEvent>(OnBodyCanDrag);
+    }
+
+    private void OnBodyInserted(EntityUid uid, BodyComponent component, EntInsertedIntoContainerMessage args)
+    {
+        // Root body part?
+        var slotId = args.Container.ID;
+
+        if (slotId != BodyRootContainerId)
+            return;
+
+        var entity = args.Entity;
+
+        if (TryComp(entity, out BodyPartComponent? childPart))
+        {
+            AddPart(uid, entity, slotId, childPart);
+            RecursiveBodyUpdate(entity, uid, childPart);
+        }
+
+        if (TryComp(entity, out OrganComponent? organ))
+        {
+            AddOrgan(entity, uid, uid, organ);
+        }
+    }
+
+    private void OnBodyRemoved(EntityUid uid, BodyComponent component, EntRemovedFromContainerMessage args)
+    {
+        // TODO: lifestage shenanigans
+        if (LifeStage(uid) >= EntityLifeStage.Terminating)
+            return;
+
+        // Root body part?
+        var slotId = args.Container.ID;
+
+        if (slotId != BodyRootContainerId)
+            return;
+
+        var entity = args.Entity;
+
+        if (TryComp(entity, out BodyPartComponent? childPart))
+        {
+            RemovePart(uid, entity, slotId, childPart);
+            RecursiveBodyUpdate(entity, null, childPart);
+        }
+
+        if (TryComp(entity, out OrganComponent? organ))
+        {
+            RemoveOrgan(entity, uid, uid, organ);
+        }
+    }
+
+    private void OnBodyHandleState(EntityUid uid, BodyComponent component, ref ComponentHandleState args)
+    {
+        if (args.Current is not BodyComponentState state)
+            return;
+
+        component.Prototype = state.Prototype != null ? state.Prototype : null!;
+        component.GibSound = state.GibSound;
+        component.RequiredLegs = state.RequiredLegs;
+        component.LegEntities = EntityManager.EnsureEntitySet<BodyComponent>(state.LegNetEntities, uid);
+    }
+
+    private void OnBodyGetState(EntityUid uid, BodyComponent component, ref ComponentGetState args)
+    {
+        args.State = new BodyComponentState(
+            component.Prototype,
+            component.RootPartSlot,
+            component.GibSound,
+            component.RequiredLegs,
+            EntityManager.GetNetEntitySet(component.LegEntities)
+        );
+    }
+
+    private void OnBodyInit(EntityUid bodyId, BodyComponent body, ComponentInit args)
+    {
+        // Setup the initial container.
+        body.RootContainer = Containers.EnsureContainer<ContainerSlot>(bodyId, BodyRootContainerId);
+    }
+
+    private void OnBodyMapInit(EntityUid bodyId, BodyComponent body, MapInitEvent args)
+    {
+        if (body.Prototype == null)
+            return;
+
+        // One-time setup
+        // Obviously can't run in Init to avoid double-spawns on save / load.
+        var prototype = Prototypes.Index(body.Prototype.Value);
+        MapInitBody(bodyId, prototype);
+    }
+
+    private void MapInitBody(EntityUid bodyEntity, BodyPrototype prototype)
+    {
+        var protoRoot = prototype.Slots[prototype.Root];
+        if (protoRoot.Part == null)
+            return;
+
+        // This should already handle adding the entity to the root.
+        var rootPartEntity = SpawnInContainerOrDrop(protoRoot.Part, bodyEntity, BodyRootContainerId);
+        var rootPart = Comp<BodyPartComponent>(rootPartEntity);
+        rootPart.Body = bodyEntity;
+        Dirty(rootPartEntity, rootPart);
+
+        // Setup the rest of the body entities.
+        SetupOrgans(rootPartEntity, rootPart, protoRoot.Organs);
+        MapInitParts(rootPartEntity, prototype);
     }
 
     private void OnBodyCanDrag(EntityUid uid, BodyComponent component, ref CanDragEvent args)
@@ -30,148 +143,114 @@ public partial class SharedBodySystem
         args.Handled = true;
     }
 
-    private void OnBodyInit(EntityUid bodyId, BodyComponent body, ComponentInit args)
+    /// <summary>
+    /// Sets up all of the relevant body parts for a particular body entity and root part.
+    /// </summary>
+    private void MapInitParts(EntityUid rootPartId, BodyPrototype prototype)
     {
-        // ReSharper disable once ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
+        // Start at the root part and traverse the body graph, setting up parts as we go.
-        if (body.Prototype == null || body.Root != null)
+        // Basic BFS pathfind.
-            return;
+        var rootSlot = prototype.Root;
+        var frontier = new Queue<string>();
+        frontier.Enqueue(rootSlot);
 
-        var prototype = Prototypes.Index<BodyPrototype>(body.Prototype);
+        // Child -> Parent connection.
+        var cameFrom = new Dictionary<string, string>();
+        // Maps slot to its relevant entity.
+        var cameFromEntities = new Dictionary<string, EntityUid>();
+        cameFromEntities[rootSlot] = rootPartId;
 
-        if (!_netManager.IsClient || IsClientSide(bodyId))
+        while (frontier.TryDequeue(out var currentSlotId))
-            InitBody(body, prototype);
-
-        Dirty(body); // Client doesn't actually spawn the body, need to sync it
-    }
-
-    private void OnBodyGetState(EntityUid uid, BodyComponent body, ref ComponentGetState args)
-    {
-        args.State = new BodyComponentState(body.Root, body.GibSound);
-    }
-
-    private void OnBodyHandleState(EntityUid uid, BodyComponent body, ref ComponentHandleState args)
-    {
-        if (args.Current is not BodyComponentState state)
-            return;
-
-        body.Root = state.Root; // TODO use containers. This is broken and does not work.
-        body.GibSound = state.GibSound;
-    }
-
-    public bool TryCreateBodyRootSlot(
-        EntityUid? bodyId,
-        string slotId,
-        [NotNullWhen(true)] out BodyPartSlot? slot,
-        BodyComponent? body = null)
-    {
-        slot = null;
-
-        // ReSharper disable once ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
-        if (bodyId == null ||
-            !Resolve(bodyId.Value, ref body, false) ||
-            body.Root != null)
-            return false;
-
-        slot = new BodyPartSlot
         {
-            Id = slotId,
+            var currentSlot = prototype.Slots[currentSlotId];
-            Parent = bodyId.Value,
-            NetParent = GetNetEntity(bodyId.Value),
-        };
-        body.Root = slot;
 
-        return true;
+            foreach (var connection in currentSlot.Connections)
+            {
+                // Already been handled
+                if (!cameFrom.TryAdd(connection, currentSlotId))
+                    continue;
+
+                // Setup part
+                var connectionSlot = prototype.Slots[connection];
+                var parentEntity = cameFromEntities[currentSlotId];
+                var parentPartComponent = Comp<BodyPartComponent>(parentEntity);
+
+                // Spawn the entity on the target
+                // then get the body part type, create the slot, and finally
+                // we can insert it into the container.
+                var childPart = Spawn(connectionSlot.Part, new EntityCoordinates(parentEntity, Vector2.Zero));
+                cameFromEntities[connection] = childPart;
+
+                var childPartComponent = Comp<BodyPartComponent>(childPart);
+                var partSlot = CreatePartSlot(parentEntity, connection, childPartComponent.PartType, parentPartComponent);
+                var cont = Containers.GetContainer(parentEntity, GetPartSlotContainerId(connection));
+
+                if (partSlot == null || !cont.Insert(childPart))
+                {
+                    Log.Error($"Could not create slot for connection {connection} in body {prototype.ID}");
+                    QueueDel(childPart);
+                    continue;
+                }
+
+                // Add organs
+                SetupOrgans(childPart, childPartComponent, connectionSlot.Organs);
+
+                // Enqueue it so we can also get its neighbors.
+                frontier.Enqueue(connection);
+            }
+        }
     }
 
-    protected void InitBody(BodyComponent body, BodyPrototype prototype)
+    private void SetupOrgans(EntityUid partId, BodyPartComponent partComponent, Dictionary<string, string> organs)
     {
-        var root = prototype.Slots[prototype.Root];
+        foreach (var (organSlotId, organProto) in organs)
-        Containers.EnsureContainer<Container>(body.Owner, BodyContainerId);
-        if (root.Part == null)
-            return;
-        var bodyId = Spawn(root.Part, body.Owner.ToCoordinates());
-        var partComponent = Comp<BodyPartComponent>(bodyId);
-        var slot = new BodyPartSlot
         {
-            Id = root.Part,
+            var slot = CreateOrganSlot(organSlotId, partId, partComponent);
-            Type = partComponent.PartType,
+            SpawnInContainerOrDrop(organProto, partId, GetOrganContainerId(organSlotId));
-            Parent = body.Owner,
-            NetParent = GetNetEntity(body.Owner),
-        };
-        body.Root = slot;
-        partComponent.Body = bodyId;
 
-        AttachPart(bodyId, slot, partComponent);
-        InitPart(partComponent, prototype, prototype.Root);
-    }
-
-    protected void InitPart(BodyPartComponent parent, BodyPrototype prototype, string slotId, HashSet<string>? initialized = null)
-    {
-        initialized ??= new HashSet<string>();
-
-        if (initialized.Contains(slotId))
-            return;
-
-        initialized.Add(slotId);
-
-        var (_, connections, organs) = prototype.Slots[slotId];
-        connections = new HashSet<string>(connections);
-        connections.ExceptWith(initialized);
-
-        var coordinates = parent.Owner.ToCoordinates();
-        var subConnections = new List<(BodyPartComponent child, string slotId)>();
-
-        Containers.EnsureContainer<Container>(parent.Owner, BodyContainerId);
-
-        foreach (var connection in connections)
-        {
-            var childSlot = prototype.Slots[connection];
-            if (childSlot.Part == null)
-                continue;
-
-            var childPart = Spawn(childSlot.Part, coordinates);
-            var childPartComponent = Comp<BodyPartComponent>(childPart);
-            var slot = CreatePartSlot(connection, parent.Owner, childPartComponent.PartType, parent);
             if (slot == null)
             {
-                Logger.Error($"Could not create slot for connection {connection} in body {prototype.ID}");
+                Log.Error($"Could not create organ for slot {organSlotId} in {ToPrettyString(partId)}");
-                continue;
             }
-
-            AttachPart(childPart, slot, childPartComponent);
-            subConnections.Add((childPartComponent, connection));
-        }
-
-        foreach (var (organSlotId, organId) in organs)
-        {
-            var organ = Spawn(organId, coordinates);
-            var organComponent = Comp<OrganComponent>(organ);
-
-            var slot = CreateOrganSlot(organSlotId, parent.Owner, parent);
-            if (slot == null)
-            {
-                Logger.Error($"Could not create slot for connection {organSlotId} in body {prototype.ID}");
-                continue;
-            }
-
-            InsertOrgan(organ, slot, organComponent);
-        }
-
-        foreach (var connection in subConnections)
-        {
-            InitPart(connection.child, prototype, connection.slotId, initialized);
         }
     }
-    public IEnumerable<(EntityUid Id, BodyPartComponent Component)> GetBodyChildren(EntityUid? id, BodyComponent? body = null)
+
+    /// <summary>
+    /// Gets all body containers on this entity including the root one.
+    /// </summary>
+    public IEnumerable<BaseContainer> GetBodyContainers(EntityUid id, BodyComponent? body = null,
+        BodyPartComponent? rootPart = null)
+    {
+        if (!Resolve(id, ref body, false) ||
+            body.RootContainer.ContainedEntity == null ||
+            !Resolve(body.RootContainer.ContainedEntity.Value, ref rootPart))
+        {
+            yield break;
+        }
+
+        yield return body.RootContainer;
+
+        foreach (var childContainer in GetPartContainers(body.RootContainer.ContainedEntity.Value, rootPart))
+        {
+            yield return childContainer;
+        }
+    }
+
+    /// <summary>
+    /// Gets all child body parts of this entity, including the root entity.
+    /// </summary>
+    public IEnumerable<(EntityUid Id, BodyPartComponent Component)> GetBodyChildren(EntityUid? id, BodyComponent? body = null,
+        BodyPartComponent? rootPart = null)
     {
         if (id == null ||
             !Resolve(id.Value, ref body, false) ||
-            !TryComp(body.Root?.Child, out BodyPartComponent? part))
+            body.RootContainer.ContainedEntity == null ||
+            !Resolve(body.RootContainer.ContainedEntity.Value, ref rootPart))
+        {
             yield break;
+        }
 
-        yield return (body.Root.Child.Value, part);
+        foreach (var child in GetBodyPartChildren(body.RootContainer.ContainedEntity.Value, rootPart))
-
-        foreach (var child in GetPartChildren(body.Root.Child))
         {
             yield return child;
         }
@@ -191,55 +270,37 @@ public partial class SharedBodySystem
         }
     }
 
-    public IEnumerable<BodyPartSlot> GetBodyAllSlots(EntityUid? bodyId, BodyComponent? body = null)
-    {
-        if (bodyId == null || !Resolve(bodyId.Value, ref body, false))
-            yield break;
-
-        foreach (var slot in GetPartAllSlots(body.Root?.Child))
-        {
-            yield return slot;
-        }
-    }
-
     /// <summary>
-    /// Returns all body part slots in the graph, including ones connected by
+    /// Returns all body part slots for this entity.
-    /// body parts which are null.
     /// </summary>
-    /// <param name="partId"></param>
+    /// <param name="bodyId"></param>
-    /// <param name="part"></param>
+    /// <param name="body"></param>
     /// <returns></returns>
-    public IEnumerable<BodyPartSlot> GetAllBodyPartSlots(EntityUid partId, BodyPartComponent? part = null)
+    public IEnumerable<BodyPartSlot> GetBodyAllSlots(EntityUid bodyId, BodyComponent? body = null)
     {
-        if (!Resolve(partId, ref part, false))
+        if (!Resolve(bodyId, ref body, false) || body.RootContainer.ContainedEntity == null)
             yield break;
 
-        foreach (var slot in part.Children.Values)
+        foreach (var slot in GetAllBodyPartSlots(body.RootContainer.ContainedEntity.Value))
         {
-            if (!TryComp<BodyPartComponent>(slot.Child, out var childPart))
-                continue;
-
             yield return slot;
-
-            foreach (var child in GetAllBodyPartSlots(slot.Child.Value, childPart))
-            {
-                yield return child;
-            }
         }
     }
 
-    public virtual HashSet<EntityUid> GibBody(EntityUid? partId, bool gibOrgans = false,
+    public virtual HashSet<EntityUid> GibBody(EntityUid bodyId, bool gibOrgans = false,
         BodyComponent? body = null, bool deleteItems = false)
     {
-        if (partId == null || !Resolve(partId.Value, ref body, false))
+        var gibs = new HashSet<EntityUid>();
-            return new HashSet<EntityUid>();
 
-        var parts = GetBodyChildren(partId, body).ToArray();
+        if (!Resolve(bodyId, ref body, false))
-        var gibs = new HashSet<EntityUid>(parts.Length);
+            return gibs;
+
+        var parts = GetBodyChildren(bodyId, body).ToArray();
+        gibs.EnsureCapacity(parts.Length);
 
         foreach (var part in parts)
         {
-            DropPart(part.Id, part.Component);
+            SharedTransform.AttachToGridOrMap(part.Id);
             gibs.Add(part.Id);
 
             if (!gibOrgans)
@@ -247,7 +308,7 @@ public partial class SharedBodySystem
 
             foreach (var organ in GetPartOrgans(part.Id, part.Component))
             {
-                DropOrgan(organ.Id, organ.Component);
+                SharedTransform.AttachToGridOrMap(organ.Id);
                 gibs.Add(organ.Id);
             }
         }

Content.Shared/Body/Systems/SharedBodySystem.Organs.cs

@@ -3,194 +3,142 @@ using Content.Shared.Body.Components;
 using Content.Shared.Body.Events;
 using Content.Shared.Body.Organ;
 using Content.Shared.Body.Part;
-using Content.Shared.Random.Helpers;
 using Robust.Shared.Containers;
-using Robust.Shared.GameStates;
-using Robust.Shared.Map;
 
 namespace Content.Shared.Body.Systems;
 
 public partial class SharedBodySystem
 {
-    [Dependency] private readonly SharedContainerSystem _container = default!;
+    private void AddOrgan(EntityUid uid, EntityUid bodyUid, EntityUid parentPartUid, OrganComponent component)
-
-    private void InitializeOrgans()
     {
-        SubscribeLocalEvent<OrganComponent, ComponentGetState>(OnOrganGetState);
+        component.Body = bodyUid;
-        SubscribeLocalEvent<OrganComponent, ComponentHandleState>(OnOrganHandleState);
+        RaiseLocalEvent(uid, new AddedToPartEvent(bodyUid));
+
+        if (component.Body != null)
+            RaiseLocalEvent(uid, new AddedToPartInBodyEvent(component.Body.Value, parentPartUid));
+
+        Dirty(uid, component);
     }
 
+    private void RemoveOrgan(EntityUid uid, EntityUid bodyUid, EntityUid parentPartUid, OrganComponent component)
+    {
+        RaiseLocalEvent(uid, new RemovedFromPartEvent(bodyUid));
+
+        if (component.Body != null)
+            RaiseLocalEvent(uid, new RemovedFromPartInBodyEvent(component.Body.Value, parentPartUid));
+
+        component.Body = null;
+        Dirty(uid, component);
+    }
+
+    /// <summary>
+    /// Creates the specified organ slot on the parent entity.
+    /// </summary>
     private OrganSlot? CreateOrganSlot(string slotId, EntityUid parent, BodyPartComponent? part = null)
     {
         if (!Resolve(parent, ref part, false))
             return null;
 
-        var slot = new OrganSlot()
+        Containers.EnsureContainer<ContainerSlot>(parent, GetOrganContainerId(slotId));
-        {
+        var slot = new OrganSlot(slotId);
-            Id = slotId,
-            Parent = parent,
-            NetParent = GetNetEntity(parent),
-        };
         part.Organs.Add(slotId, slot);
-
         return slot;
     }
 
-    private bool CanInsertOrgan(EntityUid? organId, OrganSlot slot, OrganComponent? organ = null)
+    /// <summary>
+    /// Attempts to create the specified organ slot on the specified parent if it exists.
+    /// </summary>
+    public bool TryCreateOrganSlot(
+        EntityUid? parent,
+        string slotId,
+        [NotNullWhen(true)] out OrganSlot? slot,
+        BodyPartComponent? part = null)
     {
-        return organId != null &&
+        slot = null;
-               slot.Child == null &&
-               Resolve(organId.Value, ref organ, false) &&
-               Containers.TryGetContainer(slot.Parent, BodyContainerId, out var container) &&
-               _container.CanInsert(organId.Value, container);
-    }
 
-    private void OnOrganGetState(EntityUid uid, OrganComponent organ, ref ComponentGetState args)
+        if (parent == null || !Resolve(parent.Value, ref part, false))
-    {
-        args.State = new OrganComponentState(GetNetEntity(organ.Body), organ.ParentSlot);
-    }
-
-    private void OnOrganHandleState(EntityUid uid, OrganComponent organ, ref ComponentHandleState args)
-    {
-        if (args.Current is not OrganComponentState state)
-            return;
-
-        organ.Body = EnsureEntity<OrganComponent>(state.Body, uid);
-        organ.ParentSlot = state.Parent;
-    }
-
-    public bool InsertOrgan(EntityUid? organId, OrganSlot slot, OrganComponent? organ = null)
-    {
-        if (organId == null ||
-            !Resolve(organId.Value, ref organ, false) ||
-            !CanInsertOrgan(organId, slot, organ))
-            return false;
-
-        DropOrgan(slot.Child);
-        DropOrgan(organId, organ);
-
-        var container = Containers.EnsureContainer<Container>(slot.Parent, BodyContainerId);
-        if (!container.Insert(organId.Value))
-            return false;
-
-        slot.Child = organId;
-        organ.ParentSlot = slot;
-        organ.Body = CompOrNull<BodyPartComponent>(slot.Parent)?.Body;
-
-        DirtyAllComponents(slot.Parent);
-        Dirty(organId.Value, organ);
-
-        if (organ.Body == null)
         {
-            RaiseLocalEvent(organId.Value, new AddedToPartEvent(slot.Parent));
+            return false;
-        }
-        else
-        {
-            RaiseLocalEvent(organId.Value, new AddedToPartInBodyEvent(organ.Body.Value, slot.Parent));
         }
 
-        return true;
+        Containers.EnsureContainer<ContainerSlot>(parent.Value, GetOrganContainerId(slotId));
+        slot = new OrganSlot(slotId);
+        return part.Organs.TryAdd(slotId,slot.Value);
     }
 
-    public void DirtyAllComponents(EntityUid uid)
+    /// <summary>
+    /// Returns whether the slotId exists on the partId.
+    /// </summary>
+    public bool CanInsertOrgan(EntityUid partId, string slotId, BodyPartComponent? part = null)
     {
-        // TODO just use containers. Please
+        return Resolve(partId, ref part) && part.Organs.ContainsKey(slotId);
-        if (TryComp(uid, out BodyPartComponent? part))
-            Dirty(uid, part);
-
-        if (TryComp(uid, out OrganComponent? organ))
-            Dirty(uid, organ);
-
-        if (TryComp(uid, out BodyComponent? body))
-            Dirty(uid, body);
     }
 
+    /// <summary>
+    /// Returns whether the specified organ slot exists on the partId.
+    /// </summary>
+    public bool CanInsertOrgan(EntityUid partId, OrganSlot slot, BodyPartComponent? part = null)
+    {
+        return CanInsertOrgan(partId, slot.Id, part);
+    }
 
+    public bool InsertOrgan(EntityUid partId, EntityUid organId, string slotId, BodyPartComponent? part = null, OrganComponent? organ = null)
+    {
+        if (!Resolve(organId, ref organ, false) ||
+            !Resolve(partId, ref part, false) ||
+            !CanInsertOrgan(partId, slotId, part))
+        {
+            return false;
+        }
+
+        var containerId = GetOrganContainerId(slotId);
+
+        if (!Containers.TryGetContainer(partId, containerId, out var container))
+            return false;
+
+        return container.Insert(organId);
+    }
+
+    /// <summary>
+    /// Removes the organ if it is inside of a body part.
+    /// </summary>
+    public bool RemoveOrgan(EntityUid organId, OrganComponent? organ = null)
+    {
+        if (!Containers.TryGetContainingContainer(organId, out var container))
+            return false;
+
+        var parent = container.Owner;
+
+        if (!HasComp<BodyPartComponent>(parent))
+            return false;
+
+        return container.Remove(organId);
+    }
+
+    /// <summary>
+    /// Tries to add this organ to any matching slot on this body part.
+    /// </summary>
     public bool AddOrganToFirstValidSlot(
-        EntityUid? childId,
+        EntityUid partId,
-        EntityUid? parentId,
+        EntityUid organId,
-        OrganComponent? child = null,
+        BodyPartComponent? part = null,
-        BodyPartComponent? parent = null)
+        OrganComponent? organ = null)
     {
-        if (childId == null ||
+        if (!Resolve(partId, ref part, false) ||
-            !Resolve(childId.Value, ref child, false) ||
+            !Resolve(organId, ref organ, false))
-            parentId == null ||
-            !Resolve(parentId.Value, ref parent, false))
-            return false;
-
-        foreach (var slot in parent.Organs.Values)
         {
-            if (slot.Child == null)
+            return false;
-                continue;
+        }
 
-            InsertOrgan(childId, slot, child);
+        foreach (var slotId in part.Organs.Keys)
+        {
+            InsertOrgan(partId, organId, slotId, part, organ);
             return true;
         }
 
         return false;
     }
 
-    public bool DropOrgan(EntityUid? organId, OrganComponent? organ = null)
-    {
-        if (organId == null ||
-            !Resolve(organId.Value, ref organ, false) ||
-            organ.ParentSlot is not { } slot)
-            return false;
-
-        var oldParent = CompOrNull<BodyPartComponent>(organ.ParentSlot.Parent);
-
-        slot.Child = null;
-        organ.ParentSlot = null;
-        organ.Body = null;
-
-        if (Containers.TryGetContainer(slot.Parent, BodyContainerId, out var container))
-            container.Remove(organId.Value);
-
-        if (TryComp(organId, out TransformComponent? transform))
-            transform.AttachToGridOrMap();
-
-        organ.Owner.RandomOffset(0.25f);
-
-        if (oldParent == null)
-            return true;
-
-        if (oldParent.Body != null)
-        {
-            RaiseLocalEvent(organId.Value, new RemovedFromPartInBodyEvent(oldParent.Body.Value, oldParent.Owner));
-        }
-        else
-        {
-            RaiseLocalEvent(organId.Value, new RemovedFromPartEvent(oldParent.Owner));
-        }
-
-        return true;
-    }
-
-    public bool DropOrganAt(EntityUid? organId, EntityCoordinates dropAt, OrganComponent? organ = null)
-    {
-        if (organId == null || !DropOrgan(organId, organ))
-            return false;
-
-        if (TryComp(organId.Value, out TransformComponent? transform))
-            transform.Coordinates = dropAt;
-
-        return true;
-    }
-
-    public bool DeleteOrgan(EntityUid? id, OrganComponent? part = null)
-    {
-        if (id == null || !Resolve(id.Value, ref part, false))
-            return false;
-
-        DropOrgan(id, part);
-
-        if (Deleted(id.Value))
-            return false;
-
-        Del(id.Value);
-        return true;
-    }
-
     /// <summary>
     ///     Returns a list of ValueTuples of <see cref="T"/> and OrganComponent on each organ
     ///     in the given body.

Content.Shared/Body/Systems/SharedBodySystem.cs

@@ -8,14 +8,31 @@ namespace Content.Shared.Body.Systems;
 
 public abstract partial class SharedBodySystem : EntitySystem
 {
-    protected const string BodyContainerId = "BodyContainer";
+    /*
+     * See the body partial for how this works.
+     */
+
+    /// <summary>
+    /// Container ID prefix for any body parts.
+    /// </summary>
+    protected const string PartSlotContainerIdPrefix = "body_part_slot_";
+
+    /// <summary>
+    /// Container ID for the ContainerSlot on the body entity itself.
+    /// </summary>
+    protected const string BodyRootContainerId = "body_root_part";
+
+    /// <summary>
+    /// Container ID prefix for any body organs.
+    /// </summary>
+    protected const string OrganSlotContainerIdPrefix = "body_organ_slot_";
 
     [Dependency] protected readonly IPrototypeManager Prototypes = default!;
-
-    [Dependency] protected readonly SharedContainerSystem Containers = default!;
     [Dependency] protected readonly DamageableSystem Damageable = default!;
-    [Dependency] protected readonly StandingStateSystem Standing = default!;
     [Dependency] protected readonly MovementSpeedModifierSystem Movement = default!;
+    [Dependency] protected readonly SharedContainerSystem Containers = default!;
+    [Dependency] protected readonly SharedTransformSystem SharedTransform = default!;
+    [Dependency] protected readonly StandingStateSystem Standing = default!;
 
     public override void Initialize()
     {
@@ -23,6 +40,36 @@ public abstract partial class SharedBodySystem : EntitySystem
 
         InitializeBody();
         InitializeParts();
-        InitializeOrgans();
+    }
+
+    /// <summary>
+    /// Inverse of <see cref="GetPartSlotContainerId"/>
+    /// </summary>
+    protected static string? GetPartSlotContainerIdFromContainer(string containerSlotId)
+    {
+        // This is blursed
+        var slotIndex = containerSlotId.IndexOf(PartSlotContainerIdPrefix, StringComparison.Ordinal);
+
+        if (slotIndex < -1)
+            return null;
+
+        var slotId = containerSlotId.Remove(slotIndex, PartSlotContainerIdPrefix.Length);
+        return slotId;
+    }
+
+    /// <summary>
+    /// Gets the container Id for the specified slotId.
+    /// </summary>
+    public static string GetPartSlotContainerId(string slotId)
+    {
+        return PartSlotContainerIdPrefix + slotId;
+    }
+
+    /// <summary>
+    /// Gets the container Id for the specified slotId.
+    /// </summary>
+    public static string GetOrganContainerId(string slotId)
+    {
+        return OrganSlotContainerIdPrefix + slotId;
     }
 }

Resources/Prototypes/Body/Prototypes/a_ghost.yml

@@ -6,17 +6,17 @@
     torso:
       part: TorsoHuman
       connections:
-      - left arm
+      - left_arm
-      - right arm
+      - right_arm
-    right arm:
+    right_arm:
       part: RightArmHuman
       connections:
-      - right hand
+      - right_hand
-    left arm:
+    left_arm:
       part: LeftArmHuman
       connections:
-      - left hand
+      - left_hand
-    right hand:
+    right_hand:
       part: RightHandHuman
-    left hand:
+    left_hand:
       part: LeftHandHuman

Resources/Prototypes/Body/Prototypes/human.yml

@@ -13,37 +13,37 @@
     torso:
       part: TorsoHuman
       connections:
-      - left arm
+      - left_arm
-      - right arm
+      - right_arm
-      - left leg
+      - left_leg
-      - right leg
+      - right_leg
       organs:
         heart: OrganHumanHeart
         lungs: OrganHumanLungs
         stomach: OrganHumanStomach
         liver: OrganHumanLiver
         kidneys: OrganHumanKidneys
-    right arm:
+    right_arm:
       part: RightArmHuman
       connections:
-      - right hand
+      - right_hand
-    left arm:
+    left_arm:
       part: LeftArmHuman
       connections:
-      - left hand
+      - left_hand
-    right hand:
+    right_hand:
       part: RightHandHuman
-    left hand:
+    left_hand:
       part: LeftHandHuman
-    right leg:
+    right_leg:
       part: RightLegHuman
       connections:
-      - right foot
+      - right_foot
-    left leg:
+    left_leg:
       part: LeftLegHuman
       connections:
-      - left foot
+      - left_foot
-    right foot:
+    right_foot:
       part: RightFootHuman
-    left foot:
+    left_foot:
       part: LeftFootHuman

Resources/Prototypes/Catalog/Cargo/cargo_livestock.yml

@@ -4,7 +4,7 @@
     sprite: Mobs/Animals/bee.rsi
     state: 0
   product: CrateNPCBee
-  cost: 4200
+  cost: 7000
   category: Livestock
   group: market
 
@@ -14,7 +14,7 @@
     sprite: Mobs/Animals/butterfly.rsi
     state: butterfly
   product: CrateNPCButterflies
-  cost: 2700
+  cost: 4400
   category: Livestock
   group: market
 
@@ -24,7 +24,7 @@
     sprite: Mobs/Pets/cat.rsi
     state: cat
   product: CrateNPCCat
-  cost: 1000
+  cost: 1200
   category: Livestock
   group: market
 
@@ -34,7 +34,7 @@
     sprite: Mobs/Animals/chicken.rsi
     state: icon-1
   product: CrateNPCChicken
-  cost: 2600
+  cost: 4000
   category: Livestock
   group: market
 
@@ -44,7 +44,7 @@
     sprite: Mobs/Animals/crab.rsi
     state: crab
   product: CrateNPCCrab
-  cost: 2000
+  cost: 3000
   category: Livestock
   group: market
 
@@ -54,7 +54,7 @@
     sprite: Mobs/Animals/duck.rsi
     state: icon-0
   product: CrateNPCDuck
-  cost: 3800
+  cost: 6000
   category: Livestock
   group: market
 
@@ -64,7 +64,7 @@
     sprite: Mobs/Pets/corgi.rsi
     state: corgi
   product: CrateNPCCorgi
-  cost: 1000
+  cost: 1200
   category: Livestock
   group: market
 
@@ -84,7 +84,7 @@
     sprite: Mobs/Animals/goat.rsi
     state: goat
   product: CrateNPCGoat
-  cost: 1000
+  cost: 1200
   category: Livestock
   group: market
 
@@ -94,7 +94,7 @@
     sprite: Mobs/Animals/goose.rsi
     state: goose
   product: CrateNPCGoose
-  cost: 1500
+  cost: 2100
   category: Livestock
   group: market
 
@@ -104,7 +104,7 @@
     sprite: Mobs/Animals/gorilla.rsi
     state: icon
   product: CrateNPCGorilla
-  cost: 1000
+  cost: 1100
   category: Livestock
   group: market
 
@@ -124,7 +124,7 @@
     sprite: Mobs/Animals/mouse.rsi
     state: icon-0
   product: CrateNPCMouse
-  cost: 2700
+  cost: 4400
   category: Livestock
   group: market
 
@@ -134,7 +134,7 @@
     sprite: Mobs/Animals/parrot.rsi
     state: parrot
   product: CrateNPCParrot
-  cost: 2000
+  cost: 3000
   category: Livestock
   group: market
 
@@ -144,7 +144,7 @@
     sprite: Mobs/Animals/penguin.rsi
     state: penguin
   product: CrateNPCPenguin
-  cost: 1500
+  cost: 2100
   category: Livestock
   group: market
 
@@ -154,7 +154,7 @@
     sprite: Mobs/Animals/pig.rsi
     state: pig
   product: CrateNPCPig
-  cost: 1000
+  cost: 1100
   category: Livestock
   group: market
 
@@ -164,7 +164,7 @@
     sprite: Mobs/Animals/snake.rsi
     state: snake
   product: CrateNPCSnake
-  cost: 2000
+  cost: 3000
   category: Livestock
   group: market
 
@@ -184,7 +184,7 @@
     sprite: Mobs/Animals/lizard.rsi
     state: lizard
   product: CrateNPCLizard
-  cost: 1000
+  cost: 1100
   category: Livestock
   group: market