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

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

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;
     }
 }