Slay bobby pt. 1 (#5632)

Content.Shared/Body/Part/BodyPartSlot.cs

@@ -0,0 +1,108 @@
+using System;
+using System.Collections.Generic;
+using Content.Shared.Body.Components;
+using Content.Shared.Body.Part;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Shared.Body.Part
+{
+    public class BodyPartSlot
+    {
+        public BodyPartSlot(string id, BodyPartType partType, IEnumerable<BodyPartSlot> connections)
+        {
+            Id = id;
+            PartType = partType;
+            Connections = new HashSet<BodyPartSlot>(connections);
+        }
+
+        public BodyPartSlot(string id, BodyPartType partType)
+        {
+            Id = id;
+            PartType = partType;
+            Connections = new HashSet<BodyPartSlot>();
+        }
+
+        /// <summary>
+        ///     The ID of this slot.
+        /// </summary>
+        [ViewVariables]
+        public string Id { get; }
+
+        /// <summary>
+        ///     The part type that this slot accepts.
+        /// </summary>
+        [ViewVariables]
+        public BodyPartType PartType { get; }
+
+        /// <summary>
+        ///     The part currently in this slot, if any.
+        /// </summary>
+        [ViewVariables]
+        public SharedBodyPartComponent? Part { get; private set; }
+
+        /// <summary>
+        ///     List of slots that this slot connects to.
+        /// </summary>
+        [ViewVariables]
+        public HashSet<BodyPartSlot> Connections { get; private set; }
+
+        public event Action<SharedBodyPartComponent>? PartAdded;
+
+        public event Action<SharedBodyPartComponent>? PartRemoved;
+
+        internal void SetConnectionsInternal(IEnumerable<BodyPartSlot> connections)
+        {
+            Connections = new HashSet<BodyPartSlot>(connections);
+        }
+
+        public bool CanAddPart(SharedBodyPartComponent part)
+        {
+            return Part == null && part.PartType == PartType;
+        }
+
+        public bool TryAddPart(SharedBodyPartComponent part)
+        {
+            if (!CanAddPart(part))
+            {
+                return false;
+            }
+
+            SetPart(part);
+            return true;
+        }
+
+        public void SetPart(SharedBodyPartComponent part)
+        {
+            if (Part != null)
+            {
+                RemovePart();
+            }
+
+            Part = part;
+            PartAdded?.Invoke(part);
+        }
+
+        public bool RemovePart()
+        {
+            if (Part == null)
+            {
+                return false;
+            }
+
+            var old = Part;
+            Part = null;
+
+            PartRemoved?.Invoke(old);
+
+            return true;
+        }
+
+        public void Shutdown()
+        {
+            Part = null;
+            Connections.Clear();
+            PartAdded = null;
+            PartRemoved = null;
+        }
+    }
+}