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

* Make mechanisms properly update and fix eating and drinking

* Remove outdated component ignores

* Fix nullable error

* Fix mechanism behavior events

* Remove unnecessary code

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

@@ -0,0 +1,112 @@
+#nullable enable
+using Content.Shared.GameObjects.Components.Body;
+using Content.Shared.GameObjects.Components.Body.Behavior;
+using Content.Shared.GameObjects.Components.Body.Mechanism;
+using Content.Shared.GameObjects.Components.Body.Part;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Serialization;
+using Robust.Shared.Utility;
+
+namespace Content.Server.GameObjects.Components.Body.Behavior
+{
+    public abstract class MechanismBehavior : IMechanismBehavior
+    {
+        public IBody? Body => Part?.Body;
+
+        public IBodyPart? Part => Parent.Part;
+
+        public IMechanism Parent { get; private set; } = default!;
+
+        public IEntity Owner => Parent.Owner;
+
+        public virtual void ExposeData(ObjectSerializer serializer) { }
+
+        public virtual void Initialize(IMechanism parent)
+        {
+            Parent = parent;
+        }
+
+        public virtual void Startup()
+        {
+            if (Part == null)
+            {
+                return;
+            }
+
+            if (Body == null)
+            {
+                AddedToPart(Part);
+            }
+            else
+            {
+                AddedToPartInBody(Body, Part);
+            }
+        }
+
+        public void AddedToBody(IBody body)
+        {
+            DebugTools.AssertNotNull(Body);
+            DebugTools.AssertNotNull(body);
+
+            OnAddedToBody(body);
+        }
+
+        public void AddedToPart(IBodyPart part)
+        {
+            DebugTools.AssertNotNull(Part);
+            DebugTools.AssertNotNull(part);
+
+            OnAddedToPart(part);
+        }
+
+        public void AddedToPartInBody(IBody body, IBodyPart part)
+        {
+            DebugTools.AssertNotNull(Body);
+            DebugTools.AssertNotNull(body);
+            DebugTools.AssertNotNull(Part);
+            DebugTools.AssertNotNull(part);
+
+            OnAddedToPartInBody(body, part);
+        }
+
+        public void RemovedFromBody(IBody old)
+        {
+            DebugTools.AssertNull(Body);
+            DebugTools.AssertNotNull(old);
+
+            OnRemovedFromBody(old);
+        }
+
+        public void RemovedFromPart(IBodyPart old)
+        {
+            DebugTools.AssertNull(Part);
+            DebugTools.AssertNotNull(old);
+
+            OnRemovedFromPart(old);
+        }
+
+        public void RemovedFromPartInBody(IBody oldBody, IBodyPart oldPart)
+        {
+            DebugTools.AssertNull(Body);
+            DebugTools.AssertNull(Part);
+            DebugTools.AssertNotNull(oldBody);
+            DebugTools.AssertNotNull(oldPart);
+
+            OnRemovedFromPartInBody(oldBody, oldPart);
+        }
+
+        protected virtual void OnAddedToBody(IBody body) { }
+
+        protected virtual void OnAddedToPart(IBodyPart part) { }
+
+        protected virtual void OnAddedToPartInBody(IBody body, IBodyPart part) { }
+
+        protected virtual void OnRemovedFromBody(IBody old) { }
+
+        protected virtual void OnRemovedFromPart(IBodyPart old) { }
+
+        protected virtual void OnRemovedFromPartInBody(IBody oldBody, IBodyPart oldPart) { }
+
+        public virtual void Update(float frameTime) { }
+    }
+}