Refactor mind and ghost deletion code (#3680)

* Refactor mind and ghost deletion code

* Refactor to use EventBus and clean up deletes

* Fix mind eject when being deleted

* Refactor entity manager calls to use IEntity.EntityManager

Content.Server/Administration/Commands/ControlMob.cs

@@ -61,15 +61,8 @@ namespace Content.Server.Administration.Commands
 
             DebugTools.AssertNotNull(mind);
 
-            var oldEntity = mind!.CurrentEntity;
-
             mindComponent.Mind?.TransferTo(null);
-            mind.TransferTo(target);
-
-            DebugTools.AssertNotNull(oldEntity);
-
-            if (oldEntity!.HasComponent<GhostComponent>())
-                oldEntity.Delete();
+            mind!.TransferTo(target);
         }
     }
 }

Content.Server/GameObjects/Components/Medical/CloningPodComponent.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 using System;
 using Content.Server.Eui;
 using Content.Server.GameObjects.Components.Mobs;
@@ -203,9 +203,6 @@ namespace Content.Server.GameObjects.Components.Medical
         {
             if (message.Sender == _capturedMind)
             {
-                //If the captured mind is in a ghost, we want to get rid of it.
-                _capturedMind.VisitingEntity?.Delete();
-
                 //Transfer the mind to the new mob
                 _capturedMind.TransferTo(_bodyContainer.ContainedEntity);
 

Content.Server/GameObjects/Components/Mobs/MindComponent.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 using Content.Server.GameObjects.Components.Observer;
 using Content.Server.GameTicking;
 using Content.Server.Interfaces.GameTicking;
@@ -22,9 +22,6 @@ namespace Content.Server.GameObjects.Components.Mobs
     [RegisterComponent]
     public class MindComponent : Component, IExamine
     {
-        [DataField("show_examine_info")]
-        private bool _showExamineInfo;
-
         /// <inheritdoc />
         public override string Name => "Mind";
 
@@ -61,6 +58,8 @@ namespace Content.Server.GameObjects.Components.Mobs
         /// </summary>
         public void InternalEjectMind()
         {
+            if (!Deleted)
+                Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new MindRemovedMessage());
             Mind = null;
         }
 
@@ -94,7 +93,7 @@ namespace Content.Server.GameObjects.Components.Mobs
 
                     Mind!.TransferTo(visiting);
                 }
-                else if(GhostOnShutdown)
+                else if (GhostOnShutdown)
                 {
                     var spawnPosition = Owner.Transform.Coordinates;
                     // Use a regular timer here because the entity has probably been deleted.
@@ -153,4 +152,8 @@ namespace Content.Server.GameObjects.Components.Mobs
             }
         }
     }
+
+    public class MindRemovedMessage : EntityEventArgs
+    {
+    }
 }

Content.Server/GameObjects/Components/Mobs/VisitingMindComponent.cs

@@ -1,4 +1,5 @@
-using Content.Server.Mobs;
+#nullable enable
+using Content.Server.Mobs;
 using Robust.Shared.GameObjects;
 using Robust.Shared.ViewVariables;
 
@@ -18,4 +19,8 @@ namespace Content.Server.GameObjects.Components.Mobs
             Mind?.UnVisit();
         }
     }
+
+    public class MindUnvisitedMessage : EntityEventArgs
+    {
+    }
 }

Content.Server/GameObjects/Components/Observer/AcceptCloningEui.cs

@@ -28,7 +28,9 @@ namespace Content.Server.GameObjects.Components.Observer
                 return;
             }
 
-            Player.ContentData()?.Mind?.TransferTo(_newMob);
+            var mind = Player.ContentData()?.Mind;
+            mind?.TransferTo(_newMob);
+            mind?.UnVisit();
             Close();
         }
     }

Content.Server/GameObjects/Components/Observer/GhostComponent.cs

@@ -72,6 +72,26 @@ namespace Content.Server.GameObjects.Components.Observer
             base.Shutdown();
         }
 
+        public override void OnAdd()
+        {
+            base.OnAdd();
+
+            if (Owner.TryGetComponent<MindComponent>(out var mind))
+            {
+                mind.GhostOnShutdown = false;
+            }
+        }
+
+        public override void OnRemove()
+        {
+            base.OnRemove();
+
+            if (Owner.TryGetComponent<MindComponent>(out var mind))
+            {
+                mind.GhostOnShutdown = true;
+            }
+        }
+
         public override ComponentState GetComponentState(ICommonSession player) => new GhostComponentState(CanReturnToBody);
 
         public override void HandleNetworkMessage(ComponentMessage message, INetChannel netChannel, ICommonSession? session = null!)
@@ -92,13 +112,12 @@ namespace Content.Server.GameObjects.Components.Observer
                     {
                         var o = actor.playerSession.ContentData()!.Mind;
                         o?.UnVisit();
-                        Owner.Delete();
                     }
                     break;
                 }
                 case ReturnToCloneComponentMessage _:
 
-                    if (Owner.TryGetComponent(out VisitingMindComponent? mind))
+                    if (Owner.TryGetComponent(out VisitingMindComponent? mind) && mind.Mind != null)
                     {
                         Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new GhostReturnMessage(mind.Mind));
                     }

Content.Server/GameObjects/EntitySystems/GhostSystem.cs

@@ -0,0 +1,44 @@
+#nullable enable
+using Content.Server.GameObjects.Components.Mobs;
+using Content.Server.GameObjects.Components.Observer;
+using JetBrains.Annotations;
+using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects;
+using System;
+
+namespace Content.Server.GameObjects.EntitySystems
+{
+    [UsedImplicitly]
+    public class GhostSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<GhostComponent, MindRemovedMessage>(OnMindRemovedMessage);
+            SubscribeLocalEvent<GhostComponent, MindUnvisitedMessage>(OnMindUnvisitedMessage);
+        }
+
+        private void OnMindRemovedMessage(EntityUid uid, GhostComponent component, MindRemovedMessage args)
+        {
+            if (!EntityManager.TryGetEntity(uid, out var entity))
+                return;
+            DeleteEntity(entity);
+        }
+
+        private void OnMindUnvisitedMessage(EntityUid uid, GhostComponent component, MindUnvisitedMessage args)
+        {
+            if (!EntityManager.TryGetEntity(uid, out var entity))
+                return;
+            DeleteEntity(entity);
+        }
+
+        private void DeleteEntity(IEntity? entity)
+        {
+            if (entity?.Deleted == true)
+                return;
+
+            entity?.Delete();
+        }
+    }
+}

Content.Server/GameTicking/GamePreset.cs

@@ -45,7 +45,6 @@ namespace Content.Server.GameTicking
             if (mind.VisitingEntity != null)
             {
                 mind.UnVisit();
-                mind.VisitingEntity.Delete();
             }
 
             var position = playerEntity?.Transform.Coordinates ?? IoCManager.Resolve<IGameTicker>().GetObserverSpawnPoint();

Content.Server/GameTicking/GameTicker.cs

@@ -416,13 +416,8 @@ namespace Content.Server.GameTicking
 
         public void Respawn(IPlayerSession targetPlayer)
         {
-            var ghost = targetPlayer.AttachedEntity?.GetComponentOrNull<GhostComponent>();
-
             targetPlayer.ContentData()?.WipeMind();
 
-            if (ghost?.Deleted == false)
-                ghost.Owner.Delete();
-
             if (LobbyEnabled)
                 _playerJoinLobby(targetPlayer);
             else

Content.Server/GlobalVerbs/ControlMobVerb.cs

@@ -55,13 +55,9 @@ namespace Content.Server.GlobalVerbs
             var userMind = player.ContentData()?.Mind;
 
             var targetMind = target.GetComponent<MindComponent>();
-            var oldEntity = userMind?.CurrentEntity;
 
             targetMind.Mind?.TransferTo(null);
             userMind?.TransferTo(target);
-
-            if (oldEntity != null && oldEntity.HasComponent<GhostComponent>())
-                oldEntity.Delete();
         }
     }
 }

Content.Server/Mobs/Mind.cs

@@ -313,6 +313,8 @@ namespace Content.Server.Mobs
             {
                 oldVisitingEnt.RemoveComponent<VisitingMindComponent>();
             }
+
+            oldVisitingEnt.EntityManager.EventBus.RaiseLocalEvent(oldVisitingEnt.Uid, new MindUnvisitedMessage());
         }
 
         public bool TryGetSession([NotNullWhen(true)] out IPlayerSession? session)