Fix error spamming in update loop of artifact scanner (#46149)

* refactor: make relations etween node scanner and artifact more clear, remove errors on crushing artifact while scanner is attached, add generic `attached entities` collection for artifact to be used for other purposes

* Apply xml-doc suggestion from @Tayrtahn

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

* fix: attaching scanner to other artifact now detaches it from original one

* refactor: fix whitespaces in SharedXenoArtifactSystem

* refactor: fix detaching artifact when scanning same artifact twice

---------

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

Content.Shared/Xenoarchaeology/Artifact/Components/XenoArtifactComponent.cs

@@ -14,7 +14,8 @@ namespace Content.Shared.Xenoarchaeology.Artifact.Components;
 /// This is used for handling interactions with artifacts as well as
 /// storing data about artifact node graphs.
 /// </summary>
-[RegisterComponent, NetworkedComponent, Access(typeof(SharedXenoArtifactSystem)), AutoGenerateComponentState, AutoGenerateComponentPause]
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState, AutoGenerateComponentPause]
+[Access(typeof(SharedXenoArtifactSystem))]
 public sealed partial class XenoArtifactComponent : Component
 {
     public static string NodeContainerId = "node-container";
@@ -192,6 +193,15 @@ public sealed partial class XenoArtifactComponent : Component
     /// </summary>
     [DataField]
     public LocId? UnlockFailureMsg = "artifact-unlock-state-end-failure";
+
+    /// <summary>
+    /// List of currently attached entities - node scanners, etc.
+    /// </summary>
+    /// <remarks>
+    /// TODO: replace with relationship system.
+    /// </remarks>
+    [DataField, AutoNetworkedField]
+    public HashSet<EntityUid> AttachedEntities = new();
 }
 
 /// <summary>

Content.Shared/Xenoarchaeology/Artifact/SharedXenoArtifactSystem.cs

@@ -40,6 +40,17 @@ public abstract partial class SharedXenoArtifactSystem : EntitySystem
         UpdateUnlock(frameTime);
     }
 
+    /// <summary> Clears all attached scanners.  </summary>
+    [SubscribeLocalEvent]
+    private void OnShutdown(Entity<XenoArtifactComponent> ent, ref ComponentRemove shutdown)
+    {
+        var removedEvent = new XenoArtifactDestroyedEvent();
+        foreach (var entity in ent.Comp.AttachedEntities)
+        {
+            RaiseLocalEvent(entity, ref removedEvent);
+        }
+    }
+
     /// <summary> As all artifacts have to contain nodes - we ensure that they are containers. </summary>
     private void OnStartup(Entity<XenoArtifactComponent> ent, ref ComponentStartup args)
     {
@@ -52,6 +63,51 @@ public abstract partial class SharedXenoArtifactSystem : EntitySystem
         args.Handled = TryActivateXenoArtifact(ent, ent, null, Transform(ent).Coordinates, false);
     }
 
+    /// <summary>
+    /// Tries to remove an entity from the list of attached entities.
+    /// This helps with tracking relationship.
+    /// </summary>
+    /// <param name="ent">Artifact entity.</param>
+    /// <param name="entityToDetach">Entity to detach.</param>
+    /// <returns>
+    /// Returns false if <paramref name="ent"/> is not artifact,
+    /// or if there is no such entity in list of attached ones.
+    /// Otherwise, returns true.
+    /// </returns>
+    public bool TryDetachEntity(Entity<XenoArtifactComponent?> ent, EntityUid entityToDetach)
+    {
+        if (!Resolve(ent, ref ent.Comp))
+            return false;
+
+        var result = ent.Comp.AttachedEntities.Remove(entityToDetach);
+        if (result)
+            Dirty(ent);
+
+        return result;
+    }
+
+    /// <summary>
+    /// Tries to add an entity to list of attached entities.
+    /// This helps with tracking relationship.
+    /// </summary>
+    /// <param name="ent">Artifact entity.</param>
+    /// <param name="entityToAttach">Entity to attach.</param>
+    /// <returns>
+    /// Returns False if <paramref name="ent"/> is not artifact,
+    /// or entity is already added, otherwise true.
+    /// </returns>
+    public bool TryAttachEntity(Entity<XenoArtifactComponent?> ent, EntityUid entityToAttach)
+    {
+        if (!Resolve(ent, ref ent.Comp))
+            return false;
+
+        var result = ent.Comp.AttachedEntities.Add(entityToAttach);
+        if (result)
+            Dirty(ent);
+
+        return result;
+    }
+
     public void SetSuppressed(Entity<XenoArtifactComponent> ent, bool val)
     {
         if (ent.Comp.Suppressed == val)
@@ -61,3 +117,7 @@ public abstract partial class SharedXenoArtifactSystem : EntitySystem
         Dirty(ent);
     }
 }
+
+/// <summary> Event of artifact destruction. </summary>
+[ByRefEvent]
+public record struct XenoArtifactDestroyedEvent;

Content.Shared/Xenoarchaeology/Equipment/Components/NodeScannerComponent.cs

@@ -28,6 +28,7 @@ public sealed partial class NodeScannerComponent : Component
 /// Component-marker that node scanner device (<see cref="NodeScannerComponent"/>) is connected to artifact.
 /// </summary>
 [RegisterComponent, NetworkedComponent, AutoGenerateComponentState(true), AutoGenerateComponentPause]
+[Access(typeof(NodeScannerSystem))]
 public sealed partial class NodeScannerConnectedComponent : Component
 {
     /// <summary>

Content.Shared/Xenoarchaeology/Equipment/NodeScannerSystem.cs

@@ -1,6 +1,7 @@
 using Content.Shared.Interaction;
 using Content.Shared.Timing.Systems;
 using Content.Shared.Verbs;
+using Content.Shared.Xenoarchaeology.Artifact;
 using Content.Shared.Xenoarchaeology.Artifact.Components;
 using Content.Shared.Xenoarchaeology.Equipment.Components;
 using Robust.Shared.Timing;
@@ -14,13 +15,7 @@ public sealed partial class NodeScannerSystem : EntitySystem
     [Dependency] private IGameTiming _timing = default!;
     [Dependency] private SharedUserInterfaceSystem _ui = default!;
     [Dependency] private SharedTransformSystem _transform = default!;
-
-    /// <inheritdoc/>
-    public override void Initialize()
-    {
-        SubscribeLocalEvent<NodeScannerComponent, BeforeRangedInteractEvent>(OnBeforeRangedInteract);
-        SubscribeLocalEvent<NodeScannerComponent, GetVerbsEvent<UtilityVerb>>(AddScanVerb);
-    }
+    [Dependency] private SharedXenoArtifactSystem _artifact = default!;
 
     /// <inheritdoc />
     public override void Update(float frameTime)
@@ -43,7 +38,27 @@ public sealed partial class NodeScannerSystem : EntitySystem
         }
     }
 
-    private void OnBeforeRangedInteract(EntityUid uid, NodeScannerComponent component, BeforeRangedInteractEvent args)
+    /// <summary> Disconnect if artifact is destroyed </summary>
+    [SubscribeLocalEvent]
+    private void OnArtifactRemoved(Entity<NodeScannerConnectedComponent> ent, ref XenoArtifactDestroyedEvent args)
+    {
+        RemCompDeferred(ent, ent.Comp);
+    }
+
+    /// <summary> Detach if scanner is disconnected, or destroyed. </summary>
+    [SubscribeLocalEvent]
+    private void OnScannerRemoved(Entity<NodeScannerConnectedComponent> ent, ref ComponentRemove args)
+    {
+        var artifact = ent.Comp.AttachedTo;
+        if (!TerminatingOrDeleted(artifact))
+        {
+            _artifact.TryDetachEntity((artifact, null), ent);
+        }
+    }
+
+    /// <summary> Attach scanner if target is fitting. </summary>
+    [SubscribeLocalEvent]
+    private void OnBeforeRangedInteract(Entity<NodeScannerComponent> ent, ref BeforeRangedInteractEvent args)
     {
         if (args.Handled || !args.CanReach || args.Target is not { } target || !HasComp<XenoArtifactComponent>(target))
             return;
@@ -52,22 +67,26 @@ public sealed partial class NodeScannerSystem : EntitySystem
             ? (target, unlockingComponent)
             : (target, null);
 
-        Attach((uid, component), unlockingEnt, args.User);
+        Attach(ent, unlockingEnt, args.User);
 
         args.Handled = true;
     }
 
-    private void AddScanVerb(EntityUid uid, NodeScannerComponent component, GetVerbsEvent<UtilityVerb> args)
+    /// <summary> Add `scan` verb if target is fitting. </summary>
+    [SubscribeLocalEvent]
+    private void AddScanVerb(Entity<NodeScannerComponent> ent, ref GetVerbsEvent<UtilityVerb> args)
     {
         if (!args.CanAccess)
             return;
 
-        if (!TryComp<XenoArtifactUnlockingComponent>(args.Target, out var unlockingComponent))
+        var target = args.Target;
+        if (!TryComp<XenoArtifactUnlockingComponent>(target, out var unlockingComponent))
             return;
 
+        var user = args.User;
         var verb = new UtilityVerb
         {
-            Act = () => Attach((uid, component), (args.Target, unlockingComponent), args.User),
+            Act = () => Attach(ent, (target, unlockingComponent), user),
             Text = Loc.GetString("node-scan-tooltip")
         };
 
@@ -84,11 +103,17 @@ public sealed partial class NodeScannerSystem : EntitySystem
             return;
 
         var connected = EnsureComp<NodeScannerConnectedComponent>(device);
+
         EntityUid artifact = unlockingEnt;
         if (connected.AttachedTo != artifact)
         {
+            // Remove connection from previous scanner.
+            if (connected.AttachedTo.Valid)
+                _artifact.TryDetachEntity(connected.AttachedTo, device);
+
             connected.AttachedTo = artifact;
             Dirty(device, connected);
+            _artifact.TryAttachEntity(artifact, device);
         }
 
         _ui.TryOpenUi((device, null), NodeScannerUiKey.Key, actor, predicted: true);