Fix ChemMaster labelling behavior (#11290)

Content.Server/Chemistry/EntitySystems/ChemMasterSystem.cs

@@ -1,6 +1,7 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Content.Server.Chemistry.Components;
+using Content.Server.Labels;
 using Content.Server.Labels.Components;
 using Content.Server.Popups;
 using Content.Server.Storage.Components;
@@ -33,6 +34,7 @@ namespace Content.Server.Chemistry.EntitySystems
         [Dependency] private readonly ItemSlotsSystem _itemSlotsSystem = default!;
         [Dependency] private readonly UserInterfaceSystem _userInterfaceSystem = default!;
         [Dependency] private readonly StorageSystem _storageSystem = default!;
+        [Dependency] private readonly LabelSystem _labelSystem = default!;
         
         private const string PillPrototypeId = "Pill";
 
@@ -191,13 +193,13 @@ namespace Content.Server.Chemistry.EntitySystems
             if (!WithdrawFromBuffer(chemMaster, needed, user, out var withdrawal))
                 return;
             
-            Label(container, message.Label);
+            _labelSystem.Label(container, message.Label);
             
             for (var i = 0; i < message.Number; i++)
             {
                 var item = Spawn(PillPrototypeId, Transform(container).Coordinates);
                 _storageSystem.Insert(container, item, storage);
-                Label(item, message.Label);
+                _labelSystem.Label(item, message.Label);
 
                 var itemSolution = _solutionContainerSystem.EnsureSolution(item, SharedChemMaster.PillSolutionName);
                 
@@ -231,7 +233,7 @@ namespace Content.Server.Chemistry.EntitySystems
             if (!WithdrawFromBuffer(chemMaster, message.Dosage, user, out var withdrawal))
                 return;
 
-            Label(container, message.Label);
+            _labelSystem.Label(container, message.Label);
             _solutionContainerSystem.TryAddSolution(
                 container, solution, withdrawal);
 
@@ -270,18 +272,6 @@ namespace Content.Server.Chemistry.EntitySystems
             return true;
         }
 
-        private void Label(EntityUid ent, string label)
-        {
-            if (string.IsNullOrEmpty(label)) 
-                return;
-            var labelComponent = EnsureComp<LabelComponent>(ent);
-            
-            labelComponent.OriginalName = Name(ent);
-            var val = Name(ent) + $" ({label})";
-            MetaData(ent).EntityName = val;
-            labelComponent.CurrentLabel = label;
-        }
-
         private void ClickSound(ChemMasterComponent chemMaster)
         {
             _audioSystem.Play(chemMaster.ClickSound, Filter.Pvs(chemMaster.Owner), chemMaster.Owner, AudioParams.Default.WithVolume(-2f));

Content.Server/Labels/Label/HandLabelerSystem.cs

@@ -15,6 +15,7 @@ namespace Content.Server.Labels
     public sealed class HandLabelerSystem : EntitySystem
     {
         [Dependency] private readonly UserInterfaceSystem _userInterfaceSystem = default!;
+        [Dependency] private readonly LabelSystem _labelSystem = default!;
 
         public override void Initialize()
         {
@@ -44,23 +45,14 @@ namespace Content.Server.Labels
                 return;
             }
 
-            LabelComponent label = target.EnsureComponent<LabelComponent>();
-
-            if (label.OriginalName != null)
-                EntityManager.GetComponent<MetaDataComponent>(target).EntityName = label.OriginalName;
-            label.OriginalName = null;
-
             if (handLabeler.AssignedLabel == string.Empty)
             {
-                label.CurrentLabel = null;
+                _labelSystem.Label(target, null);
                 result = Loc.GetString("hand-labeler-successfully-removed");
                 return;
             }
 
-            label.OriginalName = EntityManager.GetComponent<MetaDataComponent>(target).EntityName;
-            string val = EntityManager.GetComponent<MetaDataComponent>(target).EntityName + $" ({handLabeler.AssignedLabel})";
-            EntityManager.GetComponent<MetaDataComponent>(target).EntityName = val;
-            label.CurrentLabel = handLabeler.AssignedLabel;
+            _labelSystem.Label(target, handLabeler.AssignedLabel);
             result = Loc.GetString("hand-labeler-successfully-applied");
         }
 

Content.Server/Labels/Label/LabelSystem.cs

@@ -31,6 +31,39 @@ namespace Content.Server.Labels
             SubscribeLocalEvent<PaperLabelComponent, ExaminedEvent>(OnExamined);
         }
 
+        /// <summary>
+        /// Apply or remove a label on an entity.
+        /// </summary>
+        /// <param name="uid">EntityUid to change label on</param>
+        /// <param name="text">intended label text (null to remove)</param>
+        /// <param name="label">label component for resolve</param>
+        /// <param name="metadata">metadata component for resolve</param>
+        public void Label(EntityUid uid, string? text, MetaDataComponent? metadata = null, LabelComponent? label = null)
+        {
+            if (!Resolve(uid, ref metadata))
+                return;
+            if (!Resolve(uid, ref label, false))
+                label = EnsureComp<LabelComponent>(uid);
+
+            if (string.IsNullOrEmpty(text))
+            {
+                if (label.OriginalName is null)
+                    return;
+
+                // Remove label
+                metadata.EntityName = label.OriginalName;
+                label.CurrentLabel = null;
+                label.OriginalName = null;
+
+                return;
+            }
+
+            // Update label
+            label.OriginalName ??= metadata.EntityName;
+            label.CurrentLabel = text;
+            metadata.EntityName = $"{label.OriginalName} ({text})";
+        }
+
         private void OnComponentInit(EntityUid uid, PaperLabelComponent component, ComponentInit args)
         {
             _itemSlotsSystem.AddItemSlot(uid, ContainerName, component.LabelSlot);