zero appreciation for my work, part 2

Content.Server/Objectives/Components/TargetObjectiveImmuneComponent.cs

@@ -0,0 +1,9 @@
+namespace Content.Server.Objectives.Components;
+
+/// <summary>
+/// Use this to mark a player as immune to any target objectives, useful for ghost roles or events.
+/// </summary>
+[RegisterComponent]
+public sealed partial class TargetObjectiveImmuneComponent : Component
+{
+}

Content.Server/Objectives/Systems/KillPersonConditionSystem.cs

@@ -1,3 +1,4 @@
+using System.Linq;
 using Content.Server.Objectives.Components;
 using Content.Server.Revolutionary.Components;
 using Content.Server.Shuttles.Systems;
@@ -25,9 +26,7 @@ public override void Initialize()
         base.Initialize();
 
         SubscribeLocalEvent<KillPersonConditionComponent, ObjectiveGetProgressEvent>(OnGetProgress);
-
         SubscribeLocalEvent<PickRandomPersonComponent, ObjectiveAssignedEvent>(OnPersonAssigned);
-
         SubscribeLocalEvent<PickRandomHeadComponent, ObjectiveAssignedEvent>(OnHeadAssigned);
     }
 
@@ -41,29 +40,15 @@ private void OnGetProgress(EntityUid uid, KillPersonConditionComponent comp, ref
 
     private void OnPersonAssigned(EntityUid uid, PickRandomPersonComponent comp, ref ObjectiveAssignedEvent args)
     {
-        // invalid objective prototype
-        if (!TryComp<TargetObjectiveComponent>(uid, out var target))
-        {
-            args.Cancelled = true;
-            return;
-        }
-
-        // target already assigned
-        if (target.Target != null)
-            return;
-
-        // no other humans to kill
-        var allHumans = _mind.GetAliveHumansExcept(args.MindId);
-        if (allHumans.Count == 0)
-        {
-            args.Cancelled = true;
-            return;
-        }
-
-        _target.SetTarget(uid, _random.Pick(allHumans), target);
+        AssignRandomTarget(uid, args, _ => true);
     }
 
     private void OnHeadAssigned(EntityUid uid, PickRandomHeadComponent comp, ref ObjectiveAssignedEvent args)
+    {
+        AssignRandomTarget(uid, args, mind => HasComp<CommandStaffComponent>(uid));
+    }
+
+    private void AssignRandomTarget(EntityUid uid, ObjectiveAssignedEvent args, Predicate<EntityUid> filter, bool fallbackToAny = true)
     {
         // invalid prototype
         if (!TryComp<TargetObjectiveComponent>(uid, out var target))
@@ -76,25 +61,30 @@ private void OnHeadAssigned(EntityUid uid, PickRandomHeadComponent comp, ref Obj
         if (target.Target != null)
             return;
 
-        // no other humans to kill
-        var allHumans = _mind.GetAliveHumansExcept(args.MindId);
-        if (allHumans.Count == 0)
+        // Get all alive humans, filter out any with TargetObjectiveImmuneComponent
+        var allHumans = _mind.GetAliveHumansExcept(args.MindId)
+            .Where(mindId =>
+            {
+                if (!TryComp<MindComponent>(mindId, out var mindComp) || mindComp.OwnedEntity == null)
+                    return false;
+                return !HasComp<TargetObjectiveImmuneComponent>(mindComp.OwnedEntity.Value);
+            })
+            .ToList();
+
+        // Filter out targets based on the filter
+        var filteredHumans = allHumans.Where(mind => filter(mind)).ToList();
+
+        // There's no humans and we can't fall back to any other target
+        if (filteredHumans.Count == 0 && !fallbackToAny)
         {
             args.Cancelled = true;
             return;
         }
 
-        var allHeads = new List<EntityUid>();
-        foreach (var person in allHumans)
-        {
-            if (TryComp<MindComponent>(person, out var mind) && mind.OwnedEntity is { } ent && HasComp<CommandStaffComponent>(ent))
-                allHeads.Add(person);
-        }
-
-        if (allHeads.Count == 0)
-            allHeads = allHumans; // fallback to non-head target
+        // Pick between humans matching our filter or fall back to all humans alive
+        var selectedHumans = filteredHumans.Count > 0 ? filteredHumans : allHumans;
 
-        _target.SetTarget(uid, _random.Pick(allHeads), target);
+        _target.SetTarget(uid, _random.Pick(selectedHumans), target);
     }
 
     private float GetProgress(EntityUid target, bool requireDead)