Cardboard Box and Stealth Components (#11569)

Content.Client/CardboardBox/CardboardBoxSystem.cs

@@ -0,0 +1,60 @@
+using Content.Shared.CardboardBox;
+using Content.Shared.CardboardBox.Components;
+using Content.Shared.Examine;
+using Content.Shared.Movement.Components;
+using Robust.Client.GameObjects;
+
+namespace Content.Client.CardboardBox;
+
+public sealed class CardboardBoxSystem : SharedCardboardBoxSystem
+{
+    [Dependency] private readonly EntityLookupSystem _entityLookup = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeNetworkEvent<PlayBoxEffectMessage>(OnBoxEffect);
+    }
+
+    private void OnBoxEffect(PlayBoxEffectMessage msg)
+    {
+        if (!TryComp<CardboardBoxComponent>(msg.Source, out var box))
+            return;
+
+        var xformQuery = GetEntityQuery<TransformComponent>();
+
+        if (!xformQuery.TryGetComponent(msg.Source, out var xform))
+            return;
+
+        var sourcePos = xform.MapPosition;
+
+        //Any mob that can move should be surprised?
+        //God mind rework needs to come faster so it can just check for mind
+        //TODO: Replace with Mind Query when mind rework is in.
+        var mobMoverEntities = new HashSet<EntityUid>();
+
+        //Filter out entities in range to see that they're a mob and add them to the mobMoverEntities hash for faster lookup
+        foreach (var moverComp in _entityLookup.GetComponentsInRange<MobMoverComponent>(xform.Coordinates, box.Distance))
+        {
+            if (moverComp.Owner == msg.Mover)
+                continue;
+
+            mobMoverEntities.Add(moverComp.Owner);
+        }
+
+        //Play the effect for the mobs as long as they can see the box and are in range.
+        foreach (var mob in mobMoverEntities)
+        {
+            if (!xformQuery.TryGetComponent(mob, out var moverTransform) || !ExamineSystemShared.InRangeUnOccluded(sourcePos, moverTransform.MapPosition, box.Distance, null))
+                continue;
+
+            var ent = Spawn(box.Effect, moverTransform.MapPosition);
+
+            if (!xformQuery.TryGetComponent(ent, out var entTransform) || !TryComp<SpriteComponent>(ent, out var sprite))
+                continue;
+
+            sprite.Offset = new Vector2(0, 1);
+            entTransform.AttachParent(mob);
+        }
+    }
+}