Add ammo consumption and item pickup systems

GameCore/Inventory/ItemAcquisitionSystem.cs

@@ -0,0 +1,47 @@
+using GameCore.Combat;
+using GameCore.Combat.Effects;
+using GameCore.ECS;
+using GameCore.ECS.Interfaces;
+using GameCore.Events;
+
+namespace GameCore.Inventory;
+
+public class ItemAcquisitionSystem : ISystem
+{
+    private readonly World _world;
+
+    public ItemAcquisitionSystem(World world)
+    {
+        _world = world;
+        _world.Subscribe<ItemPickupAttemptEvent>(OnItemPickupAttempt);
+    }
+
+    public void Update(World world, float deltaTime)
+    {
+    }
+
+    private void OnItemPickupAttempt(ItemPickupAttemptEvent e)
+    {
+        var pickupComponent = _world.GetComponent<PickupComponent>(e.ItemEntity);
+        if (pickupComponent == null) return;
+
+        if (pickupComponent.IsInstantUse)
+        {
+            var context = new EffectContext
+            {
+                World = _world,
+                Owner = e.Picker,
+                Target = e.Picker
+            };
+
+            foreach (var effect in pickupComponent.OnAcquireEffects) effect.Execute(context);
+        }
+        else
+        {
+            var item = new Item(e.ItemId, e.Quantity);
+            _world.PublishEvent(new AddItemToInventoryEvent(e.Picker, item));
+        }
+
+        _world.AddComponent(e.ItemEntity, new DeathComponent());
+    }
+}