moved ProductionItem into Traits.ProductionQueue's file

OpenRa.Game/Traits/ProductionQueue.cs

@@ -168,4 +168,57 @@ namespace OpenRa.Traits
 				FinishProduction( newUnitType.Category );
 		}
 	}
+
+	class ProductionItem
+	{
+		public readonly string Item;
+
+		public readonly int TotalTime;
+		public readonly int TotalCost;
+		public int RemainingTime { get; private set; }
+		public int RemainingCost { get; private set; }
+
+		public bool Paused = false, Done = false;
+		public Action OnComplete;
+
+		int slowdown = 0;
+
+		public ProductionItem(string item, int time, int cost, Action onComplete)
+		{
+			if (time <= 0)
+				time = 1;
+			Item = item;
+			RemainingTime = TotalTime = time;
+			RemainingCost = TotalCost = cost;
+			OnComplete = onComplete;
+		}
+
+		public void Tick(Player player)
+		{
+			if (Done)
+			{
+				if (OnComplete != null) OnComplete();
+				return;
+			}
+
+			if (Paused) return;
+
+			if (player.GetPowerState() != PowerState.Normal)
+			{
+				if (--slowdown <= 0)
+					slowdown = Rules.General.LowPowerSlowdown;
+				else
+					return;
+			}
+
+			var costThisFrame = RemainingCost / RemainingTime;
+			if (costThisFrame != 0 && !player.TakeCash(costThisFrame)) return;
+
+			RemainingCost -= costThisFrame;
+			RemainingTime -= 1;
+			if (RemainingTime > 0) return;
+
+			Done = true;
+		}
+	}
 }