Locked resources are always unavailable.

src/engine/gameManager/ForgeManager.java

@@ -14,6 +14,7 @@ import engine.net.client.msg.ErrorPopupMsg;
 import engine.objects.Item;
 import engine.objects.ItemTemplate;
 import engine.objects.PlayerCharacter;
+import engine.objects.Warehouse;
 import engine.powers.EffectsBase;
 import org.pmw.tinylog.Logger;
 
@@ -30,6 +31,25 @@ public enum ForgeManager implements Runnable {
     public static final AtomicInteger wordOrderCounter = new AtomicInteger(0);
     public static HashMap<Item, WorkOrder> oven = new HashMap<Item, WorkOrder>();
 
+    public static HashMap<mbEnums.ResourceType, Integer> calcWarehouseOverflow(Warehouse warehouse, HashMap<mbEnums.ResourceType, Integer> cost_map) {
+
+        // Method returns a map of resourceType that a transaction overdrafts.
+
+        HashMap<mbEnums.ResourceType, Integer> overflowMap = new HashMap<>();
+
+        for (mbEnums.ResourceType resourceType : cost_map.keySet()) {
+
+            int debit = warehouse.resources.get(resourceType) - cost_map.get(resourceType);
+
+            // Locked resources are always unavailable
+
+            if (debit < 0 || warehouse.locked.contains(resourceType))
+                overflowMap.put(resourceType, debit);
+        }
+
+        return overflowMap;
+    }
+
     @Override
     public void run() {