Allow to sell non-stackable items like stackables

Make it possible to sell non-stackable items all at once by introducing
"Duplicate Items" and a Shop that can handle them. Also fix a
trivial bug to correctly preview you money while selling.

1 files changed, 86 insertions, 4 deletions

diff --git a/src/shopitem.h b/src/shopitem.h
index 8b1ba4b2..d6226732 100644
--- a/src/shopitem.h
+++ b/src/shopitem.h
@@ -23,27 +23,100 @@
 #ifndef _SHOPITEM_H
 #define _SHOPITEM_H
 
+#include <stack>
+
 #include "item.h"
 
 /**
- * Represents an item in a shop inventory.
+ * Represents an item in a shop inventory. It can store quantity and inventory
+ * indices of duplicate entries in the shop as well.
  */
 class ShopItem : public Item
 {
     public:
         /**
-         * Constructor.
+         * Constructor. Creates a new ShopItem.
+         *
+         * @param inventoryIndex the inventory index of the item
+         * @param id the id of the item
+         * @param quantity number of available copies of the item
+         * @param price price of the item
+         */
+        ShopItem(int inventoryIndex, int id, int quantity, int price);
+
+        /**
+         * Constructor. Creates a new ShopItem. Inventory index will be set to
+         * -1 and quantity to 0.
+         *
+         * @param id the id of the item
+         * @param price price of the item
+         */
+        ShopItem(int id, int price);
+
+        /**
+         * Destructor.
+         */
+        ~ShopItem();
+
+        /**
+         * Add a duplicate. Id and price will be taken from this item.
+         *
+         * @param inventoryIndex the inventory index of the item
+         * @param quantity number of available copies of the item
+         */
+        void addDuplicate (int inventoryIndex, int quantity);
+
+        /**
+         * Add a duplicate. Id and price will be taken from this item.
+         * Needed for compatibility with ShopDuplicateItems (see) class
+         * documentation).
          */
-        ShopItem(int id, int quantity, int price);
+        void addDuplicate ();
+
+        /**
+         * Gets the quantity of the currently topmost duplicate.
+         *
+         * @return the quantity of the currently topmost duplicate
+         */
+        int getCurrentQuantity() {
+            return mDuplicates.empty() ? 0 : mDuplicates.top()->quantity;
+        }
+
+        /**
+         * Gets the inventory index of the currently topmost duplicate.
+         *
+         * @return the inventory index of the currently topmost duplicate
+         */
+        int getCurrentInvIndex() {
+            return mDuplicates.empty() ? mInvIndex :
+                    mDuplicates.top()->inventoryIndex;
+        }
+
+        /**
+         * Reduces the quantity of the topmost duplicate by the specified
+         * amount. Also reduces the total quantity of this DuplicateItem.
+         * Empty duplicates are automatically removed.
+         * 
+         * If the amount is bigger than the quantity of the current topmost,
+         * only sell as much as possible. Returns the amount actually sold (do
+         * not ignore the return value!)
+         *
+         * @return the amount, that actually was sold.
+         */
+        int sellCurrentDuplicate(int quantity);
 
         /**
          * Gets the price of the item.
+         *
+         * @return the price of the item
          */
         int getPrice() const
         { return mPrice; }
 
         /**
-         * Gets the display name for in the shop list.
+         * Gets the display name for the item in the shop list.
+         *
+         * @return the display name for the item in the shop list
          */
         const std::string& getDisplayName() const
         { return mDisplayName; }
@@ -52,6 +125,15 @@ class ShopItem : public Item
         int mPrice;
         int mIndex;
         std::string mDisplayName;
+
+        /**
+         * Struct to keep track of duplicates.
+         */
+        typedef struct {
+            int inventoryIndex;
+            int quantity;
+        } DuplicateItem;
+        std::stack<DuplicateItem*> mDuplicates; /** <-- Stores duplicates */
 };
 
 #endif