public ShoppingCart CompareShoppingCart(long storeId, ShoppingCart oldShoppingCart)
 {
     ShoppingCart newShoppingCart = new ShoppingCart(storeId);
     List<Item> items = GetItemsByStoreId(storeId);
     foreach (var item in oldShoppingCart.Items)
     {
         if (item.Key.Type == "1")
         {
             var tempList = items.Where(newItem => newItem.Code == item.Key.Code).ToList();
             if ((tempList != null) && (tempList.Count == 1))
             {
                 newShoppingCart.AddItem(tempList[0], item.Value);
             }
         }
         else
         {
             var tempList = items.Where(newItem => newItem.Name == item.Key.Name).ToList();
             if ((tempList != null) && (tempList.Count == 1))
             {
                 newShoppingCart.AddItem(tempList[0], item.Value);
             }
         }
     }
     return newShoppingCart;
 }
 public ShoppingCart GetUserShoppingCart(User user)
 {
     ShoppingCart shoppingCart = new ShoppingCart(-1);
     string[] lines = File.ReadAllLines(user.FileName);
     if(lines != null)
     {
         foreach(string line in lines)
         {
             string[] itemDetails = line.Split(',');
             Item item = new Item();
             int amount = int.Parse(itemDetails[0]);
             item.Id = long.Parse(itemDetails[1]);
             item.Name = itemDetails[2];
             item.Price = itemDetails[3];
             item.Quantity = itemDetails[4];
             item.UnitOfMeasure = itemDetails[5];
             item.Code = itemDetails[6];
             item.Type = itemDetails[7];
             item.StoreId = long.Parse(itemDetails[8]);
             shoppingCart.AddItem(item, amount);
         }
         return shoppingCart;
     }
     return null;
 }