class ItemToPurchase:
   def __init__(self, name='none', price=0, quantity=0, description='none'):
       self.item_name=name
       self.item_description=description
       self.item_price=price
       self.item_quantity=quantity

   def print_item_description(self):
       print('%s: %s' % (self.item_name, self.item_description))

      
class ShoppingCart:
  
   # constructor to initialize the shopping cart
   def __init__(self, customer_name = 'none', current_date = 'January 1, 2016', cart_items = []):
       self.customer_name = customer_name
       self.current_date = current_date
       self.cart_items = cart_items  
      
   # method to add an item to the shopping cart
   def add_item(self, itemToPurchase):
       self.cart_items.append(itemToPurchase)  
      
   # method to remove an item from the shopping cart  
   def remove_item(self, itemName):
      
       tremove_item = False
       # loop to find the item in the cart
       for item in self.cart_items:
           if item.item_name == itemName:
               self.cart_items.remove(item)
               tremove_item = True
               break
       # item not found
       if not tremove_item:          
           print('Item not found in the cart. Nothing removed')
              
   # method to modify an item's quantity in the shopping cart          
   def modify_item(self, itemToPurchase):  
      
       tmodify_item = False
       # loop to find an item
       for i in range(len(self.cart_items)):
          
           if self.cart_items[i].item_name == itemToPurchase.item_name:
               tmodify_item = True
               self.cart_items[i].item_quantity = itemToPurchase.item_quantity
               break
      
       # item not found
       if not tmodify_item:      
           print('Item not found in the cart. Nothing modified')  

   # method to return the total quantity of all items in the shopping cart      
   def get_num_items_in_cart(self):
       num_items = 0
       for item in self.cart_items:
           num_items = num_items + item.item_quantity
       return num_items
  
   # method to return the total cost of all items in the shopping cart
   def get_cost_of_cart(self):
       total_cost = 0
       cost = 0
       for item in self.cart_items:
           cost = (item.item_quantity * item.item_price)
           total_cost += cost
       return total_cost
              
   # method to print the total cost of the cart          
   def print_total(self):
       total_cost = self.get_cost_of_cart()
       if (total_cost == 0):
           print('SHOPPING CART IS EMPTY')
       else:
           print('{}\'s Shopping Cart - {}'.format(self.customer_name, self.current_date))
           print('Number of Items: %d\n' %self.get_num_items_in_cart())
           for item in self.cart_items:
               total = item.item_price * item.item_quantity
               print('%s %d @ $%d = $%d' % (item.item_name, item.item_quantity, item.item_price, total))
              
           print('\nTotal: $%d' %(total_cost))
          
   # method to print the item's description      
   def print_descriptions(self):
       if len(self.cart_items) == 0:
           print('SHOPPING CART IS EMPTY')
       else:  
           print('{}\'s Shopping Cart - {}'.format(self.customer_name, self.current_date))
           print('\nItem Descriptions')
           for item in self.cart_items:
               item.print_item_description()  
              
# method to display the menu options and based on user's choice perform the operation              
def print_menu(newCart):
   customer_Cart = newCart
   menu = ('\nMENU\n'
       'a - Add item to cart\n'
       'r - Remove item from the cart\n'
       'c - Change item quantity\n'
       "i - Output item's descriptions\n"
       'o - Output shopping cart\n'
       'q - Quit\n')
      
   command = ''
   while(command != 'q'):
       print(menu)
       command = input('Choose an option:')
       while(command != 'a' and command != 'o' and command != 'i' and command != 'q' and command != 'r' and command != 'c'):
           command = input('Choose an option:\n')
       if(command == 'a'):
           print("\nADD ITEM TO CART")
           item_name = input('Enter the item name:\n')
           item_description = input('Enter the item description:\n')
           item_price = int(input('Enter the item price:\n'))
           item_quantity = int(input('Enter the item quantity:\n'))
           itemtoPurchase = ItemToPurchase(item_name, item_price, item_quantity, item_description)
           customer_Cart.add_item(itemtoPurchase)
      
       elif(command == 'o'):
           print('\nOUTPUT SHOPPING CART')
           customer_Cart.print_total()  
       elif(command == 'i'):
           print('\nOUTPUT ITEMS\' DESCRIPTIONS')
           customer_Cart.print_descriptions()
       elif(command == 'r'):
           print('REMOVE ITEM FROM CART')
           itemName = input('Enter the name of the item to remove :\n')
           customer_Cart.remove_item(itemName)
       elif(command == 'c'):
           print('\nCHANGE ITEM QUANTITY')
           itemName = input('Enter the name of the item :\n')
           qty = int(input('Enter the new quantity :\n'))
           itemToPurchase = ItemToPurchase(itemName,0,qty)
           customer_Cart.modify_item(itemToPurchase)
      
if __name__ == "__main__":
   customer_name = input("Enter customer's name:\n")
   current_date = input("Enter today's date:\n")
   print("\nCustomer name: %s" %customer_name)
   print("Today's date: %s" %current_date)
   newCart = ShoppingCart(customer_name, current_date)
   print_menu(newCart)  

#end of program