设计一个基于MVC设计模式的点餐系统，该系统可以供用户点餐，包含的功能有： （1）显示菜品的相关信息（价格、原材料产地和生产日期等） （2）菜品加入购物车 （3）菜品从购物车删除 （4）清空购物车 （5）计算购物车中菜品的总金额 （6）*支付功能（扩展功能） 代码

以下是一个基于MVC设计模式的点餐系统的代码示例：

Model:

class MenuItem:
    def __init__(self, name, price, origin, production_date):
        self.name = name
        self.price = price
        self.origin = origin
        self.production_date = production_date

class ShoppingCart:
    def __init__(self):
        self.items = []

    def add_item(self, item):
        self.items.append(item)

    def remove_item(self, item):
        self.items.remove(item)

    def clear_items(self):
        self.items = []

    def get_total_price(self):
        return sum([item.price for item in self.items])

View:

class MenuView:
    def display_menu(self, menu_items):
        print("Menu:")
        for i, item in enumerate(menu_items):
            print(f"{i+1}. {item.name} - {item.price} yuan")

class ShoppingCartView:
    def display_cart(self, cart):
        print("Shopping Cart:")
        for item in cart.items:
            print(f"{item.name} - {item.price} yuan")

class PaymentView:
    def display_payment(self, total_price):
        print(f"Total cost: {total_price} yuan")
        print("Payment successful.")

Controller:

class OrderController:
    def __init__(self, menu_items, menu_view, cart_view, payment_view):
        self.menu_items = menu_items
        self.menu_view = menu_view
        self.cart_view = cart_view
        self.payment_view = payment_view
        self.shopping_cart = ShoppingCart()

    def display_menu(self):
        self.menu_view.display_menu(self.menu_items)

    def add_to_cart(self, item_number):
        item = self.menu_items[item_number-1]
        self.shopping_cart.add_item(item)
        self.cart_view.display_cart(self.shopping_cart)

    def remove_from_cart(self, item_number):
        item = self.shopping_cart.items[item_number-1]
        self.shopping_cart.remove_item(item)
        self.cart_view.display_cart(self.shopping_cart)

    def clear_cart(self):
        self.shopping_cart.clear_items()
        self.cart_view.display_cart(self.shopping_cart)

    def calculate_price(self):
        total_price = self.shopping_cart.get_total_price()
        self.payment_view.display_payment(total_price)

使用示例：

menu_items = [MenuItem("Hamburger", 20, "USA", "2022-01-01"),
              MenuItem("Pizza", 30, "Italy", "2022-01-01"),
              MenuItem("Hot Dog", 15, "USA", "2022-01-01")]

menu_view = MenuView()
cart_view = ShoppingCartView()
payment_view = PaymentView()

order_controller = OrderController(menu_items, menu_view, cart_view, payment_view)

order_controller.display_menu()
order_controller.add_to_cart(1)
order_controller.add_to_cart(2)
order_controller.remove_from_cart(1)
order_controller.clear_cart()
order_controller.calculate_price()