coffee_machine.py

from coffee import Coffee
from ingredient import Ingredient

class CoffeeMachine:
    _instance = None

    def __init__(self):
        if CoffeeMachine._instance is not None:
            raise Exception("This class is a singleton!")
        else:
            CoffeeMachine._instance = self
            self.coffee_menu = []
            self.ingredients = {}
            self._initialize_ingredients()
            self._initialize_coffee_menu()

    @staticmethod
    def get_instance():
        if CoffeeMachine._instance is None:
            CoffeeMachine()
        return CoffeeMachine._instance

    def _initialize_coffee_menu(self):
        espresso_recipe = {
            self.ingredients["Coffee"]: 1,
            self.ingredients["Water"]: 1
        }
        self.coffee_menu.append(Coffee("Espresso", 2.5, espresso_recipe))

        cappuccino_recipe = {
            self.ingredients["Coffee"]: 1,
            self.ingredients["Water"]: 1,
            self.ingredients["Milk"]: 1
        }
        self.coffee_menu.append(Coffee("Cappuccino", 3.5, cappuccino_recipe))

        latte_recipe = {
            self.ingredients["Coffee"]: 1,
            self.ingredients["Water"]: 1,
            self.ingredients["Milk"]: 2
        }
        self.coffee_menu.append(Coffee("Latte", 4.0, latte_recipe))

    def _initialize_ingredients(self):
        self.ingredients["Coffee"] = Ingredient("Coffee", 10)
        self.ingredients["Water"] = Ingredient("Water", 10)
        self.ingredients["Milk"] = Ingredient("Milk", 10)

    def display_menu(self):
        print("Coffee Menu:")
        for coffee in self.coffee_menu:
            print(f"{coffee.get_name()} - ${coffee.get_price()}")

    def select_coffee(self, coffee_name):
        for coffee in self.coffee_menu:
            if coffee.get_name().lower() == coffee_name.lower():
                return coffee
        return None

    def dispense_coffee(self, coffee, payment):
        if payment.get_amount() >= coffee.get_price():
            if self._has_enough_ingredients(coffee):
                self._update_ingredients(coffee)
                print(f"Dispensing {coffee.get_name()}...")
                change = payment.get_amount() - coffee.get_price()
                if change > 0:
                    print(f"Please collect your change: ${change}")
            else:
                print(f"Insufficient ingredients to make {coffee.get_name()}")
        else:
            print(f"Insufficient payment for {coffee.get_name()}")

    def _has_enough_ingredients(self, coffee):
        for ingredient, required_quantity in coffee.get_recipe().items():
            if ingredient.get_quantity() < required_quantity:
                return False
        return True

    def _update_ingredients(self, coffee):
        for ingredient, required_quantity in coffee.get_recipe().items():
            ingredient.update_quantity(-required_quantity)
            if ingredient.get_quantity() < 3:
                print(f"Low inventory alert: {ingredient.get_name()}")