design-patterns-python/decorator_pattern.py at main · Artemooon/design-patterns-python · GitHub

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from abc import ABC, abstractmethod
from enum import Enum

class BeverageSize(str, Enum):
    SMALL = "small"
    MEDIUM = "medium"
    BIG = "big"

class Beverage(ABC):

    description = "Unknown Beverage"
    size: BeverageSize = BeverageSize.MEDIUM

    def get_description(self):
        return self.description

    @abstractmethod
    def cost(self):
        raise NotImplementedError

    def get_size(self):
        return self.size

    def set_size(self, size: BeverageSize):
        self.size = size

class CondimentDecorator(Beverage):

    def __init__(self):
        self.beverage: Beverage = None

    @abstractmethod
    def get_description(self):
        raise NotImplementedError

    def get_size(self):
        return self.beverage.get_size()

class Espresso(Beverage):

    def __init__(self):
        self.description = "Espresso"

    def cost(self):
        return 1.99


class DarkRoast(Beverage):

    def __init__(self):
        self.description = "Dark Roast"

    def cost(self):
        return 0.99

class HouseBlend(Beverage):

    def __init__(self):
        self.description = "House Blend Coffee"

    def cost(self):
        return 0.89


class Mocha(CondimentDecorator):
    def __init__(self, beverage: Beverage):
        self.beverage = beverage

    def get_description(self):
        return self.beverage.get_description() + ", Mocha"

    def cost(self):
        return 0.20 + self.beverage.cost()


class Soy(CondimentDecorator):

    def __init__(self, beverage: Beverage):
        self.beverage = beverage

    def get_description(self):
        return self.beverage.get_description() + ", Soy"

    def cost(self):
        cost = self.beverage.cost()
        if self.beverage.get_size() == BeverageSize.SMALL:
            cost += 0.10
        elif self.beverage.get_size() == BeverageSize.MEDIUM:
            cost += 0.15
        elif self.beverage.get_size() == BeverageSize.BIG:
            cost += 0.20

        return cost

class Whip(CondimentDecorator):

    def __init__(self, beverage: Beverage):
        self.beverage = beverage

    def get_description(self):
        return self.beverage.get_description() + ", Whip"

    def cost(self):
        return 0.10 + self.beverage.cost()


espresso = Espresso()

print(f"{espresso.get_description()}, price: {espresso.cost()}")

dark_roast = DarkRoast()
dark_roast.set_size(BeverageSize.BIG)
dark_roast = Soy(dark_roast)
dark_roast = Whip(dark_roast)
dark_roast = Whip(dark_roast)

print(f"{dark_roast.get_description()}, price: {dark_roast.cost()}")
print(type(dark_roast))