duck.py

class QuackBehavior:

    def quack(self):
        pass


class SwimBehavior:

    def swim(self):
        pass


class NormalSwimBehavior(SwimBehavior):

    def swim(self):
        print("수영을 잘 하고 있습니다.")


class NoSwimBehavior(SwimBehavior):

    def swim(self):
        print("꼬르륵 가라앉습니다.")


class SwimWithPropeller(SwimBehavior):

    def swim(self):
        print("프로펠러 위이이잉")


class FlyBehavior:

    def fly(self):
        pass


class Duck:
    def quack(self):
        pass

    def swim(self):
        pass

    def display(self):
        pass

    def fly(self):
        print("훨훨 납니다.")


class MallardDuck(Duck):
    def quack(self):
        print('꽥꽥')

    def swim(self):
        print('어푸어푸')

    def display(self):
        print('청동오리모습')


class MallardDuck1(Duck):
    def quack(self):
        print('꽥꽥')

    def swim(self):
        print('어푸어푸')

    def display(self):
        print('청동오리모습')


class RubberDuck(Duck):
    def quack(self):
        print('삑삑')

    def swim(self):
        print('둥둥')

    def display(self):
        print('고무 장난감 오리입니다.')

    def fly(self):
        print("고무 오리는 날 수 없습니다.")


class WoodDuck(Duck):

    swim_behavior = NoSwimBehavior()  # type annotation

    # def __init__(self, swim_behavior: SwimBehavior):
    #     self.swim_behavior = swim_behavior

    def quack(self):
        print('삑삑')

    def swim(self):
        self.swim_behavior.swim()

    def display(self):
        print('고무 장난감 오리입니다.')

    def fly(self):
        print("고무 오리는 날 수 없습니다.")


class CopperDuck(Duck):

    swim_behavior: SwimBehavior

    def __init__(self, swim_behavior: SwimBehavior):
        self.swim_behavior = swim_behavior

    def quack(self):
        print('삑삑')

    def swim(self):
        self.swim_behavior.swim()

    def display(self):
        print('고무 장난감 오리입니다.')

    def fly(self):
        print("고무 오리는 날 수 없습니다.")


# wood_duck = WoodDuck(SwimWithPropeller())
# wood_duck = WoodDuck(NormalSwimBehavior())
print(WoodDuck.swim_behavior)


# 오늘 배운 것
# * 오버라이드
# * 원래 객체지향을 배울 떄에는 상태는 멤버변수에 담고, 행동은 메소드에 담는다고 배웠었습니다...만!
# * strategy 패턴에서는 behavior 를 담고있는 클래스를 만듭니다.
# * 그리고 이 class 를 상황에 맞게 "주입" 함으로써, Duck 클래스의 행동을 자유자재로 바꿀 수 있습니다.
# * "주입" -> injection


# 더 알아보면 좋을 것
# * ABC -> Abstract Base Class
# * Dependency Injection