problem3_dip.py

"""
Problem 3: Dependency Inversion Principle (DIP)
"""

from abc import ABC, abstractmethod


# ---------- BAD DESIGN ----------
class EmailNotification:
    def send_notification(self, message):
        print("Email:", message)


class BadNotificationManager:
    def notify(self, message):
        email = EmailNotification()
        email.send_notification(message)


# ---------- GOOD DESIGN ----------
class NotificationService(ABC):
    @abstractmethod
    def send_notification(self, message): pass


class EmailNotification(NotificationService):
    def send_notification(self, message):
        print("Email:", message)


class SMSNotification(NotificationService):
    def send_notification(self, message):
        print("SMS:", message)


class PushNotification(NotificationService):
    def send_notification(self, message):
        print("Push:", message)


class NotificationManager:
    def notify_user(self, user, message, service: NotificationService):
        service.send_notification(f"{user}: {message}")


if __name__ == "__main__":
    manager = NotificationManager()
    manager.notify_user("Fara", "Hello!", EmailNotification())
    manager.notify_user("Fara", "Hello!", SMSNotification())
    manager.notify_user("Fara", "Hello!", PushNotification())