LiskovSubstitution.py

"""
Liskov Substitution Principle (LSP) states that objects of a superclass should be replaceable
with objects of its subclasses without breaking the application.
In other words, what we want is to have the objects of our subclasses behaving the same way
as the objects of our superclass.
"""

from abc import ABC, abstractmethod


class Notification(ABC):
    @abstractmethod
    def notify(self, message):
        raise NotImplementedError


class Email(Notification):
    def __init__(self, email):
        self.email = email

    def notify(self, message):
        print(f'Send "{message}" to {self.email}')


class SMS(Notification):
    def __init__(self, phone):
        self.phone = phone

    def notify(self, message):
        print(f'Send "{message}" to {self.phone}')


class Contact:
    def __init__(self, name, email, phone):
        self.name = name
        self.email = email
        self.phone = phone


class NotificationManager:
    def __init__(self, notification):
        self.notification = notification

    def send(self, message):
        self.notification.notify(message)


if __name__ == '__main__':
    contact = Contact('John Doe', 'john@test.com', '(408)-888-9999')

    sms_notification = SMS(contact.phone)
    email_notification = Email(contact.email)

    notification_manager = NotificationManager(sms_notification)
    notification_manager.send('Hello John')

    notification_manager.notification = email_notification
    # notification_manager = NotificationManager(email_notification)
    notification_manager.send('Hi John')