from abc import ABC, abstractmethod

class NotificationService(ABC):
    """Abstract contract for sending notifications."""

    @abstractmethod
    async def send(self, recipient: str, subject: str, body: str) -> bool:
        """Send notification. Returns True if successful."""
        pass

    @abstractmethod
    async def send_bulk(self, recipients: list[str], subject: str, body: str) -> dict:
        """Send to multiple recipients. Returns {email: success} mapping."""
        pass


class EmailNotificationService(NotificationService):
    def __init__(self, smtp_host: str, api_key: str):
        self.smtp_host = smtp_host
        self.api_key = api_key

    async def send(self, recipient: str, subject: str, body: str) -> bool:
        # Resend / SendGrid / SES implementation
        print(f"Sending email to {recipient}: {subject}")
        return True

    async def send_bulk(self, recipients: list[str], subject: str, body: str) -> dict:
        results = {}
        for r in recipients:
            results[r] = await self.send(r, subject, body)
        return results


class SMSNotificationService(NotificationService):
    def __init__(self, twilio_sid: str, twilio_token: str):
        self.sid = twilio_sid
        self.token = twilio_token

    async def send(self, recipient: str, subject: str, body: str) -> bool:
        # Twilio implementation — subject ignored for SMS
        print(f"Sending SMS to {recipient}: {body[:160]}")
        return True

    async def send_bulk(self, recipients: list[str], subject: str, body: str) -> dict:
        import asyncio
        tasks = [self.send(r, subject, body) for r in recipients]
        results = await asyncio.gather(*tasks, return_exceptions=True)
        return {r: not isinstance(res, Exception) for r, res in zip(recipients, results)}
OOP — Inheritance, Polymorphism, super(), ABC

OOP — Inheritance, Polymorphism, super(), ABC
