"""Notification provider interface. Every alert dispatch (app/services/
alert_service.py) and every "test destination" action goes through this
Protocol, never a specific vendor SDK - swapping providers or adding a new
one doesn't touch the dispatch logic.
"""

from __future__ import annotations

from dataclasses import dataclass
from typing import Protocol


@dataclass(frozen=True)
class NotificationMessage:
    destination_value: str
    subject: str
    body_text: str
    body_html: str | None = None


@dataclass(frozen=True)
class DeliveryResult:
    success: bool
    external_message_id: str | None = None
    error: str | None = None


class NotificationProvider(Protocol):
    provider_name: str

    async def send(self, message: NotificationMessage) -> DeliveryResult: ...