"""Delivery channel interface."""

from __future__ import annotations

from typing import Protocol

from us2kr.models import BriefingResult


class DeliveryError(RuntimeError):
    pass


class Deliverer(Protocol):
    name: str

    def deliver(self, result: BriefingResult) -> str:
        """Send the briefing. Return a short receipt string (message id / path). Raise DeliveryError."""
        ...

    def notify_error(self, subject: str, detail: str) -> None:
        """Operator alert for pipeline failures. Must never raise."""
        ...