from abc import ABC, abstractmethod
from dataclasses import dataclass


@dataclass(frozen=True)
class ImageAttachment:
    filename: str
    content_type: str
    data: bytes


class Notifier(ABC):
    name = "base"

    @abstractmethod
    async def send(self, title: str, text: str,
                   images: list[ImageAttachment] | None = None) -> None:
        """Deliver one notification or raise so the caller can retry."""