from abc import ABC, abstractmethod


class StorageBackend(ABC):
    @abstractmethod
    async def put(self, key: str, data: bytes, content_type: str) -> None:
        """Store object at key with given content type."""

    @abstractmethod
    async def get_presigned_url(self, key: str, expires_in_seconds: int = 3600) -> str:
        """Return a pre-signed URL valid for expires_in_seconds."""

    @abstractmethod
    async def delete(self, key: str) -> None:
        """Delete object at key."""