from abc import ABC, abstractmethod
from typing import BinaryIO


class StorageBackend(ABC):
    """Abstract base class for storage backends"""

    @abstractmethod
    async def upload_file(self, file_data: BinaryIO, object_name: str) -> str:
        """
        Upload a file to storage

        Args:
            file_data: Binary file data
            object_name: Name/path of the object in storage

        Returns:
            Storage path/URL of uploaded file
        """
        pass

    @abstractmethod
    async def download_file(self, object_name: str) -> bytes:
        """
        Download a file from storage

        Args:
            object_name: Name/path of the object in storage

        Returns:
            Binary file data
        """
        pass

    @abstractmethod
    async def delete_file(self, object_name: str) -> bool:
        """
        Delete a file from storage

        Args:
            object_name: Name/path of the object in storage

        Returns:
            True if successful
        """
        pass

    @abstractmethod
    async def file_exists(self, object_name: str) -> bool:
        """
        Check if a file exists in storage

        Args:
            object_name: Name/path of the object in storage

        Returns:
            True if file exists
        """
        pass

    @abstractmethod
    async def get_file_url(self, object_name: str, expiration: int = 3600) -> str:
        """
        Get a presigned URL for downloading a file

        Args:
            object_name: Name/path of the object in storage
            expiration: URL expiration time in seconds

        Returns:
            Presigned URL
        """
        pass