"""Batch operations API routes."""

import os
from pathlib import Path

from fastapi import APIRouter, BackgroundTasks, status
from fastapi.responses import FileResponse

from app.api.dependencies import CurrentUser, DatabaseSession, S3ClientDep
from app.api.schemas import (
    BatchDeleteRequest,
    BatchDeleteResponse,
    BatchDownloadRequest,
    BatchMoveRequest,
    BatchMoveResponse,
)
from app.services.batch_operations_service import BatchOperationsService

router = APIRouter(prefix="/batch", tags=["batch"])


@router.post("/delete", response_model=BatchDeleteResponse)
async def batch_delete(
    request: BatchDeleteRequest,
    current_user: CurrentUser,
    session: DatabaseSession,
    s3_client: S3ClientDep,
):
    """
    Delete multiple assets.

    Args:
        request: Batch delete request
        current_user: Current authenticated user
        session: Database session
        s3_client: S3 client

    Returns:
        Deletion statistics
    """
    batch_service = BatchOperationsService(session, s3_client)
    result = await batch_service.delete_assets_batch(
        user_id=current_user.id,
        asset_ids=request.asset_ids,
    )
    return result


@router.post("/move", response_model=BatchMoveResponse)
async def batch_move(
    request: BatchMoveRequest,
    current_user: CurrentUser,
    session: DatabaseSession,
    s3_client: S3ClientDep,
):
    """
    Move multiple assets to a folder.

    Args:
        request: Batch move request
        current_user: Current authenticated user
        session: Database session
        s3_client: S3 client

    Returns:
        Move statistics
    """
    batch_service = BatchOperationsService(session, s3_client)
    result = await batch_service.move_assets_batch(
        user_id=current_user.id,
        asset_ids=request.asset_ids,
        target_folder_id=request.folder_id,
    )
    return result


@router.post("/download")
async def batch_download(
    request: BatchDownloadRequest,
    current_user: CurrentUser,
    session: DatabaseSession,
    s3_client: S3ClientDep,
    background_tasks: BackgroundTasks,
):
    """
    Download multiple assets as a ZIP archive using streaming.

    Uses temp file and FileResponse to avoid loading entire ZIP into memory.
    Temp file is automatically cleaned up after response is sent.

    Args:
        request: Batch download request
        current_user: Current authenticated user
        session: Database session
        s3_client: S3 client
        background_tasks: Background tasks for cleanup

    Returns:
        ZIP file response
    """
    batch_service = BatchOperationsService(session, s3_client)
    temp_zip_path, filename = await batch_service.download_assets_batch(
        user_id=current_user.id,
        asset_ids=request.asset_ids,
    )

    # Schedule temp file cleanup after response is sent
    def cleanup_temp_file():
        try:
            Path(temp_zip_path).unlink(missing_ok=True)
        except Exception:
            pass

    background_tasks.add_task(cleanup_temp_file)

    # Return file using streaming FileResponse
    return FileResponse(
        path=temp_zip_path,
        media_type="application/zip",
        filename=filename,
        headers={
            "Content-Disposition": f'attachment; filename="{filename}"',
        },
    )


@router.get("/folders/{folder_id}/download")
async def download_folder(
    folder_id: str,
    current_user: CurrentUser,
    session: DatabaseSession,
    s3_client: S3ClientDep,
    background_tasks: BackgroundTasks,
):
    """
    Download all assets in a folder as a ZIP archive using streaming.

    Uses temp file and FileResponse to avoid loading entire ZIP into memory.
    Temp file is automatically cleaned up after response is sent.

    Args:
        folder_id: Folder ID
        current_user: Current authenticated user
        session: Database session
        s3_client: S3 client
        background_tasks: Background tasks for cleanup

    Returns:
        ZIP file response
    """
    batch_service = BatchOperationsService(session, s3_client)
    temp_zip_path, filename = await batch_service.download_folder(
        user_id=current_user.id,
        folder_id=folder_id,
    )

    # Schedule temp file cleanup after response is sent
    def cleanup_temp_file():
        try:
            Path(temp_zip_path).unlink(missing_ok=True)
        except Exception:
            pass

    background_tasks.add_task(cleanup_temp_file)

    # Return file using streaming FileResponse
    return FileResponse(
        path=temp_zip_path,
        media_type="application/zip",
        filename=filename,
        headers={
            "Content-Disposition": f'attachment; filename="{filename}"',
        },
    )