"""ZIP export functionality for multiple images."""

import io
import zipfile

from fastapi import HTTPException, status
from fastapi.responses import StreamingResponse
from sqlalchemy.orm import Session

from app.core.storage import storage_client
from app.database.models.board_image import BoardImage
from app.database.models.image import Image


def create_zip_export(board_id: str, db: Session) -> StreamingResponse:
    """
    Create a ZIP file containing all images from a board.

    Args:
        board_id: Board UUID
        db: Database session

    Returns:
        StreamingResponse with ZIP file

    Raises:
        HTTPException: If export fails
    """
    try:
        # Get all images for the board
        board_images = (
            db.query(BoardImage, Image)
            .join(Image, BoardImage.image_id == Image.id)
            .filter(BoardImage.board_id == board_id)
            .all()
        )

        if not board_images:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="No images found for this board",
            )

        # Create ZIP file in memory
        zip_buffer = io.BytesIO()

        with zipfile.ZipFile(zip_buffer, "w", zipfile.ZIP_DEFLATED) as zip_file:
            for _board_image, image in board_images:
                try:
                    # Get image data from storage
                    image_data = storage_client.get_object(image.storage_path)

                    if image_data:
                        # Add to ZIP with sanitized filename
                        safe_filename = _sanitize_filename(image.filename)
                        zip_file.writestr(safe_filename, image_data)

                except Exception as e:
                    # Log error but continue with other images
                    print(f"Warning: Failed to add {image.filename} to ZIP: {str(e)}")
                    continue

        # Reset buffer position
        zip_buffer.seek(0)

        # Return ZIP file
        return StreamingResponse(
            zip_buffer,
            media_type="application/zip",
            headers={
                "Content-Disposition": 'attachment; filename="board_export.zip"',
                "Cache-Control": "no-cache",
            },
        )

    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to create ZIP export: {str(e)}",
        ) from e


def _sanitize_filename(filename: str) -> str:
    """
    Sanitize filename for safe inclusion in ZIP.

    Args:
        filename: Original filename

    Returns:
        Sanitized filename
    """
    # Remove any path separators and dangerous characters
    safe_chars = set("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789._- ")
    sanitized = "".join(c if c in safe_chars else "_" for c in filename)

    # Ensure it's not empty and doesn't start with a dot
    if not sanitized or sanitized[0] == ".":
        sanitized = "file_" + sanitized

    return sanitized