"""Export API endpoints for downloading and exporting images."""

from uuid import UUID

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

from app.core.deps import get_current_user, get_db
from app.database.models.board import Board
from app.database.models.board_image import BoardImage
from app.database.models.image import Image
from app.database.models.user import User
from app.images.download import download_single_image
from app.images.export_composite import create_composite_export
from app.images.export_zip import create_zip_export

router = APIRouter(tags=["export"])


@router.get("/images/{image_id}/download")
async def download_image(
    image_id: UUID,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> StreamingResponse:
    """
    Download a single image.

    Only the image owner can download it.
    """
    # Verify image exists and user owns it
    image = db.query(Image).filter(Image.id == image_id, Image.user_id == current_user.id).first()

    if image is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Image not found or access denied",
        )

    return await download_single_image(image.storage_path, image.filename)


@router.get("/boards/{board_id}/export/zip")
def export_board_zip(
    board_id: UUID,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> StreamingResponse:
    """
    Export all images from a board as a ZIP file.

    Only the board owner can export it.
    """
    # Verify board exists and user owns it
    board = db.query(Board).filter(Board.id == board_id, Board.user_id == current_user.id).first()

    if board is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Board not found or access denied",
        )

    return create_zip_export(str(board_id), db)


@router.get("/boards/{board_id}/export/composite")
def export_board_composite(
    board_id: UUID,
    scale: float = Query(1.0, ge=0.5, le=4.0, description="Resolution scale (0.5x to 4x)"),
    format: str = Query("PNG", regex="^(PNG|JPEG)$", description="Output format (PNG or JPEG)"),
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> StreamingResponse:
    """
    Export board as a single composite image showing the layout.

    Only the board owner can export it.

    Args:
        scale: Resolution multiplier (0.5x, 1x, 2x, 4x)
        format: Output format (PNG or JPEG)
    """
    # Verify board exists and user owns it
    board = db.query(Board).filter(Board.id == board_id, Board.user_id == current_user.id).first()

    if board is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Board not found or access denied",
        )

    return create_composite_export(str(board_id), db, scale=scale, format=format)


@router.get("/boards/{board_id}/export/info")
def get_export_info(
    board_id: UUID,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
) -> dict:
    """
    Get information about board export (image count, estimated size).

    Useful for showing progress estimates.
    """
    # Verify board exists and user owns it
    board = db.query(Board).filter(Board.id == board_id, Board.user_id == current_user.id).first()

    if board is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Board not found or access denied",
        )

    # Count images and calculate estimated size
    images = (
        db.query(Image).join(BoardImage, BoardImage.image_id == Image.id).filter(BoardImage.board_id == board_id).all()
    )

    total_size = sum(img.file_size for img in images)

    return {
        "board_id": str(board_id),
        "image_count": len(images),
        "total_size_bytes": total_size,
        "estimated_zip_size_bytes": int(total_size * 0.95),  # ZIP usually has small overhead
    }