from datetime import datetime

from fastapi import APIRouter, HTTPException, Query, Response

from app.services import (
    CameraCaptureError,
    CameraUnavailableError,
    get_camera_service,
)

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


@router.api_route("/capture", methods=["GET"], summary="拍照并直接返回图片")
def capture_image(
        download: bool = Query(
            default=False,
            description="是否以附件下载方式返回图片。默认 False，浏览器会直接预览。",
        ),
) -> Response:
    """
    拍照接口。

    调用这个接口时，服务会即时触发树莓派相机拍照，
    然后把最新拍到的图片直接作为 HTTP 响应返回。
    """
    camera_service = get_camera_service()

    try:
        image_bytes = camera_service.capture_jpeg()
    except (CameraUnavailableError, CameraCaptureError) as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc

    filename = f"capture_{datetime.now().strftime('%Y%m%d_%H%M%S')}.jpg"
    disposition = "attachment" if download else "inline"

    return Response(
        content=image_bytes,
        media_type="image/jpeg",
        headers={
            "Content-Disposition": f'{disposition}; filename="{filename}"',
            "Cache-Control": "no-store",
        },
    )