from __future__ import annotations

import logging

from fastapi import APIRouter
from fastapi.responses import Response

from woc_bridge.config import _require_qr_capture, _require_send_queue
from woc_bridge.messaging.ui_action_scheduler import Priority
from woc_bridge.models import BridgeError

logger = logging.getLogger("woc-bridge")
router = APIRouter()


# ---------------------------------------------------------------------------
# 路由：POST /api/screenshot
# ---------------------------------------------------------------------------
@router.post("/api/screenshot")
async def screenshot() -> Response:
    """截取完整屏幕并返回 PNG。

    用于前端「截图」按钮 / 调试时观察微信实际界面状态（如确认 UI 操作是否
    触发了正确的对话框）。截取整个 X 桌面（DISPLAY 由 _state.config.display 指定）。

    Returns:
        Response：Content-Type=image/png，body 为 PNG 二进制

    Raises:
        BridgeError(WINDOW_NOT_FOUND): X 会话未就绪，无法截图（HTTP 503）
        其他异常由全局兜底处理器返回 BRIDGE_INTERNAL_ERROR

    Notes:
        - 截图由 qr_capture.capture_full_screenshot 完成，底层调
          xdotool/getwindowgeometry + import（ImageMagick）
        - 与 /api/login/qr/start 区别：本接口截全屏，qr/start 截二维码区域
        - 大屏幕截图可能 > 1MB，调用方注意带宽
    """
    logger.info("screenshot: 收到请求")
    qr_capture = _require_qr_capture()
    scheduler = _require_send_queue()

    try:
        if hasattr(scheduler, "execute"):
            png_bytes = await scheduler.execute(
                lambda: qr_capture.capture_full_screenshot(),
                priority=Priority.LOW,
                wait_timeout_ms=10000,
                trace_id="screenshot",
            )
        else:
            png_bytes = await qr_capture.capture_full_screenshot()
    except BridgeError as e:
        logger.warning("screenshot: 失败 %s: %s", e.code, e.message)
        raise
    except Exception as e:
        logger.warning("screenshot: 失败 %s: %s", type(e).__name__, e)
        raise
    logger.info("screenshot: ✓ 截图成功 %d bytes", len(png_bytes))
    return Response(content=png_bytes, media_type="image/png")