"""
摄像头名称服务

功能：
1. 从 WVP 查询摄像头信息（按 camera_code）
2. 固定优先级提取名称：cameraName → gbName → device_id
3. 批量查询和缓存优化
"""

from typing import Optional, Dict, List
import asyncio
import time
import httpx
from app.config import CameraNameConfig
from app.utils.logger import logger


class CameraNameService:
    """摄像头名称服务（带内存缓存）"""

    # 缓存 TTL（秒）
    CACHE_TTL = 300  # 5 分钟

    def __init__(self, config: CameraNameConfig):
        self.config = config
        self._cache: Dict[str, tuple] = {}  # {device_id: (info, expire_time)}

    async def get_camera_info(self, device_id: str) -> Optional[Dict]:
        """从 WVP 查询摄像头信息（带缓存）"""
        if not device_id:
            return None

        cached = self._cache.get(device_id)
        if cached and cached[1] > time.time():
            return cached[0]

        info = await self._query_by_camera_code(device_id)

        # 写入缓存（包括 None 结果，避免反复查询不存在的设备）
        self._cache[device_id] = (info, time.time() + self.CACHE_TTL)
        return info

    async def _query_by_camera_code(self, camera_code: str) -> Optional[Dict]:
        """通过 camera_code 查询摄像头信息"""
        try:
            async with httpx.AsyncClient(timeout=self.config.query_timeout) as client:
                resp = await client.get(
                    f"{self.config.wvp_api_base}/api/ai/camera/get",
                    params={"cameraCode": camera_code},
                )

                if resp.status_code == 200:
                    data = resp.json()
                    if data.get("code") == 0:
                        return data.get("data")
                else:
                    logger.warning(
                        f"WVP查询摄像头失败: camera_code={camera_code}, "
                        f"status={resp.status_code}"
                    )
        except Exception as e:
            logger.error(f"WVP查询异常: camera_code={camera_code}, error={e}")

        return None

    def format_display_name(self, device_id: str, camera_info: Optional[Dict] = None) -> str:
        """
        格式化摄像头显示名称

        固定优先级：cameraName → gbName → device_id
        """
        if not camera_info:
            return device_id

        # 1. cameraName（用户自定义名称）
        name = camera_info.get("cameraName") or camera_info.get("camera_name")
        if name and name.lower() != "default":
            return name

        # 2. gbName（国标名称，去 "/" 后缀）
        name = camera_info.get("gbName") or camera_info.get("gb_name")
        if name:
            if "/" in name:
                name = name.split("/")[0]
            if name:
                return name

        # 3. 兜底
        return device_id

    async def get_camera_infos_batch(self, device_ids: List[str]) -> Dict[str, Optional[Dict]]:
        """批量查询摄像头信息（并发+去重优化）"""
        unique_ids = list(set(did for did in device_ids if did))
        if not unique_ids:
            return {}

        tasks = [self.get_camera_info(did) for did in unique_ids]
        results = await asyncio.gather(*tasks)
        return dict(zip(unique_ids, results))

    async def get_display_name(self, device_id: str) -> str:
        """获取摄像头显示名称（一站式方法）"""
        camera_info = await self.get_camera_info(device_id)
        return self.format_display_name(device_id, camera_info)

    async def get_display_names_batch(self, device_ids: List[str]) -> Dict[str, str]:
        """批量获取摄像头显示名称"""
        info_map = await self.get_camera_infos_batch(device_ids)
        return {
            did: self.format_display_name(did, info_map.get(did))
            for did in device_ids
        }


# 全局单例（依赖注入）
_camera_name_service: Optional[CameraNameService] = None


def get_camera_name_service() -> CameraNameService:
    """获取摄像头名称服务单例"""
    global _camera_name_service
    if _camera_name_service is None:
        from app.config import settings
        _camera_name_service = CameraNameService(settings.camera_name)
    return _camera_name_service