"""
edge_app_controller — 外部 MQTT 请求处理（请求-响应协议）

订阅主题:  /edge_app_controller
回复主题:  /edge_app_controller_reply

请求消息 (JSON): {"command": "<命令名>", ...业务字段}
                兼容协议: {"Event": "/alg_media_fetch", "BoardId": "..."}（Event 取最后一段作为命令）
回复消息 (JSON): {"code": 0, "msg": "ok", "data": {...}}
  - code: 0 成功；非 0 失败
      -1 缺少 command 字段
      -2 未知命令
      -3 命令执行异常

不回复约定:
  命令处理函数返回 None 时，该命令只处理、不回复（静默命令，如心跳/日志类）。
  适用于按命令/Event 控制是否回复，无需修改配置。

命令通过 _COMMANDS 注册表分发，新增命令只需在注册表登记一个 async 处理函数。
"""
import logging
from typing import Any, Callable, Coroutine

logger = logging.getLogger(__name__)


def _reply(code: int, msg: str, data: Any = None) -> dict:
    """统一回复封装"""
    return {"code": code, "msg": msg, "data": data}


async def edge_app_controller(payload: dict, topic: str) -> dict | None:
    """
    处理来自外部 Broker 的边缘应用控制器请求（订阅 /edge_app_controller）

    Args:
        payload: 请求消息（已解析为 dict），期望含 command 字段
        topic:   实际命中的主题

    Returns:
        回复消息（统一封装 code / msg / data），由订阅客户端发布到 reply_topic；
        命令函数返回 None 时返回 None（不回复）。
    """
    command = (
        payload.get("command")
        or payload.get("cmd")
        or payload.get("action")
        or payload.get("Event")
    )
    # Event 可能是路径形式（如 /alg_media_fetch），取最后一段作为命令名
    if isinstance(command, str) and command.startswith("/"):
        command = command.rsplit("/", 1)[-1]

    logger.info(
        f"[EdgeAppController] 收到请求 topic={topic}, command={command}, payload={payload}"
    )

    if command is None:
        return None

    handler = _COMMANDS.get(str(command))
    if handler is None:
        logger.warning(f"[EdgeAppController] 未知命令: {command}")
        return None

    try:
        data = await handler(payload)
        # 命令函数返回 None 表示该命令只处理、不回复（如心跳/日志类静默命令）
        if data is None:
            logger.info(f"[EdgeAppController] 命令 {command} 处理完成（配置为不回复）")
            return None
        logger.info(f"[EdgeAppController] 命令 {command} 执行成功")
        return data
    except Exception as e:
        logger.error(f"[EdgeAppController] 命令 {command} 执行失败: {e}")
        return None


# ============================================================
# 内置命令（示例）
# ============================================================

async def _cmd_ping(payload: dict) -> dict | None:
    """存活探测：返回服务信息"""
    return {"service": "aibox_sophon_adapter", "alive": True}


async def _cmd_ack(payload: dict) -> None:
    """
    确认命令（示例）：仅记录日志，不回复

    返回 None 表示不回复 —— 需要"某些命令静默处理"时，让命令函数返回 None 即可。
    """
    logger.info(f"[EdgeAppController] 命令 ack 已收到（不回复），payload={payload}")
    return None


async def _cmd_query_status(payload: dict) -> dict | None:
    """
    查询边缘应用/设备状态

    复用插件已有的设备查询逻辑（router.list_devices），返回设备在线状态列表。
    后续可按需扩展：查询指定应用运行状态、通道状态等。
    """
    from .router.list_devices import list_devices

    result = await list_devices()
    return result


async def _cmd_alg_media_fetch(payload: dict) -> dict | None:
    """
    算法媒体抓取：按 BoardId 返回设备最近一次心跳中的算法/通道（媒体）信息

    请求: {"Event": "/alg_media_fetch", "BoardId": "..."}
    返回: {"board_id": ..., "medias": [...], "tasks": [...]}
    """
    from .global_var import db, internal_mqtt

    board_id = payload.get("BoardId")
    if not board_id:
        return None

    print(f"[alg_media_fetch]Processing for board: {board_id}")
    print(f"[alg_media_fetch]Expected payload: {payload}")

    if db is None:
        raise RuntimeError("数据库未初始化")
    if internal_mqtt is None:
        raise RuntimeError("internal_mqtt 未初始化")

    async with db.get_session() as session:
        from .models.orm import BoardHeartbeat
        from sqlalchemy import select

        stmt = select(BoardHeartbeat).where(BoardHeartbeat.board_id == board_id) # type: ignore
        result = await session.execute(stmt)
        record: BoardHeartbeat | None = result.scalar_one_or_none()

        if record is None:
            print(f"[alg_media_fetch]Board {board_id} not found in database.")
            return None

        resp = await internal_mqtt.request(
            request_topic="/chongming/aibox_sophon_adapter/edge_app_controller",
            response_topic="/chongming/aibox_sophon_adapter/edge_app_controller_reply",
            payload=payload,
            timeout=5
        )

        print(f"[alg_media_fetch]Response from internal_mqtt: {resp}")

        return resp

async def _cmd_alg_task_fetch(payload: dict) -> dict | None:
    """
    算法任务抓取：按 BoardId 返回设备最近一次心跳中的算法任务信息

    请求: {"Event": "/alg_task_fetch", "BoardId": "..."}
    返回: {"board_id": ..., "tasks": [...]}
    """
    from .global_var import db

    board_id = payload.get("BoardId")
    if not board_id:
        return None

    print(f"[alg_task_fetch]Processing for board: {board_id}")
    print(f"[alg_task_fetch]Expected payload: {payload}")

    if db is None:
        raise RuntimeError("数据库未初始化")

    async with db.get_session() as session:
        from .models.orm import BoardHeartbeat
        from sqlalchemy import select

        stmt = select(BoardHeartbeat).where(BoardHeartbeat.board_id == board_id) # type: ignore
        result = await session.execute(stmt)
        record: BoardHeartbeat | None = result.scalar_one_or_none()

        if record is None:
            print(f"[alg_task_fetch]Board {board_id} not found in database.")
            return None

        import json
        ping_data = {}
        try:
            ping_data = json.loads(record.ping_data) if record.ping_data else {}
        except json.JSONDecodeError:
            pass

        return {
            "board_id": board_id,
            "tasks": ping_data.get("Tasks", []),
        }


# 命令注册表：command -> async handler(payload) -> data（返回 None 表示不回复）
_COMMANDS: dict[str, Callable[[dict], Coroutine[Any, Any, Any]]] = {
    "ping": _cmd_ping,
    "ack": _cmd_ack,
    "query_status": _cmd_query_status,
    "alg_media_fetch": _cmd_alg_media_fetch,
    "alg_task_fetch": _cmd_alg_task_fetch,
}