"""
定时任务调度器

使用 asyncio 循环驱动 Ping 引擎，协调 Pinger 和 Alerter。
"""

import asyncio
import logging
from datetime import datetime

from sqlalchemy.ext.asyncio import AsyncSession

from app.config import settings
from app.services.pinger import Pinger
from app.services.alerter import Alerter
from app.core.deps import async_session

logger = logging.getLogger("pingwatch.scheduler")


class PingScheduler:
    """
    调度器职责：
    1. 按间隔驱动 Ping 引擎
    2. 每轮结束后触发 Alerter 处理待发送告警
    3. 控制并发和清理
    """

    def __init__(self):
        self._pinger = Pinger()
        self._alerter = Alerter()
        self._running = False
        self._task: asyncio.Task | None = None

        # 注册状态变化回调
        self._pinger.on_state_change(self._on_state_change)

    async def _on_state_change(self, change):
        """收到设备状态变化，转给 alerter"""
        async with async_session() as db:
            try:
                await self._alerter.on_state_change(change, db)
            except Exception as e:
                logger.error(f"告警处理异常: {e}", exc_info=True)

    async def _run_loop(self):
        """主循环"""
        logger.info("Ping 调度器已启动")
        self._running = True

        while self._running:
            try:
                async with async_session() as db:
                    # 执行一轮 ping
                    results = await self._pinger.run_one_round(db)

                    if results:
                        # 直接用启用的设备数
                        total = len(results)

                        # 处理待发送告警
                        await self._alerter.flush_pending(db, total)

            except asyncio.CancelledError:
                break
            except Exception as e:
                logger.error(f"调度器异常: {e}", exc_info=True)

            # 等待下一轮
            await asyncio.sleep(settings.PING_INTERVAL_SECONDS)

        logger.info("Ping 调度器已停止")

    def start(self):
        """启动调度器（后台任务）"""
        if self._running:
            logger.warning("调度器已在运行")
            return
        self._task = asyncio.create_task(self._run_loop())

    async def stop(self):
        """停止调度器"""
        self._running = False
        if self._task:
            self._task.cancel()
            try:
                await self._task
            except asyncio.CancelledError:
                pass
            self._task = None


# 全局调度器实例
scheduler = PingScheduler()