package com.xiaoqu.watch.service

import android.app.AlarmManager
import android.app.PendingIntent
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.os.Build
import android.os.SystemClock
import com.xiaoqu.watch.service.manager.MqttManager
import dagger.hilt.android.AndroidEntryPoint
import timber.log.Timber
import javax.inject.Inject

/**
 * MQTT 连接健康检查广播接收器
 *
 * 通过 AlarmManager.setExactAndAllowWhileIdle() 定期触发，
 * 在 Doze 模式的维护窗口中检查 MQTT 连接状态，断连则重连。
 * 同时确保 MqttService 前台服务存活。
 */
@AndroidEntryPoint
class MqttAlarmReceiver : BroadcastReceiver() {

    companion object {
        /** 检查间隔：5 分钟（Doze 维护窗口至少 10 分钟，5 分钟能抓到窗口期） */
        private const val CHECK_INTERVAL_MS = 5 * 60 * 1000L

        /** 启动定时健康检查 */
        fun schedule(context: Context) {
            val alarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager
            val intent = Intent(context, MqttAlarmReceiver::class.java)
            val pendingIntent = PendingIntent.getBroadcast(
                context, 0, intent,
                PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
            )

            // setExactAndAllowWhileIdle: Doze 模式下也能触发
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                alarmManager.setExactAndAllowWhileIdle(
                    AlarmManager.ELAPSED_REALTIME_WAKEUP,
                    SystemClock.elapsedRealtime() + CHECK_INTERVAL_MS,
                    pendingIntent
                )
            } else {
                alarmManager.setExact(
                    AlarmManager.ELAPSED_REALTIME_WAKEUP,
                    SystemClock.elapsedRealtime() + CHECK_INTERVAL_MS,
                    pendingIntent
                )
            }
            Timber.d("MqttAlarm: 已设置 ${CHECK_INTERVAL_MS / 1000}s 后检查")
        }

        /** 取消定时检查 */
        fun cancel(context: Context) {
            val alarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager
            val intent = Intent(context, MqttAlarmReceiver::class.java)
            val pendingIntent = PendingIntent.getBroadcast(
                context, 0, intent,
                PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
            )
            alarmManager.cancel(pendingIntent)
            Timber.d("MqttAlarm: 已取消定时检查")
        }
    }

    @Inject lateinit var mqttManager: MqttManager

    override fun onReceive(context: Context, intent: Intent) {
        Timber.d("MqttAlarm: 健康检查触发, isConnected=${mqttManager.isConnected}")

        // 确保前台服务在运行
        MqttService.start(context)

        // MQTT 断连则重连
        if (!mqttManager.isConnected) {
            Timber.w("MqttAlarm: 连接已断开，触发重连")
            mqttManager.connect()
        }

        // 重新设置下一次闹钟（setExactAndAllowWhileIdle 是一次性的）
        schedule(context)
    }
}