const cron = require('node-cron');
const logger = require('../utils/logger');
const SpeedTester = require('./speedTester');
const TelegramNotifier = require('./notifier');
const SubscriptionManager = require('./subscriptionManager');
const { Node, TestResult } = require('../models');

class Scheduler {
  constructor() {
    this.speedTester = new SpeedTester();
    this.notifier = new TelegramNotifier();
    this.subscriptionManager = new SubscriptionManager();
    this.isRunning = false;
    this.testInterval = parseInt(process.env.SPEED_TEST_INTERVAL) || 15; // 分钟
    this.failureThreshold = parseInt(process.env.NOTIFICATION_FAILURE_THRESHOLD) || 3;
    this.recoveryThreshold = parseInt(process.env.NOTIFICATION_RECOVERY_THRESHOLD) || 2;
  }

  /**
   * 启动调度器
   */
  start() {
    logger.info('启动定时任务调度器 - 定时测速已关闭');

    // 暂时关闭定时测速
    // const cronExpression = `*/${this.testInterval} * * * *`;
    // this.speedTestJob = cron.schedule(cronExpression, async () => {
    //   await this.runSpeedTest();
    // }, {
    //   scheduled: true,
    //   timezone: 'Asia/Shanghai'
    // });

    // 每小时重试失败的通知
    this.notificationRetryJob = cron.schedule('0 * * * *', async () => {
      await this.notifier.retryFailedNotifications();
    }, {
      scheduled: true,
      timezone: 'Asia/Shanghai'
    });

    // 每天凌晨2点清理旧数据
    this.cleanupJob = cron.schedule('0 2 * * *', async () => {
      await this.cleanupOldData();
    }, {
      scheduled: true,
      timezone: 'Asia/Shanghai'
    });

    // 启动订阅自动更新
    this.subscriptionManager.startAutoUpdate();

    logger.info('定时任务调度器启动成功');
  }

  /**
   * 停止调度器
   */
  stop() {
    if (this.speedTestJob) {
      this.speedTestJob.stop();
    }
    if (this.notificationRetryJob) {
      this.notificationRetryJob.stop();
    }
    if (this.cleanupJob) {
      this.cleanupJob.stop();
    }
    this.subscriptionManager.stopAutoUpdate();
    logger.info('定时任务调度器已停止');
  }

  /**
   * 运行速度测试
   */
  async runSpeedTest() {
    if (this.isRunning) {
      logger.warn('上一次测试还在运行中，跳过本次测试');
      return;
    }

    this.isRunning = true;
    const startTime = Date.now();

    try {
      // 获取所有启用的节点
      const nodes = await Node.findAll({
        where: { isActive: true },
        order: [['group', 'ASC'], ['name', 'ASC']]
      });

      if (nodes.length === 0) {
        logger.warn('没有找到启用的节点');
        return;
      }

      logger.info(`找到 ${nodes.length} 个节点，开始测试`);

      // 批量测试节点
      const testResults = await this.speedTester.testNodes(nodes);

      // 处理测试结果
      await this.processTestResults(nodes, testResults);

      // 生成并发送摘要
      await this.sendTestSummary(nodes, testResults);

      const duration = Date.now() - startTime;
      logger.info(`定时测速完成 - ${nodes.length}个节点，${testResults.filter(r => r.isSuccess).length}个成功，耗时${duration}ms`);

    } catch (error) {
      logger.error('定时速度测试失败', { error: error.message });
      
      // 发送系统错误通知
      await this.notifier.sendSystemNotification(
        '⚠️ 系统错误通知',
        `定时速度测试过程中发生错误:\n\n${error.message}`,
        { error: error.message, timestamp: new Date().toISOString() }
      );
    } finally {
      this.isRunning = false;
    }
  }

  /**
   * 处理测试结果
   */
  async processTestResults(nodes, testResults) {
    const nodeMap = new Map(nodes.map(node => [node.id, node]));
    const resultMap = new Map(testResults.map(result => [result.nodeId, result]));

    for (const node of nodes) {
      const testResult = resultMap.get(node.id);
      if (!testResult) continue;

      const previousStatus = node.status;
      const previousFailureCount = node.failureCount;

      // 更新节点状态
      if (testResult.isSuccess) {
        // 测试成功
        if (node.status === 'offline') {
          // 节点从离线恢复
          if (previousFailureCount >= this.recoveryThreshold) {
            await this.notifier.sendRecoveryNotification(node, testResult);
          }
        }

        await node.update({
          status: 'online',
          lastTestTime: testResult.testTime,
          lastTestResult: true,
          failureCount: 0,
          averageLatency: testResult.latency,
          averageSpeed: testResult.downloadSpeed
        });

      } else {
        // 测试失败
        const newFailureCount = previousFailureCount + 1;
        
        await node.update({
          status: 'offline',
          lastTestTime: testResult.testTime,
          lastTestResult: false,
          failureCount: newFailureCount
        });

        // 检查是否需要发送故障通知
        if (newFailureCount === this.failureThreshold && previousStatus === 'online') {
          await this.notifier.sendFailureNotification(node, testResult);
        }
      }
    }
  }

  /**
   * 发送测试摘要
   */
  async sendTestSummary(nodes, testResults) {
    const totalNodes = nodes.length;
    const onlineNodes = testResults.filter(r => r.isSuccess).length;
    const offlineNodes = totalNodes - onlineNodes;
    const successRate = totalNodes > 0 ? Math.round((onlineNodes / totalNodes) * 100) : 0;

    // 计算平均延迟和速度
    const successfulResults = testResults.filter(r => r.isSuccess && r.latency);
    const averageLatency = successfulResults.length > 0 
      ? Math.round(successfulResults.reduce((sum, r) => sum + r.latency, 0) / successfulResults.length)
      : null;

    const speedResults = testResults.filter(r => r.isSuccess && r.downloadSpeed);
    const averageSpeed = speedResults.length > 0
      ? Math.round((speedResults.reduce((sum, r) => sum + r.downloadSpeed, 0) / speedResults.length) * 100) / 100
      : null;

    // 获取故障节点列表
    const failedNodes = nodes.filter(node => {
      const result = testResults.find(r => r.nodeId === node.id);
      return result && !result.isSuccess;
    }).slice(0, 10); // 最多显示10个

    // 获取最佳节点列表
    const bestNodes = testResults
      .filter(r => r.isSuccess && r.latency)
      .sort((a, b) => a.latency - b.latency)
      .slice(0, 5)
      .map(result => {
        const node = nodes.find(n => n.id === result.nodeId);
        return {
          name: node ? node.name : 'Unknown',
          latency: result.latency,
          group: node ? node.group : 'Unknown'
        };
      });

    // 按分组统计
    const groupStats = {};
    nodes.forEach(node => {
      const group = node.group || '默认';
      if (!groupStats[group]) {
        groupStats[group] = { total: 0, online: 0, offline: 0 };
      }
      groupStats[group].total++;
      
      const result = testResults.find(r => r.nodeId === node.id);
      if (result && result.isSuccess) {
        groupStats[group].online++;
      } else {
        groupStats[group].offline++;
      }
    });

    const summary = {
      totalNodes,
      onlineNodes,
      offlineNodes,
      successRate,
      averageLatency,
      averageSpeed,
      failedNodes,
      bestNodes,
      groupStats,
      testTime: new Date().toLocaleString('zh-CN')
    };

    // 每次测速完成后都发送详细的测试总结报告
    await this.notifier.sendSummaryNotification(summary);

    logger.info('测试摘要生成完成', summary);
  }

  /**
   * 清理旧数据
   */
  async cleanupOldData() {
    try {
      logger.info('开始清理旧数据');

      // 删除30天前的测试结果
      const thirtyDaysAgo = new Date();
      thirtyDaysAgo.setDate(thirtyDaysAgo.getDate() - 30);

      const deletedTestResults = await TestResult.destroy({
        where: {
          testTime: {
            [require('sequelize').Op.lt]: thirtyDaysAgo
          }
        }
      });

      // 删除7天前的通知记录
      const sevenDaysAgo = new Date();
      sevenDaysAgo.setDate(sevenDaysAgo.getDate() - 7);

      const deletedNotifications = await require('../models').Notification.destroy({
        where: {
          createdAt: {
            [require('sequelize').Op.lt]: sevenDaysAgo
          },
          isSent: true
        }
      });

      logger.info('旧数据清理完成', {
        deletedTestResults,
        deletedNotifications
      });

    } catch (error) {
      logger.error('清理旧数据失败', { error: error.message });
    }
  }

  /**
   * 手动触发测试
   */
  async triggerManualTest() {
    if (this.isRunning) {
      throw new Error('测试正在进行中，请稍后再试');
    }

    logger.info('手动触发速度测试');
    await this.runSpeedTest();
  }

  /**
   * 获取调度器状态
   */
  getStatus() {
    return {
      isRunning: this.isRunning,
      testInterval: this.testInterval,
      failureThreshold: this.failureThreshold,
      recoveryThreshold: this.recoveryThreshold,
      jobs: {
        speedTest: this.speedTestJob ? 'running' : 'stopped',
        notificationRetry: this.notificationRetryJob ? 'running' : 'stopped',
        cleanup: this.cleanupJob ? 'running' : 'stopped'
      }
    };
  }
}

module.exports = Scheduler;