const mqtt = require('mqtt');
const logger = require('./logger');

const mqttBroker = 'mqtt://192.168.3.31';
const mqttUser = 'yangfei';
const mqttPassword = 'yangfei';

const client = mqtt.connect(mqttBroker, {
  username: mqttUser,
  password: mqttPassword,
  clientId: '后台服务员', // 设置客户端 ID
  // clientId: `backend_${Date.now()}`, // 使用时间戳生成唯一客户端ID
  clean: true, // 清除会话
  reconnectPeriod: 5000, // 5秒重连间隔
  connectTimeout: 30000, // 30秒连接超时
  keepalive: 60 // 60秒心跳
});

client.on('connect', () => {
  if (!client.connected) {
    logger.info('后台管理员上线');
  }
  logger.info('MQTT 连接成功');
});

client.on('reconnect', () => {
  logger.info('正在尝试重新连接 MQTT 代理...');
});

client.on('close', () => {
  logger.warn('MQTT 连接已断开');
});

client.on('error', (err) => {
  logger.error('MQTT 连接失败:', err.message);
  // 尝试重新连接
  setTimeout(() => {
    client.reconnect();
  }, 5000);
});

client.on('offline', () => {
  logger.warn('MQTT 客户端已离线');
});

// 动态生成 relayTopic
const getRelayTopic = (deviceId) => `device/${deviceId}/relay/control`;

module.exports = { client, getRelayTopic };