dingdanquanliucheng/frontend/mini-app/utils/websocket.js

/**
 * WebSocket 连接管理工具
 * 职责：建立和维护 WebSocket 连接，接收实时推送消息
 */

var auth = require("./auth");
var config = require("../config");

var socketTask = null;
var heartbeatTimer = null;
var reconnectTimer = null;
var reconnectCount = 0;
var MAX_RECONNECT = 5;
var HEARTBEAT_INTERVAL = 30000; // 30秒心跳
var isConnecting = false;

/**
 * 建立 WebSocket 连接
 */
function connect() {
  if (socketTask || isConnecting) return;

  var token = auth.getToken();
  if (!token) {
    console.log("[WS] 未登录，跳过连接");
    return;
  }

  isConnecting = true;
  var wsUrl = config.wsBaseUrl + "/ws/reminders?token=" + token;

  console.log("[WS] 开始连接...");
  socketTask = wx.connectSocket({
    url: wsUrl,
    success: function () {
      console.log("[WS] 连接请求已发送");
    },
  });

  socketTask.onOpen(function () {
    console.log("[WS] 连接成功");
    isConnecting = false;
    reconnectCount = 0;
    startHeartbeat();
  });

  socketTask.onMessage(function (res) {
    try {
      var data = JSON.parse(res.data);
      if (data.type === "reminder") {
        console.log("[WS] 收到提醒:", data.data);
        handleMessage(data.data);
      } else if (data.type === "connected") {
        console.log("[WS] 服务端确认连接:", data.message);
      }
    } catch (e) {
      console.error("[WS] 消息解析失败:", e);
    }
  });

  socketTask.onClose(function (res) {
    console.log("[WS] 连接关闭:", res);
    isConnecting = false;
    stopHeartbeat();
    socketTask = null;
    attemptReconnect();
  });

  socketTask.onError(function (err) {
    console.error("[WS] 连接错误:", err);
    isConnecting = false;
    socketTask = null;
  });
}

/**
 * 断开 WebSocket 连接
 */
function disconnect() {
  stopHeartbeat();
  stopReconnect();

  if (socketTask) {
    try {
      socketTask.close();
    } catch (e) {
      // ignore
    }
    socketTask = null;
  }
  isConnecting = false;
  console.log("[WS] 已断开连接");
}

/**
 * 启动心跳定时器
 */
function startHeartbeat() {
  stopHeartbeat();
  heartbeatTimer = setInterval(function () {
    if (socketTask) {
      try {
        socketTask.send({ data: "ping" });
      } catch (e) {
        console.error("[WS] 心跳发送失败:", e);
      }
    }
  }, HEARTBEAT_INTERVAL);
}

/**
 * 停止心跳定时器
 */
function stopHeartbeat() {
  if (heartbeatTimer) {
    clearInterval(heartbeatTimer);
    heartbeatTimer = null;
  }
}

/**
 * 尝试重连
 */
function attemptReconnect() {
  if (reconnectCount >= MAX_RECONNECT) {
    console.log("[WS] 达到最大重连次数，停止重连");
    return;
  }

  var delay = Math.min(3000 * (reconnectCount + 1), 15000); // 递增延迟，最大15秒
  console.log("[WS] " + delay / 1000 + "秒后尝试第" + (reconnectCount + 1) + "次重连");

  reconnectTimer = setTimeout(function () {
    reconnectCount++;
    connect();
  }, delay);
}

/**
 * 停止重连
 */
function stopReconnect() {
  if (reconnectTimer) {
    clearTimeout(reconnectTimer);
    reconnectTimer = null;
  }
  reconnectCount = 0;
}

/**
 * 处理收到的消息
 */
function handleMessage(data) {
  var app = getApp();
  if (!app) return;

  // 触发全局事件
  if (app._eventHandlers && app._eventHandlers["reminder"]) {
    app._eventHandlers["reminder"].forEach(function (handler) {
      try {
        handler(data);
      } catch (e) {
        console.error("[WS] 事件处理异常:", e);
      }
    });
  }

  // 更新角标
  var badge = require("./badge");
  badge.updateTabBadge();
}

/**
 * 获取连接状态
 */
function isConnected() {
  return socketTask !== null && !isConnecting;
}

module.exports = {
  connect: connect,
  disconnect: disconnect,
  isConnected: isConnected,
};