// WebSocketService.js

class WebSocketService {
  constructor() {
    this.websocket = null;
    this.heartbeatTimer = null;
    this.reconnectTimer = null;
    this.token = null;
  }

  initWebSocket(token) {
    if (!token) {
      console.warn('❌ WebSocket token 为空');

      // 全局提示用户登录过期
      if (typeof window !== 'undefined' && window.Vue && Vue.prototype.$message) {
        Vue.prototype.$message.error('登录状态已过期，请重新登录！');
      } else {
        alert('登录状态已过期，请重新登录！');
      }

      // 退出并跳转登录页
      if (this.store) {
        this.store.dispatch("LogOut").then(() => {
          location.href = "/index";
        });
      } else {
        // 如果没有 store 引用，直接跳转
        location.href = "/index";
      }
      return;
    }

    // 如果已连接或连接中，跳过
    if (this.websocket &&
      (this.websocket.readyState === WebSocket.OPEN || this.websocket.readyState === WebSocket.CONNECTING)) {
      console.log('ℹ️ WebSocket 已连接或连接中，跳过重复连接');
      return;
    }

    this.token = token;
    const wsUrl = `${process.env.VUE_APP_WS_URL}/${token}`;
    console.log("🔌 WebSocket连接中：", wsUrl);

    this.websocket = new WebSocket(wsUrl);

    this.websocket.onopen = this.websocketonopen.bind(this);
    this.websocket.onerror = this.websocketonerror.bind(this);
    this.websocket.onmessage = this.setOnmessageMessage.bind(this);
    this.websocket.onclose = this.websocketclose.bind(this);

    // 初始化状态为 connecting
    window.dispatchEvent(new CustomEvent('ws-status', { detail: 'connecting' }));
  }

  websocketonopen() {
    console.log('✅ WebSocket连接成功');
    this.startHeartbeat();
    window.dispatchEvent(new CustomEvent('ws-status', { detail: 'open' }));
  }

  websocketonerror(e) {
    console.error('❌ WebSocket连接错误:', e);
    window.dispatchEvent(new CustomEvent('ws-status', { detail: 'error' }));
    this.reconnect();
  }

  websocketclose(e) {
    console.warn('⚠️ WebSocket连接关闭:', e);
    this.stopHeartbeat();
    window.dispatchEvent(new CustomEvent('ws-status', { detail: 'closed' }));
    this.reconnect();
  }

  reconnect() {
    if (this.reconnectTimer) return;

    if (this.websocket &&
      (this.websocket.readyState === WebSocket.OPEN || this.websocket.readyState === WebSocket.CONNECTING)) {
      console.log('ℹ️ WebSocket 已连接，无需重连');
      return;
    }

    this.reconnectTimer = setTimeout(() => {
      console.warn('🔁 尝试重新连接 WebSocket...');
      this.initWebSocket(this.token);
      this.reconnectTimer = null;
    }, 5000);
  }

  setOnmessageMessage(event) {
    try {
      const msg = JSON.parse(event.data);
      console.log("📩 收到消息:", msg);
      if (msg.type) {
        window.dispatchEvent(new CustomEvent(msg.type, { detail: msg }));
      }
    } catch (err) {
      console.error("WebSocket消息解析失败:", err);
    }
  }

  startHeartbeat() {
    this.stopHeartbeat();
    this.heartbeatTimer = setInterval(() => {
      if (this.websocket && this.websocket.readyState === WebSocket.OPEN) {
        this.websocket.send(JSON.stringify({ type: 'heartbeat', time: new Date().toISOString() }));
      }
    }, 30000);
  }

  stopHeartbeat() {
    if (this.heartbeatTimer) {
      clearInterval(this.heartbeatTimer);
      this.heartbeatTimer = null;
    }
  }

  destroy() {
    this.stopHeartbeat();
    if (this.websocket) {
      this.websocket.close();
      this.websocket = null;
    }
    console.log("🧹 WebSocket 已销毁");
    window.dispatchEvent(new CustomEvent('ws-status', { detail: 'closed' }));
  }
}

export default new WebSocketService();