websocket 方法封装

export default class WS {
    constructor(listener) {
        this.keepAlive = 8000;  // 心跳检测保活时间
        this.dogFood = 0;       // 心跳检测标志位
        this.watchDog = -1;     // 心跳检测定时器
        this.timeout = -1;      // 连接超时定时器

        this.ws = null;
        this.url = null;
        this.listener = listener;
        this.onWebSocketOpen = this.onWebSocketOpen.bind(this);
        this.onWebSocketError = this.onWebSocketError.bind(this);
        this.onWebSocketClose = this.onWebSocketClose.bind(this);
        this.onWebSocketMessage = this.onWebSocketMessage.bind(this);
    }

    /**
     * 连接 WebSocket 服务器
     * @param {String} url 连接地址
     * @param {Number} timeout 超时时间
     */
    connect(url, timeout = 3000) {
        this.disconnect();
        this.url = url;
        this.ws = new WebSocket(url);
        this.ws.addEventListener("open", this.onWebSocketOpen);
        this.ws.addEventListener("error", this.onWebSocketError);
        this.ws.addEventListener("close", this.onWebSocketClose);
        this.ws.addEventListener("message", this.onWebSocketMessage);
        this.timeout = setTimeout(() => {
            this.disconnect();
            this.onWebSocketTimeout();
        }, timeout);
    }
    /**
     * 断开 WebSocket 连接（设计原因，客户端主动关闭连接不派发 websocket:close 事件）
     * @param {Number} code 关闭代码（默认 1000 正常关闭）
     */
    disconnect(code = 1000) {
        clearTimeout(this.timeout);
        clearInterval(this.watchDog);
        if (this.ws) {
            this.ws.removeEventListener("open", this.onWebSocketOpen);
            this.ws.removeEventListener("error", this.onWebSocketError);
            this.ws.removeEventListener("close", this.onWebSocketClose);
            this.ws.removeEventListener("message", this.onWebSocketMessage);
            this.ws.close(code);
        }
    }
    /**
     * 发送消息
     * @param {*} message 消息对象
     */
    send(message) {
        if (this.ws?.readyState === WebSocket.OPEN) {
            this.ws.send(JSON.stringify(message));
        }
    }
    // 启动看门狗（心跳检测）
    startWatchDog() {
        this.send({ type: "ping" });
        this.watchDog = setInterval(() => {
            if (this.dogFood === 0) {
                clearInterval(this.watchDog);
                return this.onWebSocketTimeout();
            }
            this.dogFood = 0;
            this.send({ type: "ping" });
        }, this.keepAlive);
    }
    onWebSocketOpen(event) {
        console.log("WebSocket 连接成功！");
        clearTimeout(this.timeout);
        clearInterval(this.watchDog);
        this.startWatchDog(); // 开始心跳检测

        if (this.listener?.onOpen) {
            this.listener.onOpen(event);
        }
    }
    onWebSocketError(event) {
        console.log("WebSocket 发生错误", event);
        clearTimeout(this.timeout);
        clearInterval(this.watchDog);

        if (this.listener?.onError) {
            this.listener.onError(event);
        }
    }
    onWebSocketClose(event) {
        console.log("WebSocket 连接关闭", event);
        clearTimeout(this.timeout);
        clearInterval(this.watchDog);

        if (this.listener?.onClose) {
            this.listener.onClose(event);
        }
    }
    onWebSocketMessage(event) {
        this.dogFood = 1;
        if (this.listener?.onMessage) {
            this.listener.onMessage(JSON.parse(event.data));
        }
    }
    onWebSocketTimeout() {
        console.log("WebSocket 连接超时");
        if (this.listener?.onTimeout) {
            this.listener.onTimeout(this.ws);
        }
    }
}