class WebSocketClass {
    constructor() {
        // 用来设计单例模式的
        this.instance = null;
        // 用来保存 new WebSocket 的实例
        this.ws = null;
        // close 关闭，open  打开
        this.status = 'close';
        // 发送的心跳数值 ping 询问后端，pong 后端的响应
        this.pingPong = 'ping';
        this.callMessage = {
            // SocketSystem: () => {},
            // SocketUser: () => {},
        };
        this.connect();
    }

    static getInstance() {
        if (!this.instance) {
            this.instance = new WebSocketClass();
        }
        return this.instance
    }

    connect() {
        this.ws = new WebSocket(config.checkSocket());
        this.ws.onopen = e => {
            this.status = 'open';
            console.log(`连接成功`);
            this.heartCheck();
            this.onClose();
            this.getMessage();
        };
    }

    heartCheck() {
        this.pingPong = 'ping';
        this.pingInterval = setInterval(() => {
            if (this.ws.readyState === 1) {
                this.send({
                    type: "SocketHealthy",
                    action: null,
                    data: "ping"
                }) // 客户端发送ping
            }
        }, 5000);

        this.pongInterval = setInterval(() => {
            if (this.pingPong === 'ping') {
                this.closeHandle('服务器没有返回pong，重启webSocket');
            }
            console.log('收到服务器的 pong');
            this.pingPong = 'ping';
        }, 10000);
    }

    closeHandle(e = 'err') {
        console.log(e)
        if (this.status !== 'close') {
            if (this.pingInterval !== undefined && this.pongInterval !== undefined) {
                clearInterval(this.pingInterval);
                clearInterval(this.pongInterval);
            }
            this.connect();
        } else {
            console.log(`websocket手动关闭,或者正在连接`);
        }
    }

    getMessage() {
        this.ws.onmessage = e => {
            var res = JSON.parse(e.data);
            switch (res.type) {
                case "SocketHealthy":
                    // console.log("前端 健康检查：", res.data)
                    this.pingPong = 'pong';
                    break;
                case "SocketUser":
                    // console.log("前端 用户消息：", res.data);
                    if (res.action == "to") {
                        this.callMessage["to"](res.data);
                        return;
                    } else if (res.action == "list") {
                        this.callMessage["userList"](res.data);
                    } else {
                        this.callMessage["SocketUser"](res.data);
                    }
                    break;
                case "SocketSystem":
                    // console.log("前端 系统消息：", res.data)
                    this.callMessage["SocketSystem"](res.data)
                    break;
            }
        };
    }


    send(mes = null, callback = null, type = null) {
        if (mes == null) {
            if (callback != null) {
                this.callMessage[type] = callback
            }
        } else {
            if (callback != null) {
                this.callMessage[type] = callback
            }
            this.ws.send(JSON.stringify(mes))
        }
    }

    onClose() {
        this.ws.onclose = (evt) => {
            console.log("链接关闭: ", evt);
        };
    }

    close() {
        clearInterval(this.pingInterval);
        clearInterval(this.pongInterval);
        this.status = 'close';
        this.ws.send('close');
        this.ws.close();
        console.log('close');
    }
}