Blob.prototype.arrayBuffer = function(){
    var reader = new FileReader();
    var _resolve;
    var _Promise = new Promise(function(resolve,reject){
        _resolve = resolve;
    });
    reader.onloadend = function(){
        _resolve(reader.result);
    }
    reader.readAsArrayBuffer(this);
    return _Promise;
}
this.timer = {
    time:0,
    offset:0,
    interval:1000,
    running:false,
    timerId:-1,
    start(){
        this.running = true;
        this.time = performance.now();
        this.loop();
    },
    stop(){
        this.running = false;
    },
    loop(){
        if(!this.running) return;
        let now = performance.now();
        let span =  now - ( this.time - this.offset );
        if(span > this.interval){
            this.time = now;
            this.offset = span % this.interval ;
            this.handles.forEach(async handle=>{
                handle();
            });
        }
        this.running && (this.timerId = setTimeout(()=>this.loop(),100));
    },
    handles:new Set(),
    on(handle){
        if(!this.handles.has(handle))this.handles.add(handle);
    },
};
addEventListener("message",async function(ev){
    var {key,payload} = ev.data;
    switch(key){
        case "open":
            var {url} = payload;
            opensocket(url);
            break;
        case "send":
            var {data} = payload;
            this.socket.send(data);
            break;
        case "close":
            closesocket();
            break;
        case "bufferedAmount":
            let val = (this.socket?.bufferedAmount || 0);
            postMessage({key:"bufferedAmount",payload:val});
            break;
    }
});
this.socket = null;
let closesocket = function(){
    socket.close(1000,"user closed");
}
let opensocket = function(url){
    this.socket = new WebSocket(url);
    this.socket.onopen = function () {
        postMessage({"key":"onopen","payload":null},[]);
    }
    this.socket.onclose = function (args) {
        let { code,reason,type,target } = args;
        let { url } = target;
        postMessage({"key":"onclose","payload":{code,reason,type,url}});
    }
    this.socket.onerror = function () {
        postMessage({"key":"onerror","payload":null});
    }
    this.socket.onmessage = async function (e) {
        var buffer = await e.data.arrayBuffer();
        postMessage({"key":"onmessage","payload":buffer},[buffer]);
    }
    this.timer.start();
    this.timer.on(()=>{
        // if(this.socket.bufferedAmount > this.bufferMax){
        //     postMessage({"key":"onoverflow","payload":{size:this.socket.bufferedAmount}});
        // }
    })
}