const core = function (){
    function SocketWorker(url,token){
        var _ctx = this.$ctx = { state:null };
        this.socket = new WebSocket(url);

        this.socket.onopen = function () {
            postMessage({"name":"onopen","payload":null},[]);
        }
        this.socket.onclose = function (args) {
            let { code,reason,type,target } = args;
            let { url } = target;
            postMessage({"name":"onclose","payload":{code,reason,type,url}});
            console.log("closed",_ctx.state );
        }
        this.socket.onerror = function () {
            postMessage({"name":"onerror","payload":null});
        }
        this.socket.onmessage = function (e) {
            if(e.data.size < 32) return;
            e.data.arrayBuffer().then(function(buffer){
                postMessage({"name":"onmessage","payload":buffer},[buffer]);
            });
        }
    }
    SocketWorker.prototype.state = function(state){
        this.$ctx.state = state;
    }
    SocketWorker.prototype.close = function(){
        if(this.socket)this.socket.close();
    }
    SocketWorker.prototype.postMessage = function(){
        this.socket.postMessage(...arguments);
    }
    let _websocket;
    addEventListener('message',function(e){
        let { name , payload } = e.data;
        switch(name){
            case "create":
                let {url,token,state} = payload;
                _websocket = new SocketWorker(url,token);
                break;
            case "close":
                _websocket?.close();
                break;
            default:
                _websocket?.postMessage(e.data)
        }
    });
};