class Conn {
	constructor(id) {
		this.id = id;
		this.conn = null;
		this.gotPong = false;
		this.pongTime = 4000;
		this.state = "idle";
		this.q = [];

		this.onstatechange = () => {}
		this.onmessage = () => {};

		this.createConn();

		setInterval(() => {
			if (this.state == "pong-timeout")
				return;

			if (!this.gotPong)
				this.setState("pong-timeout");

			this.send({ type: "ping" });
			this.gotPong = false;
		}, this.pongTime);
	}

	setState(state, msg) {
		this.state = state;
		this.onstatechange(msg || state);
	}

	createConn() {
		this.conn = new WebSocket(`${location.protocol.replace("http", "ws")}//${location.host}`);
		this.setState("connecting");
		this.connected = false;

		this.conn.onclose = evt => {
			this.conn = null;
			this.setState("closed", `closed: ${evt.code}`);
			setTimeout(this.createConn.bind(this), 2000);
		}

		this.conn.onopen = () => {
			this.setState("identifying");
			this.conn.send(JSON.stringify({ type: "identify-master", id: this.id }));

			this.q.forEach(el => this.conn.send(el));
			this.q = [];
		}

		this.conn.onmessage = msg => {
			console.log(msg.data);
			let obj = JSON.parse(msg.data);
			switch (obj.type) {
			case "identify-response":
				if (obj.err == null) {
					this.connected = true;
					this.setState("waiting-for-target");
				} else {
					this.setState("error", `error: ${obj.err}`);
				}
				break;

			case "target-connect":
				this.setState("ready");
				break;

			case "target-disconnect":
				this.setState("waiting-for-target")
				break;

			case "js-result":
				this.onjsresult(obj.err, obj.result);
				break;

			case "log":
				this.onlog(obj.log);
				break;

			case "pong":
				this.onPong();
				break;

			default:
				console.warn("Unknown message type:", obj.type);
			}
		}
	}

	onPong() {
		this.gotPong = true;
		if (this.state == "pong-timeout")
			this.setState("ready");
	}

	runJavascript(js) {
		this.send({ type: "run-js", js });
	}

	send(obj) {
		if (this.connected)
			this.conn.send(JSON.stringify(obj));
	}
}