var socket;

function load() {
	socket = init_websocket();
	let intervalID = window.setInterval(update, 5000);
}

function init_websocket() {
	let socket = new WebSocket('wss://' + window.location.hostname + ws_uri);
	socket._send = socket.send;
	socket.send = function(event_title, data) {
		data = JSON.stringify({event: event_title, data: data});
		if (socket.readyState == 0) {
			console.log("Socket is still opening!");
			return;
		}
		socket._send(data);
	}
	socket.onmessage = onmessage;
	socket.onclose = onclose;
	socket.onerror = onerror;
	socket.events = {};
	socket.events['active_torrents'] = active_torrents_recv;
	socket.events['tracker_stats'] = tracker_stats_recv;
	return socket;
}

function onmessage (e) {
	let data = JSON.parse(e.data);
	let event = data.event;
	data = data.data;
	if (socket.events[event] === undefined) {
		console.log("Unknown socket event: " + event);
		return;
	}
	socket.events[event](data);
}

function onclose(e) {
	if (e.wasClean) { return; } // no need to reconnect
	console.log(e);
	console.log('Websocket lost connection to server. Re-trying...');
	socket = init_websocket();
}

function onerror(e) {
	console.log("Websocket error!")
	console.log(e);
}

/* Websocket receive */
function active_torrents_recv(data) {
	let table = document.querySelector('#torrents tbody');
	while (table.firstChild) {
		table.removeChild(table.firstChild);
	}
	data.forEach(function(torrent) {
		let template = document.querySelector('#torrent_template');
		let node = document.importNode(template.content, true);
		for (let field of node.children[0].children) {
			field.textContent = torrent[field.className];
		}
		table.appendChild(node);
	});
}
function tracker_stats(data) {
	let table = document.querySelector('#tracker_stats tbody');
	while (table.firstChild) {
		table.removeChild(table.firstChild);
	}
	for (let [tracker, values] of Object.entries(data)) {
		let template = document.querySelector('#tracker_template');
		let node = document.importNode(template.content, true);
		node.children[0].children[0].textContent = tracker;
		for (let i = 0; i < values.length; i++) {
			node.children[0].children[i+1].textContent = values[i];
		}
		table.appendChild(node);
	}
}

/* Websocket send */
function get_active_torrents() {
	socket.send('active_torrents', {});
}
function get_tracker_stats() {
	socket.send('tracker_stats', {});
}

/* Helper */
function update() {
	get_active_torrents();
	get_tracker_stats();
}