/** Handle connections */
var Conn = (function() {
	var ws;
	var heartbeatTout;
	var pingIv;
	var xoff = false;
	var autoXoffTout;

	function onOpen(evt) {
		console.log("CONNECTED");
	}

	function onClose(evt) {
		console.warn("SOCKET CLOSED, code "+evt.code+". Reconnecting...");
		setTimeout(function() {
			init();
		}, 200);
		// this happens when the buffer gets fucked up via invalid unicode.
		// we basically use polling instead of socket then
	}

	function onMessage(evt) {
		try {
			// . = heartbeat
			switch (evt.data.charAt(0)) {
				case 'B':
				case 'T':
				case 'S':
					Screen.load(evt.data);
					break;

				case '-':
					//console.log('xoff');
					xoff = true;
					autoXoffTout = setTimeout(function(){xoff=false;}, 250);
					break;

				case '+':
					//console.log('xon');
					xoff = false;
					clearTimeout(autoXoffTout);
					break;
			}
			heartbeat();
		} catch(e) {
			console.error(e);
		}
	}

	function canSend() {
		return !xoff;
	}

	function doSend(message) {
		if (_demo) {
			console.log("TX: ", message);
			return true; // Simulate success
		}
		if (xoff) {
			// TODO queue
			console.log("Can't send, flood control.");
			return false;
		}

		if (!ws) return false; // for dry testing
		if (ws.readyState != 1) {
			console.error("Socket not ready");
			return false;
		}
		if (typeof message != "string") {
			message = JSON.stringify(message);
		}
		ws.send(message);
		return true;
	}

	function init() {
		if (_demo) {
			console.log("Demo mode!");
			Screen.load(_demo_screen);
			showPage();
			return;
		}
		heartbeat();

		ws = new WebSocket("ws://"+_root+"/term/update.ws");
		ws.onopen = onOpen;
		ws.onclose = onClose;
		ws.onmessage = onMessage;

		console.log("Opening socket.");

		// Ask for initial data
		$.get('http://'+_root+'/term/init', function(resp, status) {
			if (status !== 200) location.reload(true);
			console.log("Data received!");
			Screen.load(resp);
			heartbeat();

			showPage();
		});
	}

	function heartbeat() {
		clearTimeout(heartbeatTout);
		heartbeatTout = setTimeout(heartbeatFail, 2000);
	}

	function heartbeatFail() {
		console.error("Heartbeat lost, probing server...");
		pingIv = setInterval(function() {
			console.log("> ping");
			$.get('http://'+_root+'/system/ping', function(resp, status) {
				if (status == 200) {
					clearInterval(pingIv);
					console.info("Server ready, reloading page...");
					location.reload();
				}
			}, {
				timeout: 100,
			});
		}, 500);
	}

	return {
		ws: null,
		init: init,
		send: doSend,
		canSend: canSend, // check flood control
	};
})();