// started on main page load
function init() {
	init_stats();
}

function set_status(message)
{
 if (message == "") {
	document.getElementById("status").textContent = message;
	document.getElementById("status").style.display = 'inline';
 } else {
	document.getElementById("status").textContent = "";
	document.getElementById("status").style.display = 'none';
 }
}

var websocket;

//
// Callbacks for websocket data of different types
//

function on_stats(numberofusers, numberofconnections, dbsizegross, dbsizenet)
{
	document.getElementById("numberofusers").textContent = numberofusers;
	document.getElementById("numberofconnections").textContent = numberofconnections;
	document.getElementById("dbsizegross").textContent = dbsizegross;
	document.getElementById("dbsizenet").textContent = dbsizenet;
}

function on_version(version)
{
	document.getElementById("version").textContent = version;
}

function on_message(e) {
	var parser = new DOMParser();
	var xmlDocument = parser.parseFromString(e.data, "text/xml");
	
	var type = xmlDocument.getElementsByTagName("type")[0].textContent;

	if (type == "stats") {
		on_stats(xmlDocument.getElementsByTagName("numberofusers")[0].textContent,
                         xmlDocument.getElementsByTagName("numberofconnections")[0].textContent,
                         xmlDocument.getElementsByTagName("dbsizegross")[0].textContent,
                         xmlDocument.getElementsByTagName("dbsizenet")[0].textContent);
	} else if (type == "version") {
		on_version(xmlDocument.getElementsByTagName("version")[0].textContent);
	} else if (type == "error") {
		alert(xmlDocument.getElementsByTagName("message")[0].textContent);
	} else {
		alert("Unhandled message type: " + e.data + "|" + type);
	}
}

function connect_websocket() {
	document.getElementById("reconnect").style.display = 'none';
        set_status("Connecting...");
	var newlocation = location.origin + location.pathname;
	newlocation = newlocation.replace(/^http/, 'ws');
	newlocation = newlocation.replace(/stats.html$/, '');
	if (newlocation.slice(-1) != "/")
		newlocation += "/";
	newlocation += "websocket";

	websocket = new WebSocket(newlocation);

	websocket.onmessage = function(e) { on_message(e); };

	websocket.onopen = function(e) {
		websocket.send("<request><command>getversion</command></request>");
		websocket.send("<request><command>getstats</command></request>");
                set_status(""); // ok
	};
	
	websocket.onclose = function(e) {
		alert("Server connection closed.");
		document.getElementById("reconnect").style.display = 'inline';
	};

	websocket.onerror = function(e) {
		alert("Error: Server connection closed.");
		document.getElementById("reconnect").style.display = 'inline';
	};
}

// button in html
function on_reconnect_click() {
	connect_websocket();
}

function init_stats() {
        set_status("Loading...");
        connect_websocket();
}