// Chatr - Super-simple chat for your site
//   (c) 2006 David Sterry
//   Distributed under the BSD license
//   Link: http://www.sterryit.com/chatr

//
// Global variables
//
var isFirefox;
var isIE;
var timeout;
var pingtimeout;
var textFocus   = true;
var starsadded  = false;
var md4hash     = 0;
var timedout    = 0;
var pingsent	= 0;
var requestsent = 0;
var postsent	= 0;
var chatsent	= 0;
var pingRate	= 1000 * 30;	 // 30 seconds
var refreshRate = 1000 * 3;		 // 3 seconds
var rnd			= Math.random(); // random seed

// added to reduce server load
var t = 2;
var update_period = 3;
var throttle_back = 60;		// this is in multiples of refreshRate
var lastpost = 0;			// throttling reduces traffic by 

//
// Get browser type
//
function sniff() {
	var ff = "Netscape";
	var ie = "Microsoft Internet Explorer";
	isFirefox = ( navigator.appName == ff );
	isIE = (navigator.appName == ie ); 
}
//
// Start the async fetch 
// and reset the fetch timer
//
function fetch(id_auberge) {
	window.clearTimeout( timeout );
	fetchBufferText(id_auberge);
	if (t++ % update_period) { 
		fetchUserList(id_auberge);
	}
	if ( t - lastpost > throttle_back ) {
		//alert("throttled t=" + t + " lastpost="+lastpost);  
		refreshRate = 4000;
		update_period = 4;
	} else {
		//alert("not throttled");
		refreshRate = 3000;
		update_period = 3;
	}
	if ( timedout != 1 ) { setTimers(id_auberge); }
}
//
// Start the fetch timer to update
// the chatpane and userlist
//
function setTimers(id_auberge) {
	timeout = window.setTimeout( "fetch("+id_auberge+")", refreshRate );
}
/* #############################
 * 
 * function: fetchUserList()
 * purpose:
 * 
 * This function retrieves the userlist.  
 * The userlist is returned as a set of
 * list-items from the server.  The existing
 * list is replaced and the new list is rendered
 * between two <ul> tags.  This function will 
 * call to update the chat buffer when it completes.
 *		 
 * notes: A random number is generated 
 * when this page loads.  This number is
 * incrimented and appended to the url to
 * prevent caching problems in IE
 *
 * #############################
*/
function fetchUserList(id_auberge) {
	rnd++;
	url = 'b_chat2.php?id_auberge=' + id_auberge + '&rnd=' + rnd;
	req = getAjax();
	req.onreadystatechange = function(){
		if ( req.readyState == 4 && req.status == 200 ) {
			obj = document.getElementById( "userlist" );
			if (obj != null) obj.innerHTML = req.responseText;
			fetchBufferText(id_auberge);
		}
	}
	req.open( 'GET', url, true );
	req.send( null );
	//requestsent++;
	//updateStatus();
}
/* #############################
 * 
 * function: fetchBufferText()
 * purpose:
 * 
 * This function retrieves the last 
 * twenty lines of the chat buffer.
 * The chat buffer is returned as a 
 * set of list-items and are rendered
 * in a <ul> tag.  This function calls
 * the scroll function to scroll the 
 * chat pane.
 *
 * notes: A random number is generated 
 * when this page loads.  This number is
 * incrimented and appended to the url to
 * prevent caching problems in IE
 *
 * #############################
*/
function fetchBufferText(id_auberge) {
	//user = location.search.substring( 1, location.search.length );
	rnd++;
	url = 'b_chat3.php?id_auberge=' + id_auberge + '&rnd=' + rnd;
	req = getAjax();
	req.onreadystatechange = function(){
		if ( req.readyState == 4 && req.status == 200 ) {
			objt = document.getElementById("chatbuffer");
			if (objt != null) {
				objt.innerHTML = req.responseText;
				eval(document.getElementById("eval").innerHTML);						
			}
			//obj.innerHTML = obj.innerHTML.replace(timeoutstring,"");
			//var timeoutstring = user + "timeout";
			//if ( obj.innerHTML.indexOf(timeoutstring) != -1 ) {
			//	obj.innerHTML = obj.innerHTML.replace(timeoutstring,"");
			//	timedout = 1;
			//}
			//scrollChatPane();
		}
	}
	req.open( 'GET', url , true );
	req.send( null );
	//requestsent++;
	//updateStatus();
	//changeTitle(); // this doesn't work
}
function startChat(id_auberge) {
	//sniff();
	//pingServer();
	//showLoadScreen();
	window.clearTimeout( timeout );
	setTimers(id_auberge);
	//resetPing();
	//if ( isFirefox ) {
	//	mytext = document.getElementById( "mytext" );
	//}
	//mytext.focus();
	//mytext.onkeypress = captureReturn;
}

//
// Measure and display the char count
//
function charCount() {
	if ( isFirefox ) {
		charcount = document.getElementById( "charcount" );
	}
	inputtext = document.getElementById( "mytext" );
	charcount.innerHTML = (1+inputtext.value.length) + " characters";
	lastpost = t;
}
//
// Update the status text with some 
// basic client statistics
// 
function updateStatus() {
	statistics = "<strong>Quick Stats</strong> Pings: " + pingsent + " Requests: " + requestsent + " Posts: " + postsent;
	if ( isFirefox ) {
		stats = document.getElementById( "stats" );
	}
	stats.innerHTML = statistics;
}
//
// Capture the enter key on 
// the input box and initiate a
// GET to the post url
//
function captureReturn( event ) {
	if ( isIE ) {
		event = window.event;
	}
	//
	// Supress event bubbling
	//
	if ( event.keyCode == 13 ) {
		//
		// fetch the feed
		//
		postText();
		if ( isIE ) {
			event.returnValue = false;
		} else {
			event.preventDefault();
		}
	}
	charCount();
}
//
// Auto scroll the chat window
// if the text exceeds the div 
//
function scrollChatPane() {
	pane = document.getElementById( "chatpane" );
	//while ( pane.scrollTop < pane.scrollHeight - pane.offsetHeight )
	//{
	//	pane.scrollTop = pane.scrollTop + 10;
	//}
}
//
// Show the little loading animation
// when the page starts
//
function showLoadScreen() {
	chat = document.getElementById( "chatbuffer" );
	user = document.getElementById( "userlist" );
	chat.innerHTML = Loading[GetCookie('lang')];
	user.innerHTML = Loading[GetCookie('lang')];
}
//
// ping the server to let 
// it know we're still alive
//
function resetPing() {
	pingtimeout = window.setTimeout( "pingServer()", pingRate );
}
/* #############################
 * 
 * function: postText()
 * purpose:
 * 
 * A users chat is posted to the server in 
 * the querystring of the posttext.aspx url.
 * The format of the querystring is: 
 *
 * ?u=[username]&t=[chat text]
 *
 * Because of the nature of the url encoding
 * certain chat text will fail to post.  
 * The chat text cannot contain any values
 * that are invalid in a url, or are part
 * of the url structure, such as the ampersand (&)
 * forward slash (/), etc.  
 *
 * #############################
*/
function postText() {
	chatbox = document.getElementById( "mytext" );
	chat = escape(chatbox.value);
	chatbox.value = '';
	if (chat.length == 0 ) { return; }

	user = location.search.substring( 1, location.search.length );
	url = 'posttext.php?u=' + user + '&rand=' + rnd + '&t=' + chat ;

	req = getAjax();

	req.onreadystatechange = function(){

		if ( req.readyState == 4 && req.status == 200 ) {
			fetch();
		}
	}
	req.open( 'GET', url, true );
	req.send( null );
	lastpost = t;
	postsent++;
	updateStatus();
}
/* #############################
 * 
 * function: pingServer()
 * purpose:
 * 
 * A sends a message to the server indicating
 * the browser is still open and the user is
 * still alive.
 *
 * #############################
*/
function pingServer() {
	window.clearTimeout( pingtimeout );
	user = location.search.substring( 1, location.search.length );
	url = 'ping.php?u=' + user + '&rand=' + rnd;
	req = getAjax();
	req.open( 'GET', url, true );
	req.send( null );
	pingsent++;
	updateStatus();
	if (timedout != 1) { 
		resetPing(); 
	}
}

function changeTitle( text ) {
	obj = document.getElementById( "chatbuffer" );
	temp = hex_md4(obj.innerHTML);
	if ( temp != md4hash ) {
		if ( textFocus == false && starsadded == false ) {
			text = "*** ";
			if (document.all || document.getElementById){ // Browser Check
				document.title = text + document.title;
			} else {
				self.status = text + self.status; // Default to status.
			}
			starsadded = true;
		} 
		md4hash = temp;
	}
	if ( textFocus == true ) {
		if (document.all || document.getElementById){ // Browser Check
			document.title = "Chatr";
		} else {
			self.status = "Chatr"; // Default to status.
		}
		starsadded = false;
	}
}