var countdownRemaining=0;
var countdownExecuter;
var mainExecuter;

function keepAlive() {
	// Ping a site other than the activeSessionTest.jsp to keep the remaining time updated
	new PeriodicalExecuter(function(pe) {new Ajax.Request('../web/about.jsp');},30);
}

function afterModalBox() {
	countdownExecuter.stop();
}

function warnUserTimeout() {
	var tm = $('timeoutMessage');
	if (!tm) {
		countdownExecuter = new PeriodicalExecuter(function(pe) {
			countdownRemaining--;
			if (countdownRemaining < 0 && countdownExecuter!=null) {
				countdownExecuter.stop();
				new Ajax.Request('../web/activeSessionTest.jsp', {
					method: 'post', 
					onSuccess: function(transport) {
						var timeRemaining=new Number(transport.responseText);
						if (timeRemaining < 0) {
							// Session expired, send user to the logout page
	    					window.location.href='../web/logout.jsp?expired=true';
			    		} else {
				    		Modalbox.hide();
				    	}
		    		}
				});
			
			} else {
				var p = $('timeoutMessage');
				if (p) {
					var message='Your session is about to expire.<br/>You will be logged out in ' + countdownRemaining + ' second' + (countdownRemaining==1 ? '' : 's') + '.';
					p.update(message);
					Modalbox.resizeToContent();
				}
			}
		}, 1);
	
		Modalbox.show('<p id="timeoutMessage">Your session is about to expire.</p><input type="button" onClick="Modalbox.hide();new Ajax.Request(\'../web/about.jsp\');" value="Stay logged in"/>',
			{
				title: '',
				width: 300,
				transitions: false,
				afterHide: afterModalBox
			}
		);
	}
}

mainExecuter=new PeriodicalExecuter(function(pe) { 
	new Ajax.Request('../web/activeSessionTest.jsp', {
		method: 'post', 
		onSuccess: function(transport) {
			var timeRemaining=new Number(transport.responseText);
			if (timeRemaining < 0) {
				// Session expired, send user to the logout page
	    		window.location.href='../web/logout.jsp?expired=true';
	    
			} else if (timeRemaining < 60000) {
				var tr = $('timeRemaining');
				if (tr && tr.style.display != 'none') {
					tr.blindUp();
				}
				
				countdownRemaining = (timeRemaining/1000).toFixed(0);
				warnUserTimeout();	
				
			} else {
				var message="";
				var time=timeRemaining / 1000;
				var timeMessage="second";

				if (time > 60) {
					time=time/60;
					timeMessage="minute";
				}
			
				time=time.toFixed(0);
				if (time > 1) {
					timeMessage=timeMessage + "s";
				}
					
				if (time <= 5 || timeMessage == "second") {
					message = "Your session will expire in " + time + " " + timeMessage;
					
					var p = $('timeRemaining');
					if (p) {
						p.update(message);
						if (p.style.display=='none') {
							p.blindDown();
						}
						p.resizeToContent();
					
					}
				} else {
					var p = $('timeRemaining');
					if (p && p.style.display != 'none') {
						p.blindUp();
					}
				}
			}
		}
	});
},15);