// source: http://www.pascarello.com/AjaxSessionTimer.aspx

function AjaxTimeoutTimer(strLength) {

	//Set all of the defaults      
	this.loaded = false;
	this.intHeight = 600;
	this.intDivHeight = 150;
	this.objDiv = null;
	this.objIFr = null;
	this.top = 0;
	this.sessionLength = 1000 * 60 * 20; // 20 minutes
	if(typeof(strLength)!="undefined")this.sessionLength = strLength;
	var timerWarn = window.setTimeout(loadMessage,this.sessionLength);
	this.maxWait = 1000 * 60 * 5; // 5 minutes
	this.title = "Timeout Notification";
	this.message = "Your current session is about to expire. " + 
								 "In order to remain logged in and avoid loosing " + 
								 "any data you may have entered, please press " + 
								 "the <span style='color:green'>Confirm</span> button " +
								 "to extend your session.";
	this.confirm = "Confirm";
	this.ignore = "Ignore";
	this.extendedMessage = "Your session has most likely been expired. " +
												 "Press the <span style='color:green'>Confirm</span> " +
												 "button to verify this."
	this.serverURL = null;
	var ref = this;
        
	//determine browser height and height of div
	function calcBrowserSize() {
		if( self.innerHeight ) {
			ref.intHeight = self.innerHeight;
			ref.intDivHeight = ref.objDiv.scrollHeight;
		} else if( document.documentElement && document.documentElement.clientHeight ) {
			ref.intHeight = document.documentElement.clientHeight;
			ref.intDivHeight = ref.objDiv.clientHeight;
		} else if( document.body ) {
			ref.intHeight = document.body.clientHeight;
			ref.intDivHeight = ref.objDiv.clientHeight;
		}
		ref.intHeight = parseInt(ref.intHeight);
		ref.intDivHeight = parseInt(ref.intDivHeight);
	}


	//Start to display message on scroll
	function loadMessage() {
        
		if( ref.loaded == false ) ref.loaded = createAjaxConfirm();        
		//set reference
		ref.objDiv = document.getElementById("divAjaxTimer");
		ref.objIFr = document.getElementById("ifAjaxTimer");
		
		//position block off screen and show it
		ref.objDiv.style.top = "-1000px";
		ref.objIFr.style.top = "-1000px";
		ref.objDiv.style.display = "block";
		ref.objIFr.style.display = "block";
		if( navigator.userAgent.toLowerCase().indexOf("opera") != -1 ) ref.objIFr.style.visibility = "hidden";
          
		//Set all of the elements text
		document.getElementById("divAjaxBut").style.display = "block";
		document.getElementById("divAjaxContent").innerHTML = ref.message;
		document.getElementById("divAjaxTitle").innerHTML = ref.title;
		document.getElementById("ajaxB1").value = ref.confirm;
		document.getElementById("ajaxB2").value = ref.ignore;
		  
		//position block to top edge of screen
		calcBrowserSize();
		ref.objDiv.style.top = -ref.intDivHeight + "px";
		ref.objIFr.style.top = -ref.intDivHeight + "px";
          
		//prepare block to be scrolled in
		ref.top = -ref.intDivHeight;
		timerScroll = window.setInterval(scrollIn,1);
		timerWait = window.setTimeout(extendedWait,ref.maxWait);
	}

	//Determine how much user scrolled page down
	function GetScroll() {    
		var scrollY = document.documentElement.scrollTop;
		if(!scrollY)scrollY = document.body.scrollTop;            
		if(!scrollY)scrollY = window.pageYOffset;               
		if(!scrollY)scrollY = 0;
		return scrollY;
	}
  
	//some local(private) varaibles
	var timerScroll = null;
	var timerReject = null;
	var intStep = 2;
	var intStop = Math.floor(ref.intHeight/5);
	var timerUpdate = null;
	var intDotCount = 0;
	var timerWait = null;

	//Function moves confirmation window into view
	function scrollIn() {
		if( parseInt(intStep) + parseInt(ref.top) <= parseInt(intStop) ) {
			ref.top += intStep;
			var intT = ref.top + GetScroll();;
			ref.objDiv.style.top =  intT + "px";
			ref.objIFr.style.top =  intT + "px";
		} else {
			var cancel = window.clearInterval(timerScroll);
			ref.objDiv.style.top = GetScroll() + intStop + "px";
			ref.objIFr.style.top = ref.objDiv.style.top;
		}
	}
        
	//Confirm button pressed, make request, hide buttons, start annimation
	this.confirmTimer = function() {
		timerUpdate = window.setInterval(updateMessage,250);
		document.getElementById("divAjaxBut").style.display = "none";
		makeHttpRequest();
	}

	//Hide information if the ignore button was clicked
	this.ignoreTimer = function() {
		ref.objDiv.style.display = "none";
		ref.objIFr.style.display = "none";
	}

	//Annimate the request waiting time so it looks fancy
	function updateMessage() {
		var strDotsMessage = "Updating Session.";
		for( x = 0; x < intDotCount; x++ ) strDotsMessage+=".";
		document.getElementById("divAjaxContent").innerHTML = strDotsMessage;
		intDotCount++;
		if( intDotCount > 4 ) intDotCount = 0;
	}
		
	//change message from normal to extended info
	function extendedWait() {
		document.getElementById("divAjaxContent").innerHTML = ref.extendedMessage;
	}
	
	//Function Prepares calls xmlHttpRequest
	function makeHttpRequest() {
	
		//Make sure we set the server side page          
		if( ref.serverURL == null ) {
			alert('Errror: Server Side Code was not specified by web master!');
			ref.objDiv.style.display = "none";
			ref.objIfr.style.display = "none";
			return false;
		}
		
		//create reg exp so we do not grabbed cached material
		var regEx = /(\s|:)/gi;
		var strDT = "ts=" + new Date().toString().replace(regEx,"");                              
		
		//Make the request to the server
		var loader1 = new net.ContentLoader(ref.serverURL,finishRequest,null,"POST",strDT); //Make request
	}
        
	//Function takes XML document 
	function finishRequest() {
		timerWarn = window.setTimeout(loadMessage,ref.sessionLength);
		var bx = window.clearTimeout(timerUpdate);
		var strDoc = this.req.responseText;  //Grab HTML
		if( strDoc.indexOf("Session Updated - Server Time:") >= 0 ) {
			document.getElementById("divAjaxContent").innerHTML = "Your session was updated sucessfully!";
			var timerHide = window.setTimeout(hideDiv, 2000);
		} else{
			document.getElementById("divAjaxContent").innerHTML = "Warning your session has already timed out!";
			var timerHide = window.setTimeout(hideDiv, 3000);
		}
	}
        
	function createAjaxConfirm(){
		var ifr = document.createElement("iframe");
	
		var div1 = document.createElement("div");
		var div2 = document.createElement("div");
		var div3 = document.createElement("div");
		var div4 = document.createElement("div");
	
		var btn1 = document.createElement("input");
		var btn2 = document.createElement("input");
	
		ifr.id = "ifAjaxTimer";
		div1.id = "divAjaxTimer";
		div2.id = "divAjaxTitle";
		div3.id = "divAjaxContent";
		div4.id = "divAjaxBut"; 
	
		btn1.type="button";
		btn2.type="button";
		btn1.id = "ajaxB1";
		btn2.id = "ajaxB2";
		btn1.className = "confirm";
		btn2.className = "ignore";
		btn1.onclick = function(){ ajaxTimer.confirmTimer(); return false; }
		btn2.onclick = function(){ ajaxTimer.ignoreTimer(); return false; }
		btn1.value = "text";
		btn2.value = "text";     
	
		div1.appendChild(div2);   
		div1.appendChild(div3);
		div4.appendChild(btn1);
		div4.appendChild(btn2);
		div1.appendChild(div4); 
	
		document.forms[0].appendChild(ifr);
		document.forms[0].appendChild(div1);
			
		return true;
	}
        
	//Hide div and iframe
	function hideDiv(){
		ref.objDiv.style.display = "none";
		ref.objIFr.style.display = "none";
	}
     
}

//=============================================
//Update information here for customization here!
//==============================================

//var ajaxTimer = new AjaxTimeoutTimer();      //default time 20 minutes
//var ajaxTimer = new AjaxTimeoutTimer(5000);  //Specify a time length
//ajaxTimer.serverURL = "AjaxSessionUpdate.aspx";
//ajaxTimer.maxWait = 1000 * 60 * 2;           //defualt time 5 minutes
//ajaxTimer.title = "Timeout Notification";
//ajaxTimer.message = "Your current session is about to expire.";
//ajaxTimer.confirm = "Update";
//ajaxTimer.ignore = "Cancel";
//ajaxTimer..extendedMessage = "Your session has most likely been expired. "