var RSSRequestObject = false; // XMLHttpRequest Object
var Backend = 'gcalajax/eventrss.php'; // Backend url
window.setInterval("update_timer()", 1200000); // update the data every 20 mins


if (window.XMLHttpRequest) // try to create XMLHttpRequest
	RSSRequestObject = new XMLHttpRequest();

if (window.ActiveXObject)	// if ActiveXObject use the Microsoft.XMLHTTP
	RSSRequestObject = new ActiveXObject("Microsoft.XMLHTTP");


/*
* onreadystatechange function
*/
function ReqChange() {

	// If data received correctly
	if (RSSRequestObject.readyState==4) {
	
		// if data is valid
		if (RSSRequestObject.responseText.indexOf('invalid') == -1) 
		{ 	
			// Parsing Feeds
			var node = RSSRequestObject.responseXML.documentElement; 
            var content = '';
            
			// Get the calendar title - uncomment next two lines if you want it to show up
			//var title = node.getElementsByTagName('title').item(0).firstChild.data;
			//var content = '<div class="channeltitle">' + title + '</div>';
            
			// Browse events
			var items = node.getElementsByTagName('entry');
            var itemTimePrev = new Date();
            itemTimePrev.setTime(0000);
			if (items.length == 0) {
				content += '<ul><li><div class=error>No events</div></li></ul>';
			} else {
				content += '<ul>';
				for (var n=items.length-1; n >= 0; n--)
				{
					var itemTitle = items[n].getElementsByTagName('title').item(0).firstChild.data;
                    //Here's a little love for our friend IE - he hates standards, like XML namespace.
                    try { 
						var itemTimeXML = items[n].getElementsByTagName('when')[0].getAttribute("startTime");  
                        } 
					catch (e) { var itemTimeXML = items[n].getElementsByTagName('gd:when')[0].
                    getAttribute("startTime");}
                    //var itemTimeXML = items[n].getElementsByTagName('when')[0].getAttribute("startTime");
                    var itemTime = new Date();
                    itemTime.setTime
                        (Date.UTC(itemTimeXML.substr(0,4),itemTimeXML.substr(5,2),itemTimeXML.substr(8,2)
                        ,itemTimeXML.substr(11,2),itemTimeXML.substr(14,2)));
					var itemLink =  items[n].getElementsByTagName('link')[0].getAttribute("href");
					try { 
						var itemContent = ' - ';
                        itemContent += items[n].getElementsByTagName('content').item(0).firstChild.data;  
                        } 
					catch (e) { var itemContent = '';}
                    
                    if ((itemTime.getUTCDate()==itemTimePrev.getUTCDate())&&(itemTime.getUTCMonth()==itemTimePrev.getUTCMonth())){ //Don't dupe the dates
                    content += '';}
                    else {
                    content += '<h3><li>' + getMonthName(itemTime) + ' ' + itemTime.getUTCDate() + '</li></h3>';}
                    
                    content += '<ul><li>' + getTimeFormatted(itemTime)+
                    ' <a href="' +itemLink + '">'  + itemTitle + '</a>' + itemContent + '</li></ul>';
                    itemTimePrev.setTime(itemTime); //Save the last timestamp for next iteration comparison
				}
				
	
				content += '</ul> ';
			}
			// Display the result
			document.getElementById("gcalajax").innerHTML = content;

			// Tell the reader the everything is done
			document.getElementById("status").innerHTML = "Done.";
			
		}
		else {
			// Tell the reader that there was error requesting data
			document.getElementById("status").innerHTML = "<div class=error>Error requesting data.<div>";
		}
		
		Hide('status');
	}
	
}

/*
* Time Format - Month
*/
function getMonthName(dateObject) {
    var m_names = new Array("January", "February", "March", 
    "April", "May", "June", "July", "August", "September", 
    "October", "November", "December");
    return(m_names[dateObject.getUTCMonth()-1]); //Array starts at 0, getMonth starts at 1
}

/*
* Time Format - Hour
*/
function getTimeFormatted(dateObject) {
    var hours = dateObject.getUTCHours();
    var minutes = dateObject.getUTCMinutes();
    var ampm = "AM";
    if (hours > 12){
        hours = hours - 12;
        ampm = "PM";}
    if (hours == 0) {hours = 12;}
    if (hours == 12){ampm = 'PM'}
    if (minutes < 10){minutes = "0" + minutes;}
    var formattedTime = hours + ':' + minutes + ' ' + ampm;
    return (formattedTime);
}

/*
* Main AJAX RSS reader request
*/
function RSSRequest() {

	// change the status to requesting data
	document.getElementById("status").innerHTML = "Requesting data ...";
	
	// Prepare the request
	RSSRequestObject.open("GET", Backend , true);
	// Set the onreadystatechange function
	RSSRequestObject.onreadystatechange = ReqChange;
	// Send
	RSSRequestObject.send(null); 
}

/*
* Timer
*/
function update_timer() {
	RSSRequest();
}


function Hide(id){
	var el = GetObject(id);
	//if(el.style.display=="none")
	//el.style.display='';
	//else
	el.style.display='none';
}

function GetObject(id){
	var el = document.getElementById(id);
	return(el);
}