var RSSRequestObject = false; // XMLHttpRequest Object



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

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

function kickStart() {
    RSSRequest(GCalFeed);
}

function AddOnload(myfunc) //Load before page loads if Mozilla/Firefox. If IE just do it the same old slow way. Thanks Microsoft.
{
if(window.addEventListener)
window.addEventListener('load', myfunc, false);
else if(window.attachEvent)
window.attachEvent('onload', myfunc);
}    

AddOnload(kickStart);




/*
* 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 id="nextdates">';
				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. Thanks for making a shitty product Microsoft!
                    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 isAllDay = false; //init isAllDay variable
                    if (itemTimeXML.length <= 10){isAllDay = true;} //just the date is only 10 digits = all day event
                    var itemTime = new Date();
                    itemTime.setTime
                        (Date.UTC(itemTimeXML.substr(0,4),(itemTimeXML.substr(5,2)-1),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 += '<li><span>'+ itemTime.getUTCDate() + '. ' + getMonthName(itemTime) + ' (' + getDayName(itemTime) + ')' +'</span>';}
                    
                    
                    if (!isAllDay) { content+= getTimeFormatted(itemTime); }
                    
                    content += ' <a href="' +itemLink + '">'  + itemTitle + '</a>' + itemContent + '</li>';
                    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>Fehler: Die Daten konnten nicht geladen werden.<div>";
		}
		
		Hide('status');
	}
	
}

/*
* Time Format - Month
*/
function getMonthName(dateObject) {
    var m_names = new Array("Januar", "Februar", "M&auml;rz", 
    "April", "Mai", "Juni", "Juli", "August", "September", 
    "Oktober", "November", "Dezember");
    return(m_names[dateObject.getUTCMonth()]);
}
/*
* Time Format - Day
*/
function getDayName(dateObject) {
    var daynames = new Array("Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Samstag");
    return(daynames[dateObject.getUTCDay()]);
}

/*
* Time Format - Hour
*/
function getTimeFormatted(dateObject) {
    var hours = dateObject.getUTCHours();
    var minutes = dateObject.getUTCMinutes();
    var formattedTime = null;
    if (is24Hour) {
        if (minutes < 10){minutes = "0" + minutes;}
        formattedTime = hours + ':' + minutes;
        return (formattedTime);
    }
    else {
        var ampm = "AM";
        if (hours > 12){
            hours = hours - 12;
            ampm = "PM";}
        if (hours == 12){ampm = 'PM';}
        if (hours == 0) {hours = 12;}
        if (minutes < 10){minutes = "0" + minutes;}
        formattedTime = hours + ':' + minutes + ' ' + ampm;
        return (formattedTime);
    }
}

/*
* Main AJAX RSS reader request
*/
function RSSRequest(gcal_path) {
    Backend = Backend + "?gcal_feed=" + escape(gcal_path) + "&timeLimit=" + timeLimit + "&maxResults=" + maxResults;
	// change the status to requesting data
	document.getElementById("status").innerHTML = "Lade Termindaten...";
	
	// Prepare the request
    
	RSSRequestObject.open("GET", Backend , true);
	// Set the onreadystatechange function
	RSSRequestObject.onreadystatechange = ReqChange;
	// Send
	RSSRequestObject.send(null); 
}



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);
}