//OBJECTS

var rssFeed;

// Sets up a function so we can check for nodes with a namespace
function getElementsByTagName(tagName, ns, prefix, scope){
	var elementListForReturn = scope.getElementsByTagName(prefix+":"+tagName);
	if(elementListForReturn.length == 0){
		elementListForReturn = scope.getElementsByTagName(tagName);
		if(elementListForReturn.length == 0){
			elementListForReturn = scope.getElementsByTagName("ns:"+tagName);
			if(elementListForReturn.length == 0 && document.getElementsByTagNameNS){
				elementListForReturn = scope.getElementsByTagNameNS(ns, tagName);
			}
		}
	}     

	return elementListForReturn;
}

//objects inside the RSS2Item object
function RSS2Enclosure(encElement)
{
	if (encElement == null)
	{
		this.url = null;
		this.length = null;
		this.type = null;
	}
	else
	{
		this.url = encElement.getAttribute("url");
		this.length = encElement.getAttribute("length");
		this.type = encElement.getAttribute("type");
	}
}

function RSS2Guid(guidElement)
{
	if (guidElement == null)
	{
		this.isPermaLink = null;
		this.value = null;
	}
	else
	{
		this.isPermaLink = guidElement.getAttribute("isPermaLink");
		this.value = guidElement.childNodes[0].nodeValue;
	}
}

function RSS2Source(souElement)
{
	if (souElement == null)
	{
		this.url = null;
		this.value = null;
	}
	else
	{
		this.url = souElement.getAttribute("url");
		this.value = souElement.childNodes[0].nodeValue;
	}
}

//object containing the RSS 2.0 item
function RSS2Item(itemxml)
{
	//required
	this.title;
	this.link;
	this.description;

	//optional vars
	this.author;
	this.comments;
	this.pubDate;

	//optional objects
	this.category;
	this.enclosure;
	this.guid;
	this.source;

	var properties = new Array("title", "link", "description", "author", "comments", "pubDate", "hide");
	var tmpElement = null;
	for (var i=0; i<properties.length; i++)
	{
		tmpElement = itemxml.getElementsByTagName(properties[i])[0];
		if (tmpElement != null) {
			if( tmpElement.childNodes[0] != null ) {
			eval("this."+properties[i]+"=tmpElement.childNodes[0].nodeValue");
			}
		}
	}
	
	this.hide = getElementsByTagName("hide","http://www.omniupdate.com/about","ou",itemxml);
	this.category = new RSS2Category(itemxml.getElementsByTagName("category")[0]);
	this.enclosure = new RSS2Enclosure(itemxml.getElementsByTagName("enclosure")[0]);
	this.guid = new RSS2Guid(itemxml.getElementsByTagName("guid")[0]);
	this.source = new RSS2Source(itemxml.getElementsByTagName("source")[0]);
}

//objects inside the RSS2Channel object
function RSS2Category(catElement)
{
	if (catElement == null)
	{
		this.domain = null;
		this.value = null;
	}
	else
	{
		this.domain = catElement.getAttribute("domain");
		this.value = catElement.childNodes[0].nodeValue;
	}
}

//object containing RSS image tag info
function RSS2Image(imgElement)
{
	if (imgElement == null)
	{
	this.url = null;
	this.link = null;
	this.width = null;
	this.height = null;
	this.description = null;
	}
	else
	{
		imgAttribs = new Array("url","title","link","width","height","description");
		for (var i=0; i<imgAttribs.length; i++)
			if (imgElement.getAttribute(imgAttribs[i]) != null)
				eval("this."+imgAttribs[i]+"=imgElement.getAttribute("+imgAttribs[i]+")");
	}
}

//object containing the parsed RSS 2.0 channel
function RSS2Channel(rssxml)
{
	//required
	this.title;
	this.link;
	this.description;

	//array of RSS2Item objects
	this.items = new Array();

	//optional vars
	this.language;
	this.copyright;
	this.managingEditor;
	this.webMaster;
	this.pubDate;
	this.lastBuildDate;
	this.generator;
	this.docs;
	this.ttl;
	this.rating;

	//optional objects
	this.category;
	this.image;

	var chanElement = rssxml.getElementsByTagName("channel")[0];
	var itemElements = rssxml.getElementsByTagName("item");

	for (var i=0; i<itemElements.length; i++)
	{
		Item = new RSS2Item(itemElements[i]);
		this.items.push(Item);
		//chanElement.removeChild(itemElements[i]);
	}

	var properties = new Array("title", "link", "description", "language", "copyright", "managingEditor", "webMaster", "pubDate", "lastBuildDate", "generator", "docs", "ttl", "rating");
	var tmpElement = null;
	for (var i=0; i<properties.length; i++)
	{
		tmpElement = chanElement.getElementsByTagName(properties[i])[0];
		if (tmpElement!= null)
			eval("this."+properties[i]+"=tmpElement.childNodes[0].nodeValue");
	}

	this.category = new RSS2Category(chanElement.getElementsByTagName("category")[0]);
	this.image = new RSS2Image(chanElement.getElementsByTagName("image")[0]);
}

//PROCESSES

//uses xmlhttpreq to get the raw rss xml
function getRSS( rssurl )
{
	//call the right constructor for the browser being used
	if (window.ActiveXObject)
		xhr = new ActiveXObject("Microsoft.XMLHTTP");
	else if (window.XMLHttpRequest)
		xhr = new XMLHttpRequest();
	else
		alert("not supported");

	//prepare the xmlhttprequest object
	xhr.open("GET",rssurl,true);
	xhr.setRequestHeader("Cache-Control", "no-cache");
	xhr.setRequestHeader("Pragma", "no-cache");
	xhr.onreadystatechange = function() {
		if (xhr.readyState == 4)
		{
			if (xhr.status == 200)
			{
				if (xhr.responseText != null)
					processRSS(xhr.responseXML);
				else
				{
					alert("Failed to receive RSS file from the server - file not found.");
					return false;
				}
			}
           	else
                alert("Error code " + xhr.status + " received: " + xhr.statusText);

		}
	}

	//send the request
	xhr.send(null);
}

//processes the received rss xml
function processRSS(rssxml)
{
	rssFeed = rssxml;
	RSS = new RSS2Channel(rssxml);
	showRSS(RSS);
}

function takeYear(theDate) {
	x = theDate.getYear();
	var y = x % 100;
	y += (y < 38) ? 2000 : 1900;
	return y;
}

function formatDate(theDate) {
	var d = new Date();
	d.setTime(Date.parse(theDate));
	return d;
}

//shows the RSS content in the browser
function showRSS(RSS)
{
	// Populate channel data
	var properties = new Array("title","link","description","pubDate","copyright");

	// Limit the number of news articles displayed
	var item_limit = 5;
	// var item_limit = RSS.items.length;
	
	// Populate the items
	for (var i=0; i < item_limit; i++)
	{
		var title = RSS.items[i].title;
		var desc = RSS.items[i].description;
		var link = RSS.items[i].link;
		var date = RSS.items[i].pubDate;
		var hide = RSS.items[i].hide;
		var fDate = formatDate(date);
		var result = '<a href="' + link + '" class="news">' + title + '</a>';
		/*if( self.dateFormat ) {
			var date = dateFormat(RSS.items[i].pubDate, "dddd, mmmm d, yyyy, h:MM:ss TT");
		} else {
			var date = RSS.items[i].pubDate;
		}*/
		item_html = '<p class="news"><img src="images/paper.gif" alt="" /><img alt="" width="5" height="0" border="0" src="images/blank.gif" />';
		item_html += result + '</p>';
		item_html += '<p class="teasers">' + desc + '</p>';
		
		// Don't show anything if hide has a value
		if(hide.length < 1) {
			document.getElementById("news_items").innerHTML += item_html;
		}
	}

	//we're done
	return true;
}

var xhr;