/**
  * Easy to use RSS feed viewer. 
  * NewsWidget can even combine multiple RSS feeds and show the latest news items of these feeds.
  * 
  * @author Sitebase (Wim Mostmans)
  */
(function($){
	$.fn.newswidget = function(options) {

		/**
		 * The dollar sign could be overwritten globally,
		 * but jQuery should always stay accesible
		 */
		var $ = jQuery;
	
		var defaults = {
		  	source: ['http://feeds.feedburner.com/computerfaq/rss', 'http://feeds.feedburner.com/FlexExamples', 'http://community.invisionpower.com/rss/downloads/'],
			itemWrapElement: 'li',
			itemTitleElement: 'h4',
			linkTitle: false,
			itemDescriptionElement: 'div',
			itemDateElement: 'div',
			itemLinkElement: 'span',
			itemWebsiteTitleElement: 'div',
			itemWebsiteLinkElement: 'div',
			itemLinkText: 'read more...',
			newPageLink: true,
			proxyUrl: 'proxy.php',
			limitDescription: 100,
			limitDescriptionSuffix: "...",
			limitItems: 10,
			stripHtml: true,
			prettyDate: true,
			format: "title,description,date,link",
			animationSpeed: 500,
			random: true,
			refresh: 0,
			showFilter: function(){}
		  },
		settings = $.extend({}, defaults, options);
		
		// Variables
		var newsHolder 		= this;
		var items			= new Array();
		var busyRequests 	= 0;
		var timer;
			
		// Start script
		init();
			
		/**
		 * Init
		 */
		function init(){
		
			// Kill timer
			if(settings.refresh > 0){
				clearTimeout(timer);
			}
		
			if(isArray(settings.source)){
				busyRequests = settings.source.length;
				for( source in settings.source){
					load( settings.source[source] );
				}
			}else{
				busyRequests = 1;
				load( settings.source );
			}
		}
		
		function cleanText( text ){
			
			var cleanText = text;
		
			// Remove rubisch xml
			var index = cleanText.indexOf('<?xml');
			if(index > -1){
				cleanText = cleanText.substring(0, index);
			}
			var index = cleanText.indexOf('<div class="feedflare">');
			if(index > -1){
				cleanText = cleanText.substring(0, index);
			}
			var index = cleanText.indexOf('<p>');
			if(index > -1){
				cleanText = cleanText.substring(0, index);
			}
			return cleanText;
		}
		
		/**
		 * Parse RSS XML content to an object array
		 */
		function parse(xml) {

				// Get rss title and website
				var channel = $('channel', xml).eq(0);
				var websiteTitle = $(channel).find('title:first').text();
				var websiteLink = $(channel).find('link:first').text();
			
				busyRequests--;
				$('item', xml).each( function() {
					var item 				= new Object();
					item.websiteTitle		= websiteTitle;
					item.websiteLink		= websiteLink;
					item.title				= $(this).find('title').eq(0).text();
					item.description		= cleanText($(this).find('description').eq(0).text());
					if(item.description == ""){
						item.description 	= cleanText($(this).find('content\\:encoded').eq(0).text());
					}
					if(settings.limitDescription > 0){
						
						item.description		= limitText(item.description, settings.limitDescription, settings.limitDescriptionSuffix);
					}
					if(settings.stripHtml){
						item.description = stripHtml( item.description );
					}
					item.date				= new Date($(this).find('pubDate').eq(0).text());
					item.linkUrl			= $(this).find('link').eq(0).text();
					item.linkText			= settings.itemLinkText == "" ? item.linkUrl : settings.itemLinkText;
					item.linkTarget			= settings.newPageLink ? ' target="_blank"' : '';
					
					// Call external filter
					settings.showFilter.call(item);
					
					items.push(item);
				});
				if(busyRequests == 0){
					if(settings.random){
						items.sort(sortByRandom);
					}else{
						items.sort(sortByDate);
					}
					
					// Show
					show(items);
					
					// Start timer (again)
					if(settings.refresh > 0){
						timer = setTimeout(init, settings.refresh);
					}
				}
		}
		
		// Show items in news holder
		function show( items ){
			
			// Variable
			var itemsDisplayed = 0;
			
			// Empty news holder
			newsHolder.html("");
			
			for(index in items){
				
				if(settings.limitItems > 0 && itemsDisplayed >= settings.limitItems) break;
			
				// Make item var
				var item = items[index];
			
				// Main item wrapper element
				var wrapElement				= document.createElement(settings.itemWrapElement);
				wrapElement.style.display	= 'none';
				wrapElement.id				= 'newsBlock' + index;
					
				// Create title element
				var titleElement			= document.createElement(settings.itemTitleElement);
				if(settings.linkTitle){
					titleElement.innerHTML	= '<a href="' + item.linkUrl + '"' + item.linkTarget + '>' + item.title + '</a>';
				}else{
					titleElement.innerHTML		= item.title;
				}
				titleElement.className		= "title";
					
				// Create description element
				var descElement				= document.createElement(settings.itemDescriptionElement);
				descElement.innerHTML		= item.description;
				descElement.className		= "description";
					
				// Create date element
				var dateElement				= document.createElement(settings.itemDateElement);
				if(settings.prettyDate){
					dateElement.innerHTML	= prettyDate( item.date );
				}else{
					dateElement.innerHTML	= item.date;
				}
				dateElement.className		= "date";
				
				// Create website title element
				var websiteTitleElement		= document.createElement(settings.itemWebsiteTitleElement);
				websiteTitleElement.innerHTML		= item.websiteTitle;
				websiteTitleElement.className		= "websiteTitle"
				
				// Create website link element
				var websiteLinkElement		= document.createElement(settings.itemWebsiteLinkElement);
				websiteLink 				= item.websiteLink.replace("http://", "")
				if(websiteLink.indexOf("/") > -1){
					websiteLink = websiteLink.substring(0, websiteLink.indexOf("/"));
				}
				websiteLinkElement.innerHTML	= '<a href="' + item.websiteLink + '" target="_blank" class="websiteLink">' + websiteLink + '</a>';
				websiteLinkElement.className	= "websiteLink";	
				
				// Create link element
				var linkElement				= document.createElement(settings.itemLinkElement);
				linkElement.innerHTML		= '<a href="' + item.linkUrl + '"' + item.linkTarget + '>' + item.linkText + '</a>';
				linkElement.className		= "link";	
				
				// Concat blocks
				var parts = settings.format.split(",");
				for(part in parts){
					switch(trim(parts[part])){
						case "title":
							wrapElement.appendChild( titleElement );
							break;
						case "description":
							if(descElement.innerHTML != ""){
								wrapElement.appendChild( descElement );
							}
							break;
						case "date":
							if(dateElement.innerHTML != "undefined"){
								wrapElement.appendChild( dateElement );
							}
							break;
						case "link":
							wrapElement.appendChild( linkElement );
							break;
						case "websiteTitle":
							wrapElement.appendChild( websiteTitleElement );
							break;
						case "websiteLink":
							wrapElement.appendChild( websiteLinkElement );
							break;
					}
				}

				// Add parent to main wrapper
				newsHolder.append( wrapElement );
				
				// Find block and fade in
				newsHolder.find("#newsBlock" + index).fadeIn(settings.animationSpeed);
				
				// Increment items displayed
				itemsDisplayed++;
				
			}
		}
		
		/**
		 * Convert dates to pretty format
		 */
		function prettyDate(date){
			var diff = (((new Date()).getTime() - date.getTime()) / 1000);
			var day_diff = Math.floor(diff / 86400);
					
			if ( isNaN(day_diff) || day_diff < 0 || day_diff >= 31 )
				return;
					
			return day_diff == 0 && (
					diff < 60 && "just now" ||
					diff < 120 && "1 minute ago" ||
					diff < 3600 && Math.floor( diff / 60 ) + " minutes ago" ||
					diff < 7200 && "1 hour ago" ||
					diff < 86400 && Math.floor( diff / 3600 ) + " hours ago") ||
				day_diff == 1 && "Yesterday" ||
				day_diff < 7 && day_diff + " days ago" ||
				day_diff < 31 && Math.ceil( day_diff / 7 ) + " weeks ago";
		}

		
		/**
		 * Check if an object is of type array
		 */
		function isArray(object) {
		   if (object.constructor.toString().indexOf("Array") == -1)
			  return false;
		   else
			  return true;
		}
		
		/**
		 * Load RSS
		 */
		function load( source ){
			$.ajax({
				type: 'GET',
				url: settings.proxyUrl + '?url=' + source,
				dataType: 'xml',
				success: parse
			});
		}

		/**
		 * Sort RSS items by date
		 */
		function sortByDate(a, b) {
			var x = a.date;
			var y = b.date;
			return ((x > y) ? -1 : ((x < y) ? 1 : 0));
		}
		
		/**
		 * Sort RSS items random
		 */
		function sortByRandom(){
			return (Math.round(Math.random())-0.5); 
		} 
		
		/**
		 * Limit text
		 */
		function limitText( text, limit, suffix ){
			if(text.length > limit){
				text = text.substr(0, limit) + suffix;
			}
			return text;
		}
		
		/**
		 * Strip HTML
		 */
		function stripHtml( text ){
			var matchTag = /<(?:.|\s)*?>/g;
			return text.replace(matchTag, "");
		}
		 
		 /**
		  * Trim spaces from a string
		  */
		function trim( text ) {
			 return text.replace(/^\s+|\s+$/g,"");
		}

		
		// returns the jQuery object to allow for chainability.
		return this;
	}
})(jQuery);