/**
 * jQuery-Plugin "preloadCssImages"
 * by Scott Jehl, scott@filamentgroup.com
 * http://www.filamentgroup.com
 * reference article: http://www.filamentgroup.com/lab/update_automatically_preload_images_from_css_with_jquery/
 * demo page: http://www.filamentgroup.com/examples/preloadImages/index_v2.php
 * 
 * Copyright (c) 2008 Filament Group, Inc
 * Dual licensed under the MIT (filamentgroup.com/examples/mit-license.txt) and GPL (filamentgroup.com/examples/gpl-license.txt) licenses.
 *
 * Version: 5.0, 10.31.2008
 * Changelog:
 * 	02.20.2008 initial Version 1.0
 *    06.04.2008 Version 2.0 : removed need for any passed arguments. Images load from any and all directories.
 *    06.21.2008 Version 3.0 : Added options for loading status. Fixed IE abs image path bug (thanks Sam Pohlenz).
 *    07.24.2008 Version 4.0 : Added support for @imported CSS (credit: http://marcarea.com/). Fixed support in Opera as well. 
 *    10.31.2008 Version: 5.0 : Many feature and performance enhancements from trixta
 * --------------------------------------------------------------------
 */

if ('undefined' != typeof cEasyJs) {
	cEasyJs.load('jQuery', function() {
		;jQuery.preloadCssImages = function(settings){
			settings = jQuery.extend({
				statusTextEl: null,
				statusBarEl: null,
				errorDelay: 999, // handles 404-Errors in IE
				simultaneousCacheLoading: 2
			}, settings);
			var allImgs = [],
				loaded = 0,
				imgUrls = [],
				thisSheetRules,	
				errorTimer;
			
			function onImgComplete(){
				clearTimeout(errorTimer);
				if (imgUrls && imgUrls.length && imgUrls[loaded]) {
					loaded++;
					if (settings.statusTextEl) {
						var nowloading = (imgUrls[loaded]) ? 
							'Now Loading: <span>' + imgUrls[loaded].split('/')[imgUrls[loaded].split('/').length - 1] : 
							'Loading complete'; // wrong status-text bug fixed
						jQuery(settings.statusTextEl).html('<span class="numLoaded">' + loaded + '</span> of <span class="numTotal">' + imgUrls.length + '</span> loaded (<span class="percentLoaded">' + (loaded / imgUrls.length * 100).toFixed(0) + '%</span>) <span class="currentImg">' + nowloading + '</span></span>');
					}
					if (settings.statusBarEl) {
						var barWidth = jQuery(settings.statusBarEl).width();
						jQuery(settings.statusBarEl).css('background-position', -(barWidth - (barWidth * loaded / imgUrls.length).toFixed(0)) + 'px 50%');
					}
					loadImgs();
				}
			}
			
			function loadImgs(){
				//only load 1 image at the same time / most browsers can only handle 2 http requests, 1 should remain for user-interaction (Ajax, other images, normal page requests...)
				// otherwise set simultaneousCacheLoading to a higher number for simultaneous downloads
				if(imgUrls && imgUrls.length && imgUrls[loaded]){
					var img = new Image(); //new img obj
					img.src = imgUrls[loaded];	//set src either absolute or rel to css dir
					if(!img.complete){
						jQuery(img).bind('error load onreadystatechange', onImgComplete);
					} else {
						onImgComplete();
					}
					errorTimer = setTimeout(onImgComplete, settings.errorDelay); // handles 404-Errors in IE
				}
			}
			
			function parseCSS(sheets, urls) {
				var w3cImport = false,
					imported = [],
					importedSrc = [],
					baseURL;
				var sheetIndex = sheets.length;
				while(sheetIndex--){//loop through each stylesheet
					
					var cssPile = '';//create large string of all css rules in sheet
					
					if(urls && urls[sheetIndex]){
						baseURL = urls[sheetIndex];
					} else {
						var csshref = (sheets[sheetIndex].href) ? sheets[sheetIndex].href : 'window.location.href';
						var baseURLarr = csshref.split('/');//split href at / to make array
						baseURLarr.pop();//remove file path from baseURL array
						baseURL = baseURLarr.join('/');//create base url for the images in this sheet (css file's dir)
						if (baseURL) {
							baseURL += '/'; //tack on a / if needed
						}
					}
					if(sheets[sheetIndex].cssRules || sheets[sheetIndex].rules){
						thisSheetRules = (sheets[sheetIndex].cssRules) ? //->>> http://www.quirksmode.org/dom/w3c_css.html
							sheets[sheetIndex].cssRules : //w3
							sheets[sheetIndex].rules; //ie 
						var ruleIndex = thisSheetRules.length;
						while(ruleIndex--){
							if(thisSheetRules[ruleIndex].style && thisSheetRules[ruleIndex].style.cssText){
								var text = thisSheetRules[ruleIndex].style.cssText;
								if(text.toLowerCase().indexOf('url') != -1){ // only add rules to the string if you can assume, to find an image, speed improvement
									cssPile += text; // thisSheetRules[ruleIndex].style.cssText instead of thisSheetRules[ruleIndex].cssText is a huge speed improvement
								}
							} else if(thisSheetRules[ruleIndex].styleSheet) {
								imported.push(thisSheetRules[ruleIndex].styleSheet);
								w3cImport = true;
							}
							
						}
					}
					//parse cssPile for image urls
					var tmpImage = cssPile.match(/[^\("]+\.(gif|jpg|jpeg|png)/g);//reg ex to get a string of between a "(" and a ".filename" / '"' for opera-bugfix
					if(tmpImage){
						var i = tmpImage.length;
						while(i--){ // handle baseUrl here for multiple stylesheets in different folders bug
							var imgSrc = (tmpImage[i].charAt(0) == '/' || tmpImage[i].match('://')) ? // protocol-bug fixed
								tmpImage[i] : 
								baseURL + tmpImage[i];
							
							if(jQuery.inArray(imgSrc, imgUrls) == -1){
								imgUrls.push(imgSrc);
							}
						}
					}
					
					if(!w3cImport && sheets[sheetIndex].imports && sheets[sheetIndex].imports.length) {
						for(var iImport = 0, importLen = sheets[sheetIndex].imports.length; iImport < importLen; iImport++){
							var iHref = sheets[sheetIndex].imports[iImport].href;
							iHref = iHref.split('/');
							iHref.pop();
							iHref = iHref.join('/');
							if (iHref) {
								iHref += '/'; //tack on a / if needed
							}
							var iSrc = (iHref.charAt(0) == '/' || iHref.match('://')) ? // protocol-bug fixed
								iHref : 
								baseURL + iHref;
							
							importedSrc.push(iSrc);
							imported.push(sheets[sheetIndex].imports[iImport]);
						}
						
						
					}
				}//loop
				if(imported.length){
					parseCSS(imported, importedSrc);
					return false;
				}
				var downloads = settings.simultaneousCacheLoading;
				while( downloads--){
					setTimeout(loadImgs, downloads);
				}
			}
			parseCSS(document.styleSheets);
			return imgUrls;
		};
	});
}