/**
 * jQuery (PNG Fix) v1.2
 * Microsoft Internet Explorer 24bit PNG Fix
 *
 * The MIT License
 * 
 * Copyright (c) 2007 Paul Campbell (pauljamescampbell.co.uk)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @param        Object
 * @return        Array
 */
(function($) {
    
    $.fn.pngfix = function(options) {
        
        // Review the Microsoft IE developer library for AlphaImageLoader reference 
        // http://msdn2.microsoft.com/en-us/library/ms532969(VS.85).aspx
        
        // ECMA scope fix
        var elements     = this;
        var settings     = $.extend({
            imageFixSrc:     false,
            sizingMethod:     false 
        }, options);
        
        if(!$.browser.msie || ($.browser.msie &&  $.browser.version >= 7)) {
            return(elements);
        }

        function setFilter(el, path, mode) {
            var fs = el.attr("filters");
            var alpha = "DXImageTransform.Microsoft.AlphaImageLoader";
            if (fs[alpha]) {
                fs[alpha].enabled = true;
                fs[alpha].src = path; 
                fs[alpha].sizingMethod = mode;
            } else {
                el.css("filter", 'progid:' + alpha + '(enabled="true", sizingMethod="' + mode + '", src="' + path + '")');            
            }
        }
        
        function setDOMElementWidth(el) {
            if(el.css("width") == "auto" & el.css("height") == "auto") {
                el.css("width", el.attr("offsetWidth") + "px");
            }
        }

        return(
            elements.each(function() {
                
                // Scope
                var el = $(this);
                
                if(el.attr("tagName").toUpperCase() == "IMG" && (/\.png/i).test(el.attr("src"))) {
                    if(!settings.imageFixSrc) {
                        
                        // Wrap the <img> in a <span> then apply style/filters, 
                        // removing the <img> tag from the final render 
                        el.wrap("<span></span>");
                        var par = el.parent();
                        par.css({
                            height:     el.height(),
                            width:         el.width(),
                            display:     "inline-block"
                        });
                        setFilter(par, el.attr("src"), "scale");
                        el.remove();
                    } else if((/\.gif/i).test(settings.imageFixSrc)) {
                        
                        // Replace the current image with a transparent GIF
                        // and apply the filter to the background of the 
                        // <img> tag (not the preferred route)
                        setDOMElementWidth(el);
                        setFilter(el, el.attr("src"), "image");
                        el.attr("src", settings.imageFixSrc);
                    }
                    
                } else {
                    var bg = new String(el.css("background-image"));
                    var matches = bg.match(/^url\("(.*)"\)$/);
                    if(matches && matches.length) {
                        
                        // Elements with a PNG as a backgroundImage have the
                        // filter applied with a sizing method relevant to the 
                        // background repeat type
                        setDOMElementWidth(el);
                        el.css("backgroundImage", "none");
                        
                        // Restrict scaling methods to valid MSDN defintions (or one custom)
                        var sc = "crop";
                        if(settings.sizingMethod) {
                            sc = settings.sizingMethod;
                        } 
                        setFilter(el, matches[1], sc);
                        
                        // Fix IE peek-a-boo bug for internal links
                        // within that DOM element
                        el.find("a").each(function() {
                            $(this).css("position", "relative");
                        });
                    }
                }
                
            })
        );
    }

})(jQuery)