/*
selectivizr v1.0.2 - (c) Keith Clark, freely distributable under the terms 
of the MIT license.

selectivizr.com
*/
/* 
  
Notes about this source
-----------------------

 * The #DEBUG_START and #DEBUG_END comments are used to mark blocks of code
   that will be removed prior to building a final release version (using a
   pre-compression script)
  
  
References:
-----------
 
 * CSS Syntax          : http://www.w3.org/TR/2003/WD-css3-syntax-20030813/#style
 * Selectors           : http://www.w3.org/TR/css3-selectors/#selectors
 * IE Compatability    : http://msdn.microsoft.com/en-us/library/cc351024(VS.85).aspx
 * W3C Selector Tests  : http://www.w3.org/Style/CSS/Test/CSS3/Selectors/current/html/tests/
 
*/

(function(win) {

    // If browser isn't IE, then stop execution! This handles the script 
    // being loaded by non IE browsers because the developer didn't use 
    // conditional comments.
    if (/*@cc_on!@*/true) return;

    // =========================== Init Objects ============================

    var doc = document;
    var root = doc.documentElement;
    var xhr = getXHRObject();
    var ieVersion = /MSIE (\d+)/.exec(navigator.userAgent)[1];
    
    // If were not in standards mode, IE is too old / new or we can't create
    // an XMLHttpRequest object then we should get out now.
    if (doc.compatMode != 'CSS1Compat' || ieVersion<6 || ieVersion>8 || !xhr) {
        return;
    }
    
    
    // ========================= Common Objects ============================

    // Compatiable selector engines in order of CSS3 support. Note: '*' is
    // a placholder for the object key name. (basically, crude compression)
    var selectorEngines = {
        "NW"                                : "*.Dom.select",
        "MooTools"                          : "$$",
        "DOMAssistant"                      : "*.$", 
        "Prototype"                         : "$$",
        "YAHOO"                             : "*.util.Selector.query",
        "Sizzle"                            : "*", 
        "jQuery"                            : "*",
        "dojo"                              : "*.query"
    };

    var selectorMethod;
    var enabledWatchers                     = [];     // array of :enabled/:disabled elements to poll
    var ie6PatchID                          = 0;      // used to solve ie6's multiple class bug
    var patchIE6MultipleClasses             = true;   // if true adds class bloat to ie6
    var namespace                           = "slvzr";
    
    // Stylesheet parsing regexp's
    var RE_COMMENT                          = /(\/\*[^*]*\*+([^\/][^*]*\*+)*\/)\s*/g;
    var RE_IMPORT                           = /@import\s*(?:(?:(?:url\(\s*(['"]?)(.*)\1)\s*\))|(?:(['"])(.*)\3))[^;]*;/g;
    var RE_ASSET_URL                        = /\burl\(\s*(["']?)(?!data:)([^"')]+)\1\s*\)/g;
    var RE_PSEUDO_STRUCTURAL                = /^:(empty|(first|last|only|nth(-last)?)-(child|of-type))$/;
    var RE_PSEUDO_ELEMENTS                  = /:(:first-(?:line|letter))/g;
    var RE_SELECTOR_GROUP                   = /(^|})\s*([^\{]*?[\[:][^{]+)/g;
    var RE_SELECTOR_PARSE                   = /([ +~>])|(:[a-z-]+(?:\(.*?\)+)?)|(\[.*?\])/g; 
    var RE_LIBRARY_INCOMPATIBLE_PSEUDOS     = /(:not\()?:(hover|enabled|disabled|focus|checked|target|active|visited|first-line|first-letter)\)?/g;
    var RE_PATCH_CLASS_NAME_REPLACE         = /[^\w-]/g;
    
    // HTML UI element regexp's
    var RE_INPUT_ELEMENTS                   = /^(INPUT|SELECT|TEXTAREA|BUTTON)$/;
    var RE_INPUT_CHECKABLE_TYPES            = /^(checkbox|radio)$/;

    // Broken attribute selector implementations (IE7/8 native [^=""], [$=""] and [*=""])
    var BROKEN_ATTR_IMPLEMENTATIONS         = ieVersion>6 ? /[\$\^*]=(['"])\1/ : null;

    // Whitespace normalization regexp's
    var RE_TIDY_TRAILING_WHITESPACE         = /([(\[+~])\s+/g;
    var RE_TIDY_LEADING_WHITESPACE          = /\s+([)\]+~])/g;
    var RE_TIDY_CONSECUTIVE_WHITESPACE      = /\s+/g;
    var RE_TIDY_TRIM_WHITESPACE             = /^\s*((?:[\S\s]*\S)?)\s*$/;
    
    // String constants
    var EMPTY_STRING                        = "";
    var SPACE_STRING                        = " ";
    var PLACEHOLDER_STRING                  = "$1";

    // =========================== Patching ================================

    // --[ patchStyleSheet() ]----------------------------------------------
    // Scans the passed cssText for selectors that require emulation and
    // creates one or more patches for each matched selector.
    function patchStyleSheet( cssText ) {
        return cssText.replace(RE_PSEUDO_ELEMENTS, PLACEHOLDER_STRING).
            replace(RE_SELECTOR_GROUP, function(m, prefix, selectorText) {  
                var selectorGroups = selectorText.split(",");
                for (var c = 0, cs = selectorGroups.length; c < cs; c++) {
                    var selector = normalizeSelectorWhitespace(selectorGroups[c]) + SPACE_STRING;
                    var patches = [];
                    selectorGroups[c] = selector.replace(RE_SELECTOR_PARSE, 
                        function(match, combinator, pseudo, attribute, index) {
                            if (combinator) {
                                if (patches.length>0) {
                                    applyPatches( selector.substring(0, index), patches );
                                    patches = [];
                                }
                                return combinator;
                            }       
                            else {
                                var patch = (pseudo) ? patchPseudoClass( pseudo ) : patchAttribute( attribute );
                                if (patch) {
                                    patches.push(patch);
                                    return "." + patch.className;
                                }
                                return match;
                            }
                        }
                    );
                }
                return prefix + selectorGroups.join(",");
            });
    };

    // --[ patchAttribute() ]-----------------------------------------------
    // returns a patch for an attribute selector.
    function patchAttribute( attr ) {
        return (!BROKEN_ATTR_IMPLEMENTATIONS || BROKEN_ATTR_IMPLEMENTATIONS.test(attr)) ? 
            { className: createClassName(attr), applyClass: true } : null;
    };

    // --[ patchPseudoClass() ]---------------------------------------------
    // returns a patch for a pseudo-class
    function patchPseudoClass( pseudo ) {

        var applyClass = true;
        var className = createClassName(pseudo.slice(1));
        var isNegated = pseudo.substring(0, 5) == ":not(";
        var activateEventName;
        var deactivateEventName;

        // if negated, remove :not() 
        if (isNegated) {
            pseudo = pseudo.slice(5, -1);
        }
        
        // bracket contents are irrelevant - remove them
        var bracketIndex = pseudo.indexOf("(")
        if (bracketIndex > -1) {
            pseudo = pseudo.substring(0, bracketIndex);
        }       
        
        // check we're still dealing with a pseudo-class
        if (pseudo.charAt(0) == ":") {
            switch (pseudo.slice(1)) {

                case "root":
                    applyClass = function(e) {
                        return isNegated ? e != root : e == root;
                    }
                    break;

                case "target":
                    // :target is only supported in IE8
                    if (ieVersion == 8) {
                        applyClass = function(e) {
                            var handler = function() { 
                                var hash = location.hash;
                                var hashID = hash.slice(1);
                                return isNegated ? (hash == EMPTY_STRING || e.id != hashID) : (hash != EMPTY_STRING && e.id == hashID);
                            };
                            addEvent( win, "hashchange", function() {
                                toggleElementClass(e, className, handler());
                            })
                            return handler();
                        }
                        break;
                    }
                    return false;
                
                case "checked":
                    applyClass = function(e) { 
                        if (RE_INPUT_CHECKABLE_TYPES.test(e.type)) {
                            addEvent( e, "propertychange", function() {
                                if (event.propertyName == "checked") {
                                    toggleElementClass( e, className, e.checked !== isNegated );
                                }                           
                            })
                        }
                        return e.checked !== isNegated;
                    }
                    break;
                    
                case "disabled":
                    isNegated = !isNegated;

                case "enabled":
                    applyClass = function(e) { 
                        if (RE_INPUT_ELEMENTS.test(e.tagName)) {
                            addEvent( e, "propertychange", function() {
                                if (event.propertyName == "$disabled") {
                                    toggleElementClass( e, className, e.$disabled === isNegated );
                                } 
                            });
                            enabledWatchers.push(e);
                            e.$disabled = e.disabled;
                            return e.disabled === isNegated;
                        }
                        return pseudo == ":enabled" ? isNegated : !isNegated;
                    }
                    break;
                    
                case "focus":
                    activateEventName = "focus";
                    deactivateEventName = "blur";
                                
                case "hover":
                    if (!activateEventName) {
                        activateEventName = "mouseenter";
                        deactivateEventName = "mouseleave";
                    }
                    applyClass = function(e) {
                        addEvent( e, isNegated ? deactivateEventName : activateEventName, function() {
                            toggleElementClass( e, className, true );
                        })
                        addEvent( e, isNegated ? activateEventName : deactivateEventName, function() {
                            toggleElementClass( e, className, false );
                        })
                        return isNegated;
                    }
                    break;
                    
                // everything else
                default:
                    // If we don't support this pseudo-class don't create 
                    // a patch for it
                    if (!RE_PSEUDO_STRUCTURAL.test(pseudo)) {
                        return false;
                    }
                    break;
            }
        }
        return { className: className, applyClass: applyClass };
    };

    // --[ applyPatches() ]-------------------------------------------------
    // uses the passed selector text to find DOM nodes and patch them   
    function applyPatches(selectorText, patches) {
        var elms;
        
        // Although some selector libraries can find :checked :enabled etc. 
        // we need to find all elements that could have that state because 
        // it can be changed by the user.
        var domSelectorText = selectorText.replace(RE_LIBRARY_INCOMPATIBLE_PSEUDOS, EMPTY_STRING);
        
        // If the dom selector equates to an empty string or ends with 
        // whitespace then we need to append a universal selector (*) to it.
        if (domSelectorText == EMPTY_STRING || domSelectorText.charAt(domSelectorText.length - 1) == SPACE_STRING) {
            domSelectorText += "*";
        }
        
        // Ensure we catch errors from the selector library
        try {
            elms = selectorMethod( domSelectorText );
        } catch (ex) {
            // #DEBUG_START
            log( "Selector '" + selectorText + "' threw exception '" + ex + "'" );
            // #DEBUG_END
        }


        if (elms) {
            for (var d = 0, dl = elms.length; d < dl; d++) {    
                var elm = elms[d];
                var cssClasses = elm.className;
                for (var f = 0, fl = patches.length; f < fl; f++) {
                    var patch = patches[f];
                    
                    if (!hasPatch(elm, patch)) {
                        if (patch.applyClass && (patch.applyClass === true || patch.applyClass(elm) === true)) {
                            cssClasses = toggleClass(cssClasses, patch.className, true );
                        }
                    }
                }
                elm.className = cssClasses;
            }
        }
    };

    // --[ hasPatch() ]-----------------------------------------------------
    // checks for the exsistence of a patch on an element
    function hasPatch( elm, patch ) {
        return new RegExp("(^|\\s)" + patch.className + "(\\s|$)").test(elm.className);
    };
    
    
    // =========================== Utility =================================
    
    function createClassName( className ) {
        return namespace + "-" + ((ieVersion == 6 && patchIE6MultipleClasses) ?
            ie6PatchID++
        :
            className.replace(RE_PATCH_CLASS_NAME_REPLACE, function(a) { return a.charCodeAt(0) }));
    };

    // --[ log() ]----------------------------------------------------------
    // #DEBUG_START
    function log( message ) {
        if (win.console) {
            win.console.log(message);
        }
    };
    // #DEBUG_END

    // --[ trim() ]---------------------------------------------------------
    // removes leading, trailing whitespace from a string
    function trim( text ) {
        return text.replace(RE_TIDY_TRIM_WHITESPACE, PLACEHOLDER_STRING);
    };

    // --[ normalizeWhitespace() ]------------------------------------------
    // removes leading, trailing and consecutive whitespace from a string
    function normalizeWhitespace( text ) {
        return trim(text).replace(RE_TIDY_CONSECUTIVE_WHITESPACE, SPACE_STRING);
    };

    // --[ normalizeSelectorWhitespace() ]----------------------------------
    // tidies whitespace around selector brackets and combinators
    function normalizeSelectorWhitespace( selectorText ) {
        return normalizeWhitespace(selectorText.
            replace(RE_TIDY_TRAILING_WHITESPACE, PLACEHOLDER_STRING).
            replace(RE_TIDY_LEADING_WHITESPACE, PLACEHOLDER_STRING)
        );
    };

    // --[ toggleElementClass() ]-------------------------------------------
    // toggles a single className on an element
    function toggleElementClass( elm, className, on ) {
        var oldClassName = elm.className;
        var newClassName = toggleClass(oldClassName, className, on);
        if (newClassName != oldClassName) {
            elm.className = newClassName;
            elm.parentNode.className += EMPTY_STRING;
        }
    };

    // --[ toggleClass() ]--------------------------------------------------
    // adds / removes a className from a string of classNames. Used to 
    // manage multiple class changes without forcing a DOM redraw
    function toggleClass( classList, className, on ) {
        var re = RegExp("(^|\\s)" + className + "(\\s|$)");
        var classExists = re.test(classList);
        if (on) {
            return classExists ? classList : classList + SPACE_STRING + className;
        } else {
            return classExists ? trim(classList.replace(re, PLACEHOLDER_STRING)) : classList;
        }
    };
    
    // --[ addEvent() ]-----------------------------------------------------
    function addEvent(elm, eventName, eventHandler) {
        elm.attachEvent("on" + eventName, eventHandler);
    };

    // --[ getXHRObject() ]-------------------------------------------------
    function getXHRObject()
    {
        if (win.XMLHttpRequest) {
            return new XMLHttpRequest;
        }
        try { 
            return new ActiveXObject('Microsoft.XMLHTTP');
        } catch(e) { 
            return null;
        }
    };

    // --[ loadStyleSheet() ]-----------------------------------------------
    function loadStyleSheet( url ) {
        xhr.open("GET", url, false);
        xhr.send();
        return (xhr.status==200) ? xhr.responseText : EMPTY_STRING; 
    };
    
    // --[ resolveUrl() ]---------------------------------------------------
    // Converts a URL fragment to a fully qualified URL using the specified
    // context URL. Returns null if same-origin policy is broken
    function resolveUrl( url, contextUrl ) {
    
        function getProtocolAndHost( url ) {
            return url.substring(0, url.indexOf("/", 8));
        };
        
        // absolute path
        if (/^https?:\/\//i.test(url)) {
            return getProtocolAndHost(contextUrl) == getProtocolAndHost(url) ? url : null;
        }
        
        // root-relative path
        if (url.charAt(0)=="/") {
            return getProtocolAndHost(contextUrl) + url;
        }

        // relative path
        var contextUrlPath = contextUrl.split(/[?#]/)[0]; // ignore query string in the contextUrl  
        if (url.charAt(0) != "?" && contextUrlPath.charAt(contextUrlPath.length - 1) != "/") {
            contextUrlPath = contextUrlPath.substring(0, contextUrlPath.lastIndexOf("/") + 1);
        }
        
        return contextUrlPath + url;
    };
    
    // --[ parseStyleSheet() ]----------------------------------------------
    // Downloads the stylesheet specified by the URL, removes it's comments
    // and recursivly replaces @import rules with their contents, ultimately
    // returning the full cssText.
    function parseStyleSheet( url ) {
        if (url) {
            return loadStyleSheet(url).replace(RE_COMMENT, EMPTY_STRING).
            replace(RE_IMPORT, function( match, quoteChar, importUrl, quoteChar2, importUrl2 ) { 
                return parseStyleSheet(resolveUrl(importUrl || importUrl2, url));
            }).
            replace(RE_ASSET_URL, function( match, quoteChar, assetUrl ) { 
                quoteChar = quoteChar || EMPTY_STRING;
                return " url(" + quoteChar + resolveUrl(assetUrl, url) + quoteChar + ") "; 
            });
        }
        return EMPTY_STRING;
    };
    
    // --[ init() ]---------------------------------------------------------
    function init() {
        // honour the <base> tag
        var url, stylesheet;
        var baseTags = doc.getElementsByTagName("BASE");
        var baseUrl = (baseTags.length > 0) ? baseTags[0].href : doc.location.href;
        
        /* Note: This code prevents IE from freezing / crashing when using 
        @font-face .eot files but it modifies the <head> tag and could
        trigger the IE stylesheet limit. It will also cause FOUC issues.
        If you choose to use it, make sure you comment out the for loop 
        directly below this comment.

        var head = doc.getElementsByTagName("head")[0];
        for (var c=doc.styleSheets.length-1; c>=0; c--) {
            stylesheet = doc.styleSheets[c]
            head.appendChild(doc.createElement("style"))
            var patchedStylesheet = doc.styleSheets[doc.styleSheets.length-1];
            
            if (stylesheet.href != EMPTY_STRING) {
                url = resolveUrl(stylesheet.href, baseUrl)
                if (url) {
                    patchedStylesheet.cssText = patchStyleSheet( parseStyleSheet( url ) )
                    stylesheet.disabled = true
                    setTimeout( function () {
                        stylesheet.owningElement.parentNode.removeChild(stylesheet.owningElement)
                    })
                }
            }
        }
        */
        
        for (var c = 0; c < doc.styleSheets.length; c++) {
            stylesheet = doc.styleSheets[c]
            if (stylesheet.href != EMPTY_STRING) {
                url = resolveUrl(stylesheet.href, baseUrl);
                if (url) {
                    stylesheet.cssText = patchStyleSheet( parseStyleSheet( url ) );
                }
            }
        }
        
        // :enabled & :disabled polling script (since we can't hook 
        // onpropertychange event when an element is disabled) 
        if (enabledWatchers.length > 0) {
            setInterval( function() {
                for (var c = 0, cl = enabledWatchers.length; c < cl; c++) {
                    var e = enabledWatchers[c];
                    if (e.disabled !== e.$disabled) {
                        if (e.disabled) {
                            e.disabled = false;
                            e.$disabled = true;
                            e.disabled = true;
                        }
                        else {
                            e.$disabled = e.disabled;
                        }
                    }
                }
            },250)
        }
    };
    
    // Bind selectivizr to the ContentLoaded event. 
    ContentLoaded(win, function() {
        // Determine the "best fit" selector engine
        for (var engine in selectorEngines) {
            var members, member, context = win;
            if (win[engine]) {
                members = selectorEngines[engine].replace("*", engine).split(".");
                while ((member = members.shift()) && (context = context[member])) {}
                if (typeof context == "function") {
                    selectorMethod = context;
                    init();
                    return;
                }
            }
        }
    });
    
    
    /*!
     * ContentLoaded.js by Diego Perini, modified for IE<9 only (to save space)
     *
     * Author: Diego Perini (diego.perini at gmail.com)
     * Summary: cross-browser wrapper for DOMContentLoaded
     * Updated: 20101020
     * License: MIT
     * Version: 1.2
     *
     * URL:
     * http://javascript.nwbox.com/ContentLoaded/
     * http://javascript.nwbox.com/ContentLoaded/MIT-LICENSE
     *
     */

    // @w window reference
    // @f function reference
    function ContentLoaded(win, fn) {

        var done = false, top = true,
        init = function(e) {
            if (e.type == "readystatechange" && doc.readyState != "complete") return;
            (e.type == "load" ? win : doc).detachEvent("on" + e.type, init, false);
            if (!done && (done = true)) fn.call(win, e.type || e);
        },
        poll = function() {
            try { root.doScroll("left"); } catch(e) { setTimeout(poll, 50); return; }
            init('poll');
        };

        if (doc.readyState == "complete") fn.call(win, EMPTY_STRING);
        else {
            if (doc.createEventObject && root.doScroll) {
                try { top = !win.frameElement; } catch(e) { }
                if (top) poll();
            }
            addEvent(doc,"readystatechange", init);
            addEvent(win,"load", init);
        }
    };
})(this);
