/*
Copyright (c) 2010, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://developer.yahoo.com/yui/license.html
version: 3.2.0
build: nightly
*/
YUI.add('selector-css2', function(Y) {

/**
 * The selector module provides helper methods allowing CSS2 Selectors to be used with DOM elements.
 * @module dom
 * @submodule selector-css2
 * @for Selector
 */

/**
 * Provides helper methods for collecting and filtering DOM elements.
 */

var PARENT_NODE = 'parentNode',
    TAG_NAME = 'tagName',
    ATTRIBUTES = 'attributes',
    COMBINATOR = 'combinator',
    PSEUDOS = 'pseudos',

    Selector = Y.Selector,

    SelectorCSS2 = {
        _reRegExpTokens: /([\^\$\?\[\]\*\+\-\.\(\)\|\\])/, // TODO: move?
        SORT_RESULTS: true,
        _children: function(node, tag) {
            var ret = node.children,
                i,
                children = [],
                childNodes,
                child;

            if (node.children && tag && node.children.tags) {
                children = node.children.tags(tag);
            } else if ((!ret && node[TAG_NAME]) || (ret && tag)) { // only HTMLElements have children
                childNodes = ret || node.childNodes;
                ret = [];
                for (i = 0; (child = childNodes[i++]);) {
                    if (child.tagName) {
                        if (!tag || tag === child.tagName) {
                            ret.push(child);
                        }
                    }
                }
            }

            return ret || [];
        },

        _re: {
            //attr: /(\[.*\])/g,
            attr: /(\[[^\]]*\])/g,
            pseudos: /:([\-\w]+(?:\(?:['"]?(.+)['"]?\)))*/i
        },

        /**
         * Mapping of shorthand tokens to corresponding attribute selector 
         * @property shorthand
         * @type object
         */
        shorthand: {
            '\\#(-?[_a-z]+[-\\w]*)': '[id=$1]',
            '\\.(-?[_a-z]+[-\\w]*)': '[className~=$1]'
        },

        /**
         * List of operators and corresponding boolean functions. 
         * These functions are passed the attribute and the current node's value of the attribute.
         * @property operators
         * @type object
         */
        operators: {
            '': function(node, attr) { return Y.DOM.getAttribute(node, attr) !== ''; }, // Just test for existence of attribute
            //'': '.+',
            //'=': '^{val}$', // equality
            '~=': '(?:^|\\s+){val}(?:\\s+|$)', // space-delimited
            '|=': '^{val}-?' // optional hyphen-delimited
        },

        pseudos: {
           'first-child': function(node) { 
                return Y.Selector._children(node[PARENT_NODE])[0] === node; 
            } 
        },

        _bruteQuery: function(selector, root, firstOnly) {
            var ret = [],
                nodes = [],
                tokens = Selector._tokenize(selector),
                token = tokens[tokens.length - 1],
                rootDoc = Y.DOM._getDoc(root),
                child,
                id,
                className,
                tagName;


            // if we have an initial ID, set to root when in document
            /*
            if (tokens[0] && rootDoc === root &&  
                    (id = tokens[0].id) &&
                    rootDoc.getElementById(id)) {
                root = rootDoc.getElementById(id);
            }
            */

            if (token) {
                // prefilter nodes
                id = token.id;
                className = token.className;
                tagName = token.tagName || '*';

                if (root.getElementsByTagName) { // non-IE lacks DOM api on doc frags
                    // try ID first, unless no root.all && root not in document
                    // (root.all works off document, but not getElementById)
                    // TODO: move to allById?
                    if (id && (root.all || (root.nodeType === 9 || Y.DOM.inDoc(root)))) {
                        nodes = Y.DOM.allById(id, root);
                    // try className
                    } else if (className) {
                        nodes = root.getElementsByClassName(className);
                    } else { // default to tagName
                        nodes = root.getElementsByTagName(tagName);
                    }

                } else { // brute getElementsByTagName('*')
                    child = root.firstChild;
                    while (child) {
                        if (child.tagName) { // only collect HTMLElements
                            nodes.push(child);
                        }
                        child = child.nextSilbing || child.firstChild;
                    }
                }
                if (nodes.length) {
                    ret = Selector._filterNodes(nodes, tokens, firstOnly);
                }
            }

            return ret;
        },
        
        _filterNodes: function(nodes, tokens, firstOnly) {
            var i = 0,
                j,
                len = tokens.length,
                n = len - 1,
                result = [],
                node = nodes[0],
                tmpNode = node,
                getters = Y.Selector.getters,
                operator,
                combinator,
                token,
                path,
                pass,
                //FUNCTION = 'function',
                value,
                tests,
                test;

            //do {
            for (i = 0; (tmpNode = node = nodes[i++]);) {
                n = len - 1;
                path = null;
                
                testLoop:
                while (tmpNode && tmpNode.tagName) {
                    token = tokens[n];
                    tests = token.tests;
                    j = tests.length;
                    if (j && !pass) {
                        while ((test = tests[--j])) {
                            operator = test[1];
                            if (getters[test[0]]) {
                                value = getters[test[0]](tmpNode, test[0]);
                            } else {
                                value = tmpNode[test[0]];
                                // use getAttribute for non-standard attributes
                                if (value === undefined && tmpNode.getAttribute) {
                                    value = tmpNode.getAttribute(test[0]);
                                }
                            }

                            if ((operator === '=' && value !== test[2]) ||  // fast path for equality
                                (typeof operator !== 'string' && // protect against String.test monkey-patch (Moo)
                                operator.test && !operator.test(value)) ||  // regex test
                                (!operator.test && // protect against RegExp as function (webkit)
                                        typeof operator === 'function' && !operator(tmpNode, test[0]))) { // function test

                                // skip non element nodes or non-matching tags
                                if ((tmpNode = tmpNode[path])) {
                                    while (tmpNode &&
                                        (!tmpNode.tagName ||
                                            (token.tagName && token.tagName !== tmpNode.tagName))
                                    ) {
                                        tmpNode = tmpNode[path]; 
                                    }
                                }
                                continue testLoop;
                            }
                        }
                    }

                    n--; // move to next token
                    // now that we've passed the test, move up the tree by combinator
                    if (!pass && (combinator = token.combinator)) {
                        path = combinator.axis;
                        tmpNode = tmpNode[path];

                        // skip non element nodes
                        while (tmpNode && !tmpNode.tagName) {
                            tmpNode = tmpNode[path]; 
                        }

                        if (combinator.direct) { // one pass only
                            path = null; 
                        }

                    } else { // success if we made it this far
                        result.push(node);
                        if (firstOnly) {
                            return result;
                        }
                        break;
                    }
                }
            }// while (tmpNode = node = nodes[++i]);
            node = tmpNode = null;
            return result;
        },

        combinators: {
            ' ': {
                axis: 'parentNode'
            },

            '>': {
                axis: 'parentNode',
                direct: true
            },


            '+': {
                axis: 'previousSibling',
                direct: true
            }
        },

        _parsers: [
            {
                name: ATTRIBUTES,
                re: /^\[(-?[a-z]+[\w\-]*)+([~\|\^\$\*!=]=?)?['"]?([^\]]*?)['"]?\]/i,
                fn: function(match, token) {
                    var operator = match[2] || '',
                        operators = Y.Selector.operators,
                        test;

                    // add prefiltering for ID and CLASS
                    if ((match[1] === 'id' && operator === '=') ||
                            (match[1] === 'className' &&
                            Y.config.doc.documentElement.getElementsByClassName &&
                            (operator === '~=' || operator === '='))) {
                        token.prefilter = match[1];
                        token[match[1]] = match[3];
                    }

                    // add tests
                    if (operator in operators) {
                        test = operators[operator];
                        if (typeof test === 'string') {
                            match[3] = match[3].replace(Y.Selector._reRegExpTokens, '\\$1');
                            test = Y.DOM._getRegExp(test.replace('{val}', match[3]));
                        }
                        match[2] = test;
                    }
                    if (!token.last || token.prefilter !== match[1]) {
                        return match.slice(1);
                    }
                }

            },
            {
                name: TAG_NAME,
                re: /^((?:-?[_a-z]+[\w-]*)|\*)/i,
                fn: function(match, token) {
                    var tag = match[1].toUpperCase();
                    token.tagName = tag;

                    if (tag !== '*' && (!token.last || token.prefilter)) {
                        return [TAG_NAME, '=', tag];
                    }
                    if (!token.prefilter) {
                        token.prefilter = 'tagName';
                    }
                }
            },
            {
                name: COMBINATOR,
                re: /^\s*([>+~]|\s)\s*/,
                fn: function(match, token) {
                }
            },
            {
                name: PSEUDOS,
                re: /^:([\-\w]+)(?:\(['"]?(.+)['"]?\))*/i,
                fn: function(match, token) {
                    var test = Selector[PSEUDOS][match[1]];
                    if (test) { // reorder match array
                        return [match[2], test];
                    } else { // selector token not supported (possibly missing CSS3 module)
                        return false;
                    }
                }
            }
            ],

        _getToken: function(token) {
            return {
                tagName: null,
                id: null,
                className: null,
                attributes: {},
                combinator: null,
                tests: []
            };
        },

        /**
            Break selector into token units per simple selector.
            Combinator is attached to the previous token.
         */
        _tokenize: function(selector) {
            selector = selector || '';
            selector = Selector._replaceShorthand(Y.Lang.trim(selector)); 
            var token = Selector._getToken(),     // one token per simple selector (left selector holds combinator)
                query = selector, // original query for debug report
                tokens = [],    // array of tokens
                found = false,  // whether or not any matches were found this pass
                match,         // the regex match
                test,
                i, parser;

            /*
                Search for selector patterns, store, and strip them from the selector string
                until no patterns match (invalid selector) or we run out of chars.

                Multiple attributes and pseudos are allowed, in any order.
                for example:
                    'form:first-child[type=button]:not(button)[lang|=en]'
            */
            outer:
            do {
                found = false; // reset after full pass
                for (i = 0; (parser = Selector._parsers[i++]);) {
                    if ( (match = parser.re.exec(selector)) ) { // note assignment
                        if (parser.name !== COMBINATOR ) {
                            token.selector = selector;
                        }
                        selector = selector.replace(match[0], ''); // strip current match from selector
                        if (!selector.length) {
                            token.last = true;
                        }

                        if (Selector._attrFilters[match[1]]) { // convert class to className, etc.
                            match[1] = Selector._attrFilters[match[1]];
                        }

                        test = parser.fn(match, token);
                        if (test === false) { // selector not supported
                            found = false;
                            break outer;
                        } else if (test) {
                            token.tests.push(test);
                        }

                        if (!selector.length || parser.name === COMBINATOR) {
                            tokens.push(token);
                            token = Selector._getToken(token);
                            if (parser.name === COMBINATOR) {
                                token.combinator = Y.Selector.combinators[match[1]];
                            }
                        }
                        found = true;
                    }
                }
            } while (found && selector.length);

            if (!found || selector.length) { // not fully parsed
                Y.log('query: ' + query + ' contains unsupported token in: ' + selector, 'warn', 'Selector');
                tokens = [];
            }
            return tokens;
        },

        _replaceShorthand: function(selector) {
            var shorthand = Selector.shorthand,
                attrs = selector.match(Selector._re.attr), // pull attributes to avoid false pos on "." and "#"
                pseudos = selector.match(Selector._re.pseudos), // pull attributes to avoid false pos on "." and "#"
                re, i, len;

            if (pseudos) {
                selector = selector.replace(Selector._re.pseudos, '!!REPLACED_PSEUDO!!');
            }

            if (attrs) {
                selector = selector.replace(Selector._re.attr, '!!REPLACED_ATTRIBUTE!!');
            }

            for (re in shorthand) {
                if (shorthand.hasOwnProperty(re)) {
                    selector = selector.replace(Y.DOM._getRegExp(re, 'gi'), shorthand[re]);
                }
            }

            if (attrs) {
                for (i = 0, len = attrs.length; i < len; ++i) {
                    selector = selector.replace('!!REPLACED_ATTRIBUTE!!', attrs[i]);
                }
            }
            if (pseudos) {
                for (i = 0, len = pseudos.length; i < len; ++i) {
                    selector = selector.replace('!!REPLACED_PSEUDO!!', pseudos[i]);
                }
            }
            return selector;
        },

        _attrFilters: {
            'class': 'className',
            'for': 'htmlFor'
        },

        getters: {
            href: function(node, attr) {
                return Y.DOM.getAttribute(node, attr);
            }
        }
    };

Y.mix(Y.Selector, SelectorCSS2, true);
Y.Selector.getters.src = Y.Selector.getters.rel = Y.Selector.getters.href;

// IE wants class with native queries
if (Y.Selector.useNative && Y.config.doc.querySelector) {
    Y.Selector.shorthand['\\.(-?[_a-z]+[-\\w]*)'] = '[class~=$1]';
}



}, '3.2.0' ,{requires:['selector-native']});
