/*
Copyright (c) 2008, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://developer.yahoo.net/yui/license.txt
version: 2.5.1
*/
/**
 * The selector module provides helper methods allowing CSS3 Selectors to be used with DOM elements.
 * @module selector
 * @title Selector Utility
 * @namespace YAHOO.util
 * @requires yahoo, dom
 */

(function() {
/**
 * Provides helper methods for collecting and filtering DOM elements.
 * @namespace YAHOO.util
 * @class Selector
 * @static
 */
var Selector = function() {};

var Y = YAHOO.util;

var reNth = /^(?:([-]?\d*)(n){1}|(odd|even)$)*([-+]?\d*)$/;

Selector.prototype = {
    /**
     * Default document for use queries 
     * @property document
     * @type object
     * @default window.document
     */
    document: window.document,
    /**
     * Mapping of attributes to aliases, normally to work around HTMLAttributes
     * that conflict with JS reserved words.
     * @property attrAliases
     * @type object
     */
    attrAliases: {
        'for': 'htmlFor'
    },

    /**
     * Mapping of shorthand tokens to corresponding attribute selector 
     * @property shorthand
     * @type object
     */
    shorthand: {
        //'(?:(?:[^\\)\\]\\s*>+~,]+)(?:-?[_a-z]+[-\\w]))+#(-?[_a-z]+[-\\w]*)': '[id=$1]',
        '\\#(-?[_a-z]+[-\\w]*)': '[id=$1]',
        '\\.(-?[_a-z]+[-\\w]*)': '[class~=$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(attr, val) { return attr === val; }, // Equality
        '!=': function(attr, val) { return attr !== val; }, // Inequality
        '~=': function(attr, val) { // Match one of space seperated words 
            var s = ' ';
            return (s + attr + s).indexOf((s + val + s)) > -1;
        },
        '|=': function(attr, val) { return getRegExp('^' + val + '[-]?').test(attr); }, // Match start with value followed by optional hyphen
        '^=': function(attr, val) { return attr.indexOf(val) === 0; }, // Match starts with value
        '$=': function(attr, val) { return attr.lastIndexOf(val) === attr.length - val.length; }, // Match ends with value
        '*=': function(attr, val) { return attr.indexOf(val) > -1; }, // Match contains value as substring 
        '': function(attr, val) { return attr; } // Just test for existence of attribute
    },

    /**
     * List of pseudo-classes and corresponding boolean functions. 
     * These functions are called with the current node, and any value that was parsed with the pseudo regex.
     * @property pseudos
     * @type object
     */
    pseudos: {
        'root': function(node) {
            return node === node.ownerDocument.documentElement;
        },

        'nth-child': function(node, val) {
            return getNth(node, val);
        },

        'nth-last-child': function(node, val) {
            return getNth(node, val, null, true);
        },

        'nth-of-type': function(node, val) {
            return getNth(node, val, node.tagName);
        },
         
        'nth-last-of-type': function(node, val) {
            return getNth(node, val, node.tagName, true);
        },
         
        'first-child': function(node) {
            return getChildren(node.parentNode)[0] === node;
        },

        'last-child': function(node) {
            var children = getChildren(node.parentNode);
            return children[children.length - 1] === node;
        },

        'first-of-type': function(node, val) {
            return getChildren(node.parentNode, node.tagName.toLowerCase())[0];
        },
         
        'last-of-type': function(node, val) {
            var children = getChildren(node.parentNode, node.tagName.toLowerCase());
            return children[children.length - 1];
        },
         
        'only-child': function(node) {
            var children = getChildren(node.parentNode);
            return children.length === 1 && children[0] === node;
        },

        'only-of-type': function(node) {
            return getChildren(node.parentNode, node.tagName.toLowerCase()).length === 1;
        },

        'empty': function(node) {
            return node.childNodes.length === 0;
        },

        'not': function(node, simple) {
            return !Selector.test(node, simple);
        },

        'contains': function(node, str) {
            var text = node.innerText || node.textContent || '';
            return text.indexOf(str) > -1;
        },
        'checked': function(node) {
            return node.checked === true;
        }
    },

    /**
     * Test if the supplied node matches the supplied selector.
     * @method test
     *
     * @param {HTMLElement | String} node An id or node reference to the HTMLElement being tested.
     * @param {string} selector The CSS Selector to test the node against.
     * @return{boolean} Whether or not the node matches the selector.
     * @static
    
     */
    test: function(node, selector) {
        node = Selector.document.getElementById(node) || node;

        if (!node) {
            return false;
        }

        var groups = selector ? selector.split(',') : [];
        if (groups.length) {
            for (var i = 0, len = groups.length; i < len; ++i) {
                if ( rTestNode(node, groups[i]) ) { // passes if ANY group matches
                    return true;
                }
            }
            return false;
        }
        return rTestNode(node, selector);
    },

    /**
     * Filters a set of nodes based on a given CSS selector. 
     * @method filter
     *
     * @param {array} nodes A set of nodes/ids to filter. 
     * @param {string} selector The selector used to test each node.
     * @return{array} An array of nodes from the supplied array that match the given selector.
     * @static
     */
    filter: function(nodes, selector) {
        nodes = nodes || [];

        var node,
            result = [],
            tokens = tokenize(selector);

        if (!nodes.item) { // if not HTMLCollection, handle arrays of ids and/or nodes
            YAHOO.log('filter: scanning input for HTMLElements/IDs', 'info', 'Selector');
            for (var i = 0, len = nodes.length; i < len; ++i) {
                if (!nodes[i].tagName) { // tagName limits to HTMLElements 
                    node = Selector.document.getElementById(nodes[i]);
                    if (node) { // skip IDs that return null 
                        nodes[i] = node;
                    } else {
                        YAHOO.log('filter: skipping invalid node', 'warn', 'Selector');
                    }
                }
            }
        }
        result = rFilter(nodes, tokenize(selector)[0]);
        clearParentCache();
        YAHOO.log('filter: returning:' + result.length, 'info', 'Selector');
        return result;
    },

    /**
     * Retrieves a set of nodes based on a given CSS selector. 
     * @method query
     *
     * @param {string} selector The CSS Selector to test the node against.
     * @param {HTMLElement | String} root optional An id or HTMLElement to start the query from. Defaults to Selector.document.
     * @param {Boolean} firstOnly optional Whether or not to return only the first match.
     * @return {Array} An array of nodes that match the given selector.
     * @static
     */
    query: function(selector, root, firstOnly) {
        var result = query(selector, root, firstOnly);
        YAHOO.log('query: returning ' + result, 'info', 'Selector');
        return result;
    }
};

var query = function(selector, root, firstOnly, deDupe) {
    var result =  (firstOnly) ? null : [];
    if (!selector) {
        return result;
    }

    var groups = selector.split(','); // TODO: handle comma in attribute/pseudo

    if (groups.length > 1) {
        var found;
        for (var i = 0, len = groups.length; i < len; ++i) {
            found = arguments.callee(groups[i], root, firstOnly, true);
            result = firstOnly ? found : result.concat(found); 
        }
        clearFoundCache();
        return result;
    }

    if (root && !root.nodeName) { // assume ID
        root = Selector.document.getElementById(root);
        if (!root) {
            YAHOO.log('invalid root node provided', 'warn', 'Selector');
            return result;
        }
    }

    root = root || Selector.document;
    var tokens = tokenize(selector);
    var idToken = tokens[getIdTokenIndex(tokens)],
        nodes = [],
        node,
        id,
        token = tokens.pop() || {};
        
    if (idToken) {
        id = getId(idToken.attributes);
    }

    // use id shortcut when possible
    if (id) {
        if (id === token.id) { // only one target
            nodes = [Selector.document.getElementById(id)] || root;
        } else { // reset root to id node if passes
            node = Selector.document.getElementById(id);
            if (root === Selector.document || contains(node, root)) {
                if ( node && rTestNode(node, null, idToken) ) {
                    root = node; // start from here
                }
            } else {
                return result;
            }
        }
    }

    if (root && !nodes.length) {
        nodes = root.getElementsByTagName(token.tag);
    }

    if (nodes.length) {
        result = rFilter(nodes, token, firstOnly, deDupe); 
    }
    clearParentCache();
    return result;
};

var contains = function() {
    if (document.documentElement.contains && !YAHOO.env.ua.webkit < 422)  { // IE & Opera, Safari < 3 contains is broken
        return function(needle, haystack) {
            return haystack.contains(needle);
        };
    } else if ( document.documentElement.compareDocumentPosition ) { // gecko
        return function(needle, haystack) {
            return !!(haystack.compareDocumentPosition(needle) & 16);
        };
    } else  { // Safari < 3
        return function(needle, haystack) {
            var parent = needle.parentNode;
            while (parent) {
                if (needle === parent) {
                    return true;
                }
                parent = parent.parentNode;
            } 
            return false;
        }; 
    }
}();

var rFilter = function(nodes, token, firstOnly, deDupe) {
    var result = firstOnly ? null : [];

    for (var i = 0, len = nodes.length; i < len; i++) {
        if (! rTestNode(nodes[i], '', token, deDupe)) {
            continue;
        }

        if (firstOnly) {
            return nodes[i];
        }
        if (deDupe) {
            if (nodes[i]._found) {
                continue;
            }
            nodes[i]._found = true;
            foundCache[foundCache.length] = nodes[i];
        }

        result[result.length] = nodes[i];
    }

    return result;
};

var rTestNode = function(node, selector, token, deDupe) {
    token = token || tokenize(selector).pop() || {};

    if (!node.tagName ||
        (token.tag !== '*' && node.tagName.toUpperCase() !== token.tag) ||
        (deDupe && node._found) ) {
        return false;
    }

    if (token.attributes.length) {
        var attribute;
        for (var i = 0, len = token.attributes.length; i < len; ++i) {
            attribute = node.getAttribute(token.attributes[i][0], 2);
            if (attribute === undefined) {
                return false;
            }
            if ( Selector.operators[token.attributes[i][1]] &&
                    !Selector.operators[token.attributes[i][1]](attribute, token.attributes[i][2])) {
                return false;
            }
        }
    }

    if (token.pseudos.length) {
        for (var i = 0, len = token.pseudos.length; i < len; ++i) {
            if (Selector.pseudos[token.pseudos[i][0]] &&
                    !Selector.pseudos[token.pseudos[i][0]](node, token.pseudos[i][1])) {
                return false;
            }
        }
    }

    return (token.previous && token.previous.combinator !== ',') ?
            combinators[token.previous.combinator](node, token) :
            true;
};


var foundCache = [];
var parentCache = [];
var regexCache = {};

var clearFoundCache = function() {
    YAHOO.log('getBySelector: clearing found cache of ' + foundCache.length + ' elements');
    for (var i = 0, len = foundCache.length; i < len; ++i) {
        try { // IE no like delete
            delete foundCache[i]._found;
        } catch(e) {
            foundCache[i].removeAttribute('_found');
        }
    }
    foundCache = [];
    YAHOO.log('getBySelector: done clearing foundCache');
};

var clearParentCache = function() {
    if (!document.documentElement.children) { // caching children lookups for gecko
        return function() {
            for (var i = 0, len = parentCache.length; i < len; ++i) {
                delete parentCache[i]._children;
            }
            parentCache = [];
        };
    } else return function() {}; // do nothing
}();

var getRegExp = function(str, flags) {
    flags = flags || '';
    if (!regexCache[str + flags]) {
        regexCache[str + flags] = new RegExp(str, flags);
    }
    return regexCache[str + flags];
};

var combinators = {
    ' ': function(node, token) {
        while (node = node.parentNode) {
            if (rTestNode(node, '', token.previous)) {
                return true;
            }
        }  
        return false;
    },

    '>': function(node, token) {
        return rTestNode(node.parentNode, null, token.previous);
    },
    '+': function(node, token) {
        var sib = node.previousSibling;
        while (sib && sib.nodeType !== 1) {
            sib = sib.previousSibling;
        }

        if (sib && rTestNode(sib, null, token.previous)) {
            return true; 
        }
        return false;
    },

    '~': function(node, token) {
        var sib = node.previousSibling;
        while (sib) {
            if (sib.nodeType === 1 && rTestNode(sib, null, token.previous)) {
                return true;
            }
            sib = sib.previousSibling;
        }

        return false;
    }
};

var getChildren = function() {
    if (document.documentElement.children) { // document for capability test
        return function(node, tag) {
            return (tag) ? node.children.tags(tag) : node.children || [];
        };
    } else {
        return function(node, tag) {
            if (node._children) {
                return node._children;
            }
            var children = [],
                childNodes = node.childNodes;

            for (var i = 0, len = childNodes.length; i < len; ++i) {
                if (childNodes[i].tagName) {
                    if (!tag || childNodes[i].tagName.toLowerCase() === tag) {
                        children[children.length] = childNodes[i];
                    }
                }
            }
            node._children = children;
            parentCache[parentCache.length] = node;
            return children;
        };
    }
}();

/*
    an+b = get every _a_th node starting at the _b_th
    0n+b = no repeat ("0" and "n" may both be omitted (together) , e.g. "0n+1" or "1", not "0+1"), return only the _b_th element
    1n+b =  get every element starting from b ("1" may may be omitted, e.g. "1n+0" or "n+0" or "n")
    an+0 = get every _a_th element, "0" may be omitted 
*/
var getNth = function(node, expr, tag, reverse) {
    if (tag) tag = tag.toLowerCase();
    reNth.test(expr);
    var a = parseInt(RegExp.$1, 10), // include every _a_ elements (zero means no repeat, just first _a_)
        n = RegExp.$2, // "n"
        oddeven = RegExp.$3, // "odd" or "even"
        b = parseInt(RegExp.$4, 10) || 0, // start scan from element _b_
        result = [];

    var siblings = getChildren(node.parentNode, tag);

    if (oddeven) {
        a = 2; // always every other
        op = '+';
        n = 'n';
        b = (oddeven === 'odd') ? 1 : 0;
    } else if ( isNaN(a) ) {
        a = (n) ? 1 : 0; // start from the first or no repeat
    }

    if (a === 0) { // just the first
        if (reverse) {
            b = siblings.length - b + 1; 
        }

        if (siblings[b - 1] === node) {
            return true;
        } else {
            return false;
        }

    } else if (a < 0) {
        reverse = !!reverse;
        a = Math.abs(a);
    }

    if (!reverse) {
        for (var i = b - 1, len = siblings.length; i < len; i += a) {
            if ( i >= 0 && siblings[i] === node ) {
                return true;
            }
        }
    } else {
        for (var i = siblings.length - b, len = siblings.length; i >= 0; i -= a) {
            if ( i < len && siblings[i] === node ) {
                return true;
            }
        }
    }
    return false;
};

var getId = function(attr) {
    for (var i = 0, len = attr.length; i < len; ++i) {
        if (attr[i][0] == 'id' && attr[i][1] === '=') {
            return attr[i][2];
        }
    }
};

var getIdTokenIndex = function(tokens) {
    for (var i = 0, len = tokens.length; i < len; ++i) {
        if (getId(tokens[i].attributes)) {
            return i;
        }
    }
    return -1;
};

var patterns = {
    tag: /^((?:-?[_a-z]+[\w-]*)|\*)/i,
    attributes: /^\[([a-z]+\w*)+([~\|\^\$\*!=]=?)?['"]?([^'"\]]*)['"]?\]*/i,
    pseudos: /^:([-\w]+)(?:\(['"]?(.+)['"]?\))*/i,
    combinator: /^\s*([>+~]|\s)\s*/
};

/**
    Break selector into token units per simple selector.
    Combinator is attached to left-hand selector.
 */
var tokenize = function(selector) {
    var token = {},     // one token per simple selector (left selector holds combinator)
        tokens = [],    // array of tokens
        id,             // unique id for the simple selector (if found)
        found = false,  // whether or not any matches were found this pass
        match;          // the regex match

    selector = replaceShorthand(selector); // convert ID and CLASS shortcuts to attributes

    /*
        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]'
    */
    do {
        found = false; // reset after full pass
        for (var re in patterns) {
                if (!YAHOO.lang.hasOwnProperty(patterns, re)) {
                    continue;
                }
                if (re != 'tag' && re != 'combinator') { // only one allowed
                    token[re] = token[re] || [];
                }
            if (match = patterns[re].exec(selector)) { // note assignment
                found = true;
                if (re != 'tag' && re != 'combinator') { // only one allowed
                    //token[re] = token[re] || [];

                    // capture ID for fast path to element
                    if (re === 'attributes' && match[1] === 'id') {
                        token.id = match[3];
                    }

                    token[re].push(match.slice(1));
                } else { // single selector (tag, combinator)
                    token[re] = match[1];
                }
                selector = selector.replace(match[0], ''); // strip current match from selector
                if (re === 'combinator' || !selector.length) { // next token or done
                    token.attributes = fixAttributes(token.attributes);
                    token.pseudos = token.pseudos || [];
                    token.tag = token.tag ? token.tag.toUpperCase() : '*';
                    tokens.push(token);

                    token = { // prep next token
                        previous: token
                    };
                }
            }
        }
    } while (found);

    return tokens;
};

var fixAttributes = function(attr) {
    var aliases = Selector.attrAliases;
    attr = attr || [];
    for (var i = 0, len = attr.length; i < len; ++i) {
        if (aliases[attr[i][0]]) { // convert reserved words, etc
            attr[i][0] = aliases[attr[i][0]];
        }
        if (!attr[i][1]) { // use exists operator
            attr[i][1] = '';
        }
    }
    return attr;
};

var replaceShorthand = function(selector) {
    var shorthand = Selector.shorthand;
    var attrs = selector.match(patterns.attributes); // pull attributes to avoid false pos on "." and "#"
    if (attrs) {
        selector = selector.replace(patterns.attributes, 'REPLACED_ATTRIBUTE');
    }
    for (var re in shorthand) {
        if (!YAHOO.lang.hasOwnProperty(shorthand, re)) {
            continue;
        }
        selector = selector.replace(getRegExp(re, 'gi'), shorthand[re]);
    }

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

if (YAHOO.env.ua.ie) { // rewrite class for IE (others use getAttribute('class')
    Selector.prototype.attrAliases['class'] = 'className';
}

Selector = new Selector();
Selector.patterns = patterns;
Y.Selector = Selector;
})();
YAHOO.register("selector", YAHOO.util.Selector, {version: "2.5.1", build: "984"});
