/*

Copyright (c) 2009, Yahoo! Inc. All rights reserved.

Code licensed under the BSD License:

http://developer.yahoo.net/yui/license.txt

version: 3.0.0

build: 1549

*/

YUI.add('attribute-complex', function(Y) {

    /**

     * Adds support for attribute providers to handle complex attributes in the constructor

     *

     * @module attribute

     * @submodule attribute-complex

     * @for Attribute

     */

    var O = Y.Object,

        DOT = ".";

    Y.Attribute.Complex = function() {};

    Y.Attribute.Complex.prototype = {

        /**

         * Utility method to split out simple attribute name/value pairs ("x") 

         * from complex attribute name/value pairs ("x.y.z"), so that complex

         * attributes can be keyed by the top level attribute name.

         *

         * @method _normAttrVals

         * @param {Object} valueHash An object with attribute name/value pairs

         *

         * @return {Object} An object literal with 2 properties - "simple" and "complex",

         * containing simple and complex attribute values respectively keyed 

         * by the top level attribute name, or null, if valueHash is falsey.

         *

         * @private

         */

        _normAttrVals : function(valueHash) {

            var vals = {},

                subvals = {},

                path,

                attr,

                v, k;

            if (valueHash) {

                for (k in valueHash) {

                    if (valueHash.hasOwnProperty(k)) {

                        if (k.indexOf(DOT) !== -1) {

                            path = k.split(DOT);

                            attr = path.shift();

                            v = subvals[attr] = subvals[attr] || [];

                            v[v.length] = {

                                path : path, 

                                value: valueHash[k]

                            };

                        } else {

                            vals[k] = valueHash[k];

                        }

                    }

                }

                return { simple:vals, complex:subvals };

            } else {

                return null;

            }

        },

        /**

         * Returns the initial value of the given attribute from

         * either the default configuration provided, or the 

         * over-ridden value if it exists in the set of initValues 

         * provided and the attribute is not read-only.

         *

         * @param {String} attr The name of the attribute

         * @param {Object} cfg The attribute configuration object

         * @param {Object} initValues The object with simple and complex attribute name/value pairs returned from _normAttrVals

         *

         * @return {Any} The initial value of the attribute.

         *

         * @method _getAttrInitVal

         * @private

         */

        _getAttrInitVal : function(attr, cfg, initValues) {

            var val = (cfg.valueFn) ? cfg.valueFn.call(this) : cfg.value,

                simple,

                complex,

                i,

                l,

                path,

                subval,

                subvals;

            if (!cfg.readOnly && initValues) {

                // Simple Attributes

                simple = initValues.simple;

                if (simple && simple.hasOwnProperty(attr)) {

                    val = simple[attr];

                }

                // Complex Attributes (complex values applied, after simple, incase both are set)

                complex = initValues.complex;

                if (complex && complex.hasOwnProperty(attr)) {

                    subvals = complex[attr];

                    for (i = 0, l = subvals.length; i < l; ++i) {

                        path = subvals[i].path;

                        subval = subvals[i].value;

                        O.setValue(val, path, subval);

                    }

                }

            }

            return val;

        }

    };

    Y.mix(Y.Attribute, Y.Attribute.Complex, true, null, 1);

}, '3.0.0' ,{requires:['attribute-base']});