/*
YUI 3.4.1 (build 4118)
Copyright 2011 Yahoo! Inc. All rights reserved.
Licensed under the BSD License.
http://yuilibrary.com/license/
*/
YUI.add('loader-base', function(Y) {

/**
 * The YUI loader core
 * @module loader
 * @submodule loader-base
 */

if (!YUI.Env[Y.version]) {

    (function() {
        var VERSION = Y.version,
            BUILD = '/build/',
            ROOT = VERSION + BUILD,
            CDN_BASE = Y.Env.base,
            GALLERY_VERSION = 'gallery-2011.09.14-20-40',
            TNT = '2in3',
            TNT_VERSION = '4',
            YUI2_VERSION = '2.9.0',
            COMBO_BASE = CDN_BASE + 'combo?',
            META = { version: VERSION,
                              root: ROOT,
                              base: Y.Env.base,
                              comboBase: COMBO_BASE,
                              skin: { defaultSkin: 'sam',
                                           base: 'assets/skins/',
                                           path: 'skin.css',
                                           after: ['cssreset',
                                                          'cssfonts',
                                                          'cssgrids',
                                                          'cssbase',
                                                          'cssreset-context',
                                                          'cssfonts-context']},
                              groups: {},
                              patterns: {} },
            groups = META.groups,
            yui2Update = function(tnt, yui2) {
                                  var root = TNT + '.' +
                                            (tnt || TNT_VERSION) + '/' +
                                            (yui2 || YUI2_VERSION) + BUILD;
                                  groups.yui2.base = CDN_BASE + root;
                                  groups.yui2.root = root;
                              },
            galleryUpdate = function(tag) {
                                  var root = (tag || GALLERY_VERSION) + BUILD;
                                  groups.gallery.base = CDN_BASE + root;
                                  groups.gallery.root = root;
                              };

        groups[VERSION] = {};

        groups.gallery = {
            ext: false,
            combine: true,
            comboBase: COMBO_BASE,
            update: galleryUpdate,
            patterns: { 'gallery-': { },
                        'lang/gallery-': {},
                        'gallerycss-': { type: 'css' } }
        };

        groups.yui2 = {
            combine: true,
            ext: false,
            comboBase: COMBO_BASE,
            update: yui2Update,
            patterns: {
                'yui2-': {
                    configFn: function(me) {
                        if (/-skin|reset|fonts|grids|base/.test(me.name)) {
                            me.type = 'css';
                            me.path = me.path.replace(/\.js/, '.css');
                            // this makes skins in builds earlier than
                            // 2.6.0 work as long as combine is false
                            me.path = me.path.replace(/\/yui2-skin/,
                                             '/assets/skins/sam/yui2-skin');
                        }
                    }
                }
            }
        };

        galleryUpdate();
        yui2Update();

        YUI.Env[VERSION] = META;
    }());
}


/**
 * Loader dynamically loads script and css files.  It includes the dependency
 * info for the version of the library in use, and will automatically pull in
 * dependencies for the modules requested.  It supports rollup files and will
 * automatically use these when appropriate in order to minimize the number of
 * http connections required to load all of the dependencies.  It can load the
 * files from the Yahoo! CDN, and it can utilize the combo service provided on
 * this network to reduce the number of http connections required to download
 * YUI files.
 *
 * @module loader
 * @main loader
 * @submodule loader-base
 */

var NOT_FOUND = {},
    NO_REQUIREMENTS = [],
    MAX_URL_LENGTH = 2048,
    GLOBAL_ENV = YUI.Env,
    GLOBAL_LOADED = GLOBAL_ENV._loaded,
    CSS = 'css',
    JS = 'js',
    INTL = 'intl',
    VERSION = Y.version,
    ROOT_LANG = '',
    YObject = Y.Object,
    oeach = YObject.each,
    YArray = Y.Array,
    _queue = GLOBAL_ENV._loaderQueue,
    META = GLOBAL_ENV[VERSION],
    SKIN_PREFIX = 'skin-',
    L = Y.Lang,
    ON_PAGE = GLOBAL_ENV.mods,
    modulekey,
    cache,
    _path = function(dir, file, type, nomin) {
                        var path = dir + '/' + file;
                        if (!nomin) {
                            path += '-min';
                        }
                        path += '.' + (type || CSS);

                        return path;
                    };

if (YUI.Env.aliases) {
    YUI.Env.aliases = {}; //Don't need aliases if Loader is present
}

/**
 * The component metadata is stored in Y.Env.meta.
 * Part of the loader module.
 * @property meta
 * @for YUI
 */
Y.Env.meta = META;

/**
 * Loader dynamically loads script and css files.  It includes the dependency
 * info for the version of the library in use, and will automatically pull in
 * dependencies for the modules requested.  It supports rollup files and will
 * automatically use these when appropriate in order to minimize the number of
 * http connections required to load all of the dependencies.  It can load the
 * files from the Yahoo! CDN, and it can utilize the combo service provided on
 * this network to reduce the number of http connections required to download
 * YUI files.
 *
 * While the loader can be instantiated by the end user, it normally is not.
 * @see YUI.use for the normal use case.  The use function automatically will
 * pull in missing dependencies.
 *
 * @constructor
 * @class Loader
 * @param {object} o an optional set of configuration options.  Valid options:
 * <ul>
 *  <li>base:
 *  The base dir</li>
 *  <li>comboBase:
 *  The YUI combo service base dir. Ex: http://yui.yahooapis.com/combo?</li>
 *  <li>root:
 *  The root path to prepend to module names for the combo service.
 *  Ex: 2.5.2/build/</li>
 *  <li>filter:.
 *
 * A filter to apply to result urls.  This filter will modify the default
 * path for all modules.  The default path for the YUI library is the
 * minified version of the files (e.g., event-min.js).  The filter property
 * can be a predefined filter or a custom filter.  The valid predefined
 * filters are:
 * <dl>
 *  <dt>DEBUG</dt>
 *  <dd>Selects the debug versions of the library (e.g., event-debug.js).
 *      This option will automatically include the Logger widget</dd>
 *  <dt>RAW</dt>
 *  <dd>Selects the non-minified version of the library (e.g., event.js).
 *  </dd>
 * </dl>
 * You can also define a custom filter, which must be an object literal
 * containing a search expression and a replace string:
 * <pre>
 *  myFilter: &#123;
 *      'searchExp': "-min\\.js",
 *      'replaceStr': "-debug.js"
 *  &#125;
 * </pre>
 *
 *  </li>
 *  <li>filters: per-component filter specification.  If specified
 *  for a given component, this overrides the filter config. _Note:_ This does not work on combo urls, use the filter property instead.</li>
 *  <li>combine:
 *  Use the YUI combo service to reduce the number of http connections
 *  required to load your dependencies</li>
 *  <li>ignore:
 *  A list of modules that should never be dynamically loaded</li>
 *  <li>force:
 *  A list of modules that should always be loaded when required, even if
 *  already present on the page</li>
 *  <li>insertBefore:
 *  Node or id for a node that should be used as the insertion point for
 *  new nodes</li>
 *  <li>charset:
 *  charset for dynamic nodes (deprecated, use jsAttributes or cssAttributes)
 *  </li>
 *  <li>jsAttributes: object literal containing attributes to add to script
 *  nodes</li>
 *  <li>cssAttributes: object literal containing attributes to add to link
 *  nodes</li>
 *  <li>timeout:
 *  The number of milliseconds before a timeout occurs when dynamically
 *  loading nodes.  If not set, there is no timeout</li>
 *  <li>context:
 *  execution context for all callbacks</li>
 *  <li>onSuccess:
 *  callback for the 'success' event</li>
 *  <li>onFailure: callback for the 'failure' event</li>
 *  <li>onCSS: callback for the 'CSSComplete' event.  When loading YUI
 *  components with CSS the CSS is loaded first, then the script.  This
 *  provides a moment you can tie into to improve
 *  the presentation of the page while the script is loading.</li>
 *  <li>onTimeout:
 *  callback for the 'timeout' event</li>
 *  <li>onProgress:
 *  callback executed each time a script or css file is loaded</li>
 *  <li>modules:
 *  A list of module definitions.  See Loader.addModule for the supported
 *  module metadata</li>
 *  <li>groups:
 *  A list of group definitions.  Each group can contain specific definitions
 *  for base, comboBase, combine, and accepts a list of modules.  See above
 *  for the description of these properties.</li>
 *  <li>2in3: the version of the YUI 2 in 3 wrapper to use.  The intrinsic
 *  support for YUI 2 modules in YUI 3 relies on versions of the YUI 2
 *  components inside YUI 3 module wrappers.  These wrappers
 *  change over time to accomodate the issues that arise from running YUI 2
 *  in a YUI 3 sandbox.</li>
 *  <li>yui2: when using the 2in3 project, you can select the version of
 *  YUI 2 to use.  Valid values *  are 2.2.2, 2.3.1, 2.4.1, 2.5.2, 2.6.0,
 *  2.7.0, 2.8.0, and 2.8.1 [default] -- plus all versions of YUI 2
 *  going forward.</li>
 * </ul>
 */
Y.Loader = function(o) {

    var defaults = META.modules,
        self = this;

    modulekey = META.md5;

    /**
     * Internal callback to handle multiple internal insert() calls
     * so that css is inserted prior to js
     * @property _internalCallback
     * @private
     */
    // self._internalCallback = null;

    /**
     * Callback that will be executed when the loader is finished
     * with an insert
     * @method onSuccess
     * @type function
     */
    // self.onSuccess = null;

    /**
     * Callback that will be executed if there is a failure
     * @method onFailure
     * @type function
     */
    // self.onFailure = null;

    /**
     * Callback for the 'CSSComplete' event.  When loading YUI components
     * with CSS the CSS is loaded first, then the script.  This provides
     * a moment you can tie into to improve the presentation of the page
     * while the script is loading.
     * @method onCSS
     * @type function
     */
    // self.onCSS = null;

    /**
     * Callback executed each time a script or css file is loaded
     * @method onProgress
     * @type function
     */
    // self.onProgress = null;

    /**
     * Callback that will be executed if a timeout occurs
     * @method onTimeout
     * @type function
     */
    // self.onTimeout = null;

    /**
     * The execution context for all callbacks
     * @property context
     * @default {YUI} the YUI instance
     */
    self.context = Y;

    /**
     * Data that is passed to all callbacks
     * @property data
     */
    // self.data = null;

    /**
     * Node reference or id where new nodes should be inserted before
     * @property insertBefore
     * @type string|HTMLElement
     */
    // self.insertBefore = null;

    /**
     * The charset attribute for inserted nodes
     * @property charset
     * @type string
     * @deprecated , use cssAttributes or jsAttributes.
     */
    // self.charset = null;

    /**
     * An object literal containing attributes to add to link nodes
     * @property cssAttributes
     * @type object
     */
    // self.cssAttributes = null;

    /**
     * An object literal containing attributes to add to script nodes
     * @property jsAttributes
     * @type object
     */
    // self.jsAttributes = null;

    /**
     * The base directory.
     * @property base
     * @type string
     * @default http://yui.yahooapis.com/[YUI VERSION]/build/
     */
    self.base = Y.Env.meta.base + Y.Env.meta.root;

    /**
     * Base path for the combo service
     * @property comboBase
     * @type string
     * @default http://yui.yahooapis.com/combo?
     */
    self.comboBase = Y.Env.meta.comboBase;

    /*
     * Base path for language packs.
     */
    // self.langBase = Y.Env.meta.langBase;
    // self.lang = "";

    /**
     * If configured, the loader will attempt to use the combo
     * service for YUI resources and configured external resources.
     * @property combine
     * @type boolean
     * @default true if a base dir isn't in the config
     */
    self.combine = o.base &&
        (o.base.indexOf(self.comboBase.substr(0, 20)) > -1);
    
    /**
    * The default seperator to use between files in a combo URL
    * @property comboSep
    * @type {String}
    * @default Ampersand
    */
    self.comboSep = '&';
    /**
     * Max url length for combo urls.  The default is 2048. This is the URL
     * limit for the Yahoo! hosted combo servers.  If consuming
     * a different combo service that has a different URL limit
     * it is possible to override this default by supplying
     * the maxURLLength config option.  The config option will
     * only take effect if lower than the default.
     *
     * @property maxURLLength
     * @type int
     */
    self.maxURLLength = MAX_URL_LENGTH;

    /**
     * Ignore modules registered on the YUI global
     * @property ignoreRegistered
     * @default false
     */
    // self.ignoreRegistered = false;

    /**
     * Root path to prepend to module path for the combo
     * service
     * @property root
     * @type string
     * @default [YUI VERSION]/build/
     */
    self.root = Y.Env.meta.root;

    /**
     * Timeout value in milliseconds.  If set, self value will be used by
     * the get utility.  the timeout event will fire if
     * a timeout occurs.
     * @property timeout
     * @type int
     */
    self.timeout = 0;

    /**
     * A list of modules that should not be loaded, even if
     * they turn up in the dependency tree
     * @property ignore
     * @type string[]
     */
    // self.ignore = null;

    /**
     * A list of modules that should always be loaded, even
     * if they have already been inserted into the page.
     * @property force
     * @type string[]
     */
    // self.force = null;

    self.forceMap = {};

    /**
     * Should we allow rollups
     * @property allowRollup
     * @type boolean
     * @default false
     */
    self.allowRollup = false;

    /**
     * A filter to apply to result urls.  This filter will modify the default
     * path for all modules.  The default path for the YUI library is the
     * minified version of the files (e.g., event-min.js).  The filter property
     * can be a predefined filter or a custom filter.  The valid predefined
     * filters are:
     * <dl>
     *  <dt>DEBUG</dt>
     *  <dd>Selects the debug versions of the library (e.g., event-debug.js).
     *      This option will automatically include the Logger widget</dd>
     *  <dt>RAW</dt>
     *  <dd>Selects the non-minified version of the library (e.g., event.js).
     *  </dd>
     * </dl>
     * You can also define a custom filter, which must be an object literal
     * containing a search expression and a replace string:
     * <pre>
     *  myFilter: &#123;
     *      'searchExp': "-min\\.js",
     *      'replaceStr': "-debug.js"
     *  &#125;
     * </pre>
     * @property filter
     * @type string| {searchExp: string, replaceStr: string}
     */
    // self.filter = null;

    /**
     * per-component filter specification.  If specified for a given
     * component, this overrides the filter config.
     * @property filters
     * @type object
     */
    self.filters = {};

    /**
     * The list of requested modules
     * @property required
     * @type {string: boolean}
     */
    self.required = {};

    /**
     * If a module name is predefined when requested, it is checked againsts
     * the patterns provided in this property.  If there is a match, the
     * module is added with the default configuration.
     *
     * At the moment only supporting module prefixes, but anticipate
     * supporting at least regular expressions.
     * @property patterns
     * @type Object
     */
    // self.patterns = Y.merge(Y.Env.meta.patterns);
    self.patterns = {};

    /**
     * The library metadata
     * @property moduleInfo
     */
    // self.moduleInfo = Y.merge(Y.Env.meta.moduleInfo);
    self.moduleInfo = {};

    self.groups = Y.merge(Y.Env.meta.groups);

    /**
     * Provides the information used to skin the skinnable components.
     * The following skin definition would result in 'skin1' and 'skin2'
     * being loaded for calendar (if calendar was requested), and
     * 'sam' for all other skinnable components:
     *
     *   <code>
     *   skin: {
     *
     *      // The default skin, which is automatically applied if not
     *      // overriden by a component-specific skin definition.
     *      // Change this in to apply a different skin globally
     *      defaultSkin: 'sam',
     *
     *      // This is combined with the loader base property to get
     *      // the default root directory for a skin. ex:
     *      // http://yui.yahooapis.com/2.3.0/build/assets/skins/sam/
     *      base: 'assets/skins/',
     *
     *      // Any component-specific overrides can be specified here,
     *      // making it possible to load different skins for different
     *      // components.  It is possible to load more than one skin
     *      // for a given component as well.
     *      overrides: {
     *          calendar: ['skin1', 'skin2']
     *      }
     *   }
     *   </code>
     *   @property skin
     */
    self.skin = Y.merge(Y.Env.meta.skin);

    /*
     * Map of conditional modules
     * @since 3.2.0
     */
    self.conditions = {};

    // map of modules with a hash of modules that meet the requirement
    // self.provides = {};

    self.config = o;
    self._internal = true;


    cache = GLOBAL_ENV._renderedMods;

    if (cache) {
        oeach(cache, function modCache(v, k) {
            //self.moduleInfo[k] = Y.merge(v);
            self.moduleInfo[k] = v;
        });

        cache = GLOBAL_ENV._conditions;

        oeach(cache, function condCache(v, k) {
            //self.conditions[k] = Y.merge(v);
            self.conditions[k] = v;
        });

    } else {
        oeach(defaults, self.addModule, self);
    }

    if (!GLOBAL_ENV._renderedMods) {
        //GLOBAL_ENV._renderedMods = Y.merge(self.moduleInfo);
        //GLOBAL_ENV._conditions = Y.merge(self.conditions);
        GLOBAL_ENV._renderedMods = self.moduleInfo;
        GLOBAL_ENV._conditions = self.conditions;
    }

    self._inspectPage();

    self._internal = false;

    self._config(o);

    self.testresults = null;

    if (Y.config.tests) {
        self.testresults = Y.config.tests;
    }

    /**
     * List of rollup files found in the library metadata
     * @property rollups
     */
    // self.rollups = null;

    /**
     * Whether or not to load optional dependencies for
     * the requested modules
     * @property loadOptional
     * @type boolean
     * @default false
     */
    // self.loadOptional = false;

    /**
     * All of the derived dependencies in sorted order, which
     * will be populated when either calculate() or insert()
     * is called
     * @property sorted
     * @type string[]
     */
    self.sorted = [];

    /**
     * Set when beginning to compute the dependency tree.
     * Composed of what YUI reports to be loaded combined
     * with what has been loaded by any instance on the page
     * with the version number specified in the metadata.
     * @property loaded
     * @type {string: boolean}
     */
    self.loaded = GLOBAL_LOADED[VERSION];

    /*
     * A list of modules to attach to the YUI instance when complete.
     * If not supplied, the sorted list of dependencies are applied.
     * @property attaching
     */
    // self.attaching = null;

    /**
     * Flag to indicate the dependency tree needs to be recomputed
     * if insert is called again.
     * @property dirty
     * @type boolean
     * @default true
     */
    self.dirty = true;

    /**
     * List of modules inserted by the utility
     * @property inserted
     * @type {string: boolean}
     */
    self.inserted = {};

    /**
     * List of skipped modules during insert() because the module
     * was not defined
     * @property skipped
     */
    self.skipped = {};

    // Y.on('yui:load', self.loadNext, self);

    self.tested = {};

    /*
     * Cached sorted calculate results
     * @property results
     * @since 3.2.0
     */
    //self.results = {};

};

Y.Loader.prototype = {

    FILTER_DEFS: {
        RAW: {
            'searchExp': '-min\\.js',
            'replaceStr': '.js'
        },
        DEBUG: {
            'searchExp': '-min\\.js',
            'replaceStr': '-debug.js'
        }
    },
    /*
    * Check the pages meta-data and cache the result.
    * @method _inspectPage
    * @private
    */
    _inspectPage: function() {
        oeach(ON_PAGE, function(v, k) {
           if (v.details) {
               var m = this.moduleInfo[k],
                   req = v.details.requires,
                   mr = m && m.requires;
               if (m) {
                   if (!m._inspected && req && mr.length != req.length) {
                       // console.log('deleting ' + m.name);
                       // m.requres = YObject.keys(Y.merge(YArray.hash(req), YArray.hash(mr)));
                       delete m.expanded;
                       // delete m.expanded_map;
                   }
               } else {
                   m = this.addModule(v.details, k);
               }
               m._inspected = true;
           }
       }, this);
    },
    /*
    * returns true if b is not loaded, and is required directly or by means of modules it supersedes.
    * @private
    * @method _requires
    * @param {String} mod1 The first module to compare
    * @param {String} mod2 The second module to compare
    */
   _requires: function(mod1, mod2) {

        var i, rm, after_map, s,
            info = this.moduleInfo,
            m = info[mod1],
            other = info[mod2];

        if (!m || !other) {
            return false;
        }

        rm = m.expanded_map;
        after_map = m.after_map;

        // check if this module should be sorted after the other
        // do this first to short circut circular deps
        if (after_map && (mod2 in after_map)) {
            return true;
        }

        after_map = other.after_map;

        // and vis-versa
        if (after_map && (mod1 in after_map)) {
            return false;
        }

        // check if this module requires one the other supersedes
        s = info[mod2] && info[mod2].supersedes;
        if (s) {
            for (i = 0; i < s.length; i++) {
                if (this._requires(mod1, s[i])) {
                    return true;
                }
            }
        }

        s = info[mod1] && info[mod1].supersedes;
        if (s) {
            for (i = 0; i < s.length; i++) {
                if (this._requires(mod2, s[i])) {
                    return false;
                }
            }
        }

        // check if this module requires the other directly
        // if (r && YArray.indexOf(r, mod2) > -1) {
        if (rm && (mod2 in rm)) {
            return true;
        }

        // external css files should be sorted below yui css
        if (m.ext && m.type == CSS && !other.ext && other.type == CSS) {
            return true;
        }

        return false;
    },
    /**
    * Apply a new config to the Loader instance
    * @method _config
    * @param {Object} o The new configuration
    */
    _config: function(o) {
        var i, j, val, f, group, groupName, self = this;
        // apply config values
        if (o) {
            for (i in o) {
                if (o.hasOwnProperty(i)) {
                    val = o[i];
                    if (i == 'require') {
                        self.require(val);
                    } else if (i == 'skin') {
                        Y.mix(self.skin, o[i], true);
                    } else if (i == 'groups') {
                        for (j in val) {
                            if (val.hasOwnProperty(j)) {
                                groupName = j;
                                group = val[j];
                                self.addGroup(group, groupName);
                            }
                        }

                    } else if (i == 'modules') {
                        // add a hash of module definitions
                        oeach(val, self.addModule, self);
                    } else if (i == 'gallery') {
                        this.groups.gallery.update(val);
                    } else if (i == 'yui2' || i == '2in3') {
                        this.groups.yui2.update(o['2in3'], o.yui2);
                    } else if (i == 'maxURLLength') {
                        self[i] = Math.min(MAX_URL_LENGTH, val);
                    } else {
                        self[i] = val;
                    }
                }
            }
        }

        // fix filter
        f = self.filter;

        if (L.isString(f)) {
            f = f.toUpperCase();
            self.filterName = f;
            self.filter = self.FILTER_DEFS[f];
            if (f == 'DEBUG') {
                self.require('yui-log', 'dump');
            }
        }

        if (self.lang) {
            self.require('intl-base', 'intl');
        }

    },

    /**
     * Returns the skin module name for the specified skin name.  If a
     * module name is supplied, the returned skin module name is
     * specific to the module passed in.
     * @method formatSkin
     * @param {string} skin the name of the skin.
     * @param {string} mod optional: the name of a module to skin.
     * @return {string} the full skin module name.
     */
    formatSkin: function(skin, mod) {
        var s = SKIN_PREFIX + skin;
        if (mod) {
            s = s + '-' + mod;
        }

        return s;
    },

    /**
     * Adds the skin def to the module info
     * @method _addSkin
     * @param {string} skin the name of the skin.
     * @param {string} mod the name of the module.
     * @param {string} parent parent module if this is a skin of a
     * submodule or plugin.
     * @return {string} the module name for the skin.
     * @private
     */
    _addSkin: function(skin, mod, parent) {
        var mdef, pkg, name, nmod,
            info = this.moduleInfo,
            sinf = this.skin,
            ext = info[mod] && info[mod].ext;

        // Add a module definition for the module-specific skin css
        if (mod) {
            name = this.formatSkin(skin, mod);
            if (!info[name]) {
                mdef = info[mod];
                pkg = mdef.pkg || mod;
                nmod = {
                    name: name,
                    group: mdef.group,
                    type: 'css',
                    after: sinf.after,
                    path: (parent || pkg) + '/' + sinf.base + skin +
                          '/' + mod + '.css',
                    ext: ext
                };
                if (mdef.base) {
                    nmod.base = mdef.base;
                }
                if (mdef.configFn) {
                    nmod.configFn = mdef.configFn;
                }
                this.addModule(nmod, name);

            }
        }

        return name;
    },

    /**
     * Add a new module group
     * <dl>
     *   <dt>name:</dt>      <dd>required, the group name</dd>
     *   <dt>base:</dt>      <dd>The base dir for this module group</dd>
     *   <dt>root:</dt>      <dd>The root path to add to each combo
     *   resource path</dd>
     *   <dt>combine:</dt>   <dd>combo handle</dd>
     *   <dt>comboBase:</dt> <dd>combo service base path</dd>
     *   <dt>modules:</dt>   <dd>the group of modules</dd>
     * </dl>
     * @method addGroup
     * @param {object} o An object containing the module data.
     * @param {string} name the group name.
     */
    addGroup: function(o, name) {
        var mods = o.modules,
            self = this;
        name = name || o.name;
        o.name = name;
        self.groups[name] = o;

        if (o.patterns) {
            oeach(o.patterns, function(v, k) {
                v.group = name;
                self.patterns[k] = v;
            });
        }

        if (mods) {
            oeach(mods, function(v, k) {
                v.group = name;
                self.addModule(v, k);
            }, self);
        }
    },

    /**
     * Add a new module to the component metadata.
     * <dl>
     *     <dt>name:</dt>       <dd>required, the component name</dd>
     *     <dt>type:</dt>       <dd>required, the component type (js or css)
     *     </dd>
     *     <dt>path:</dt>       <dd>required, the path to the script from
     *     "base"</dd>
     *     <dt>requires:</dt>   <dd>array of modules required by this
     *     component</dd>
     *     <dt>optional:</dt>   <dd>array of optional modules for this
     *     component</dd>
     *     <dt>supersedes:</dt> <dd>array of the modules this component
     *     replaces</dd>
     *     <dt>after:</dt>      <dd>array of modules the components which, if
     *     present, should be sorted above this one</dd>
     *     <dt>after_map:</dt>  <dd>faster alternative to 'after' -- supply
     *     a hash instead of an array</dd>
     *     <dt>rollup:</dt>     <dd>the number of superseded modules required
     *     for automatic rollup</dd>
     *     <dt>fullpath:</dt>   <dd>If fullpath is specified, this is used
     *     instead of the configured base + path</dd>
     *     <dt>skinnable:</dt>  <dd>flag to determine if skin assets should
     *     automatically be pulled in</dd>
     *     <dt>submodules:</dt> <dd>a hash of submodules</dd>
     *     <dt>group:</dt>      <dd>The group the module belongs to -- this
     *     is set automatically when it is added as part of a group
     *     configuration.</dd>
     *     <dt>lang:</dt>
     *       <dd>array of BCP 47 language tags of languages for which this
     *           module has localized resource bundles,
     *           e.g., ["en-GB","zh-Hans-CN"]</dd>
     *     <dt>condition:</dt>
     *       <dd>Specifies that the module should be loaded automatically if
     *           a condition is met.  This is an object with up to three fields:
     *           [trigger] - the name of a module that can trigger the auto-load
     *           [test] - a function that returns true when the module is to be
     *           loaded.
     *           [when] - specifies the load order of the conditional module
     *           with regard to the position of the trigger module.
     *           This should be one of three values: 'before', 'after', or
     *           'instead'.  The default is 'after'.
     *       </dd>
     *     <dt>testresults:</dt><dd>a hash of test results from Y.Features.all()</dd>
     * </dl>
     * @method addModule
     * @param {object} o An object containing the module data.
     * @param {string} name the module name (optional), required if not
     * in the module data.
     * @return {object} the module definition or null if
     * the object passed in did not provide all required attributes.
     */
    addModule: function(o, name) {
        name = name || o.name;
        
        //Only merge this data if the temp flag is set
        //from an earlier pass from a pattern or else
        //an override module (YUI_config) can not be used to
        //replace a default module.
        if (this.moduleInfo[name] && this.moduleInfo[name].temp) {
            //This catches temp modules loaded via a pattern
            // The module will be added twice, once from the pattern and
            // Once from the actual add call, this ensures that properties
            // that were added to the module the first time around (group: gallery)
            // are also added the second time around too.
            o = Y.merge(this.moduleInfo[name], o);
        }

        o.name = name;

        if (!o || !o.name) {
            return null;
        }

        if (!o.type) {
            o.type = JS;
        }

        if (!o.path && !o.fullpath) {
            o.path = _path(name, name, o.type);
        }
        o.supersedes = o.supersedes || o.use;

        o.ext = ('ext' in o) ? o.ext : (this._internal) ? false : true;
        o.requires = this.filterRequires(o.requires) || [];

        // Handle submodule logic
        var subs = o.submodules, i, l, t, sup, s, smod, plugins, plug,
            j, langs, packName, supName, flatSup, flatLang, lang, ret,
            overrides, skinname, when,
            conditions = this.conditions, trigger;
            // , existing = this.moduleInfo[name], newr;

        this.moduleInfo[name] = o;

        if (!o.langPack && o.lang) {
            langs = YArray(o.lang);
            for (j = 0; j < langs.length; j++) {
                lang = langs[j];
                packName = this.getLangPackName(lang, name);
                smod = this.moduleInfo[packName];
                if (!smod) {
                    smod = this._addLangPack(lang, o, packName);
                }
            }
        }

        if (subs) {
            sup = o.supersedes || [];
            l = 0;

            for (i in subs) {
                if (subs.hasOwnProperty(i)) {
                    s = subs[i];

                    s.path = s.path || _path(name, i, o.type);
                    s.pkg = name;
                    s.group = o.group;

                    if (s.supersedes) {
                        sup = sup.concat(s.supersedes);
                    }

                    smod = this.addModule(s, i);
                    sup.push(i);

                    if (smod.skinnable) {
                        o.skinnable = true;
                        overrides = this.skin.overrides;
                        if (overrides && overrides[i]) {
                            for (j = 0; j < overrides[i].length; j++) {
                                skinname = this._addSkin(overrides[i][j],
                                         i, name);
                                sup.push(skinname);
                            }
                        }
                        skinname = this._addSkin(this.skin.defaultSkin,
                                        i, name);
                        sup.push(skinname);
                    }

                    // looks like we are expected to work out the metadata
                    // for the parent module language packs from what is
                    // specified in the child modules.
                    if (s.lang && s.lang.length) {

                        langs = YArray(s.lang);
                        for (j = 0; j < langs.length; j++) {
                            lang = langs[j];
                            packName = this.getLangPackName(lang, name);
                            supName = this.getLangPackName(lang, i);
                            smod = this.moduleInfo[packName];

                            if (!smod) {
                                smod = this._addLangPack(lang, o, packName);
                            }

                            flatSup = flatSup || YArray.hash(smod.supersedes);

                            if (!(supName in flatSup)) {
                                smod.supersedes.push(supName);
                            }

                            o.lang = o.lang || [];

                            flatLang = flatLang || YArray.hash(o.lang);

                            if (!(lang in flatLang)) {
                                o.lang.push(lang);
                            }

// Add rollup file, need to add to supersedes list too

                            // default packages
                            packName = this.getLangPackName(ROOT_LANG, name);
                            supName = this.getLangPackName(ROOT_LANG, i);

                            smod = this.moduleInfo[packName];

                            if (!smod) {
                                smod = this._addLangPack(lang, o, packName);
                            }

                            if (!(supName in flatSup)) {
                                smod.supersedes.push(supName);
                            }

// Add rollup file, need to add to supersedes list too

                        }
                    }

                    l++;
                }
            }
            //o.supersedes = YObject.keys(YArray.hash(sup));
            o.supersedes = YArray.dedupe(sup);
            if (this.allowRollup) {
                o.rollup = (l < 4) ? l : Math.min(l - 1, 4);
            }
        }

        plugins = o.plugins;
        if (plugins) {
            for (i in plugins) {
                if (plugins.hasOwnProperty(i)) {
                    plug = plugins[i];
                    plug.pkg = name;
                    plug.path = plug.path || _path(name, i, o.type);
                    plug.requires = plug.requires || [];
                    plug.group = o.group;
                    this.addModule(plug, i);
                    if (o.skinnable) {
                        this._addSkin(this.skin.defaultSkin, i, name);
                    }

                }
            }
        }

        if (o.condition) {
            t = o.condition.trigger;
            if (YUI.Env.aliases[t]) {
                t = YUI.Env.aliases[t];
            }
            if (!Y.Lang.isArray(t)) {
                t = [t];
            }

            for (i = 0; i < t.length; i++) {
                trigger = t[i];
                when = o.condition.when;
                conditions[trigger] = conditions[trigger] || {};
                conditions[trigger][name] = o.condition;
                // the 'when' attribute can be 'before', 'after', or 'instead'
                // the default is after.
                if (when && when != 'after') {
                    if (when == 'instead') { // replace the trigger
                        o.supersedes = o.supersedes || [];
                        o.supersedes.push(trigger);
                    } else { // before the trigger
                        // the trigger requires the conditional mod,
                        // so it should appear before the conditional
                        // mod if we do not intersede.
                    }
                } else { // after the trigger
                    o.after = o.after || [];
                    o.after.push(trigger);
                }
            }
        }

        if (o.after) {
            o.after_map = YArray.hash(o.after);
        }

        // this.dirty = true;

        if (o.configFn) {
            ret = o.configFn(o);
            if (ret === false) {
                delete this.moduleInfo[name];
                o = null;
            }
        }

        return o;
    },

    /**
     * Add a requirement for one or more module
     * @method require
     * @param {string[] | string*} what the modules to load.
     */
    require: function(what) {
        var a = (typeof what === 'string') ? YArray(arguments) : what;
        this.dirty = true;
        this.required = Y.merge(this.required, YArray.hash(this.filterRequires(a)));

        this._explodeRollups();
    },
    /**
    * Grab all the items that were asked for, check to see if the Loader
    * meta-data contains a "use" array. If it doesm remove the asked item and replace it with 
    * the content of the "use".
    * This will make asking for: "dd"
    * Actually ask for: "dd-ddm-base,dd-ddm,dd-ddm-drop,dd-drag,dd-proxy,dd-constrain,dd-drop,dd-scroll,dd-drop-plugin"
    * @private
    * @method _explodeRollups
    */
    _explodeRollups: function() {
        var self = this, m,
        r = self.required;
        if (!self.allowRollup) {
            oeach(r, function(v, name) {
                m = self.getModule(name);
                if (m && m.use) {
                    //delete r[name];
                    YArray.each(m.use, function(v) {
                        m = self.getModule(v);
                        if (m && m.use) {
                            //delete r[v];
                            YArray.each(m.use, function(v) {
                                r[v] = true;
                            });
                        } else {
                            r[v] = true;
                        }
                    });
                }
            });
            self.required = r;
        }

    },
    /**
    * Explodes the required array to remove aliases and replace them with real modules
    * @method filterRequires
    * @param {Array} r The original requires array
    * @return {Array} The new array of exploded requirements
    */
    filterRequires: function(r) {
        if (r) {
            if (!Y.Lang.isArray(r)) {
                r = [r];
            }
            r = Y.Array(r);
            var c = [], i, mod, o, m;

            for (i = 0; i < r.length; i++) {
                mod = this.getModule(r[i]);
                if (mod && mod.use) {
                    for (o = 0; o < mod.use.length; o++) {
                        //Must walk the other modules in case a module is a rollup of rollups (datatype)
                        m = this.getModule(mod.use[o]);
                        if (m && m.use) {
                            c = Y.Array.dedupe([].concat(c, this.filterRequires(m.use)));
                        } else {
                            c.push(mod.use[o]);
                        }
                    }
                } else {
                    c.push(r[i]);
                }
            }
            r = c;
        }
        return r;
    },
    /**
     * Returns an object containing properties for all modules required
     * in order to load the requested module
     * @method getRequires
     * @param {object}  mod The module definition from moduleInfo.
     * @return {array} the expanded requirement list.
     */
    getRequires: function(mod) {

        if (!mod || mod._parsed) {
            return NO_REQUIREMENTS;
        }

        var i, m, j, add, packName, lang, testresults = this.testresults,
            name = mod.name, cond, go,
            adddef = ON_PAGE[name] && ON_PAGE[name].details,
            d, k, m1,
            r, old_mod,
            o, skinmod, skindef, skinpar, skinname,
            intl = mod.lang || mod.intl,
            info = this.moduleInfo,
            ftests = Y.Features && Y.Features.tests.load,
            hash;

        // console.log(name);

        // pattern match leaves module stub that needs to be filled out
        if (mod.temp && adddef) {
            old_mod = mod;
            mod = this.addModule(adddef, name);
            mod.group = old_mod.group;
            mod.pkg = old_mod.pkg;
            delete mod.expanded;
        }

        // console.log('cache: ' + mod.langCache + ' == ' + this.lang);

        // if (mod.expanded && (!mod.langCache || mod.langCache == this.lang)) {
        if (mod.expanded && (!this.lang || mod.langCache === this.lang)) {
            return mod.expanded;
        }
        

        d = [];
        hash = {};
        
        r = this.filterRequires(mod.requires);
        if (mod.lang) {
            //If a module has a lang attribute, auto add the intl requirement.
            d.unshift('intl');
            r.unshift('intl');
            intl = true;
        }
        o = this.filterRequires(mod.optional);


        mod._parsed = true;
        mod.langCache = this.lang;

        for (i = 0; i < r.length; i++) {
            if (!hash[r[i]]) {
                d.push(r[i]);
                hash[r[i]] = true;
                m = this.getModule(r[i]);
                if (m) {
                    add = this.getRequires(m);
                    intl = intl || (m.expanded_map &&
                        (INTL in m.expanded_map));
                    for (j = 0; j < add.length; j++) {
                        d.push(add[j]);
                    }
                }
            }
        }

        // get the requirements from superseded modules, if any
        r = this.filterRequires(mod.supersedes);
        if (r) {
            for (i = 0; i < r.length; i++) {
                if (!hash[r[i]]) {
                    // if this module has submodules, the requirements list is
                    // expanded to include the submodules.  This is so we can
                    // prevent dups when a submodule is already loaded and the
                    // parent is requested.
                    if (mod.submodules) {
                        d.push(r[i]);
                    }

                    hash[r[i]] = true;
                    m = this.getModule(r[i]);

                    if (m) {
                        add = this.getRequires(m);
                        intl = intl || (m.expanded_map &&
                            (INTL in m.expanded_map));
                        for (j = 0; j < add.length; j++) {
                            d.push(add[j]);
                        }
                    }
                }
            }
        }

        if (o && this.loadOptional) {
            for (i = 0; i < o.length; i++) {
                if (!hash[o[i]]) {
                    d.push(o[i]);
                    hash[o[i]] = true;
                    m = info[o[i]];
                    if (m) {
                        add = this.getRequires(m);
                        intl = intl || (m.expanded_map &&
                            (INTL in m.expanded_map));
                        for (j = 0; j < add.length; j++) {
                            d.push(add[j]);
                        }
                    }
                }
            }
        }

        cond = this.conditions[name];

        if (cond) {
            if (testresults && ftests) {
                oeach(testresults, function(result, id) {
                    var condmod = ftests[id].name;
                    if (!hash[condmod] && ftests[id].trigger == name) {
                        if (result && ftests[id]) {
                            hash[condmod] = true;
                            d.push(condmod);
                        }
                    }
                });
            } else {
                oeach(cond, function(def, condmod) {
                    if (!hash[condmod]) {
                        go = def && ((def.ua && Y.UA[def.ua]) ||
                                     (def.test && def.test(Y, r)));
                        if (go) {
                            hash[condmod] = true;
                            d.push(condmod);
                            m = this.getModule(condmod);
                            if (m) {
                                add = this.getRequires(m);
                                for (j = 0; j < add.length; j++) {
                                    d.push(add[j]);
                                }
                            }
                        }
                    }
                }, this);
            }
        }

        // Create skin modules
        if (mod.skinnable) {
            skindef = this.skin.overrides;
            oeach(YUI.Env.aliases, function(o, n) {
                if (Y.Array.indexOf(o, name) > -1) {
                    skinpar = n;
                }
            });
            if (skindef && (skindef[name] || (skinpar && skindef[skinpar]))) {
                skinname = name;
                if (skindef[skinpar]) {
                    skinname = skinpar;
                }
                for (i = 0; i < skindef[skinname].length; i++) {
                    skinmod = this._addSkin(skindef[skinname][i], name);
                    d.push(skinmod);
                }
            } else {
                skinmod = this._addSkin(this.skin.defaultSkin, name);
                d.push(skinmod);
            }
        }

        mod._parsed = false;

        if (intl) {

            if (mod.lang && !mod.langPack && Y.Intl) {
                lang = Y.Intl.lookupBestLang(this.lang || ROOT_LANG, mod.lang);
                packName = this.getLangPackName(lang, name);
                if (packName) {
                    d.unshift(packName);
                }
            }
            d.unshift(INTL);
        }

        mod.expanded_map = YArray.hash(d);

        mod.expanded = YObject.keys(mod.expanded_map);

        return mod.expanded;
    },


    /**
     * Returns a hash of module names the supplied module satisfies.
     * @method getProvides
     * @param {string} name The name of the module.
     * @return {object} what this module provides.
     */
    getProvides: function(name) {
        var m = this.getModule(name), o, s;
            // supmap = this.provides;

        if (!m) {
            return NOT_FOUND;
        }

        if (m && !m.provides) {
            o = {};
            s = m.supersedes;

            if (s) {
                YArray.each(s, function(v) {
                    Y.mix(o, this.getProvides(v));
                }, this);
            }

            o[name] = true;
            m.provides = o;

        }

        return m.provides;
    },

    /**
     * Calculates the dependency tree, the result is stored in the sorted
     * property.
     * @method calculate
     * @param {object} o optional options object.
     * @param {string} type optional argument to prune modules.
     */
    calculate: function(o, type) {
        if (o || type || this.dirty) {

            if (o) {
                this._config(o);
            }

            if (!this._init) {
                this._setup();
            }

            this._explode();

            if (this.allowRollup) {
                this._rollup();
            } else {
                this._explodeRollups();
            }
            this._reduce();
            this._sort();
        }
    },
    /**
    * Creates a "psuedo" package for languages provided in the lang array
    * @method _addLangPack
    * @param {String} lang The language to create
    * @param {Object} m The module definition to create the language pack around
    * @param {String} packName The name of the package (e.g: lang/datatype-date-en-US)
    * @return {Object} The module definition
    */
    _addLangPack: function(lang, m, packName) {
        var name = m.name,
            packPath,
            existing = this.moduleInfo[packName];

        if (!existing) {

            packPath = _path((m.pkg || name), packName, JS, true);

            this.addModule({ path: packPath,
                             intl: true,
                             langPack: true,
                             ext: m.ext,
                             group: m.group,
                             supersedes: [] }, packName);

            if (lang) {
                Y.Env.lang = Y.Env.lang || {};
                Y.Env.lang[lang] = Y.Env.lang[lang] || {};
                Y.Env.lang[lang][name] = true;
            }
        }

        return this.moduleInfo[packName];
    },

    /**
     * Investigates the current YUI configuration on the page.  By default,
     * modules already detected will not be loaded again unless a force
     * option is encountered.  Called by calculate()
     * @method _setup
     * @private
     */
    _setup: function() {
        var info = this.moduleInfo, name, i, j, m, l,
            packName;

        for (name in info) {
            if (info.hasOwnProperty(name)) {
                m = info[name];
                if (m) {

                    // remove dups
                    //m.requires = YObject.keys(YArray.hash(m.requires));
                    m.requires = YArray.dedupe(m.requires);

                    // Create lang pack modules
                    if (m.lang && m.lang.length) {
                        // Setup root package if the module has lang defined,
                        // it needs to provide a root language pack
                        packName = this.getLangPackName(ROOT_LANG, name);
                        this._addLangPack(null, m, packName);
                    }

                }
            }
        }


        //l = Y.merge(this.inserted);
        l = {};

        // available modules
        if (!this.ignoreRegistered) {
            Y.mix(l, GLOBAL_ENV.mods);
        }

        // add the ignore list to the list of loaded packages
        if (this.ignore) {
            Y.mix(l, YArray.hash(this.ignore));
        }

        // expand the list to include superseded modules
        for (j in l) {
            if (l.hasOwnProperty(j)) {
                Y.mix(l, this.getProvides(j));
            }
        }

        // remove modules on the force list from the loaded list
        if (this.force) {
            for (i = 0; i < this.force.length; i++) {
                if (this.force[i] in l) {
                    delete l[this.force[i]];
                }
            }
        }

        Y.mix(this.loaded, l);

        this._init = true;
    },

    /**
     * Builds a module name for a language pack
     * @method getLangPackName
     * @param {string} lang the language code.
     * @param {string} mname the module to build it for.
     * @return {string} the language pack module name.
     */
    getLangPackName: function(lang, mname) {
        return ('lang/' + mname + ((lang) ? '_' + lang : ''));
    },
    /**
     * Inspects the required modules list looking for additional
     * dependencies.  Expands the required list to include all
     * required modules.  Called by calculate()
     * @method _explode
     * @private
     */
    _explode: function() {
        var r = this.required, m, reqs, done = {},
            self = this;

        // the setup phase is over, all modules have been created
        self.dirty = false;

        self._explodeRollups();
        r = self.required;
        
        oeach(r, function(v, name) {
            if (!done[name]) {
                done[name] = true;
                m = self.getModule(name);
                if (m) {
                    var expound = m.expound;

                    if (expound) {
                        r[expound] = self.getModule(expound);
                        reqs = self.getRequires(r[expound]);
                        Y.mix(r, YArray.hash(reqs));
                    }

                    reqs = self.getRequires(m);
                    Y.mix(r, YArray.hash(reqs));
                }
            }
        });

    },
    /**
    * Get's the loader meta data for the requested module
    * @method getModule
    * @param {String} mname The module name to get
    * @return {Object} The module metadata
    */
    getModule: function(mname) {
        //TODO: Remove name check - it's a quick hack to fix pattern WIP
        if (!mname) {
            return null;
        }

        var p, found, pname,
            m = this.moduleInfo[mname],
            patterns = this.patterns;

        // check the patterns library to see if we should automatically add
        // the module with defaults
        if (!m) {
            for (pname in patterns) {
                if (patterns.hasOwnProperty(pname)) {
                    p = patterns[pname];

                    // use the metadata supplied for the pattern
                    // as the module definition.
                    if (mname.indexOf(pname) > -1) {
                        found = p;
                        break;
                    }
                }
            }

            if (found) {
                if (p.action) {
                    p.action.call(this, mname, pname);
                } else {
                    // ext true or false?
                    m = this.addModule(Y.merge(found), mname);
                    m.temp = true;
                }
            }
        }

        return m;
    },

    // impl in rollup submodule
    _rollup: function() { },

    /**
     * Remove superceded modules and loaded modules.  Called by
     * calculate() after we have the mega list of all dependencies
     * @method _reduce
     * @return {object} the reduced dependency hash.
     * @private
     */
    _reduce: function(r) {

        r = r || this.required;

        var i, j, s, m, type = this.loadType,
        ignore = this.ignore ? YArray.hash(this.ignore) : false;

        for (i in r) {
            if (r.hasOwnProperty(i)) {
                m = this.getModule(i);
                // remove if already loaded
                if (((this.loaded[i] || ON_PAGE[i]) &&
                        !this.forceMap[i] && !this.ignoreRegistered) ||
                        (type && m && m.type != type)) {
                    delete r[i];
                }
                if (ignore && ignore[i]) {
                    delete r[i];
                }
                // remove anything this module supersedes
                s = m && m.supersedes;
                if (s) {
                    for (j = 0; j < s.length; j++) {
                        if (s[j] in r) {
                            delete r[s[j]];
                        }
                    }
                }
            }
        }

        return r;
    },
    /**
    * Handles the queue when a module has been loaded for all cases
    * @method _finish
    * @private
    * @param {String} msg The message from Loader
    * @param {Boolean} success A boolean denoting success or failure
    */
    _finish: function(msg, success) {

        _queue.running = false;

        var onEnd = this.onEnd;
        if (onEnd) {
            onEnd.call(this.context, {
                msg: msg,
                data: this.data,
                success: success
            });
        }
        this._continue();
    },
    /**
    * The default Loader onSuccess handler, calls this.onSuccess with a payload
    * @method _onSuccess
    * @private
    */
    _onSuccess: function() {
        var self = this, skipped = Y.merge(self.skipped), fn,
            failed = [], rreg = self.requireRegistration,
            success, msg;

        oeach(skipped, function(k) {
            delete self.inserted[k];
        });

        self.skipped = {};

        oeach(self.inserted, function(v, k) {
            var mod = self.getModule(k);
            if (mod && rreg && mod.type == JS && !(k in YUI.Env.mods)) {
                failed.push(k);
            } else {
                Y.mix(self.loaded, self.getProvides(k));
            }
        });

        fn = self.onSuccess;
        msg = (failed.length) ? 'notregistered' : 'success';
        success = !(failed.length);
        if (fn) {
            fn.call(self.context, {
                msg: msg,
                data: self.data,
                success: success,
                failed: failed,
                skipped: skipped
            });
        }
        self._finish(msg, success);
    },
    /**
    * The default Loader onFailure handler, calls this.onFailure with a payload
    * @method _onFailure
    * @private
    */
    _onFailure: function(o) {
        var f = this.onFailure, msg = 'failure: ' + o.msg;
        if (f) {
            f.call(this.context, {
                msg: msg,
                data: this.data,
                success: false
            });
        }
        this._finish(msg, false);
    },

    /**
    * The default Loader onTimeout handler, calls this.onTimeout with a payload
    * @method _onTimeout
    * @private
    */
    _onTimeout: function() {
        var f = this.onTimeout;
        if (f) {
            f.call(this.context, {
                msg: 'timeout',
                data: this.data,
                success: false
            });
        }
        this._finish('timeout', false);
    },

    /**
     * Sorts the dependency tree.  The last step of calculate()
     * @method _sort
     * @private
     */
    _sort: function() {

        // create an indexed list
        var s = YObject.keys(this.required),
            // loaded = this.loaded,
            done = {},
            p = 0, l, a, b, j, k, moved, doneKey;

        // keep going until we make a pass without moving anything
        for (;;) {

            l = s.length;
            moved = false;

            // start the loop after items that are already sorted
            for (j = p; j < l; j++) {

                // check the next module on the list to see if its
                // dependencies have been met
                a = s[j];

                // check everything below current item and move if we
                // find a requirement for the current item
                for (k = j + 1; k < l; k++) {
                    doneKey = a + s[k];

                    if (!done[doneKey] && this._requires(a, s[k])) {

                        // extract the dependency so we can move it up
                        b = s.splice(k, 1);

                        // insert the dependency above the item that
                        // requires it
                        s.splice(j, 0, b[0]);

                        // only swap two dependencies once to short circut
                        // circular dependencies
                        done[doneKey] = true;

                        // keep working
                        moved = true;

                        break;
                    }
                }

                // jump out of loop if we moved something
                if (moved) {
                    break;
                // this item is sorted, move our pointer and keep going
                } else {
                    p++;
                }
            }

            // when we make it here and moved is false, we are
            // finished sorting
            if (!moved) {
                break;
            }

        }

        this.sorted = s;
    },
    /**
    * (Unimplemented)
    * @method partial
    * @unimplemented
    */
    partial: function(partial, o, type) {
        this.sorted = partial;
        this.insert(o, type, true);
    },
    /**
    * Handles the actual insertion of script/link tags
    * @method _insert
    * @param {Object} source The YUI instance the request came from
    * @param {Object} o The metadata to include
    * @param {String} type JS or CSS
    * @param {Boolean} [skipcalc=false] Do a Loader.calculate on the meta
    */
    _insert: function(source, o, type, skipcalc) {


        // restore the state at the time of the request
        if (source) {
            this._config(source);
        }

        // build the dependency list
        // don't include type so we can process CSS and script in
        // one pass when the type is not specified.
        if (!skipcalc) {
            this.calculate(o);
        }

        this.loadType = type;

        if (!type) {

            var self = this;

            this._internalCallback = function() {

                var f = self.onCSS, n, p, sib;

                // IE hack for style overrides that are not being applied
                if (this.insertBefore && Y.UA.ie) {
                    n = Y.config.doc.getElementById(this.insertBefore);
                    p = n.parentNode;
                    sib = n.nextSibling;
                    p.removeChild(n);
                    if (sib) {
                        p.insertBefore(n, sib);
                    } else {
                        p.appendChild(n);
                    }
                }

                if (f) {
                    f.call(self.context, Y);
                }
                self._internalCallback = null;

                self._insert(null, null, JS);
            };

            this._insert(null, null, CSS);

            return;
        }

        // set a flag to indicate the load has started
        this._loading = true;

        // flag to indicate we are done with the combo service
        // and any additional files will need to be loaded
        // individually
        this._combineComplete = {};

        // start the load
        this.loadNext();

    },
    /**
    * Once a loader operation is completely finished, process any additional queued items.
    * @method _continue
    * @private
    */
    _continue: function() {
        if (!(_queue.running) && _queue.size() > 0) {
            _queue.running = true;
            _queue.next()();
        }
    },

    /**
     * inserts the requested modules and their dependencies.
     * <code>type</code> can be "js" or "css".  Both script and
     * css are inserted if type is not provided.
     * @method insert
     * @param {object} o optional options object.
     * @param {string} type the type of dependency to insert.
     */
    insert: function(o, type, skipsort) {
        var self = this, copy = Y.merge(this);
        delete copy.require;
        delete copy.dirty;
        _queue.add(function() {
            self._insert(copy, o, type, skipsort);
        });
        this._continue();
    },

    /**
     * Executed every time a module is loaded, and if we are in a load
     * cycle, we attempt to load the next script.  Public so that it
     * is possible to call this if using a method other than
     * Y.register to determine when scripts are fully loaded
     * @method loadNext
     * @param {string} mname optional the name of the module that has
     * been loaded (which is usually why it is time to load the next
     * one).
     */
    loadNext: function(mname) {
        // It is possible that this function is executed due to something
        // else on the page loading a YUI module.  Only react when we
        // are actively loading something
        if (!this._loading) {
            return;
        }

        var s, len, i, m, url, fn, msg, attr, group, groupName, j, frag,
            comboSource, comboSources, mods, combining, urls, comboBase,
            self = this,
            type = self.loadType,
            handleSuccess = function(o) {
                self.loadNext(o.data);
            },
            handleCombo = function(o) {
                self._combineComplete[type] = true;
                var i, len = combining.length;

                for (i = 0; i < len; i++) {
                    self.inserted[combining[i]] = true;
                }

                handleSuccess(o);
            };

        if (self.combine && (!self._combineComplete[type])) {

            combining = [];

            self._combining = combining;
            s = self.sorted;
            len = s.length;

            // the default combo base
            comboBase = self.comboBase;

            url = comboBase;
            urls = [];

            comboSources = {};

            for (i = 0; i < len; i++) {
                comboSource = comboBase;
                m = self.getModule(s[i]);
                groupName = m && m.group;
                if (groupName) {

                    group = self.groups[groupName];

                    if (!group.combine) {
                        m.combine = false;
                        continue;
                    }
                    m.combine = true;
                    if (group.comboBase) {
                        comboSource = group.comboBase;
                    }

                    if ("root" in group && L.isValue(group.root)) {
                        m.root = group.root;
                    }

                }

                comboSources[comboSource] = comboSources[comboSource] || [];
                comboSources[comboSource].push(m);
            }

            for (j in comboSources) {
                if (comboSources.hasOwnProperty(j)) {
                    url = j;
                    mods = comboSources[j];
                    len = mods.length;

                    for (i = 0; i < len; i++) {
                        // m = self.getModule(s[i]);
                        m = mods[i];

                        // Do not try to combine non-yui JS unless combo def
                        // is found
                        if (m && (m.type === type) && (m.combine || !m.ext)) {

                            frag = ((L.isValue(m.root)) ? m.root : self.root) + m.path;
                            frag = self._filter(frag, m.name);
                            if ((url !== j) && (i <= (len - 1)) &&
                            ((frag.length + url.length) > self.maxURLLength)) {
                                //Hack until this is rewritten to use an array and not string concat:
                                if (url.substr(url.length - 1, 1) === self.comboSep) {
                                    url = url.substr(0, (url.length - 1));
                                }
                                urls.push(self._filter(url));
                                url = j;
                            }

                            url += frag;
                            if (i < (len - 1)) {
                                url += self.comboSep;
                            }

                            combining.push(m.name);
                        }

                    }

                    if (combining.length && (url != j)) {
                        //Hack until this is rewritten to use an array and not string concat:
                        if (url.substr(url.length - 1, 1) === self.comboSep) {
                            url = url.substr(0, (url.length - 1));
                        }
                        urls.push(self._filter(url));
                    }
                }
            }

            if (combining.length) {


                // if (m.type === CSS) {
                if (type === CSS) {
                    fn = Y.Get.css;
                    attr = self.cssAttributes;
                } else {
                    fn = Y.Get.script;
                    attr = self.jsAttributes;
                }

                fn(urls, {
                    data: self._loading,
                    onSuccess: handleCombo,
                    onFailure: self._onFailure,
                    onTimeout: self._onTimeout,
                    insertBefore: self.insertBefore,
                    charset: self.charset,
                    attributes: attr,
                    timeout: self.timeout,
                    autopurge: false,
                    context: self
                });

                return;

            } else {
                self._combineComplete[type] = true;
            }
        }

        if (mname) {

            // if the module that was just loaded isn't what we were expecting,
            // continue to wait
            if (mname !== self._loading) {
                return;
            }


            // The global handler that is called when each module is loaded
            // will pass that module name to this function.  Storing this
            // data to avoid loading the same module multiple times
            // centralize this in the callback
            self.inserted[mname] = true;
            // self.loaded[mname] = true;

            // provided = self.getProvides(mname);
            // Y.mix(self.loaded, provided);
            // Y.mix(self.inserted, provided);

            if (self.onProgress) {
                self.onProgress.call(self.context, {
                        name: mname,
                        data: self.data
                    });
            }
        }

        s = self.sorted;
        len = s.length;

        for (i = 0; i < len; i = i + 1) {
            // this.inserted keeps track of what the loader has loaded.
            // move on if this item is done.
            if (s[i] in self.inserted) {
                continue;
            }

            // Because rollups will cause multiple load notifications
            // from Y, loadNext may be called multiple times for
            // the same module when loading a rollup.  We can safely
            // skip the subsequent requests
            if (s[i] === self._loading) {
                return;
            }

            // log("inserting " + s[i]);
            m = self.getModule(s[i]);

            if (!m) {
                if (!self.skipped[s[i]]) {
                    msg = 'Undefined module ' + s[i] + ' skipped';
                    // self.inserted[s[i]] = true;
                    self.skipped[s[i]] = true;
                }
                continue;

            }

            group = (m.group && self.groups[m.group]) || NOT_FOUND;

            // The load type is stored to offer the possibility to load
            // the css separately from the script.
            if (!type || type === m.type) {
                self._loading = s[i];

                if (m.type === CSS) {
                    fn = Y.Get.css;
                    attr = self.cssAttributes;
                } else {
                    fn = Y.Get.script;
                    attr = self.jsAttributes;
                }

                url = (m.fullpath) ? self._filter(m.fullpath, s[i]) :
                      self._url(m.path, s[i], group.base || m.base);

                fn(url, {
                    data: s[i],
                    onSuccess: handleSuccess,
                    insertBefore: self.insertBefore,
                    charset: self.charset,
                    attributes: attr,
                    onFailure: self._onFailure,
                    onTimeout: self._onTimeout,
                    timeout: self.timeout,
                    autopurge: false,
                    context: self
                });

                return;
            }
        }

        // we are finished
        self._loading = null;

        fn = self._internalCallback;

        // internal callback for loading css first
        if (fn) {
            self._internalCallback = null;
            fn.call(self);
        } else {
            self._onSuccess();
        }
    },

    /**
     * Apply filter defined for this instance to a url/path
     * @method _filter
     * @param {string} u the string to filter.
     * @param {string} name the name of the module, if we are processing
     * a single module as opposed to a combined url.
     * @return {string} the filtered string.
     * @private
     */
    _filter: function(u, name) {
        var f = this.filter,
            hasFilter = name && (name in this.filters),
            modFilter = hasFilter && this.filters[name],
	    groupName = this.moduleInfo[name] ? this.moduleInfo[name].group:null;		
	    if (groupName && this.groups[groupName].filter) {		
	 	   modFilter = this.groups[groupName].filter;
		   hasFilter = true;		
	     };

        if (u) {
            if (hasFilter) {
                f = (L.isString(modFilter)) ?
                    this.FILTER_DEFS[modFilter.toUpperCase()] || null :
                    modFilter;
            }
            if (f) {
                u = u.replace(new RegExp(f.searchExp, 'g'), f.replaceStr);
            }
        }

        return u;
    },

    /**
     * Generates the full url for a module
     * @method _url
     * @param {string} path the path fragment.
     * @param {String} name The name of the module
     * @pamra {String} [base=self.base] The base url to use
     * @return {string} the full url.
     * @private
     */
    _url: function(path, name, base) {
        return this._filter((base || this.base || '') + path, name);
    },
    /**
    * Returns an Object hash of file arrays built from `loader.sorted` or from an arbitrary list of sorted modules.
    * @method resolve
    * @param {Boolean} [calc=false] Perform a loader.calculate() before anything else
    * @param {Array} [s=loader.sorted] An override for the loader.sorted array
    * @return {Object} Object hash (js and css) of two arrays of file lists
    * @example This method can be used as an off-line dep calculator
    *
    *        var Y = YUI();
    *        var loader = new Y.Loader({
    *            filter: 'debug',
    *            base: '../../',
    *            root: 'build/',
    *            combine: true,
    *            require: ['node', 'dd', 'console']
    *        });
    *        var out = loader.resolve(true);
    *
    */
    resolve: function(calc, s) {
        var self = this, i, m, url, out = { js: [], css: [] };

        if (calc) {
            self.calculate();
        }
        s = s || self.sorted;

        for (i = 0; i < s.length; i++) {
            m = self.getModule(s[i]);
            if (m) {
                if (self.combine) {
                    url = self._filter((self.root + m.path), m.name, self.root);
                } else {
                    url = self._filter(m.fullpath, m.name, '') || self._url(m.path, m.name);
                }
                out[m.type].push(url);
            }
        }
        if (self.combine) {
            out.js = [self.comboBase + out.js.join(self.comboSep)];
            out.css = [self.comboBase + out.css.join(self.comboSep)];
        }

        return out;
    },
    /**
    * Returns an Object hash of hashes built from `loader.sorted` or from an arbitrary list of sorted modules.
    * @method hash
    * @private
    * @param {Boolean} [calc=false] Perform a loader.calculate() before anything else
    * @param {Array} [s=loader.sorted] An override for the loader.sorted array
    * @return {Object} Object hash (js and css) of two object hashes of file lists, with the module name as the key
    * @example This method can be used as an off-line dep calculator
    *
    *        var Y = YUI();
    *        var loader = new Y.Loader({
    *            filter: 'debug',
    *            base: '../../',
    *            root: 'build/',
    *            combine: true,
    *            require: ['node', 'dd', 'console']
    *        });
    *        var out = loader.hash(true);
    *
    */
    hash: function(calc, s) {
        var self = this, i, m, url, out = { js: {}, css: {} };

        if (calc) {
            self.calculate();
        }
        s = s || self.sorted;

        for (i = 0; i < s.length; i++) {
            m = self.getModule(s[i]);
            if (m) {
                url = self._filter(m.fullpath, m.name, '') || self._url(m.path, m.name);
                out[m.type][m.name] = url;
            }
        }

        return out;
    }
};



}, '3.4.1' ,{requires:['get']});
