YUI.add('tree-node', function (Y, NAME) {

/*jshint expr:true, onevar:false */

/**

Provides the `Tree.Node` class, which represents a tree node contained in a

`Tree` data structure.

@module tree

@submodule tree-node

**/

/**

Represents a tree node in a `Tree` data structure.

@class Tree.Node

@param {Tree} tree `Tree` instance with which this node should be associated.

@param {Object} [config] Configuration hash for this node.

    @param {Boolean} [config.canHaveChildren=false] Whether or not this node can

        contain child nodes. Will be automatically set to `true` if not

        specified and `config.children` contains one or more children.

    @param {Tree.Node[]} [config.children] Array of `Tree.Node` instances

        for child nodes of this node.

    @param {Object} [config.data] Implementation-specific data related to this

        node. You may add arbitrary properties to this hash for your own use.

    @param {String} [config.id] Unique id for this node. This id must be unique

        among all tree nodes on the entire page, and will also be used as this

        node's DOM id when it's rendered by a TreeView. A unique id will be

        automatically generated unless you specify a custom value.

    @param {Object} [config.state] State hash for this node. You may add

        arbitrary state properties to this hash for your own use. See the

        docs for `Tree.Node`'s `state` property for details on state values used

        internally by `Tree.Node`.

@constructor

**/

function TreeNode(tree, config) {

    config || (config = {});

    this.id   = this._yuid = config.id || this.id || Y.guid('treeNode-');

    this.tree = tree;

    this.children = config.children || [];

    this.data     = config.data || {};

    this.state    = config.state || {};

    if (config.canHaveChildren) {

        this.canHaveChildren = config.canHaveChildren;

    } else if (this.children.length) {

        this.canHaveChildren = true;

    }

    // Mix in arbitrary properties on the config object, but don't overwrite any

    // existing properties of this node.

    Y.mix(this, config);

    // If this node has children, loop through them and ensure their parent

    // references are all set to this node.

    for (var i = 0, len = this.children.length; i < len; i++) {

        this.children[i].parent = this;

    }

}

TreeNode.prototype = {

    // -- Public Properties ----------------------------------------------------

    /**

    Whether or not this node can contain child nodes.

    This value is falsy by default unless child nodes are added at instantiation

    time, in which case it will be automatically set to `true`. You can also

    manually set it to `true` to indicate that a node can have children even

    though it might not currently have any children.

    Note that regardless of the value of this property, appending, prepending,

    or inserting a node into this node will cause `canHaveChildren` to be set to

    true automatically.

    @property {Boolean} canHaveChildren

    **/

    /**

    Child nodes contained within this node.

    @property {Tree.Node[]} children

    @default []

    @readOnly

    **/

    /**

    Arbitrary serializable data related to this node.

    Use this property to store any data that should accompany this node when it

    is serialized to JSON.

    @property {Object} data

    @default {}

    **/

    /**

    Unique id for this node.

    @property {String} id

    @readOnly

    **/

    /**

    Parent node of this node, or `undefined` if this is an unattached node or

    the root node.

    @property {Tree.Node} parent

    @readOnly

    **/

    /**

    Current state of this node.

    Use this property to store state-specific info -- such as whether this node

    is "open", "selected", or any other arbitrary state -- that should accompany

    this node when it is serialized to JSON.

    @property {Object} state

    **/

    /**

    The Tree instance with which this node is associated.

    @property {Tree} tree

    @readOnly

    **/

    // -- Protected Properties -------------------------------------------------

    /**

    Mapping of child node ids to indices.

    @property {Object} _indexMap

    @protected

    **/

    /**

    Flag indicating whether the `_indexMap` is stale and needs to be rebuilt.

    @property {Boolean} _isIndexStale

    @default true

    @protected

    **/

    _isIndexStale: true,

    /**

    Simple way to type-check that this is an instance of Tree.Node.

    @property {Boolean} _isYUITreeNode

    @default true

    @protected

    **/

    _isYUITreeNode: true,

    /**

    Array of property names on this node that should be serialized to JSON when

    `toJSON()` is called.

    Note that the `children` property is a special case that is managed

    separately.

    @property {String[]} _serializable

    @protected

    **/

    _serializable: ['canHaveChildren', 'data', 'id', 'state'],

    // -- Public Methods -------------------------------------------------------

    /**

    Appends the given tree node or array of nodes to the end of this node's

    children.

    @method append

    @param {Object|Object[]|Tree.Node|Tree.Node[]} node Child node, node config

        object, array of child nodes, or array of node config objects to append

        to the given parent. Node config objects will automatically be converted

        into node instances.

    @param {Object} [options] Options.

        @param {Boolean} [options.silent=false] If `true`, the `add` event will

            be suppressed.

    @return {Tree.Node|Tree.Node[]} Node or array of nodes that were appended.

    **/

    append: function (node, options) {

        return this.tree.appendNode(this, node, options);

    },

    /**

    Returns this node's depth.

    The root node of a tree always has a depth of 0. A child of the root has a

    depth of 1, a child of that child will have a depth of 2, and so on.

    @method depth

    @return {Number} This node's depth.

    @since 3.11.0

    **/

    depth: function () {

        if (this.isRoot()) {

            return 0;

        }

        var depth  = 0,

            parent = this.parent;

        while (parent) {

            depth += 1;

            parent = parent.parent;

        }

        return depth;

    },

    /**

    Removes all children from this node. The removed children will still be

    reusable unless the `destroy` option is truthy.

    @method empty

    @param {Object} [options] Options.

        @param {Boolean} [options.destroy=false] If `true`, the children will

            also be destroyed, which makes them available for garbage collection

            and means they can't be reused.

        @param {Boolean} [options.silent=false] If `true`, `remove` events will

            be suppressed.

        @param {String} [options.src] Source of the change, to be passed along

            to the event facade of the resulting event. This can be used to

            distinguish between changes triggered by a user and changes

            triggered programmatically, for example.

    @return {Tree.Node[]} Array of removed child nodes.

    **/

    empty: function (options) {

        return this.tree.emptyNode(this, options);

    },

    /**

    Performs a depth-first traversal of this node, passing it and each of its

    descendants to the specified _callback_, and returning the first node for

    which the callback returns a truthy value.

    Traversal will stop as soon as a truthy value is returned from the callback.

    See `Tree#traverseNode()` for more details on how depth-first traversal

    works.

    @method find

    @param {Object} [options] Options.

        @param {Number} [options.depth] Depth limit. If specified, descendants

            will only be traversed to this depth before backtracking and moving

            on.

    @param {Function} callback Callback function to call with the traversed

        node and each of its descendants. If this function returns a truthy

        value, traversal will be stopped and the current node will be returned.

        @param {Tree.Node} callback.node Node being traversed.

    @param {Object} [thisObj] `this` object to use when executing _callback_.

    @return {Tree.Node|null} Returns the first node for which the _callback_

        returns a truthy value, or `null` if the callback never returns a truthy

        value.

    **/

    find: function (options, callback, thisObj) {

        return this.tree.findNode(this, options, callback, thisObj);

    },

    /**

    Returns `true` if this node has one or more child nodes.

    @method hasChildren

    @return {Boolean} `true` if this node has one or more child nodes, `false`

        otherwise.

    **/

    hasChildren: function () {

        return !!this.children.length;

    },

    /**

    Returns the numerical index of this node within its parent node, or `-1` if

    this node doesn't have a parent node.

    @method index

    @return {Number} Index of this node within its parent node, or `-1` if this

        node doesn't have a parent node.

    **/

    index: function () {

        return this.parent ? this.parent.indexOf(this) : -1;

    },

    /**

    Returns the numerical index of the given child node, or `-1` if the node is

    not a child of this node.

    @method indexOf

    @param {Tree.Node} node Child node.

    @return {Number} Index of the child, or `-1` if the node is not a child of

        this node.

    **/

    indexOf: function (node) {

        var index;

        if (this._isIndexStale) {

            this._reindex();

        }

        index = this._indexMap[node.id];

        return typeof index === 'undefined' ? -1 : index;

    },

    /**

    Inserts a node or array of nodes at the specified index under this node, or

    appends them to this node if no index is specified.

    If a node being inserted is from another tree, it and all its children will

    be removed from that tree and moved to this one.

    @method insert

    @param {Object|Object[]|Tree.Node|Tree.Node[]} node Child node, node config

        object, array of child nodes, or array of node config objects to insert

        under the given parent. Node config objects will automatically be

        converted into node instances.

    @param {Object} [options] Options.

        @param {Number} [options.index] Index at which to insert the child node.

            If not specified, the node will be appended as the last child of the

            parent.

        @param {Boolean} [options.silent=false] If `true`, the `add` event will

            be suppressed.

        @param {String} [options.src='insert'] Source of the change, to be

            passed along to the event facade of the resulting event. This can be

            used to distinguish between changes triggered by a user and changes

            triggered programmatically, for example.

    @return {Tree.Node[]} Node or array of nodes that were inserted.

    **/

    insert: function (node, options) {

        return this.tree.insertNode(this, node, options);

    },

    /**

    Returns `true` if this node has been inserted into a tree, `false` if it is

    merely associated with a tree and has not yet been inserted.

    @method isInTree

    @return {Boolean} `true` if this node has been inserted into a tree, `false`

        otherwise.

    **/

    isInTree: function () {

        if (this.tree && this.tree.rootNode === this) {

            return true;

        }

        return !!(this.parent && this.parent.isInTree());

    },

    /**

    Returns `true` if this node is the root of the tree.

    @method isRoot

    @return {Boolean} `true` if this node is the root of the tree, `false`

        otherwise.

    **/

    isRoot: function () {

        return !!(this.tree && this.tree.rootNode === this);

    },

    /**

    Returns this node's next sibling, or `undefined` if this node is the last

    child.

    @method next

    @return {Tree.Node} This node's next sibling, or `undefined` if this node is

        the last child.

    **/

    next: function () {

        if (this.parent) {

            return this.parent.children[this.index() + 1];

        }

    },

    /**

    Prepends a node or array of nodes at the beginning of this node's children.

    If a node being prepended is from another tree, it and all its children will

    be removed from that tree and moved to this one.

    @method prepend

    @param {Object|Object[]|Tree.Node|Tree.Node[]} node Child node, node config

        object, array of child nodes, or array of node config objects to prepend

        to this node. Node config objects will automatically be converted into

        node instances.

    @param {Object} [options] Options.

        @param {Boolean} [options.silent=false] If `true`, the `add` event will

            be suppressed.

    @return {Tree.Node|Tree.Node[]} Node or array of nodes that were prepended.

    **/

    prepend: function (node, options) {

        return this.tree.prependNode(this, node, options);

    },

    /**

    Returns this node's previous sibling, or `undefined` if this node is the

    first child

    @method previous

    @return {Tree.Node} This node's previous sibling, or `undefined` if this

        node is the first child.

    **/

    previous: function () {

        if (this.parent) {

            return this.parent.children[this.index() - 1];

        }

    },

    /**

    Removes this node from its parent node.

    @method remove

    @param {Object} [options] Options.

        @param {Boolean} [options.destroy=false] If `true`, this node and all

            its children will also be destroyed, which makes them available for

            garbage collection and means they can't be reused.

        @param {Boolean} [options.silent=false] If `true`, the `remove` event

            will be suppressed.

        @param {String} [options.src] Source of the change, to be passed along

            to the event facade of the resulting event. This can be used to

            distinguish between changes triggered by a user and changes

            triggered programmatically, for example.

    @chainable

    **/

    remove: function (options) {

        return this.tree.removeNode(this, options);

    },

    /**

    Returns the total number of nodes contained within this node, including all

    descendants of this node's children.

    @method size

    @return {Number} Total number of nodes contained within this node, including

        all descendants.

    **/

    size: function () {

        var children = this.children,