/**
 * @class Ext.tree.TreeSorter
 * Provides sorting of nodes in a {@link Ext.tree.TreePanel}.  The TreeSorter automatically monitors events on the 
 * associated TreePanel that might affect the tree's sort order (beforechildrenrendered, append, insert and textchange).
 * Example usage:

 * 

new Ext.tree.TreeSorter(myTree, {
    folderSort: true,
    dir: "desc",
    sortType: function(node) {
        // sort by a custom, typed attribute:
        return parseInt(node.id, 10);
    }
});

 * @constructor
 * @param {TreePanel} tree
 * @param {Object} config
 */
Ext.tree.TreeSorter = function(tree, config){
    
/**
     * @cfg {Boolean} folderSort True to sort leaf nodes under non-leaf nodes (defaults to false)
     */
    
/** 
     * @cfg {String} property The named attribute on the node to sort by (defaults to "text").  Note that this 
     * property is only used if no {@link #sortType} function is specified, otherwise it is ignored.
     */
    
/** 
     * @cfg {String} dir The direction to sort ("asc" or "desc," case-insensitive, defaults to "asc")
     */
    
/** 
     * @cfg {String} leafAttr The attribute used to determine leaf nodes when {@link #folderSort} = true (defaults to "leaf")
     */
    
/** 
     * @cfg {Boolean} caseSensitive true for case-sensitive sort (defaults to false)
     */
    
/** 
     * @cfg {Function} sortType A custom "casting" function used to convert node values before sorting.  The function
     * will be called with a single parameter (the {@link Ext.tree.TreeNode} being evaluated) and is expected to return
     * the node's sort value cast to the specific data type required for sorting.  This could be used, for example, when
     * a node's text (or other attribute) should be sorted as a date or numeric value.  See the class description for 
     * example usage.  Note that if a sortType is specified, any {@link #property} config will be ignored.
     */
    
    Ext.apply(this, config);
    tree.on("beforechildrenrendered", this.doSort, this);
    tree.on("append", this.updateSort, this);
    tree.on("insert", this.updateSort, this);
    tree.on("textchange", this.updateSortParent, this);
    
    var dsc = this.dir && this.dir.toLowerCase() == "desc";
    var p = this.property || "text";
    var sortType = this.sortType;
    var fs = this.folderSort;
    var cs = this.caseSensitive === true;
    var leafAttr = this.leafAttr || 'leaf';

    this.sortFn = function(n1, n2){
        if(fs){
            if(n1.attributes[leafAttr] && !n2.attributes[leafAttr]){
                return 1;
            }
            if(!n1.attributes[leafAttr] && n2.attributes[leafAttr]){
                return -1;
            }
        }
    	var v1 = sortType ? sortType(n1) : (cs ? n1.attributes[p] : n1.attributes[p].toUpperCase());
    	var v2 = sortType ? sortType(n2) : (cs ? n2.attributes[p] : n2.attributes[p].toUpperCase());
    	if(v1 < v2){
			return dsc ? +1 : -1;
		}else if(v1 > v2){
			return dsc ? -1 : +1;
        }else{
	    	return 0;
        }
    };
};

Ext.tree.TreeSorter.prototype = {
    doSort : function(node){
        node.sort(this.sortFn);
    },
    
    compareNodes : function(n1, n2){
        return (n1.text.toUpperCase() > n2.text.toUpperCase() ? 1 : -1);
    },
    
    updateSort : function(tree, node){
        if(node.childrenRendered){
            this.doSort.defer(1, this, [node]);
        }
    },
    
    updateSortParent : function(node){
		var p = node.parentNode;
		if(p && p.childrenRendered){
            this.doSort.defer(1, this, [p]);
        }
    }
};