/*
	Copyright (c) 2004-2005, The Dojo Foundation
	All Rights Reserved.

	Licensed under the Academic Free License version 2.1 or above OR the
	modified BSD license. For more information on Dojo licensing, see:

		http://dojotoolkit.org/community/licensing.shtml
*/

dojo.provide("dojo.collections.BinaryTree");
dojo.require("dojo.collections.Collections");

dojo.collections.BinaryTree = function(data){
	function node(data, rnode, lnode){
		this.value = data || null;
		this.right = rnode || null;
		this.left = lnode || null;
		this.clone = function(){
			var c = new node();
			if (this.value.value) c.value = this.value.clone();
			else c.value = this.value;
			if (this.left) c.left = this.left.clone();
			if (this.right) c.right = this.right.clone();
		}
		this.compare = function(n){
			if (this.value > n.value) return 1;
			if (this.value < n.value) return -1;
			return 0;
		}
		this.compareData = function(d){
			if (this.value > d) return 1;
			if (this.value < d) return -1;
			return 0;
		}
	}

	function inorderTraversalBuildup(current, a){
		if (current){
			inorderTraversalBuildup(current.left, a);
			a.add(current);
			inorderTraversalBuildup(current.right, a);
		}
	}

	function preorderTraversal(current, sep){
		var s = "";
		if (current){
			s = current.value.toString() + sep;
			s += preorderTraversal(current.left, sep);
			s += preorderTraversal(current.right, sep);
		}
		return s;
	}
	function inorderTraversal(current, sep){
		var s = "";
		if (current){
			s = inorderTraversal(current.left, sep);
			s += current.value.toString() + sep;
			s += inorderTraversal(current.right, sep);
		}
		return s;
	}
	function postorderTraversal(current, sep){
		var s = "";
		if (current){
			s = postorderTraversal(current.left, sep);
			s += postorderTraversal(current.right, sep);
			s += current.value.toString() + sep;
		}
		return s;
	}
	
	function searchHelper(current, data){
		if (!current) return null;
		var i = current.compareData(data);
		if (i == 0) return current;
		if (result > 0) return searchHelper(current.left, data);
		else return searchHelper(current.right, data);
	}

	this.add = function(data){
		var n = new node(data);
		var i;
		var current = root;
		var parent = null;
		while (current){
			i = current.compare(n);
			if (i == 0) return;
			parent = current;
			if (i > 0) current = current.left;
			else current = current.right;
		}
		this.count++;
		if (!parent) root = n;
		else {
			i = parent.compare(n);
			if (i > 0) parent.left = n;
			else parent.right = n;
		}
	};
	this.clear = function(){
		root = null;
		this.count = 0;
	};
	this.clone = function(){
		var c = new dojo.collections.BinaryTree();
		c.root = root.clone();
		c.count = this.count;
		return c;
	};
	this.contains = function(data){
		return this.search(data) != null;
	};
	this.deleteData = function(data){
		var current = root;
		var parent = null;
		var i = current.compareData(data);
		while (i != 0 && current != null){
			if (i > 0){
				parent = current;
				current = current.left;
			} else if (i < 0) {
				parent = current;
				current = current.right;
			}
			i = current.compareData(data);
		}
		if (!current) return;
		this.count--;
		if (!current.right) {
			if (!parent) root = current.left;
			else {
				i = parent.compare(current);
				if (i > 0) parent.left = current.left;
				else if (i < 0) parent.right = current.left;
			}
		} else if (!current.right.left){
			if (!parent) root = current.right;
			else {
				i = parent.compare(current);
				if (i > 0) parent.left = current.right;
				else if (i < 0) parent.right = current.right;
			}
		} else {
			var leftmost = current.right.left;
			var lmParent = current.right;
			while (leftmost.left != null){
				lmParent = leftmost;
				leftmost = leftmost.left;
			}
			lmParent.left = leftmost.right;
			leftmost.left = current.left;
			leftmost.right = current.right;
			if (!parent) root = leftmost;
			else {
				i = parent.compare(current);
				if (i > 0) parent.left = leftmost;
				else if (i < 0) parent.right = leftmost;
			}
		}
	};
	this.getIterator = function(){
		var a = new ArrayList();
		inorderTraversalBuildup(root, a);
		return a.getIterator();
	};
	this.search = function(data){
		return searchHelper(root, data);
	};
	this.toString = function(order, sep){
		if (!order) var order = dojo.collections.BinaryTree.TraversalMethods.Inorder;
		if (!sep) var sep = " ";
		var s = "";
		switch (order){
			case dojo.collections.BinaryTree.TraversalMethods.Preorder:
				s = preorderTraversal(root, sep);
				break;
			case dojo.collections.BinaryTree.TraversalMethods.Inorder:
				s = inorderTraversal(root, sep);
				break;
			case dojo.collections.BinaryTree.TraversalMethods.Postorder:
				s = postorderTraversal(root, sep);
				break;
		};
		if (s.length == 0) return "";
		else return s.substring(0, s.length - sep.length);
	};

	this.count = 0;
	var root = this.root = null;
	if (data) {
		this.add(data);
	}
}
dojo.collections.BinaryTree.TraversalMethods = {
	Preorder : 0,
	Inorder : 1,
	Postorder : 2
};