/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 * Copyright (C) 2006-2010 - Frictional Games
 *
 * This file is part of HPL1 Engine.
 */

#ifndef HPL_BINTREE_H
#define HPL_BINTREE_H

#include "common/list.h"

namespace hpl {

enum eBinTreeNode {
	eBinTreeNode_Left,
	eBinTreeNode_Right
};

//////////////////////////////////////////////////////////////////////////
// TREE NODE CLASS
//////////////////////////////////////////////////////////////////////////

template<class T>
class BinTreeNode {
public:
	T *GetData() {
		return &mData;
	}

	BinTreeNode(T aData, BinTreeNode<T> *aParent, eBinTreeNode aParentDir) {
		for (int i = 0; i < 2; i++)
			mChild[i] = NULL;
		mData = aData;
		mParent = aParent;
		mParentDir = aParentDir;
	}

	BinTreeNode<T> *AddChild(eBinTreeNode i, T aData) {
		if (mChild[i] == NULL) {
			mChild[i] = hplNew(BinTreeNode<T>, (aData, this, i));
			return mChild[i];
		}
		return NULL;
	}

	BinTreeNode<T> *GetChild(eBinTreeNode i) {
		return mChild[i];
	}

	BinTreeNode<T> *GetParent() {
		return mParent;
	}

private:
	BinTreeNode<T> *mChild[2];
	BinTreeNode<T> *mParent;
	T mData;
	eBinTreeNode mParentDir;
};

//////////////////////////////////////////////////////////////////////////
// MAIN TREE CLASS
//////////////////////////////////////////////////////////////////////////

template<class T>
class BinTree {
public:
	BinTree() {
		mlNumOfNodes = 0;
		mFirstNode = NULL;
	}

	~BinTree() {
		Clear();
	}

	/**
	 * Clears the entire tree
	 * \return number of nodes deleted
	 */
	int Clear() {
		mlNum = 0;
		DeleteNode(mFirstNode);
		mFirstNode = NULL;
		return mlNum;
	}

	/**
	 * Insert a node to the tree.
	 * \todo only works to set the root node.
	 * \param aData the data to insert
	 * \return
	 */
	BinTreeNode<T> *Insert(T aData) {
		if (mFirstNode == NULL) {
			mFirstNode = hplNew(BinTreeNode<T>, (aData, NULL, eBinTreeNode_Left));
			mlNumOfNodes++;

			return mFirstNode;
		}

		// Insertion other then at the root is not supported!
		BinTreeNode<T> *Node = mFirstNode;
		eBinTreeNode c;
		while (true) {
			// if(Node->GetData()<aData)
			c = eBinTreeNode_Left;
			// else
			//	c = eBinTreeNode_Right;

			if (Node->GetChild(c) == NULL) {
				Node = Node->AddChild(c, aData);
				break;
			} else {
				Node = Node->GetChild(c);
			}
		}
		mlNumOfNodes++;

		return Node;
	}

	/**
	 * Insert a node into a certain node in the tree
	 * \param aData the data to insert
	 * \param aNode the node to insert the data in
	 * \param aChild what child to insert at
	 * \return
	 */
	BinTreeNode<T> *InsertAt(T aData, BinTreeNode<T> *aNode, eBinTreeNode aChild = eBinTreeNode_Left) {
		if (aNode == NULL)
			return NULL;

		if (aNode->GetChild(aChild) != NULL) {
			aChild = aChild == eBinTreeNode_Left ? eBinTreeNode_Right : eBinTreeNode_Left;
			if (aNode->GetChild(aChild) != NULL)
				return NULL;
		}

		return aNode->AddChild(aChild, aData);
	}

	/**
	 * Get the size of the tree
	 * \return
	 */
	int Size() {
		return mlNumOfNodes;
	}

	const Common::List<BinTreeNode<T> *> &GetLeafList() {
		mlstNodes.clear();
		PopulateLeafList(mFirstNode);
		return mlstNodes;
	}

	/**
	 * Get a list of all the nodes in the tree
	 * \return
	 */
	const Common::List<BinTreeNode<T> *> &GetNodeList() {
		mlstNodes.clear();
		PopulateNodeList(mFirstNode);
		return mlstNodes;
	}

private:
	int mlNumOfNodes;
	BinTreeNode<T> *mFirstNode;
	int mlNum;

	Common::List<BinTreeNode<T> *> mlstNodes;

	void DeleteNode(BinTreeNode<T> *aNode) {
		if (aNode == NULL)
			return;

		DeleteNode(aNode->GetChild(eBinTreeNode_Left));
		DeleteNode(aNode->GetChild(eBinTreeNode_Right));

		hplDelete(aNode);
		mlNum++;
	}

	void PopulateNodeList(BinTreeNode<T> *aNode) {
		if (aNode == NULL)
			return;

		PopulateNodeList(aNode->GetChild(eBinTreeNode_Left));
		mlstNodes.push_back(aNode);
		PopulateNodeList(aNode->GetChild(eBinTreeNode_Right));
	}

	void PopulateLeafList(BinTreeNode<T> *aNode) {
		if (aNode == NULL)
			return;

		if (aNode->GetChild(eBinTreeNode_Left) == NULL &&
			aNode->GetChild(eBinTreeNode_Right) == NULL) {
			mlstNodes.push_back(aNode);
		}

		PopulateLeafList(aNode->GetChild(eBinTreeNode_Left));
		PopulateLeafList(aNode->GetChild(eBinTreeNode_Right));
	}
};

} // namespace hpl

#endif // HPL_BINTREE_H