/*
 * CTree.h
 * $Id: CTree.h,v 1.10 2001/11/23 02:03:35 mjanich Exp $
 *
 * Copyright (C) 2001 Markus Janich
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * As a special exception to the GPL, the QGLViewer authors (Markus
 * Janich, Michael Meissner, Richard Guenther, Alexander Buck and Thomas
 * Woerner) give permission to link this program with Qt (non-)commercial
 * edition, and distribute the resulting executable, without including
 * the source code for the Qt (non-)commercial edition in the source
 * distribution.
 *
 */



#ifndef CTREE_H
#define CTREE_H


// Own
////////
#include "CList.h"


// System
///////////
#include <iostream.h>


// forward declarations
/////////////////////////
class CTreeTraverserBase;



/** This class implements a node that can be inserted
  * into a tree. */
class CTreeNode {
public:

  enum Where { Front, End }; /**< */ 

  /** Default constructor. */
  CTreeNode() 
    : m_pcParent(0)
    {
#ifdef DEBUG_TREE
      cerr << "called CTreeNode<NodeDataType>::CTreeNode()" << endl;
#endif
      /* nothing to do */};


  /** Copy constructor. */
  CTreeNode(const CTreeNode &cSource);

  /** Destructor. */
  virtual ~CTreeNode();


  /** Appends the node 'cNode' to the children list
    * of this node. */
  virtual CTreeNode *append(CTreeNode *pcNode, Where w=End) {
    return append(this, pcNode, w);
  };

  /** Appends the node 'pcAppend' to the children list
    * of node 'pcWhere'. The tree makes a copy of the node, so
    * you can delete the source after appending. */
  virtual CTreeNode *append(CTreeNode *pcWhere,
			    CTreeNode *pcAppend, Where w=End) {
    if (pcWhere) {
      switch (w) {
      case End: 
	pcWhere->m_cChildrenList.insertAsLast(pcAppend);
	break;
      case Front:
	pcWhere->m_cChildrenList.insertAsFirst(pcAppend);
	break;
      }
      pcAppend->m_pcParent = pcWhere;

      return pcAppend;
    }
    return 0;
  };

  /** Exchanges the node 'pcWhere' against 'pcInsert'. The node
    * 'pcWhere' will be appended to the children list of 'pcInsert'.
    * The parent node of the inserted one is returned. */
  virtual CTreeNode *insert(CTreeNode *pcWhere,
			    CTreeNode *pcInsert);


  // FIXME: conflicts with traversers
  ///////////////////////////////////////
  /** Remove the specified node from the tree. */
  virtual void remove(CTreeNode *pcRemove);

  /** Remove the node which the iterater points to from the tree. */
  virtual void remove(CTreeTraverserBase *pcTraverser);

  /** Replaces the node given by 'pcReplace' with another
    * given by 'pcWith'. */
  virtual void replace(CTreeNode *pcReplace, CTreeNode *pcWith);

  /** Returns the parent node. */
  virtual CTreeNode *getParent() const { return m_pcParent; };

  /** Returns the number of children of this node. */
  virtual int numChildren() const {
    return m_cChildrenList.getNumObjects();
  };

  /** Returns the list of children nodes of this node. */
  virtual const CList<CTreeNode> &getChildrenList() const {
    return m_cChildrenList;
  }

  /** Assigns one node to another. */
  virtual CTreeNode &operator=(const CTreeNode &cSource);

  /** Returns the i-th child of this node.
    * \par NOTE: If i<0 the program will exit with a message
    *            and if i>numCildren() the last child is returned. */
  virtual CTreeNode &operator[](int i) const;

  /** Compares two node. */
  virtual bool isEqual(const CTreeNode *pcNode) const; 

  /** Prints the tree that starts at this node in breath-first-order. */
  virtual void printTree(ostream &out=cout) const;

  friend ostream& operator<<(ostream &out, CTreeNode *pcTreeNode);


protected:

  /** */
  virtual void print(ostream &out) const;


  ///////////
  // DATA  //
  ///////////

  CTreeNode *m_pcParent;
  CList<CTreeNode> m_cChildrenList;
};



///////////////////////////////////////////////////////////
////  HERE STARTS THE DECLARATION OF CTREETRAVERSBASE  ////
///////////////////////////////////////////////////////////



/** Base class of all tree traversers.
  * Declares the interface that all traverses
  * should implement. */
class CTreeTraverserBase {
  friend class CTreeNode;

public:

  CTreeTraverserBase() {};
  CTreeTraverserBase(CTreeNode *) {};
  virtual ~CTreeTraverserBase() {};

  virtual bool atStart() = 0;
  virtual bool atEnd() = 0;

  virtual const CTreeNode *operator++() = 0;
  virtual const CTreeNode *operator++(int dummy) = 0;

  //virtual const CTreeNode *operator--() = 0;
  //virtual const CTreeNode *operator--(int dummy) = 0;

  virtual CTreeNode *operator*() = 0;


protected:

  virtual CTreeNode *getCurrentNode() const = 0;
  virtual void removeCurrentNode() = 0;
};



////////////////////////////////////////////////
////  HERE STARTS THE DECLARATION OF        ////
////  CTREETRAVERSBASE'S IMPLEMENTATIONS    ////
////////////////////////////////////////////////

// FIXME:: They better should do their work directly
//         on the data of the tree instead of making
//         a list

/** This class implements a traverser which
  * traverses a tree in depth-first-order. */
class CDepthFirstTraverser : public CTreeTraverserBase {
public:

  CDepthFirstTraverser(CTreeNode *pcNode);
  virtual ~CDepthFirstTraverser() {};

  virtual bool atStart();
  virtual bool atEnd();

  virtual const CTreeNode *operator++();
  virtual const CTreeNode *operator++(int dummy);

  //virtual const CTreeNode *operator--();
  //virtual const CTreeNode *operator--(int dummy);

  virtual CTreeNode *operator*() {
    return getCurrentNode();
  }


protected:

  virtual CTreeNode *getCurrentNode() const;
  virtual void removeCurrentNode();


private:

  void parseSubTree(CTreeNode *pcNode);

  CList<CTreeNode> m_cNodeList;
  CListContainer<CTreeNode> *m_pcCurrentNode;
  bool m_fAtEnd, m_fAtStart;
  int m_nLastOp;  // 0: ++, 1: --
};



/** This class implements a traverser which
  * traverses a tree in breath-first-order. */
class CBreathFirstTraverser : public CTreeTraverserBase {
public:

  CBreathFirstTraverser(CTreeNode *pcNode);
  virtual ~CBreathFirstTraverser() {};

  virtual bool atStart();
  virtual bool atEnd();

  virtual const CTreeNode *operator++();
  virtual const CTreeNode *operator++(int dummy);

  //virtual const CTreeNode *operator--();
  //virtual const CTreeNode *operator--(int dummy);

  virtual CTreeNode *operator*() {
    return getCurrentNode();
  }


protected:

  virtual CTreeNode *getCurrentNode() const;
  virtual void removeCurrentNode();


private:

  CList<CTreeNode> m_cNodeList;
  CListContainer<CTreeNode> *m_pcCurrentNode;
  bool m_fAtEnd, m_fAtStart;
  int m_nLastOp;  // 0: ++, 1: --
};


#endif // CTREE_H