/*
  <moBestImprSelect.h>
  Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2006-2008
  (C) OPAC Team, LIFL, 2002-2008

  Sébastien Cahon, Jean-Charles Boisson (Jean-Charles.Boisson@lifl.fr)

  This software is governed by the CeCILL license under French law and
  abiding by the rules of distribution of free software.  You can  use,
  modify and/ or redistribute the software under the terms of the CeCILL
  license as circulated by CEA, CNRS and INRIA at the following URL
  "http://www.cecill.info".

  As a counterpart to the access to the source code and  rights to copy,
  modify and redistribute granted by the license, users are provided only
  with a limited warranty  and the software's author,  the holder of the
  economic rights,  and the successive licensors  have only  limited liability.

  In this respect, the user's attention is drawn to the risks associated
  with loading,  using,  modifying and/or developing or reproducing the
  software by the user in light of its specific status of free software,
  that may mean  that it is complicated to manipulate,  and  that  also
  therefore means  that it is reserved for developers  and  experienced
  professionals having in-depth computer knowledge. Users are therefore
  encouraged to load and test the software's suitability as regards their
  requirements in conditions enabling the security of their systems and/or
  data to be ensured and,  more generally, to use and operate it in the
  same conditions as regards security.
  The fact that you are presently reading this means that you have had
  knowledge of the CeCILL license and that you accept its terms.

  ParadisEO WebSite : http://paradiseo.gforge.inria.fr
  Contact: paradiseo-help@lists.gforge.inria.fr
*/

#ifndef _moBestImprSelect_h
#define _moBestImprSelect_h

#include <moMoveSelect.h>

//! One of the possible moMoveSelect.
/*!
  All neighbors are considered, and the movement
  which enables the best improvement is selected.
*/
template < class M >
class moBestImprSelect:public moMoveSelect < M >
{
 public:
  
  //! Alias for the fitness.
  typedef typename M::EOType::Fitness Fitness;
    
  //! Procedure which initialise the exploration
  /*!
    \param _fitness The current fitness.
  */
  void init (const Fitness & _fitness)
  {
    //Code only used to avoid warning because _fitness is not used in this procedure.
    Fitness fitness;
    fitness=(Fitness)_fitness;

    first_time = true;
  }


  //!Function that indicates if the current move has not improved the fitness.
  /*!
    If the given fitness enables an improvment,
    the move (moMove) and the fitness linked to this move are saved.

    \param _move a move.
    \param _fitness a fitness linked to the move.
    \return TRUE if the move does not improve the fitness.
  */
  bool update (const M & _move, const Fitness & _fitness)
  {
    if ( first_time || (_fitness > best_fitness) )
      {
	best_fitness = _fitness;
	best_move = _move;
	  
	first_time = false;
      }

    return true;
  }

  //! Procedure which saved the best move and fitness.
  /*!
    \param _move the current move (result of the procedure).
    \param _fitness the current fitness (result of the procedure).
  */
  void operator () (M & _move, Fitness & _fitness)
  {
    if(first_time)
      {
	throw std::runtime_error("[moBestImprSelect.h]: no move or/and no fitness already saved, update has to be called first.");
      }

    _move = best_move;
    _fitness = best_fitness;
  }

 private:

  //! Allowing to know if at least one move has been generated.
  bool first_time;

  //! The best move.
  M best_move;
    
  //! The best fitness.
  Fitness best_fitness;
};

#endif
