/*
* <moBestImprSelect.h>
* Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2006-2007
* (C) OPAC Team, LIFL, 2002-2007
*
* 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
    void init (const Fitness & __fit)
    {

      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 __fit a fitness linked to the move.
       \return TRUE if the move does not improve the fitness.
     */
    bool update (const M & __move, const Fitness & __fit)
    {

      if (first_time || __fit > best_fit)
        {

          best_fit = __fit;
          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 __fit the current fitness (result of the procedure).
       \throws EmptySelection if no move has improved the fitness.
     */
    void operator   () (M & __move, Fitness & __fit) throw (EmptySelection)
    {

      if (!first_time)
        {
          __move = best_move;
          __fit = best_fit;
        }
      else
        throw EmptySelection ();
    }

  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_fit;

  };

#endif