/*
  <moNeighborhoodStat.h>
  Copyright (C) DOLPHIN Project-Team, INRIA Lille - Nord Europe, 2006-2010

  Sébastien Verel, Arnaud Liefooghe, Jérémie Humeau

  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
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  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 moNeighborhoodStat_h
#define moNeighborhoodStat_h

#include <continuator/moStat.h>

#include <explorer/moNeighborhoodExplorer.h>
#include <comparator/moNeighborComparator.h>
#include <comparator/moSolNeighborComparator.h>

/**
 * All possible statitic on the neighborhood fitness
 * to combine with other specific statistic to print them
 */
template< class Neighborhood >
class moNeighborhoodStat : public moStat<typename Neighborhood::EOT, bool>
{
public :
  typedef typename Neighborhood::EOT EOT ;
  typedef typename Neighborhood::Neighbor Neighbor ;
  typedef typename EOT::Fitness Fitness ;

  using moStat< EOT, bool >::value;

  /**
   * Default Constructor
   * @param _neighborhood a neighborhood
   * @param _eval an evaluation function
   * @param _neighborComparator a neighbor Comparator
   * @param _solNeighborComparator a comparator between a solution and a neighbor
   */
  moNeighborhoodStat(Neighborhood& _neighborhood, moEval<Neighbor>& _eval, moNeighborComparator<Neighbor>& _neighborComparator, moSolNeighborComparator<Neighbor>& _solNeighborComparator):
	  moStat<EOT, bool>(true, "neighborhood"),
      neighborhood(_neighborhood), eval(_eval), 
      neighborComparator(_neighborComparator),
      solNeighborComparator(_solNeighborComparator)
      {}

  /**
   * Compute classical statistics of a solution's neighborhood
   * @param _solution the corresponding solution
   */
  virtual void operator()(EOT & _solution){
	  Neighbor current ;
	  Neighbor best ;
	  Neighbor lowest ;

	  if(neighborhood.hasNeighbor(_solution)){
		  //init the first neighbor
		  neighborhood.init(_solution, current);

		  //eval the _solution moved with the neighbor and stock the result in the neighbor
		  eval(_solution, current);
      
		  // init the statistics
		  value() = true;

		  mean = current.fitness();
		  sd   = mean * mean;
		  nb      = 1;
		  nbInf   = 0;
		  nbEqual = 0;
		  nbSup   = 0;

		  if (solNeighborComparator.equals(_solution, current))
			  nbEqual++;
		  else if (solNeighborComparator(_solution, current))
			  nbSup++;
		  else
			  nbInf++;

		  //initialize the best neighbor
		  best   = current;
		  lowest = current;

		  //test all others neighbors
		  while (neighborhood.cont(_solution)) {
			  //next neighbor
			  neighborhood.next(_solution, current);
			  //eval
			  eval(_solution, current);

			  mean += current.fitness();
			  sd += current.fitness() * current.fitness();
			  nb++;
	
			  if (solNeighborComparator.equals(_solution, current))
				  nbEqual++;
			  else if (solNeighborComparator(_solution, current))
				  nbSup++;
			  else
				  nbInf++;

			  //if we found a better neighbor, update the best
			  if (neighborComparator(best, current))
				  best = current;
	
			  if (neighborComparator(current, lowest))
				  lowest = current;
		  }

		  max = best.fitness();
		  min = lowest.fitness();

		  mean /= nb;
		  if (nb > 1)
			  sd = sqrt( (sd - nb * mean * mean) / (nb - 1.0) );
		  else
			  sd = 0.0;
	  }
	  else{
		  //if _solution hasn't neighbor,
		  value() = false;
	  }
  }

  /**
   * @return the worst fitness value found in the neighborhood
   */
  Fitness getMin(){
	  return min;
  }

  /**
   * @return the best fitness value found in the neighborhood
   */
  Fitness getMax(){
	  return max;
  }

  /**
   * @return the mean fitness value of the neighborhood
   */
  double getMean(){
	  return mean;
  }

  /**
   * @return the standard deviation value of the neighborhood
   */
  double getSD(){
	  return sd;
  }

  /**
   * @return the size of the neighborhood
   */
  unsigned getSize(){
	  return nb;
  }

  /**
   * @return the number of neighbors having a better fitness than the current solution
   */
  unsigned getNbSup(){
	  return nbSup;
  }

  /**
   * @return the number of neighbors having the same fitness than the current solution
   */
  unsigned getNbEqual(){
	  return nbEqual;
  }
  
  /**
   * @return the number of neighbors having a worst fitness than the current solution
   */
  unsigned getNbInf() {
	  return nbInf;
  }

  /**
   * @return the class name
   */
  virtual std::string className(void) const {
	  return "moNeighborhoodStat";
  }

private:

  // to explore the neighborhood
  Neighborhood& neighborhood ;
  moEval<Neighbor>& eval;

  // comparator betwenn solution and neighbor or between neighbors
  moNeighborComparator<Neighbor>& neighborComparator;
  moSolNeighborComparator<Neighbor>& solNeighborComparator;

  // the stastics of the fitness
  Fitness max, min;
  //mean and standard deviation
  double mean, sd ;

  // number of neighbors in the neighborhood;
  unsigned int nb;

  // number of neighbors with lower, equal and higher fitness
  unsigned int nbInf, nbEqual, nbSup ;
};

#endif