/*
* <moeoComparator.h>
* Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2009
*
*
* Waldo Cancino, Arnaud Liefooghe
*
* 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 MOEOBESTOBJVECSTAT_H_
#define MOEOBESTOBJVECSTAT_H_

#include <utils/moeoObjVecStat.h>

/** Calculate the best solution for each objective (extreme points
*/

template <class MOEOT>
class moeoBestObjVecStat : public moeoObjVecStat<MOEOT>
{
public:

	using moeoObjVecStat<MOEOT>::value;
    typedef typename moeoObjVecStat<MOEOT>::ObjectiveVector ObjectiveVector;


    moeoBestObjVecStat(std::string _description = "Best ")
        : moeoObjVecStat<MOEOT>(_description)
        {}


    virtual std::string className(void) const { return "moeoBestObjVecStat"; }

	/**
		Return the best solutions for an given objective function
		* @param which the objective function number
	*/
	const MOEOT & bestindividuals(unsigned int which) {
		typedef typename moeoObjVecStat<MOEOT>::Traits traits;
		if(which > traits::nObjectives() ) throw std::logic_error("which is larger than the number of objectives");
		return *(best_individuals[which]);
	}

private :

	/** Vector of iterators pointing to best individuals for each objective function */

	std::vector<typename eoPop<MOEOT>::const_iterator> best_individuals;

    struct CmpObjVec
    {
      CmpObjVec(unsigned _which, bool _maxim) : which(_which), maxim(_maxim) {}

      bool operator()(const MOEOT& a, const MOEOT& b)
      {
        if (maxim)
          return a.objectiveVector()[which] < b.objectiveVector()[which];

        return a.objectiveVector()[which] > b.objectiveVector()[which];
      }

      unsigned which;
      bool maxim;
    };

    // Specialization for objective vector
    void doit(const eoPop<MOEOT>& _pop)
    {
      typedef typename moeoObjVecStat<MOEOT>::Traits traits;

      value().resize(traits::nObjectives());

      for (unsigned o = 0; o < traits::nObjectives(); ++o)
      {
        typename eoPop<MOEOT>::const_iterator it = std::max_element(_pop.begin(), _pop.end(), CmpObjVec(o, traits::maximizing(o)));
		value()[o] = it->objectiveVector()[o];
		best_individuals.push_back( it );
      }
    }
    // default
};
#endif