// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-

//-----------------------------------------------------------------------------
// moeoComparator.h
// (c) OPAC Team (LIFL), Dolphin Project (INRIA), 2007
/*
    This library...

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

#ifndef MOEOCOMPARATOR_H_
#define MOEOCOMPARATOR_H_

#include <eoFunctor.h>

/**
 * Functor allowing to compare two solutions.
 */
template < class MOEOT >
class moeoComparator : public eoBF < const MOEOT &, const MOEOT &, const bool >
{};


/**
 * Functor allowing to compare two solutions according to their first objective value, then their second, and so on.
 */
template < class MOEOT >
class moeoObjectiveComparator : public moeoComparator < MOEOT >
{
public:
	/**
	 * Returns true if _moeo1 is smaller than _moeo2 on the first objective, then on the second, and so on
	 * @param _moeo1 the first solution
	 * @param _moeo2 the second solution
	 */
	const bool operator()(const MOEOT & _moeo1, const MOEOT & _moeo2)
	{
		return _moeo1.objectiveVector() < _moeo2.objectiveVector();
	}
};


/**
 * Functor allowing to compare two solutions according to their fitness values, then according to their diversity values.
 */
template < class MOEOT >
class moeoFitnessThenDiversityComparator : public moeoComparator < MOEOT >
{
public:
	/**
	 * Returns true if _moeo1 is smaller than _moeo2 according to their fitness values, then according to their diversity values	 
	 * @param _moeo1 the first solution
	 * @param _moeo2 the second solution
	 */
	const bool operator()(const MOEOT & _moeo1, const MOEOT & _moeo2)
	{
		if (_moeo1.fitness() == _moeo2.fitness())
		{
			return _moeo1.diversity() < _moeo2.diversity();
		}
		else
		{
			return _moeo1.fitness() < _moeo2.fitness();
		}
	}
};


/**
 * Functor allowing to compare two solutions according to their diversity values, then according to their fitness values.
 */
template < class MOEOT >
class moeoDiversityThenFitnessComparator : public moeoComparator < MOEOT >
{
public:
	/**
	 * Returns true if _moeo1 is smaller than _moeo2 according to their diversity values, then according to their fitness values
	 * @param _moeo1 the first solution
	 * @param _moeo2 the second solution
	 */
	const bool operator()(const MOEOT & _moeo1, const MOEOT & _moeo2)
	{
		if (_moeo1.diversity() == _moeo2.diversity())
		{
			return _moeo1.fitness() < _moeo2.fitness();
		}
		else
		{
			return _moeo1.diversity() < _moeo2.diversity();
		}
	}
};


#endif /*MOEOCOMPARATOR_H_*/