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

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

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

#ifndef MOEOOBJECTIVEVECTORCOMPARATOR_H_
#define MOEOOBJECTIVEVECTORCOMPARATOR_H_

#include <math.h>
#include <eoFunctor.h>

/**
 * Abstract class allowing to compare 2 objective vectors.
 * The template argument ObjectiveVector have to be a moeoObjectiveVector. 
 */
template < class ObjectiveVector > class moeoObjectiveVectorComparator:public eoBF < const ObjectiveVector &, const ObjectiveVector &,
  int >
{
};


/**
 * This functor class allows to compare 2 objective vectors according to Pareto dominance
 */
template < class ObjectiveVector > class moeoParetoObjectiveVectorComparator:public moeoObjectiveVectorComparator <
  ObjectiveVector
  >
{
public:

	/**
	 * Returns 1 if _objectiveVector1 dominates _objectiveVector2, -1 if _objectiveVector2 dominates _objectiveVector1 and 0 if no one dominates the other
	 * @param _objectiveVector1 the first objective vector
	 * @param _objectiveVector2 the second objective vector	  
	 */
  int operator () (const ObjectiveVector & _objectiveVector1,
		   const ObjectiveVector & _objectiveVector2)
  {
    bool dom1 = false;
    bool dom2 = false;
    for (unsigned i = 0; i < ObjectiveVector::nObjectives (); i++)
      {
	// first, we have to check if the 2 objective values are not equal for the ith objective
	if (fabs (_objectiveVector1[i] - _objectiveVector2[i]) >
	    ObjectiveVector::Traits::tolerance ())
	  {
	    // if the ith objective have to be minimized...
	    if (ObjectiveVector::minimizing (i))
	      {
		if (_objectiveVector1[i] > _objectiveVector2[i])
		  {
		    dom2 = true;	//_objectiveVector2[i] is better than _objectiveVector1[i]
		  }
		else		// _objectiveVector1[i] < _objectiveVector2[i]
		  {
		    dom1 = true;	//_objectiveVector1[i] is better than _objectiveVector2[i]
		  }
	      }
	    // if the ith objective have to be maximized...
	    else if (ObjectiveVector::maximizing (i))
	      {
		if (_objectiveVector1[i] > _objectiveVector2[i])
		  {
		    dom1 = true;	//_objectiveVector1[i] is better than _objectiveVector2[i]                                              
		  }
		else		// _objectiveVector1[i] < _objectiveVector2[i]
		  {
		    dom2 = true;	//_objectiveVector2[i] is better than _objectiveVector1[i]
		  }
	      }
	  }
      }
    if (dom1 == dom2)
      {
	return 0;		// no one dominates the other
      }
    if (dom1)
      {
	return 1;		//_objectiveVector1 dominates _objectiveVector2
      }
    return -1;			//_objectiveVector2 dominates _objectiveVector1
  }

};

#endif /*MOEOOBJECTIVEVECTORCOMPARATOR_H_ */