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

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

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

#ifndef MOEOBINARYMETRICSAVINGUPDATER_H_
#define MOEOBINARYMETRICSAVINGUPDATER_H_

#include <fstream>
#include <string>
#include <vector>
#include <eoPop.h>
#include <utils/eoUpdater.h>
#include <metric/moeoMetric.h>

/**
 * This class allows to save the progression of a binary metric comparing the objective vectors of the current population (or archive)
 * with the objective vectors of the population (or archive) of the generation (n-1) into a file
 */
template < class MOEOT >
class moeoBinaryMetricSavingUpdater : public eoUpdater
{
public:

    /** The objective vector type of a solution */
    typedef typename MOEOT::ObjectiveVector ObjectiveVector;


    /**
     * Ctor
     * @param _metric the binary metric comparing two Pareto sets
     * @param _pop the main population
     * @param _filename the target filename
     */
    moeoBinaryMetricSavingUpdater (moeoVectorVsVectorBinaryMetric < ObjectiveVector, double > & _metric, const eoPop < MOEOT > & _pop, std::string _filename) :
            metric(_metric), pop(_pop), filename(_filename), counter(1)
    {}


    /**
     * Saves the metric's value for the current generation
     */
    void operator()() {
        if (pop.size()) {
            if (firstGen) {
                firstGen = false;
            }
            else {
                // creation of the two Pareto sets
                std::vector < ObjectiveVector > from;
                std::vector < ObjectiveVector > to;
                for (unsigned int i=0; i<pop.size(); i++)
                    from.push_back(pop[i].objectiveVector());
                for (unsigned int i=0 ; i<oldPop.size(); i++)
                    to.push_back(oldPop[i].objectiveVector());
                // writing the result into the file
                std::ofstream f (filename.c_str(), std::ios::app);
                f << counter++ << ' ' << metric(from,to) << std::endl;
                f.close();
            }
            oldPop = pop;
        }
    }


private:

    /** binary metric comparing two Pareto sets */
    moeoVectorVsVectorBinaryMetric < ObjectiveVector, double > & metric;
    /** main population */
    const eoPop < MOEOT > & pop;
    /** (n-1) population */
    eoPop< MOEOT > oldPop;
    /** target filename */
    std::string filename;
    /** is it the first generation ? */
    bool firstGen;
    /** counter */
    unsigned int counter;

};

#endif /*MOEOBINARYMETRICSAVINGUPDATER_H_*/