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

//-----------------------------------------------------------------------------
// eoSequential.h
// (c) GeNeura Team, 1998 - Maarten Keijzer 2000, Marc Schoenauer, 2002
/*
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Contact: todos@geneura.ugr.es, http://geneura.ugr.es
             Marc.Schoenauer@polytechnique.fr
             mak@dhi.dk
 */
//-----------------------------------------------------------------------------

#ifndef eoSequential_h
#define eoSequential_h

/** Contains the following classes:
 *  - eoSequentialSelect, returns all individuals one by one, 
 *    either sorted or shuffled
 *  - eoEliteSequentialSelect, returns all indivisuals one by one
 *    starting with best, continuing shuffled (see G3 engine)
 */

#include <utils/eoRNG.h>
#include <eoSelectOne.h>

//-----------------------------------------------------------------------------
/** eoSequentialSelect: returns all individual in order
 *       looping back to the beginning when exhasuted
 * can be from best to worse, or in random order
 *
 * It is the eoSelectOne equivalent of eoDetSelect -
 *    though eoDetSelect always returns individuals from best to worst
 */
//-----------------------------------------------------------------------------

template <class EOT> class eoSequentialSelect: public eoSelectOne<EOT>
{
 public:
  /** Ctor: sets the current pter to MAXINT so init will take place first time
      not very elegant, maybe ...
  */
#ifdef _MSC_VER
  eoSequentialSelect(bool _ordered = true)
  	: ordered(_ordered), current(std::MAXINT) {}
#else
  eoSequentialSelect(bool _ordered = true)
  	: ordered(_ordered), current(MAXINT) {}
#endif

  void setup(const eoPop<EOT>& _pop)
  {
    eoPters.resize(_pop.size());
    if (ordered)    // probably we could have a marker to avoid re-sorting
	    _pop.sort(eoPters);
    else
      _pop.shuffle(eoPters);
    current=0;
  }

  virtual const EOT& operator()(const eoPop<EOT>& _pop)
  {
    if (current >= _pop.size())
      setup(_pop);

    unsigned eoN = current;
    current++;
    return *eoPters[eoN] ;
  }
private:
  bool ordered;
  unsigned current;
  std::vector<const EOT*> eoPters;
};


//-----------------------------------------------------------------------------
/** eoEliteSequentialSelect: returns the best individual first,
 *              then the others in sequence (random order).
 *              for G3 evolution engine, see Deb, Anad and Joshi, CEC 2002
 *
 * As eoSequentialSelect, it is an eoSelectOne to be used within the eoEaseyEA
 * algo, but conceptually it should be a global eoSelect, as
 * it selects a bunch of guys in one go (done in the setup function now)
 */

template <class EOT> class eoEliteSequentialSelect: public eoSelectOne<EOT>
{
 public:

  /** Ctor: sets the current pter to MAXINT so init will take place first time
      not very elegant, maybe ...
  */
  #ifdef _MSC_VER
  eoEliteSequentialSelect(): current(std::MAXINT) {}
  #else
  eoEliteSequentialSelect(): current(MAXINT) {}
  #endif

  void setup(const eoPop<EOT>& _pop)
  {
    eoPters.resize(_pop.size());
    _pop.shuffle(eoPters);
    // now get the best
    unsigned int ibest = 0;
    const EOT * best = eoPters[0];
    if (_pop.size() == 1)
      throw std::runtime_error("Trying eoEliteSequentialSelect with only one individual!");
    for (unsigned i=1; i<_pop.size(); i++)
      if (*eoPters[i]>*best)
	{
	  ibest = i;
	  best = eoPters[ibest];
	}
    // and put it upfront
    const EOT *ptmp = eoPters[0];
    eoPters[0]=best;
    eoPters[ibest] = ptmp;
    // exit after setting current 
    current=0;
  }

  virtual const EOT& operator()(const eoPop<EOT>& _pop)
  {
    if (current >= _pop.size())
      setup(_pop);

    unsigned eoN = current;
    current++;
    return *eoPters[eoN] ;
  }
private:
  unsigned current;
  std::vector<const EOT*> eoPters;
};


#endif