/*
 *  Open BEAGLE
 *  Copyright (C) 2001-2005 by Christian Gagne and Marc Parizeau
 *
 *  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 2.1 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:
 *  Laboratoire de Vision et Systemes Numeriques
 *  Departement de genie electrique et de genie informatique
 *  Universite Laval, Quebec, Canada, G1K 7P4
 *  http://vision.gel.ulaval.ca
 *
 */

/*!
 *  \file   beagle/GP/src/MutationStandardConstrainedOp.cpp
 *  \brief  Source code of class GP::MutationStandardConstrainedOp.
 *  \author Christian Gagne
 *  \author Marc Parizeau
 *  $Revision: 1.13 $
 *  $Date: 2005/10/04 16:25:10 $
 */

#include "beagle/GP.hpp"

#include <algorithm>
#include <string>

using namespace Beagle;


/*!
 *  \brief Construct a constrained GP tree standard mutation operator.
 *  \param inInitOp Initialization operator used to mutate the GP subtree.
 *  \param inMutationPbName Mutation probability parameter name used in register.
 *  \param inMaxRegenDepthName Maximum regeneration depth in mutation parameter name.
 *  \param inName Name of the operator.
 */
GP::MutationStandardConstrainedOp::MutationStandardConstrainedOp(GP::InitializationOp::Handle inInitOp,
                                                                 Beagle::string inMutationPbName,
                                                                 Beagle::string inMaxRegenDepthName,
                                                                 Beagle::string inName) :
  MutationStandardOp(inInitOp, inMutationPbName, inMaxRegenDepthName, inName)
{ }


/*!
 *  \brief Initialize the constrained GP tree standard mutation operator.
 *  \param ioSystem System of the evolution.
 */
void GP::MutationStandardConstrainedOp::initialize(Beagle::System& ioSystem)
{
  Beagle_StackTraceBeginM();
  MutationStandardOp::initialize(ioSystem);

  if(ioSystem.getRegister().isRegistered("gp.try")) {
    mNumberAttempts = castHandleT<UInt>(ioSystem.getRegister()["gp.try"]);
  } else {
    mNumberAttempts = new UInt(2);
    string lLongDescrip = "Maximum number of attempts to modify a GP tree in a genetic ";
    lLongDescrip += "operation. As there is topological constraints on GP trees (i.e. tree ";
    lLongDescrip += "depth limit), it is often necessary to try a genetic operation several times.";
    Register::Description lDescription(
      "Max number of attempts",
      "UInt",
      "2",
      lLongDescrip
    );
    ioSystem.getRegister().addEntry("gp.try", mNumberAttempts, lDescription);
  }
  Beagle_StackTraceEndM("void GP::MutationStandardConstrainedOp::initialize(Beagle::System& ioSystem)");
}


/*!
 *  \brief Standard mutate a constrained GP individual.
 *  \param ioIndividual GP individual to standard mutate.
 *  \param ioContext Context of the evolution.
 *  \return True if the individual is effectively mutated, false if not.
 */
bool GP::MutationStandardConstrainedOp::mutate(Beagle::Individual& ioIndividual, Beagle::Context& ioContext)
{
  Beagle_StackTraceBeginM();
  GP::Individual& lIndividual        = castObjectT<GP::Individual&>(ioIndividual);
  GP::Context& lContext              = castObjectT<GP::Context&>(ioContext);
  unsigned int lMaxTreeDepth         = mMaxTreeDepth->getWrappedValue();
  unsigned int lMaxRegenerationDepth = mMaxRegenerationDepth->getWrappedValue();

  unsigned int lNbNodes = 0;  
  for(unsigned int i=0; i<lIndividual.size(); i++) lNbNodes += lIndividual[i]->size();
  if(lNbNodes == 0) return false;
  unsigned int lChoosenNode = lContext.getSystem().getRandomizer().rollInteger(0, lNbNodes-1);
  unsigned int lChoosenTree = 0;
  for(; (lChoosenTree+1)<lIndividual.size(); lChoosenTree++) {
    if(lChoosenNode < lIndividual[lChoosenTree]->size()) break;
    else lChoosenNode -= lIndividual[lChoosenTree]->size();
  }

  unsigned int lOldGenotypeIndex = lContext.getGenotypeIndex();
  GP::Tree::Handle lOldGenotypeHandle = lContext.getGenotypeHandle();

  Beagle_LogDebugM(
    ioContext.getSystem().getLogger(),
    "mutation", "Beagle::GP::MutationStandardConstrainedOp",
    string("Individual before GP standard mutation: ")+
    ioIndividual.serialize()
  );

  GP::Tree::Handle lActualTree = lIndividual[lChoosenTree];
  GP::Tree::Handle lNewTree    = castHandleT<GP::Tree>(lIndividual.getTypeAlloc()->allocate());
  lNewTree->setPrimitiveSetIndex(lActualTree->getPrimitiveSetIndex());
  lNewTree->setNumberArguments(lActualTree->getNumberArguments());
  unsigned int lChoosenNodeSubTreeSize = (*lActualTree)[lChoosenNode].mSubTreeSize;
  lNewTree->insert(lNewTree->end(), lActualTree->begin(), lActualTree->begin()+lChoosenNode);
  lContext.setGenotypeIndex(lChoosenTree);
  lContext.setGenotypeHandle(lActualTree);
  lContext.emptyCallStack();
  lActualTree->setContextToNode(lChoosenNode, lContext);
  lContext.popCallStack();
  const unsigned int lMaxSubTreeDepth = 
    minOf<unsigned int>(lMaxTreeDepth - lContext.getCallStackSize(), lMaxRegenerationDepth);
  lIndividual[lChoosenTree] = lNewTree;
  lContext.setGenotypeHandle(lNewTree);

  unsigned int lAttempt=0;
  for(; lAttempt < mNumberAttempts->getWrappedValue(); lAttempt++) {
    if(mInitOp->initTree(*lNewTree, 1, lMaxSubTreeDepth, lContext) != 0) break;
  }
  if(lAttempt == mNumberAttempts->getWrappedValue()) {
    lIndividual[lChoosenTree] = lActualTree;
    lContext.setGenotypeIndex(lOldGenotypeIndex);
    lContext.setGenotypeHandle(lOldGenotypeHandle);
    Beagle_LogVerboseM(
      ioContext.getSystem().getLogger(),
      "mutation", "Beagle::GP::MutationStandardConstrainedOp",
      "Unable to GP standard mutate the individual"
    );
    return false;
  }

  Beagle_LogVerboseM(
    ioContext.getSystem().getLogger(),
    "mutation", "Beagle::GP::MutationStandardConstrainedOp",
    string("GP standard mutate the ")+uint2ordinal(lChoosenNode+1)+
    string(" node of the ")+uint2ordinal(lChoosenTree+1)+
    string(" tree with max depth ")+uint2str(lMaxSubTreeDepth)
  ); 

  lNewTree->insert(lNewTree->end(),
                   lActualTree->begin()+lChoosenNode+lChoosenNodeSubTreeSize,
                   lActualTree->end());
  unsigned int lDiffSize =
    (*lActualTree)[lChoosenNode].mSubTreeSize - (*lNewTree)[lChoosenNode].mSubTreeSize;
  for(unsigned int l=0; l<lContext.getCallStackSize(); l++) {
    (*lNewTree)[lContext.getCallStackElement(l)].mSubTreeSize -= lDiffSize;
  }

  lContext.setGenotypeIndex(lOldGenotypeIndex);
  lContext.setGenotypeHandle(lOldGenotypeHandle);

  Beagle_LogDebugM(
    ioContext.getSystem().getLogger(),
    "mutation", "Beagle::GP::MutationStandardConstrainedOp",
    string("Individual after GP standard mutation: ")+
    ioIndividual.serialize()
  );

  return true;
  Beagle_StackTraceEndM("bool GP::MutationStandardConstrainedOp::mutate(Beagle::Individual& ioIndividual, Beagle::Context& ioContext)");
}