/*
 *  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/MutationSwapConstrainedOp.cpp
 *  \brief  Source code of class GP::MutationSwapConstrainedOp.
 *  \author Christian Gagne
 *  \author Marc Parizeau
 *  $Revision: 1.12 $
 *  $Date: 2005/10/04 16:25:10 $
 */

#include "beagle/GP.hpp"

#include <algorithm>
#include <string>

using namespace Beagle;


/*!
 *  \brief Construct a constrained GP tree swap mutation operator.
 *  \param inMutationPbName Mutation probability parameter name used in register.
 *  \param inDistribPbName Swap mutation distribution probability parameter name.
 *  \param inName Name of the operator.
 */
GP::MutationSwapConstrainedOp::MutationSwapConstrainedOp(Beagle::string inMutationPbName,
                                                         Beagle::string inDistribPbName,
                                                         Beagle::string inName) :
  MutationSwapOp(inMutationPbName, inDistribPbName, inName)
{ }


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

  if(ioSystem.getRegister().isRegistered("gp.try")) {
    mNumberAttempts = castHandleT<UInt>(ioSystem.getRegister().getEntry("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::MutationSwapConstrainedOp::initialize(Beagle::System& ioSystem)");
}


/*!
 *  \brief Swap mutate a constrained GP individual.
 *  \param ioIndividual GP individual to swap mutate.
 *  \param ioContext Context of the evolution.
 *  \return True if the individual is effectively mutated, false if not.
 */
bool GP::MutationSwapConstrainedOp::mutate(Beagle::Individual& ioIndividual, Beagle::Context& ioContext)
{
  Beagle_StackTraceBeginM();
  GP::Individual& lIndividual  = castObjectT<GP::Individual&>(ioIndividual);
  GP::Context& lContext        = castObjectT<GP::Context&>(ioContext);
  double lDistrProba           = mDistributionProba->getWrappedValue();
  unsigned int lNumberAttempts = mNumberAttempts->getWrappedValue();
  bool lMutationDone           = false;

  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();
  }
  GP::Tree& lTree = *lIndividual[lChoosenTree];
  if(lTree.size() == 0) return false;

  GP::Tree::Handle lOldTreeHandle = lContext.getGenotypeHandle();
  unsigned int lOldTreeIndex = lContext.getGenotypeIndex();
  lContext.setGenotypeHandle(lIndividual[lChoosenTree]);
  lContext.setGenotypeIndex(lChoosenTree);

  Beagle_LogDebugM(
    ioContext.getSystem().getLogger(),
    "mutation", "Beagle::GP::MutationSwapConstrainedOp",
    string("Individual before constrained GP tree swap mutation: ")+ioIndividual.serialize()
  );

  if(lTree.size() > 1) {
    bool lTypeNode = (lContext.getSystem().getRandomizer().rollUniform(0., 1.) < lDistrProba);
    while((lTree[lChoosenNode].mPrimitive->getNumberArguments() != 0) != lTypeNode) {
      lChoosenNode = lContext.getSystem().getRandomizer().rollInteger(0, lTree.size()-1);
    }
  }
  Primitive::Handle lOriginalPrimitive = lTree[lChoosenNode].mPrimitive;

  Beagle_LogVerboseM(
    ioContext.getSystem().getLogger(),
    "mutation", "Beagle::GP::MutationSwapConstrainedOp",
    string("Trying to constrained GP tree swap mutate the ")+uint2ordinal(lChoosenNode+1)+
    string(" node (primitive: \"")+lOriginalPrimitive->getName()+
    string("\" nb args: ")+uint2str(lOriginalPrimitive->getNumberArguments())+
    string(") of the ")+uint2ordinal(lChoosenTree+1)+string(" tree")
  ); 

  GP::PrimitiveSet& lPrimitiveSet = lTree.getPrimitiveSet(lContext);
  unsigned int lNbArgsPrimit = lTree[lChoosenNode].mPrimitive->getNumberArguments();
  lTree.setContextToNode(lChoosenNode, lContext);
  for(unsigned int lAttempt=0; lAttempt < lNumberAttempts; ++lAttempt) {
    Primitive::Handle lChoosenPrimitive = lPrimitiveSet.select(lNbArgsPrimit, lContext);
    if(lChoosenPrimitive==NULL) break;

    lTree[lChoosenNode].mPrimitive = lChoosenPrimitive->giveReference(lNbArgsPrimit, lContext);

    Beagle_LogVerboseM(
      ioContext.getSystem().getLogger(),
      "mutation", "Beagle::GP::MutationSwapConstrainedOp",
      string("Trying the primitive \"")+lChoosenPrimitive->getName()+
      string("\"")
    );

    if(lTree.validateSubTree(lChoosenNode, lContext)) {
      lMutationDone = true;
      Beagle_LogVerboseM(
        ioContext.getSystem().getLogger(),
        "mutation", "Beagle::GP::MutationSwapConstrainedOp",
        "Constrained GP tree swap mutation valid"
      );
      break;
    }
    else {
      lTree[lChoosenNode].mPrimitive = lOriginalPrimitive;
      Beagle_LogVerboseM(
        ioContext.getSystem().getLogger(),
        "mutation", "Beagle::GP::MutationSwapConstrainedOp",
        "Constrained GP tree swap mutation invalid"
      );
    }
  }

  lContext.setGenotypeHandle(lOldTreeHandle);
  lContext.setGenotypeIndex(lOldTreeIndex);

  if(lMutationDone) {
    Beagle_LogDebugM(
      ioContext.getSystem().getLogger(),
      "mutation", "Beagle::GP::MutationSwapConstrainedOp",
      string("Individual after constrained GP swap mutation: ")+
      ioIndividual.serialize()
    ); 
  }
  else {
    Beagle_LogVerboseM(
      ioContext.getSystem().getLogger(),
      "mutation", "Beagle::GP::MutationSwapConstrainedOp",
      "Unable to swap mutate the constrained individual"
    );
  }

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