/*
 *  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/Invoker.cpp
 *  \brief  Implementation of GP::Invoker.
 *  \author Christian Gagne
 *  \author Matthew Walker
 *  $Revision: 1.9 $
 *  $Date: 2005/10/04 16:25:10 $
 */

#include "beagle/GP.hpp"

using namespace Beagle;


/*!
 *  \brief Construct a new Invoker primitive.
 *  \param inIndex Index of the associated tree.
 *  \param inNumberArgs Number of arguments of the Invoker.
 *  \param inName Name of the Invoker primitive.
 *  \param inArgsName Name of the associated argument primitive.
 */
GP::Invoker::Invoker(unsigned int inIndex,
                     unsigned int inNumberArgs,
                     Beagle::string inName,
                     Beagle::string inArgsName) :
  GP::Primitive(inNumberArgs, inName),
  mArgsName(inArgsName),
  mIndex(inIndex)
{ }


#ifdef BEAGLE_HAVE_RTTI

/*!
 *  \brief Return the tag of the type of data needed as input for the primitive.
 *  \param inN Index of the argument to get the type tag.
 *  \param ioContext Evolutionary context.
 *  \return String tagging the data type needed.
 *  \throw AssertException If the index inN given is > to 1.
 *  \throw InternalException If RTTI is disabled and the method is not properly overdefined.
 */
const std::type_info* GP::Invoker::getArgType(unsigned int inN, GP::Context& ioContext) const
{
  Beagle_StackTraceBeginM();
  Beagle_AssertM(inN < getNumberArguments());
  if(mIndex == eGenerator) {
    std::ostringstream lOSS;
    lOSS << "Could not get the arguments typing of the \"" << getName() << "\" invoker primitive. ";
    lOSS << "The primitive is actually in a generator state, so the index of the tree ";
    lOSS << "refered by the primitive is not specified. It is likely that there is a problem ";
    lOSS << "in the setting of your system, as the argument typing is called only when the ";
    lOSS << "primitive is completely instanciated, that is used as the part of a GP tree, ";
    lOSS << "with an index value refering to another GP tree to invoke.";
    throw Beagle_RunTimeExceptionM(lOSS.str().c_str());
  }
  GP::Tree::Handle lTree = getInvokedTree(ioContext);
  GP::Tree::Handle lOldTreeHandle = ioContext.getGenotypeHandle();
  ioContext.setGenotypeHandle(lTree);
  GP::Argument::Handle lArg =
    castHandleT<GP::Argument>(lTree->getPrimitiveSet(ioContext).getPrimitiveByName(mArgsName));
  const std::type_info* lArgType = lArg->getReturnType(ioContext);
  ioContext.setGenotypeHandle(lOldTreeHandle);
  return lArgType;
  Beagle_StackTraceEndM("const std::type_info* GP::Invoker::getArgType(unsigned int inN, GP::Context& ioContext) const");
}


/*!
 *  \brief  Return the string tagging the type of data returned by the primitive.
 *  \param  ioContext Evolutionary context.
 *  \return String tagging the type of data returned.
 *  \throw  InternalException If RTTI is disabled and the method is not properly overdefined.
 */
const std::type_info* GP::Invoker::getReturnType(GP::Context& ioContext) const
{
  Beagle_StackTraceBeginM();
  if(mIndex == eGenerator) return NULL;
  GP::Tree::Handle lTree = getInvokedTree(ioContext);
  GP::Tree::Handle lOldTreeHandle = ioContext.getGenotypeHandle();
  const unsigned int lOldTreeIndex = ioContext.getGenotypeIndex();
  ioContext.setGenotypeHandle(lTree);
  ioContext.setGenotypeIndex(mIndex);
  const std::type_info* lReturnType = lTree->getRootType(ioContext);
  ioContext.setGenotypeIndex(lOldTreeIndex);
  ioContext.setGenotypeHandle(lOldTreeHandle);
  return lReturnType;
  Beagle_StackTraceEndM("const std::type_info* GP::Invoker::getArgType(unsigned int inN, GP::Context& ioContext) const");
}

#endif // BEAGLE_HAVE_RTTI


/*!
 *  \brief Return selection weight (in primitive set) of the ADF primitive.
 *  \param inNumberArguments Number of arguments called for the selection weight.
 *  \param ioContext Evolutionary context.
 *  \return Selection weight.
 */
double GP::Invoker::getSelectionWeight(unsigned int inNumberArguments,
                                       GP::Context& ioContext) const
{
  Beagle_StackTraceBeginM();
  // If not a generator, return the default primitive weight value.
  if(mIndex!=eGenerator)
    return Beagle::GP::Primitive::getSelectionWeight(inNumberArguments, ioContext);

  // Get the number of possibles trees that can be invoked in the actual context.
  std::vector< unsigned int,BEAGLE_STLALLOCATOR<unsigned int> > lCandidates;
  getCandidatesToInvoke(lCandidates, inNumberArguments, ioContext);
  return double(lCandidates.size());
  Beagle_StackTraceEndM("double GP::Invoker::getSelectionWeight(unsigned int inNumberArguments, GP::Context& ioContext) const");
}


/*!
 *  \brief Return a reference of the ADF primitive.
 *  \param inNumberArguments Number of arguments asked for the reference.
 *  \param ioContext Evolutionary context.
 *  \return Handle to the reference generated.
 */
GP::Primitive::Handle GP::Invoker::giveReference(unsigned int inNumberArguments,
                                                 GP::Context& ioContext)
{
  Beagle_StackTraceBeginM();
  // If not an invoker, return this directly.
  if(mIndex!=eGenerator) return this;

  // Generate new invoker.
  std::vector< unsigned int,BEAGLE_STLALLOCATOR<unsigned int> > lCandidates;
  getCandidatesToInvoke(lCandidates, inNumberArguments, ioContext);
  Beagle_AssertM(lCandidates.size() > 0);
  const unsigned int lIndex =
    lCandidates[ioContext.getSystem().getRandomizer().rollInteger(0,lCandidates.size()-1)];
  Handle lGeneratedInvoker = generateInvoker(lIndex, getName(), mArgsName, ioContext);

  // Return newly generated invoker.
  return lGeneratedInvoker;
  Beagle_StackTraceEndM("GP::Primitive::Handle GP::Invoker::giveReference(unsigned int inNumberArguments, GP::Context& ioContext)");
}


/*!
 *  \brief Execute the call to the associated tree with the given parameters.
 *  \param outResult Result of the invocation.
 *  \param ioContext Evolutionary context.
 */
void GP::Invoker::execute(GP::Datum& outResult, GP::Context& ioContext)
{
  Beagle_StackTraceBeginM();
  GP::Tree::Handle lTree = getInvokedTree(ioContext);
  Beagle_AssertM(lTree->getNumberArguments() == getNumberArguments());
  GP::Argument::Handle lArg =
    castHandleT<GP::Argument>(lTree->getPrimitiveSet(ioContext).getPrimitiveByName(mArgsName));
  if(lArg==NULL) {
    string lMessage = "The argument named \"";
    lMessage += mArgsName;
    lMessage += " associated to the invoker named \"";
    lMessage += getName();
    lMessage += "\" does not refer to a valid primitive in the set";
    lMessage += " of the tree associated to the invoker.";
    throw Beagle_RunTimeExceptionM(lMessage);
  }
  lArg->pushExecutionContext(getNumberArguments(), ioContext);
  invoke(outResult, lTree, ioContext);
  lArg->popExecutionContext();
  Beagle_StackTraceEndM("void GP::Invoker::execute(GP::Datum& outResult, GP::Context& ioContext)");
}


/*!
 *  \brief Return whether selection weight in primitive set is stable.
 *  \param inNumberArguments Number of arguments for given selection weight.
 *  \return True is selection weight stable, false if not.
 */
bool GP::Invoker::isSelectionWeightStable(unsigned int inNumberArguments) const
{
  Beagle_StackTraceBeginM();
  const unsigned int lNbArgsPrimit = getNumberArguments();
  if((inNumberArguments == GP::Primitive::eAny) ||
     (lNbArgsPrimit == GP::Primitive::eAny)) return false;
  else if(inNumberArguments == GP::Primitive::eBranch) {
    return (lNbArgsPrimit == 0);
  }
  return (lNbArgsPrimit == inNumberArguments);
  Beagle_StackTraceEndM("bool GP::Invoker::isSelectionWeightStable(unsigned int inNumberArguments) const");
}


/*!
 *  \brief Read invoker primitive from XML subtree.
 *  \param inIter XML iterator to read the primitive from.
 *  \param ioContext Evolutionary context.
 */
void GP::Invoker::readWithContext(PACC::XML::ConstIterator inIter, GP::Context& ioContext)
{
  Beagle_StackTraceBeginM();
  GP::Primitive::readWithContext(inIter, ioContext);
  string lIndexValue = inIter->getAttribute("id").c_str();
  if(lIndexValue.empty()==false) mIndex = str2uint(lIndexValue);
  unsigned int lArgsCount = 0;
  for(PACC::XML::ConstIterator lChild=inIter->getFirstChild(); lChild; ++lChild) {
    if(lChild->getType()==PACC::XML::eData) ++lArgsCount;
  }
  setNumberArguments(lArgsCount);
  Beagle_StackTraceEndM("void GP::Invoker::readWithContext(PACC::XML::ConstIterator inIter, GP::Context& ioContext)");
}


/*!
 *  \brief Validate the invoker position in the tree.
 *  \param ioContext Evolutionary context.
 *  \return True if the invoker is correctly positioned, false if not.
 *  \throw Beagle::AssertException If the context is in a bad state.
 */
bool GP::Invoker::validate(GP::Context& ioContext) const
{
  Beagle_StackTraceBeginM();
  std::vector <unsigned int,BEAGLE_STLALLOCATOR<unsigned int> > lCandidates;
  getCandidatesToInvoke(lCandidates, getNumberArguments(), ioContext);
  for(unsigned int i=0; i<lCandidates.size(); ++i) {
    if(mIndex==lCandidates[i]) return GP::Primitive::validate(ioContext);
  }
  return false;
  Beagle_StackTraceEndM("bool GP::Invoker::validate(GP::Context& ioContext) const");
}


/*!
 *  \brief Write the content of a primitive into a XML stream.
 *  \param ioStreamer Streamer to write primitive into.
 *  \param inIndent Whether XML output should be indented.
 */
void GP::Invoker::writeContent(PACC::XML::Streamer& ioStreamer, bool inIndent) const
{
  Beagle_StackTraceBeginM();
  if(mIndex!=eGenerator) ioStreamer.insertAttribute("id", uint2str(mIndex));
  Beagle_StackTraceEndM("void GP::Invoker::writeContent(PACC::XML::Streamer& ioStreamer, bool inIndent) const");
}