/*
 * Project: MoleCuilder
 * Description: creates and alters molecular systems
 * Copyright (C)  2016 Frederik Heber. All rights reserved.
 * 
 *
 *   This file is part of MoleCuilder.
 *
 *    MoleCuilder is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    MoleCuilder 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 General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with MoleCuilder.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * FitFragmentPartialChargesAction.cpp
 *
 *  Created on: Oct 09, 2016
 *      Author: heber
 */

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

// needs to come before MemDebug due to placement new
#include <boost/archive/text_iarchive.hpp>

#include "CodePatterns/MemDebug.hpp"

#include "Atom/atom.hpp"
#include "CodePatterns/Log.hpp"
#include "Fragmentation/Exporters/ExportGraph_ToFiles.hpp"
#include "Fragmentation/Graph.hpp"
#include "World.hpp"

#include <boost/bimap.hpp>
#include <boost/bimap/multiset_of.hpp>
#include <boost/bind.hpp>
#include <boost/filesystem.hpp>
#include <boost/foreach.hpp>
#include <boost/mpl/for_each.hpp>

#include <algorithm>
#include <functional>
#include <iostream>
#include <string>

#include "Actions/PotentialAction/FitFragmentPartialChargesAction.hpp"

#include "Potentials/PartialNucleiChargeFitter.hpp"

#include "AtomIdSet.hpp"
#include "Descriptors/AtomIdDescriptor.hpp"
#include "Element/element.hpp"
#include "Element/periodentafel.hpp"
#include "Fragmentation/Homology/AtomFragmentsMap.hpp"
#include "Fragmentation/Homology/HomologyGraph.hpp"
#include "Fragmentation/Summation/Containers/FragmentationResultContainer.hpp"
#include "Fragmentation/Summation/Containers/PartialChargesFused.hpp"
#include "Fragmentation/Summation/Containers/PartialChargesMap.hpp"
#include "Fragmentation/Summation/SetValues/IndexedPartialCharges.hpp"
#include "Fragmentation/Summation/SetValues/SamplingGrid.hpp"
#include "Fragmentation/Summation/ZeroInstanceInitializer.hpp"
#include "FunctionApproximation/Extractors.hpp"
#include "Potentials/PartialNucleiChargeFitter.hpp"
#include "Potentials/Particles/ParticleFactory.hpp"
#include "Potentials/Particles/ParticleRegistry.hpp"
#include "Potentials/SerializablePotential.hpp"
#include "World.hpp"

using namespace MoleCuilder;

// and construct the stuff
#include "FitFragmentPartialChargesAction.def"
#include "Action_impl_pre.hpp"
/** =========== define the function ====================== */

namespace detail {
  typedef std::map<KeySet, HomologyGraph> KeysetsToGraph_t;

  typedef std::map<HomologyGraph, PartialNucleiChargeFitter::charges_t> GraphFittedChargeMap_t;

  typedef std::map<atomId_t, double> fitted_charges_t;

  typedef std::map<HomologyGraph, size_t> GraphIndex_t;

  typedef std::set<size_t> AtomsGraphIndices_t;
  typedef boost::bimaps::bimap<
      boost::bimaps::multiset_of<AtomsGraphIndices_t>,
      atomId_t > GraphIndices_t;

  typedef std::map<std::set<size_t>, std::map<atomicNumber_t, std::string> > AtomParticleNames_t;

  typedef std::map<std::set<size_t>, std::string> GraphToNameMap_t;

  typedef std::map<KeySet, IndexedPartialCharges::values_t> fittedcharges_per_fragment_t;

  typedef std::map<AtomFragmentsMap::indices_t, KeySet> indices_to_keysets_t;

  typedef std::map< std::string, std::pair<double, size_t> > average_charge_map_t;
};

static void enforceZeroTotalCharge(
    PartialNucleiChargeFitter::charges_t &_averaged_charges)
{
  double charge_sum = 0.;
  charge_sum = std::accumulate(_averaged_charges.begin(), _averaged_charges.end(), charge_sum);
  if (fabs(charge_sum) > MYEPSILON) {
    std::transform(
        _averaged_charges.begin(), _averaged_charges.end(),
        _averaged_charges.begin(),
        boost::bind(std::minus<double>(), _1, charge_sum/_averaged_charges.size()));
  }
  charge_sum = 0.;
  charge_sum = std::accumulate(_averaged_charges.begin(), _averaged_charges.end(), charge_sum);
  ASSERT( fabs(charge_sum) < MYEPSILON,
      "enforceZeroTotalCharge() - enforcing neutral net charge failed, "
      +toString(charge_sum)+" is the remaining net charge.");

  LOG(2, "DEBUG: final charges with net zero charge are " << _averaged_charges);
}

static
std::set<KeySet> accumulateKeySetsForAtoms(
    const AtomFragmentsMap::AtomFragmentsMap_t &_atommap,
    const std::vector<const atom *> &_selected_atoms)
{
  std::set<KeySet> fragments;
  for (std::vector<const atom *>::const_iterator iter = _selected_atoms.begin();
      iter != _selected_atoms.end(); ++iter) {
    const atomId_t atomid = (*iter)->getId();
    const AtomFragmentsMap::AtomFragmentsMap_t::const_iterator atomiter =
        _atommap.find(atomid);
    if ((*iter)->getElementNo() != 1) {
      if (atomiter == _atommap.end()) {
        ELOG(2, "There are no fragments associated to " << atomid << ".");
        continue;
      }
      const AtomFragmentsMap::keysets_t &keysets = atomiter->second;
      LOG(2, "DEBUG: atom " << atomid << " has " << keysets.size() << " fragments.");
      fragments.insert( keysets.begin(), keysets.end() );
    } else {
      LOG(3, "DEBUG: Skipping atom " << atomid << " as it's hydrogen.");
    }
  }
  return fragments;
}

static
void getKeySetsToGraphMapping(
    detail::KeysetsToGraph_t &_keyset_graphs,
    const std::set<KeySet> &_fragments,
    const AtomFragmentsMap &_atomfragments)
{
  for (std::set<KeySet>::const_iterator fragmentiter = _fragments.begin();
      fragmentiter != _fragments.end(); ++fragmentiter) {
    const KeySet &keyset = *fragmentiter;
    const AtomFragmentsMap::indices_t &forceindices = _atomfragments.getFullKeyset(keyset);
    ASSERT( !forceindices.empty(),
        "getKeySetsToGraphMapping() - force keyset to "+toString(keyset)+" is empty.");
    KeySet forcekeyset;
    forcekeyset.insert(forceindices.begin(), forceindices.end());
    forcekeyset.erase(-1);
    const HomologyGraph graph(forcekeyset);
    LOG(2, "DEBUG: Associating keyset " << forcekeyset << " with graph " << graph);
    _keyset_graphs.insert( std::make_pair(keyset, graph) );
  }
}

static
bool getPartialChargesForAllIndexSets(
    detail::fittedcharges_per_fragment_t &_fittedcharges_per_fragment,
    const FragmentationResultContainer &_container,
    const std::set<KeySet> &_fragments,
    const double _mask_radius,
    const bool enforceZeroCharge)
{
  const std::map<JobId_t, MPQCData> &shortrangedata = _container.getShortRangeResults();
  const std::map<JobId_t, VMGData> &longrangedata = _container.getLongRangeResults();
  const KeySetsContainer &keysets = _container.getKeySets();

  std::map<JobId_t, MPQCData>::const_iterator shortiter = shortrangedata.begin();
  std::map<JobId_t, VMGData>::const_iterator longiter = longrangedata.begin();
  KeySetsContainer::ArrayOfIntVectors::const_iterator keysetiter = keysets.KeySets.begin();
  for (; keysetiter != keysets.KeySets.end(); ++keysetiter, ++shortiter, ++longiter) {
    // check whether its an allowed keyset (atomfragments has keyset, not forcekeyset)
    KeySet currentset;
    currentset.insert(keysetiter->begin(), keysetiter->end());
    if (_fragments.find(currentset) == _fragments.end())
      continue;

    // obtain positions and sampled potential
    const Fragment::positions_t &fragmentpositions = shortiter->second.positions;
    const SamplingGrid &potential = longiter->second.both_sampled_potential;
    if ((potential.level == 0)
        || ((potential.begin[0] == potential.end[0])
            && (potential.begin[1] == potential.end[1])
            && (potential.begin[2] == potential.end[2]))) {
      ELOG(1, "Sampled grid contains grid made of zero points.");
      return 0;
    }

    // convert std::vector<double> to Vector
    PartialNucleiChargeFitter::positions_t positions;
    positions.reserve(fragmentpositions.size());
    BOOST_FOREACH( Fragment::position_t pos, fragmentpositions) {
      positions.push_back( Vector(pos[0], pos[1], pos[2]) );
    }

    // fit charges
    PartialNucleiChargeFitter fitter(potential, positions, _mask_radius);
    fitter();
    PartialNucleiChargeFitter::charges_t return_charges = fitter.getSolutionAsCharges_t();
    LOG(2, "DEBUG: fitted charges are " << return_charges);

    // make sum of charges zero if desired
    if (enforceZeroCharge)
      enforceZeroTotalCharge(return_charges);

    // output status info fitted charges
    LOG(2, "DEBUG: For fragment " << *keysetiter
        << " we have fitted the following charges " << return_charges << ".");

    IndexedPartialCharges::values_t values;
    for (PartialNucleiChargeFitter::charges_t::const_iterator chargeiter = return_charges.begin();
        chargeiter != return_charges.end(); ++chargeiter) {
      values.push_back(partial_charge_t(*chargeiter));
    }
    _fittedcharges_per_fragment.insert( std::make_pair(currentset, values) );
  }
  return true;
}

static const atom * getNonHydrogenSurrogate(const atom * const _walker)
{
  const atom * surrogate = _walker;
  if (surrogate->getElementNo() == 1) {
    // it's hydrogen, check its bonding and use its bond partner instead to request
    // keysets
    const BondList &ListOfBonds = surrogate->getListOfBonds();
    if ( ListOfBonds.size() != 1) {
      ELOG(1, "Solitary hydrogen in atom " << surrogate->getId() << " detected.");
      return _walker;
    }
    surrogate = (*ListOfBonds.begin())->GetOtherAtom(surrogate);
  }
  return surrogate;
}

static void addToParticleRegistry(
    const ParticleFactory &factory,
    ParticleRegistry &registry,
    const periodentafel &periode,
    const detail::fitted_charges_t &_fitted_charges,
    const detail::GraphIndices_t &_GraphIndices,
    detail::AtomParticleNames_t &_atom_particlenames)
{
  /// We step here through the atoms and check for all atoms of the
  /// same element and which belong to the same set of graphs (via the set
  /// of their unique enumeration indices) then they get the same particle
  detail::average_charge_map_t average_charge_map;
  for (detail::fitted_charges_t::const_iterator chargeiter = _fitted_charges.begin();
      chargeiter != _fitted_charges.end(); ++chargeiter) {
    const atomId_t &atomid = chargeiter->first;
    const double &charge = chargeiter->second;
    const atom * const walker = World::getInstance().getAtom(AtomById(atomid));
    ASSERT( walker != NULL,
        "addToParticleRegistry() - atom "+toString(atomid)
        +" not present in the World?");
    const detail::GraphIndices_t::right_const_iterator graphiter =
        _GraphIndices.right.find(atomid);
    ASSERT(graphiter != _GraphIndices.right.end(),
        "addToParticleRegistry() - atom #"+toString(atomid)
        +" not contained in GraphIndices.");
    const detail::AtomParticleNames_t::iterator nameiter =
        _atom_particlenames.find(graphiter->second);
    const atomicNumber_t elementno = walker->getElementNo();
    std::string name;
    if ((nameiter != _atom_particlenames.end()) && (nameiter->second.count(elementno))) {
        name = (nameiter->second)[elementno];
        detail::average_charge_map_t::iterator averageiter = average_charge_map.find(name);
        ASSERT( averageiter != average_charge_map.end(),
            "addToParticleRegistry() - could not find name "+toString(nameiter->second)
            +" in average charge map.");
        // add charge to particle
        averageiter->second.first += charge;
        ++(averageiter->second.second);
        LOG(1, "INFO: Adding additional charge " << charge << " to particle " << name << " for atom "
            << *walker << " with element " << elementno << ".");
    } else {
      if (nameiter == _atom_particlenames.end())
        _atom_particlenames.insert(
            std::make_pair(graphiter->second, std::map<atomicNumber_t, std::string>()) );
      name = Particle::findFreeName(periode, elementno);
      _atom_particlenames[graphiter->second][elementno] = name;
      LOG(1, "INFO: Adding particle " << name << " for atom "
          << *walker << " with element " << elementno << " and initial charge "
          << charge << ".");
      factory.createInstance(name, elementno, charge);
#ifndef NDEBUG
      std::pair< detail::average_charge_map_t::iterator, bool> inserter =
#endif
          average_charge_map.insert( std::make_pair(name, std::make_pair(charge,1)) );
      ASSERT( inserter.second,
          "addToParticleRegistry() - name "+name+" already present in average charge map?");
    }
  }

  // go through map, average and insert average charge into factory
  for (detail::average_charge_map_t::const_iterator averageiter = average_charge_map.begin();
      averageiter != average_charge_map.end(); ++averageiter) {
    const std::string &name = averageiter->first;
    const double &charge = averageiter->second.first;
    const size_t &times = averageiter->second.second;
    ASSERT( times != 0,
        "addToParticleRegistry() - zero times in average charge map is not allowed.");
    Particle *particle = registry.getByName(name);
    particle->charge = charge/(double)times;
  }
}

static bool isNotHydrogen(const atom * const _atom)
{
  return (_atom->getElementNo() != (atomicNumber_t) 1);
}

static struct KeySetSizeComp {
  bool operator() (const KeySet &a, const KeySet &b) { return a.size()<b.size(); }
} keyset_comparator;

#include <boost/fusion/sequence.hpp>
#include <boost/mpl/for_each.hpp>

#include "Fragmentation/Summation/AllLevelOrthogonalSummator.hpp"
#include "Fragmentation/Summation/IndexSet.hpp"
#include "Fragmentation/Summation/IndexSetContainer.hpp"
#include "Fragmentation/Summation/SubsetMap.hpp"
#include "Fragmentation/Summation/Containers/PartialChargesFused.hpp"
#include "Fragmentation/Summation/Containers/PartialChargesMap.hpp"
#include "Fragmentation/Summation/SetValues/IndexedPartialCharges.hpp"

ActionState::ptr PotentialFitFragmentPartialChargesAction::performCall()
{
  // check for selected atoms
  const World &world = World::getConstInstance();
  const std::vector<const atom *> selected_atoms = world.getSelectedAtoms();
  if (selected_atoms.empty()) {
    STATUS("There are no atoms selected for fitting partial charges to.");
    return Action::failure;
  }
  LOG(3, "There are  " << selected_atoms.size() << " selected atoms.");

  /// obtain possible fragments to each selected atom
  const AtomFragmentsMap &atomfragments = AtomFragmentsMap::getConstInstance();
  if (!atomfragments.checkCompleteness()) {
    ELOG(0, "AtomFragmentsMap failed internal consistency check, missing forcekeysets?");
    return Action::failure;
  }
  const std::set<KeySet> fragments =
      accumulateKeySetsForAtoms( atomfragments.getMap(), selected_atoms);
  const size_t NoNonHydrogens =
      std::count_if(selected_atoms.begin(), selected_atoms.end(), isNotHydrogen);
  if (fragments.size() < NoNonHydrogens) {
    ELOG(0, "Obtained fewer fragments than there are atoms, has AtomFragments been loaded?");
    return Action::failure;
  }

  // get results from container
  FragmentationResultContainer& resultscontainer = FragmentationResultContainer::getInstance();
#if defined(HAVE_JOBMARKET) && defined(HAVE_VMG)
  const bool DoLongrange = resultscontainer.areFullRangeResultsPresent();
  if (!DoLongrange) {
    ELOG(1, "FragmentationResultContainer does not contain long-range results, cannot fit partial charges.");
    return Action::failure;
  }

  if (resultscontainer.getKeySets().KeySets.empty()) {
    STATUS("There are no results in the container.");
    return Action::failure;
  }

  // reduce given fragments to homologous graphs for later lookup
  detail::KeysetsToGraph_t keyset_graphs;
  detail::fittedcharges_per_fragment_t fittedcharges_per_fragment;
  getKeySetsToGraphMapping(keyset_graphs, fragments, atomfragments);

  /// then go through all fragments and get partial charges for each
  const bool status = getPartialChargesForAllIndexSets(
      fittedcharges_per_fragment,
      resultscontainer,
      fragments,
      params.radius.get(),
      params.enforceZeroCharge.get());
  if (!status)
    return Action::failure;

  /// obtain average charge for each atom the fitted charges over all its fragments
  detail::fitted_charges_t fitted_charges;
  {
    // place all into boost::fusion map for summation
    std::map<JobId_t, PartialChargesMap_t> PartialCharges_fused;
    std::vector<IndexSet> indexsets;
    JobId_t counter = 0;
    for (detail::fittedcharges_per_fragment_t::const_iterator iter = fittedcharges_per_fragment.begin();
        iter != fittedcharges_per_fragment.end(); ++iter) {
      const KeySet &currentset = iter->first;
      // place as IndexSet into container
      {
        IndexSet tempset;
        tempset.insert(currentset.begin(), currentset.end());
        indexsets.push_back(tempset);
      }
      LOG(3, "Inserting " << iter->first << " with charges " << iter->second << " into chargemap instance.");
      PartialChargesMap_t chargemap;
      const AtomFragmentsMap::indices_t &full_currentset = atomfragments.getFullKeyset(currentset);
      IndexedPartialCharges::indices_t indices(full_currentset.begin(), full_currentset.end());
      boost::fusion::at_key<PartialChargesFused::partial_charges_t>(chargemap) =
          IndexedPartialCharges(full_currentset, iter->second);
      PartialCharges_fused.insert( std::make_pair(counter++, chargemap) );
    }
    ASSERT( counter == fragments.size(),
        "PotentialFitPartialChargesAction::performCall() - not all fragments' keysets were created?");
    ASSERT( indexsets.size() == fragments.size(),
        "PotentialFitPartialChargesAction::performCall() - not all fragments' keysets were created?");

    // prepare index set hierarchy
    std::map< JobId_t, size_t > IdentityLookup;
    size_t MaxLevel = std::max_element(fragments.begin(), fragments.end(), keyset_comparator)->size();
    LOG(3, "The maximum level is " << MaxLevel);
    size_t max_indices = fragments.size();
    LOG(3, "There are " << max_indices << " keysets for the selected atoms.");
    {
      for (size_t index = 0; index < max_indices; ++index)
        IdentityLookup.insert( std::make_pair( (JobId_t)index, index ) );
    }
    IndexSetContainer::ptr container(new IndexSetContainer(indexsets));
    SubsetMap::ptr subsetmap(new SubsetMap(*container));

    // and sum up
    PartialChargesMap_t ZeroInstances;
    ZeroInstanceInitializer<PartialChargesMap_t> initZeroInstance(ZeroInstances);
    boost::mpl::for_each<PartialChargesVector_t>(boost::ref(initZeroInstance));
    //!> results per level of summed up partial charges
    std::vector<PartialChargesMap_t> Result_PartialCharges_fused(MaxLevel);
    //!> results per index set in terms of value and contribution
    std::map<
        IndexSet::ptr,
        std::pair<PartialChargesMap_t, PartialChargesMap_t> > Result_perIndexSet_PartialCharges;
    AllLevelOrthogonalSummator<PartialChargesMap_t> partialchargeSummer(
                subsetmap,
                PartialCharges_fused,
                container->getContainer(),
                IdentityLookup,
                Result_PartialCharges_fused,
                Result_perIndexSet_PartialCharges,
                ZeroInstances);
    boost::mpl::for_each<PartialChargesVector_t>(boost::ref(partialchargeSummer));

    // TODO: place results into fitted_charges
    const IndexedPartialCharges::indexedvalues_t indexed_partial_charges =
        boost::fusion::at_key<PartialChargesFused::partial_charges_t>(
            Result_PartialCharges_fused.back()
            ).getValues();
    for (IndexedPartialCharges::indexedvalues_t::const_iterator iter = indexed_partial_charges.begin();
        iter != indexed_partial_charges.end(); ++iter)
      fitted_charges.insert( std::make_pair( iter->first, iter->second.charge));
    LOG(3, "Summation has brought forth the following charges per atom index: " << fitted_charges);
  }

  // make a unique list of the present HomologyGraphs
  typedef std::set<HomologyGraph> unique_graphs_t;
  unique_graphs_t unique_graphs;
  for (detail::KeysetsToGraph_t::const_iterator keysetiter = keyset_graphs.begin();
      keysetiter != keyset_graphs.end(); ++keysetiter)
    unique_graphs.insert(keysetiter->second);

  /// make Particles be used for every atom that was fitted on the same number of graphs
  detail::GraphIndex_t GraphIndex;
  size_t index = 0;
  for (unique_graphs_t::const_iterator graphiter = unique_graphs.begin();
      graphiter != unique_graphs.end(); ++graphiter) {
    GraphIndex.insert( std::make_pair( *graphiter, index++));
  }
  LOG(2, "DEBUG: There are " << index << " unique graphs in the homology container.");
  ASSERT( index == unique_graphs.size(),
      "PotentialFitFragmentPartialChargesAction::performCall() - could not enumerate all unique graphs?");

  // go through every non-hydrogen atom, get all graphs, convert to GraphIndex and store
  detail::GraphIndices_t GraphIndices;
  const AtomFragmentsMap::AtomFragmentsMap_t &atommap = atomfragments.getMap();
  for (std::vector<const atom *>::const_iterator atomiter = selected_atoms.begin();
      atomiter != selected_atoms.end(); ++atomiter) {
    // use the non-hydrogen here
    const atomId_t walkerid = (*atomiter)->getId();
    const atomId_t surrogateid = getNonHydrogenSurrogate(*atomiter)->getId();
    if (surrogateid != walkerid)
      continue;
    const AtomFragmentsMap::AtomFragmentsMap_t::const_iterator keysetsiter =
        atommap.find(walkerid);
    ASSERT(keysetsiter != atommap.end(),
        "PotentialFitFragmentPartialChargesAction::performCall() - we checked already that "
        +toString(surrogateid)+" should be present!");
    const AtomFragmentsMap::keysets_t & keysets = keysetsiter->second;

    // go over all fragments associated to this atom
    detail::AtomsGraphIndices_t AtomsGraphIndices;
    for (AtomFragmentsMap::keysets_t::const_iterator keysetsiter = keysets.begin();
        keysetsiter != keysets.end(); ++keysetsiter) {
      const KeySet &keyset = *keysetsiter;
      const std::map<KeySet, HomologyGraph>::const_iterator keysetgraphiter =
          keyset_graphs.find(keyset);
      ASSERT( keysetgraphiter != keyset_graphs.end(),
          "PotentialFitFragmentPartialChargesAction::performCall() - keyset "+toString(keyset)
          +" not contained in keyset_graphs.");
      const HomologyGraph &graph = keysetgraphiter->second;
      const detail::GraphIndex_t::const_iterator indexiter = GraphIndex.find(graph);
      ASSERT( indexiter != GraphIndex.end(),
          "PotentialFitFragmentPartialChargesAction::performCall() - graph "+toString(graph)
          +" not contained in GraphIndex.");
      AtomsGraphIndices.insert( indexiter->second );
    }

    GraphIndices.insert( detail::GraphIndices_t::value_type(AtomsGraphIndices, walkerid) );

    LOG(2, "DEBUG: Atom #" << walkerid << "," << **atomiter << ". has graph indices "
        << AtomsGraphIndices);
  }
  // then graphs from non-hydrogen bond partner for all hydrogens
  for (std::vector<const atom *>::const_iterator atomiter = selected_atoms.begin();
      atomiter != selected_atoms.end(); ++atomiter) {
    // use the non-hydrogen here
    const atomId_t walkerid = (*atomiter)->getId();
    const atomId_t surrogateid = getNonHydrogenSurrogate((*atomiter))->getId();
    if (surrogateid == walkerid)
      continue;
    detail::GraphIndices_t::right_const_iterator graphiter = GraphIndices.right.find(surrogateid);
    ASSERT( graphiter != GraphIndices.right.end(),
        "PotentialFitFragmentPartialChargesAction::performCall() - atom #"+toString(surrogateid)
        +" not contained in GraphIndices.");
    const detail::AtomsGraphIndices_t &AtomsGraphIndices = graphiter->second;
    GraphIndices.insert( detail::GraphIndices_t::value_type(AtomsGraphIndices, walkerid) );
    LOG(2, "DEBUG: Hydrogen #" << walkerid << ", " << **atomiter
        << ", has graph indices " << AtomsGraphIndices);
  }

  /// place all fitted (and now averaged) charges into ParticleRegistry
  detail::AtomParticleNames_t atom_particlenames;
  addToParticleRegistry(
      ParticleFactory::getConstInstance(),
      ParticleRegistry::getInstance(),
      *World::getInstance().getPeriode(),
      fitted_charges,
      GraphIndices,
      atom_particlenames);

  for (World::AtomSelectionIterator atomiter = World::getInstance().beginAtomSelection();
      atomiter != World::getInstance().endAtomSelection(); ++atomiter) {
    atom * const walker = atomiter->second;
    const atomId_t walkerid = atomiter->first;
    const detail::GraphIndices_t::right_const_iterator graphiter =
        GraphIndices.right.find(walkerid);
    ASSERT( graphiter != GraphIndices.right.end(),
        "PotentialFitFragmentPartialChargesAction::performCall() - cannot find "
        +toString(walkerid)+" in GraphIndices.");
    const detail::AtomsGraphIndices_t &graphindex = graphiter->second;
    const detail::AtomParticleNames_t::const_iterator particlesetiter =
        atom_particlenames.find(graphindex);
    ASSERT( particlesetiter != atom_particlenames.end(),
        "PotentialFitFragmentPartialChargesAction::performCall() - cannot find "
        +toString(graphindex)+" in atom_particlenames.");
    const std::map<atomicNumber_t, std::string>::const_iterator nameiter =
        particlesetiter->second.find(walker->getElementNo());
    ASSERT( nameiter != particlesetiter->second.end(),
        "PotentialFitFragmentPartialChargesAction::performCall() - ");
    walker->setParticleName(nameiter->second);
    LOG(1, "INFO: atom " << *walker << " received the following particle "
        << walker->getParticleName());
  }

  return Action::success;
#else
  ELOG(0, "Long-range support not compiled in, cannot fit partial charges to fragment's potential grids.");
  return Action::failure;
#endif
}

ActionState::ptr PotentialFitFragmentPartialChargesAction::performUndo(ActionState::ptr _state) {
  return Action::success;
}

ActionState::ptr PotentialFitFragmentPartialChargesAction::performRedo(ActionState::ptr _state){
  return Action::success;
}

bool PotentialFitFragmentPartialChargesAction::canUndo() {
  return false;
}

bool PotentialFitFragmentPartialChargesAction::shouldUndo() {
  return false;
}
/** =========== end of function ====================== */