/*
 * Interfragmenter.hpp
 *
 *  Created on: Jul 5, 2013
 *      Author: heber
 */

#ifndef INTERFRAGMENTER_HPP_
#define INTERFRAGMENTER_HPP_

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

#include <vector>

#include "Fragmentation/HydrogenSaturation_enum.hpp"

class atom;
class KeySet;
class Graph;

/** This functor adds the union of certain fragments to a given set of fragments
 * (a Graph) by combining them depending on whether they are (not) bonded and
 * how far their centers are apart and which bond order they have.
 *
 * This is to allow calculation of interfragment energies. As fragments are
 * always of the same molecule, energies in between molecules so far are only
 * attained electrostratically, whereas dynamic correlation is totally missed.
 * Interfragments that are calculate with e.g. a sensible Post-HF method contain
 * dynamic correlation which can then be used for later potential fitting.
 */
class Interfragmenter
{
public:
  /** Constructor for class Interfragmenter.
   *
   * \param _TotalGraph Graph with all fragments to interrelate
   */
  Interfragmenter(Graph &_TotalGraph) :
    TotalGraph(_TotalGraph)
  {}

  /** Adds interrelated fragments to TotalGraph up to \a MaxOrder and \a Rcut.
   *
   * \param MaxOrder maximum order for fragments to interrelate
   * \param Rcut maximum distance to check for interrelatable fragments
   * \param treatment whether hydrogens are treated specially or not
   */
  void operator()(
      size_t MaxOrder,
      double Rcut,
      const enum HydrogenTreatment treatment);

private:
  /** Helper to translate a keyset into a set of atoms.
   *
   * \param keyset
   * \return vector of atom refs
   */
  std::vector<atom *> getAtomsFromKeySet(const KeySet &keyset) const;


private:
  Graph &TotalGraph;
};

#endif /* INTERFRAGMENTER_HPP_ */