//
// ********************************************************************
// * License and Disclaimer                                           *
// *                                                                  *
// * The  Geant4 software  is  copyright of the Copyright Holders  of *
// * the Geant4 Collaboration.  It is provided  under  the terms  and *
// * conditions of the Geant4 Software License,  included in the file *
// * LICENSE and available at  http://cern.ch/geant4/license .  These *
// * include a list of copyright holders.                             *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.  Please see the license in the file  LICENSE  and URL above *
// * for the full disclaimer and the limitation of liability.         *
// *                                                                  *
// * This  code  implementation is the result of  the  scientific and *
// * technical work of the GEANT4 collaboration.                      *
// * By using,  copying,  modifying or  distributing the software (or *
// * any work based  on the software)  you  agree  to acknowledge its *
// * use  in  resulting  scientific  publications,  and indicate your *
// * acceptance of all terms of the Geant4 Software license.          *
// ********************************************************************
//
//
// Author: Mathieu Karamitros

// The code is developed in the framework of the ESA AO7146
//
// We would be very happy hearing from you, send us your feedback! :)
//
// In order for Geant4-DNA to be maintained and still open-source,
// article citations are crucial. 
// If you use Geant4-DNA chemistry and you publish papers about your software, 
// in addition to the general paper on Geant4-DNA:
//
// Int. J. Model. Simul. Sci. Comput. 1 (2010) 157–178
//
// we would be very happy if you could please also cite the following
// reference papers on chemistry:
//
// J. Comput. Phys. 274 (2014) 841-882
// Prog. Nucl. Sci. Tec. 2 (2011) 503-508 

#ifndef G4MOLECULEENCOUNTERSTEPPER_H
#define G4MOLECULEENCOUNTERSTEPPER_H

#include "G4VITTimeStepComputer.hh"
#include "G4KDTreeResult.hh"

class G4VDNAReactionModel;
class G4DNAMolecularReactionTable;
class G4MolecularConfiguration;

class G4Molecule;

/**
 * Given a molecule G4DNAMoleculeEncounterStepper will calculate for its possible reactants
 * what will be the minimum encounter time and the associated molecules.*
 *
 * This model includes dynamical time steps as explained in
 * "Computer-Aided Stochastic Modeling of the Radiolysis of Liquid Water",
 * V. Michalik, M. Begusová, E. A. Bigildeev,
 * Radiation Research, Vol. 149, No. 3 (Mar., 1998), pp. 224-236
 *
 */

class G4DNAMoleculeEncounterStepper : public G4VITTimeStepComputer
{
public:
  G4DNAMoleculeEncounterStepper();
  virtual ~G4DNAMoleculeEncounterStepper();
  G4DNAMoleculeEncounterStepper(const G4DNAMoleculeEncounterStepper&);
  G4IT_ADD_CLONE(G4VITTimeStepComputer,G4DNAMoleculeEncounterStepper)

  virtual void Prepare();
  //    virtual void PrepareForAllProcessors();
  virtual G4double CalculateStep(const G4Track&, const G4double&);

  inline void SetReactionModel(G4VDNAReactionModel*);
  inline G4VDNAReactionModel* GetReactionModel();

  inline void SetVerbose(int);
  // Final time returned when reaction is avalaible in the reaction table = 1
  // All details = 2

private:
  void InitializeForNewTrack();

  class Utils;
  void CheckAndRecordResults(const Utils&,
#ifdef G4VERBOSE
                             const G4double reactionRange,
#endif
                             G4KDTreeResultHandle&);

  G4bool fHasAlreadyReachedNullTime;

  G4DNAMoleculeEncounterStepper& operator=(const G4DNAMoleculeEncounterStepper&);
  const G4DNAMolecularReactionTable*& fMolecularReactionTable;
  G4VDNAReactionModel* fReactionModel;
  G4int fVerbose;

  class Utils
  {
  public:
    Utils(const G4Track& tA, G4MolecularConfiguration* mB);
    ~Utils(){;}

    G4double GetConstant() const
    {
      return Constant;
    }

    const G4Track& trackA;
    G4MolecularConfiguration* moleculeB;
    const G4Molecule* moleculeA;
    G4double DA;
    G4double DB;
    G4double Constant;
  };

};

inline void G4DNAMoleculeEncounterStepper::SetReactionModel(G4VDNAReactionModel* reactionModel)
{
  fReactionModel = reactionModel;
}

inline G4VDNAReactionModel* G4DNAMoleculeEncounterStepper::GetReactionModel()
{
  return fReactionModel;
}

inline void G4DNAMoleculeEncounterStepper::SetVerbose(int flag)
{
  fVerbose = flag;
}

#endif // G4MOLECULEENCOUNTERSTEPPER_H
