////////////////////////////////////////////////////////////////////
#ifndef __RAT_VertexGen_IBD__
#define __RAT_VertexGen_IBD__


/**
	\class RAT::VertexGen_IBD
	vertex generator that can generate the products of a inverse
    beta-decay reaction from a reactor anti-neutrino.  The direction
    of the neutrino is supplied, and the energy and angle of the
    produced positron and neutron are drawn from the distribution
    produced by the differential cross-section and a reactor anti-neutrino
    energy spectrum.

    17-10-2016 - N. Barros - Added a couple of updates to follow with the overload of
                            the reactor generator
*/

#include <RAT/NeutrinoVertexGen.hh>
#ifdef RATDEBUG
#include <RAT/Profiler.hh>
#endif
#include <G4LorentzVector.hh>
#include <G4ThreeVector.hh>

#include <vector>

class TH1D;
class G4ParticleDefinition;

namespace RAT {

class IBDCrossSec;

class VertexGen_IBD : public NeutrinoVertexGen {
public:
  VertexGen_IBD(const char *arg_dbname="IBD");
  virtual ~VertexGen_IBD();
  virtual void GeneratePrimaryVertex( G4Event *argEvent,
				      G4ThreeVector &dx,
				      G4double dt);

  // This one only makes sense for neutrino sources such as ES and IBD
  virtual void GeneratePrimaryVertex( G4Event *argEvent,
                G4ThreeVector &dx,
                G4double dt,
                G4ThreeVector &nu_dir);

  // generates a primary vertex with given particle type, direction, energy,
  // and consistent polarization.
  virtual void SetState( G4String newValues );
  // format: dir_x dir_y dir_z
  // If dir_x==dir_y==dir_z==0, the directions are isotropic.
  virtual G4String GetState();
  // returns current state formatted as above

  virtual void BeginOfRun();
  virtual void EndOfRun();

  void SetSpectrum(TH1D *flux);

  void GenEvent(const G4ThreeVector &nu_dir,
      G4LorentzVector &neutrino,
      G4LorentzVector &positron,
      G4LorentzVector &neutron);

  void GenInteraction(double &E, double &CosThetaLab);


  virtual G4double GetRatePerTarget();



private:
  const G4ParticleDefinition *fANu, *fNeutron, *fEplus;
  G4ThreeVector         fNuDir;
  double                fCrossSecMax;
  double                fFluxMax;
  IBDCrossSec           *fCrossSec;

  static const double   sDeltaM;

  TH1D *fFlux;
  std::vector<double>   fSpectrumX;
  std::vector<double>   fSpectrumY;

  bool                  fSpectrumLoaded;
  bool                  fStandaloneMode;
#ifdef RATDEBUG
  Profiler              fProfiler;
#endif
};


} // namespace RAT

#endif