//--------------------------------------------------------------------------
//
// Module: EvtGen/EvtD0gammaDalitz.hh
//
// Modification history:
//
//    JGT     February 13, 2012         Module created
//
//------------------------------------------------------------------------

#ifndef __EVTD0GAMMADALITZ_HH__
#define __EVTD0GAMMADALITZ_HH__

#include <vector>

#include "EvtGenBase/EvtDecayAmp.hh"
#include "EvtGenBase/EvtFlatte.hh"

#include "EvtGenBase/EvtSpinType.hh"
#include "EvtGenBase/EvtDalitzReso.hh"
#include "EvtGenBase/EvtCyclic3.hh"

class EvtParticle;

class EvtD0gammaDalitz : public EvtDecayAmp
{
private:
  int _d1;
  int _d2;
  int _d3;
  int _flag;

  bool _isKsPiPi;

  // Useful constants.
  static const EvtSpinType::spintype& _SCALAR;
  static const EvtSpinType::spintype& _VECTOR;
  static const EvtSpinType::spintype& _TENSOR;

  static const EvtDalitzReso::CouplingType& _EtaPic;
  static const EvtDalitzReso::CouplingType& _PicPicKK;

  static const EvtDalitzReso::NumType& _RBW;
  static const EvtDalitzReso::NumType& _GS;
  static const EvtDalitzReso::NumType& _KMAT;

  static const EvtCyclic3::Pair& _AB;
  static const EvtCyclic3::Pair& _AC;
  static const EvtCyclic3::Pair& _BC;

  // Values to be read or computed based on values in the evt.pdl file.
  // IDs of the relevant particles.
  EvtId _BP;
  EvtId _BM;
  EvtId _B0;
  EvtId _B0B;
  EvtId _D0;
  EvtId _D0B;
  EvtId _KM;
  EvtId _KP;
  EvtId _K0;
  EvtId _K0B;
  EvtId _KL;
  EvtId _KS;
  EvtId _PIM;
  EvtId _PIP;

  // Flavor of the B mother.
  EvtId _bFlavor;

  // Masses of the relevant particles.
  double _mD0;
  double _mKs;
  double _mPi;
  double _mK;

  void readPDGValues();
  void reportInvalidAndExit() const;

  EvtComplex dalitzKsPiPi( const EvtDalitzPoint& point ) const;
  EvtComplex dalitzKsKK  ( const EvtDalitzPoint& point ) const;

public:
  EvtD0gammaDalitz();
  virtual ~EvtD0gammaDalitz();

  std::string getName();
  EvtDecayBase* clone();

  void init();
  void initProbMax();

  void decay( EvtParticle* p );
};

#endif