////////////////////////////////////////////////////////////////////
/// \class RAT::VertexGen_Spectrum
///
/// \brief  Vertex Generator - events of given particle (or ion) type, with energies sampled from spectrum via DB
///
/// \author Jeanne Wilson <j.r.wilson@qmul.ac.uk> -- contact person
///
/// REVISION HISTORY:
///   - first version : 18-July-2008
///  - 2014-11-26: Matt Strait - doxygen fixes
///  - 2015-08-04: Matt Mottram - Use G4IonTable to get ions
///  - 2017-02-10: Nuno Barros - Added BeginOfRun to load database contents
///
/// \details This vertex generator (to be used in composite generators like combo of coincidence) produces isotropic particles
/// or ions with kinetic energies sampled from a data-base defined distribution. An option to limit the range
/// of the energy distribution is available
////////////////////////////////////////////////////////////////////////

#ifndef __RAT_VertexGen_Spectrum__
#define __RAT_VertexGen_Spectrum__

#include <RAT/GLG4VertexGen.hh>
#include "RAT/DB.hh"

#include <G4Event.hh>
#include <G4ThreeVector.hh>
#include <globals.hh>
#include <vector>

namespace RAT {

class VertexGen_Spectrum: public GLG4VertexGen {
public:

  VertexGen_Spectrum(const char *arg_dbname = "SPECTRUM");
  virtual ~VertexGen_Spectrum();
  /** generate and add new vertex to this event.  Position and
   * time of vertex are offset from 0 by dx and dt.  (These
   * are usually derived from GLG4PosGen and GLG4TimeGen.)
   */
  virtual void GeneratePrimaryVertex(G4Event* argEvent, G4ThreeVector& dx,
      G4double dt);
  /** set the state for generator. Format: pname specname
   * where pname is the particle name, and specname is the database spectrum name
   */
  virtual void SetState(G4String newValues);
  /** return current state */
  virtual G4String GetState();

  /** Set up the spectrum array in memory - create normalised cumulative magnitude for easy sampling*/
  virtual void InitialiseSpectrum();

  /** Sample energy from spectrum between bounds Elim_lo and Elim_hi */
  virtual float SampleEnergy();

  /** For this generator, it is possible to limit the output energies */
  virtual bool ELimitable() {
    return true;
  }
  ;

  /** Set the limits on the generated energy */
  virtual void LimitEnergies(float Elo, float Ehi);

  /** Return the maximum possible energy */
  virtual float EMaximum();

  /** Return the minimum possible energy */
  virtual float EMinimum();

  virtual void BeginOfRun();

private:
  G4String fParticle;           // name of the particle type
  G4ParticleDefinition* fPDef;  // particle definition
  G4String fSpectrum;           // name of the spectrum to use
  DBLinkPtr fLSpec;             // link to spectrum entry in database
  float fEMin;                  // valid range for spectrum in MeV
  float fEMax;
  std::vector<float> fSpecE;    // spectrum energy values
  std::vector<float> fSpecMag;  // spectrum magnitude values
  std::vector<float> fSpecCumMag;// spectrum cumulative non-normalised magnitude values
  float fELimUniLow;            // user applied universal lower limit to energy range
  float fELimUniHigh;           // user applied universal higher limit to energy range
  float fELimTempLow;           // temporary lower energy limit (applies to one event)
  float fELimTempHigh;          // temporary higher energy limit (applies to one event)
};

} // namespace RAT

#endif