//
// ********************************************************************
// * 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.          *
// ********************************************************************
//
//
//
// P. Arce, June-2014 Conversion neutron_hp to particle_hp
//
#ifndef G4ParticleHPArbitaryTab_h
#define G4ParticleHPArbitaryTab_h 1

#include "G4InterpolationManager.hh"
#include "G4ParticleHPVector.hh"
#include "G4VParticleHPEDis.hh"
#include "G4ios.hh"
#include "Randomize.hh"
#include "globals.hh"

#include <CLHEP/Units/SystemOfUnits.h>

#include <fstream>

// we will need a List of these .... one per term.

class G4ParticleHPArbitaryTab : public G4VParticleHPEDis
{
  public:
    G4ParticleHPArbitaryTab()
    {
      theDistFunc = nullptr;
      nDistFunc = 0;
    }
    ~G4ParticleHPArbitaryTab() override { delete[] theDistFunc; }

    inline void Init(std::istream& theData) override
    {
      std::size_t i;
      theFractionalProb.Init(theData, CLHEP::eV);
      theData >> nDistFunc;  // = number of incoming n energy points
      const std::size_t dsize = nDistFunc > 0 ? nDistFunc : 1;
      theDistFunc = new G4ParticleHPVector[dsize];
      theManager.Init(theData);
      G4double currentEnergy;
      for (i = 0; i < dsize; ++i) {
        theData >> currentEnergy;
        theDistFunc[i].SetLabel(currentEnergy * CLHEP::eV);
        theDistFunc[i].Init(theData, CLHEP::eV);
        theDistFunc[i].IntegrateAndNormalise();
        //************************************************************************
        // EMendoza:
        // ThinOut() assumes that the data is linear-linear, what is false:
        // theDistFunc[i].ThinOut(0.02); // @@@ optimization to be finished.
        //************************************************************************
      }

      //************************************************************************
      // EMendoza:
      // Here we calculate the thresholds for the 2D sampling:
      for (i = 0; i < dsize; ++i) {
        G4int np = theDistFunc[i].GetVectorLength();
        theLowThreshold[i] = theDistFunc[i].GetEnergy(0);
        theHighThreshold[i] = theDistFunc[i].GetEnergy(np - 1);
        for (G4int j = 0; j < np - 1; ++j) {
          if (theDistFunc[i].GetXsec(j + 1) > 1.e-20) {
            theLowThreshold[i] = theDistFunc[i].GetEnergy(j);
            break;
          }
        }
        for (G4int j = 1; j < np; ++j) {
          if (theDistFunc[i].GetXsec(j - 1) > 1.e-20) {
            theHighThreshold[i] = theDistFunc[i].GetEnergy(j);
          }
        }
      }
      //************************************************************************
    }

    inline G4double GetFractionalProbability(G4double anEnergy) override
    {
      return theFractionalProb.GetY(anEnergy);
    }

    G4double Sample(G4double anEnergy) override;

  private:
    G4ParticleHPVector theFractionalProb;
    G4int nDistFunc;
    G4InterpolationManager theManager;  // knows the interpolation between stores
    G4ParticleHPVector* theDistFunc;  // one per incoming energy
    G4ParticleHPVector theBuffer;
    //************************************************************************
    // EMendoza:
    G4double theLowThreshold[1000];
    G4double theHighThreshold[1000];
    //************************************************************************
};

#endif