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//
//
//
// Author: Maria Grazia Pia (Maria.Grazia.Pia@cern.ch)
//
// History:
// -----------
// 16 Sep 2001   MGP                Created
// 26 Sep 2001   V.Ivanchenko       Hide copy constructor and assignement operator
// 18 Apr 2002   V.Ivanchenko       Move member function ValueForMaterial to public
// 21 Jan 2003   V.Ivanchenko       Cut per region
// 15 Jul 2009   N.A.Karakatsanis   New methods added for loading logarithmic data
//                                  to enhance computing performance of interpolation
//
// -------------------------------------------------------------------

// Class description:
// Low Energy Electromagnetic Physics
// Base class for cross section manager for an electromagnetic physics process

// -------------------------------------------------------------------

#ifndef G4VCROSSSECTIONHANDLER_HH
#define G4VCROSSSECTIONHANDLER_HH 1

#include <map>
#include <vector>
#include <CLHEP/Units/SystemOfUnits.h>

#include "globals.hh"
#include "G4DataVector.hh"
#include "G4MaterialCutsCouple.hh"

class G4VDataSetAlgorithm;
class G4VEMDataSet;
class G4Material;
class G4Element;

class G4VCrossSectionHandler {

public:
  explicit G4VCrossSectionHandler();
  explicit G4VCrossSectionHandler(G4VDataSetAlgorithm* interpolation,
			 G4double minE = 250*CLHEP::eV,
                         G4double maxE = 100*CLHEP::GeV,
			 G4int nBins = 200,
			 G4double unitE = CLHEP::MeV,
                         G4double unitData = CLHEP::barn,
			 G4int minZ = 1, G4int maxZ = 99);

  virtual ~G4VCrossSectionHandler();

  void Initialise(G4VDataSetAlgorithm* interpolation = nullptr,
		  G4double minE = 250*CLHEP::eV,
                  G4double maxE = 100*CLHEP::GeV,
		  G4int numberOfBins = 200,
		  G4double unitE = CLHEP::MeV,
                  G4double unitData = CLHEP::barn,
		  G4int minZ = 1, G4int maxZ = 99);

  G4int SelectRandomAtom(const G4MaterialCutsCouple* couple, G4double e) const;
  const G4Element* SelectRandomElement(const G4MaterialCutsCouple* material,
				             G4double e) const;

  G4int SelectRandomShell(G4int Z, G4double e) const;
  G4VEMDataSet* BuildMeanFreePathForMaterials(const G4DataVector* energyCuts = nullptr);
  G4double FindValue(G4int Z, G4double e) const;
  G4double FindValue(G4int Z, G4double e, G4int shellIndex) const;
  G4double ValueForMaterial(const G4Material* material, G4double e) const;
  void LoadData(const G4String& dataFile);
  void LoadNonLogData(const G4String& dataFile);
  void LoadShellData(const G4String& dataFile);
  void PrintData() const;
  void Clear();

  G4VCrossSectionHandler(const G4VCrossSectionHandler&) = delete;
  G4VCrossSectionHandler & operator=(const G4VCrossSectionHandler &right) = delete;

protected:

  G4int NumberOfComponents(G4int Z) const;
  void ActiveElements();

  // Factory method
  virtual std::vector<G4VEMDataSet*>* BuildCrossSectionsForMaterials(const G4DataVector& energyVector,
								       const G4DataVector* energyCuts = nullptr) = 0;

  // Factory method
  virtual G4VDataSetAlgorithm* CreateInterpolation();
  const G4VDataSetAlgorithm* GetInterpolation() const { return interpolation; }

private:
  G4VDataSetAlgorithm* interpolation;
  G4DataVector activeZ;

  std::map<G4int,G4VEMDataSet*,std::less<G4int> > dataMap;
  std::vector<G4VEMDataSet*>* crossSections;

  G4double eMin;
  G4double eMax;
  G4double unit1;
  G4double unit2;

  G4int zMin;
  G4int zMax;
  G4int nBins;
};

#endif











