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//
// Calculation of the total, elastic and inelastic cross-sections
// based on Barashenkov parametrisations of pion data
//
// 16.08.06 V.Ivanchenko - first implementation
// 22.01.07 V.Ivanchenko - add cross section interfaces with Z and A
// 05.03.07 V.Ivanchenko - add IfZAApplicable
//

#ifndef G4UPiNuclearCrossSection_h
#define G4UPiNuclearCrossSection_h

#include "G4VCrossSectionDataSet.hh"
#include "G4DynamicParticle.hh"
#include "G4ParticleDefinition.hh"
#include "globals.hh"

class G4PhysicsTable;

class G4UPiNuclearCrossSection : public G4VCrossSectionDataSet
{
public:
  
  explicit G4UPiNuclearCrossSection();

  ~G4UPiNuclearCrossSection() override = default;

  G4bool IsElementApplicable(const G4DynamicParticle* aParticle, 
			     G4int Z, const G4Material*) final;

  inline
  G4double GetElasticCrossSection(const G4DynamicParticle* aParticle, 
				  G4int Z, G4int A) const;

  inline
  G4double GetInelasticCrossSection(const G4DynamicParticle* aParticle, 
				    G4int Z, G4int A) const;

  void BuildPhysicsTable(const G4ParticleDefinition&) final;

  void DumpPhysicsTable(const G4ParticleDefinition&) final;

  void CrossSectionDescription(std::ostream&) const final;
  
private:

  G4double Interpolate(G4int Z, G4int A, G4double ekin, 
                       const G4PhysicsTable*) const;

  void AddDataSet(const G4String& p, const G4double* tot, 
		  const G4double* in, const G4double* e, G4int n); 

  void LoadData();

  const G4ParticleDefinition* piPlus;
  const G4ParticleDefinition* piMinus;

  static const G4int NZ = 16;
  static G4int theZ[NZ];
  static G4int idxZ[93];

  static G4double theA[NZ];
  static G4double APower[93];

  static G4PhysicsTable* piPlusElastic;
  static G4PhysicsTable* piPlusInelastic;
  static G4PhysicsTable* piMinusElastic;
  static G4PhysicsTable* piMinusInelastic;

  G4double aPower{0.75};
  G4double elow;

  G4bool spline{false};
};

inline G4double 
G4UPiNuclearCrossSection::GetElasticCrossSection(
       const G4DynamicParticle* dp, G4int Z, G4int A) const
{
  const G4PhysicsTable* table = 
    (dp->GetDefinition() == piPlus) ? piPlusElastic : piMinusElastic; 
  return Interpolate(Z, A, dp->GetKineticEnergy(), table);
}

inline G4double 
G4UPiNuclearCrossSection::GetInelasticCrossSection(
       const G4DynamicParticle* dp, G4int Z, G4int A) const
{
  const G4PhysicsTable* table = 
    (dp->GetDefinition() == piPlus) ? piPlusInelastic : piMinusInelastic; 
  return Interpolate(Z, A, dp->GetKineticEnergy(), table);
}

#endif