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//
//---------------------------------------------------------------
//
// G4ChannelingOptrChangeCrossSection
// Based On GB01BOptrChangeCrossSection
// Class Description:
//        A G4VBiasingOperator concrete implementation example to
//    illustrate how to bias physics processes cross-section for
//    one particle type.
//        The G4VBiasingOperation G4BOptnChangeCrossSection is
//    selected by this operator, and is sent to each process
//    calling the operator.
//        A simple constant bias to the cross-section is applied,
//    but more sophisticated changes can be applied.
//
//---------------------------------------------------------------
//

#ifndef G4ChannelingOptrChangeCrossSection_hh
#define G4ChannelingOptrChangeCrossSection_hh 1

#include "G4VBiasingOperator.hh"
class G4BOptnChangeCrossSection;
class G4ParticleDefinition;
#include <map>
#include <unordered_map>

enum G4ChannelingDensityRatio{
    fDensityRatioNotDefined = -1,
    fDensityRatioNone = 0,
    fDensityRatioNuDElD = 1,
    fDensityRatioNuD = 2,
    fDensityRatioElD = 3
};

class G4ChannelingOptrChangeCrossSection : public G4VBiasingOperator {
public:
    // ------------------------------------------------------------
    // -- Constructor: takes the name of the particle type to bias:
    // ------------------------------------------------------------
    G4ChannelingOptrChangeCrossSection(const G4String& particleToBias,
				       const G4String& name = "ChannelingChangeXS");
    virtual ~G4ChannelingOptrChangeCrossSection();
    virtual void StartRun();
    
private:
    G4int fChannelingID;
    
private:
    virtual G4VBiasingOperation*
    ProposeOccurenceBiasingOperation(const G4Track*                            track,
                                     const G4BiasingProcessInterface* callingProcess);
    virtual G4VBiasingOperation*
    ProposeFinalStateBiasingOperation(const G4Track*, const G4BiasingProcessInterface*)
    {return 0;}
    virtual G4VBiasingOperation*
    ProposeNonPhysicsBiasingOperation(const G4Track*, const G4BiasingProcessInterface*)
    {return 0;}
    
private:
    using G4VBiasingOperator::OperationApplied;
    virtual void OperationApplied( const G4BiasingProcessInterface*                callingProcess,
                                  G4BiasingAppliedCase                               biasingCase,
                                  G4VBiasingOperation*                 occurenceOperationApplied,
                                  G4double                         weightForOccurenceInteraction,
                                  G4VBiasingOperation*                finalStateOperationApplied,
                                  const G4VParticleChange*                particleChangeProduced );
    
private:
    std::map< const G4BiasingProcessInterface*,
    G4BOptnChangeCrossSection*       > fChangeCrossSectionOperations;
    G4bool                                  fSetup;
    const G4ParticleDefinition*    fParticleToBias;
    
private:
    std::unordered_map<std::string,G4ChannelingDensityRatio> fProcessToDensity;
};

#endif