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//
// Identical to G4VRestDiscreteProcess with dependency from G4VITProcess
//
// WARNING : This class is released as a prototype.
// It might strongly evolve or even disapear in the next releases.
//
// Author: Mathieu Karamitros (kara (AT) cenbg . in2p3 . fr) 
//
// History:
// -----------
// 10 Oct 2011 M.Karamitros created
//
// -------------------------------------------------------------------

#ifndef G4VITRESTDISCRETEPROCESS_H
#define G4VITRESTDISCRETEPROCESS_H

#include "G4VITProcess.hh"

/**
  * Identical to G4VRestDiscreteProcess with dependency from G4VITProcess
  */

class G4VITRestDiscreteProcess : public G4VITProcess
{
  //  Abstract class which defines the public behavior of
  //  rest + discrete physics interactions.
  public:

     G4VITRestDiscreteProcess(const G4String& ,
			    G4ProcessType   aType = fNotDefined );
     G4VITRestDiscreteProcess(G4VITRestDiscreteProcess &);

     virtual ~G4VITRestDiscreteProcess();

  public :// with description
     virtual G4double PostStepGetPhysicalInteractionLength(
                             const G4Track& track,
			     G4double   previousStepSize,
			     G4ForceCondition* condition
			    );

     virtual G4VParticleChange* PostStepDoIt(
			     const G4Track& ,
			     const G4Step&
			    );

     virtual G4double AtRestGetPhysicalInteractionLength(
                             const G4Track& ,
			     G4ForceCondition*
			    );

     virtual G4VParticleChange* AtRestDoIt(
			     const G4Track& ,
			     const G4Step&
			    );

     //  no operation in  AlongStepDoIt
     virtual G4double AlongStepGetPhysicalInteractionLength(
                             const G4Track&,
			     G4double  ,
			     G4double  ,
			     G4double& ,
                             G4GPILSelection*
                            ){ return -1.0; }

     //  no operation in  AlongStepDoIt
     virtual G4VParticleChange* AlongStepDoIt(
			     const G4Track& ,
			     const G4Step&
                            ) {return 0;}

  protected:// with description
     virtual G4double GetMeanFreePath(const G4Track& aTrack,
                             G4double   previousStepSize,
                             G4ForceCondition* condition
                           )=0;
      //  Calculates from the macroscopic cross section a mean
      //  free path, the value is returned in units of distance.

     virtual G4double GetMeanLifeTime(const G4Track& aTrack,G4ForceCondition* condition)=0;
      //  Calculates the mean life-time (i.e. for decays) of the
      //  particle at rest due to the occurence of the given process,
      //  or converts the probability of interaction (i.e. for
      //  annihilation) into the life-time of the particle for the
      //  occurence of the given process.

  private:
  // hide default constructor and assignment operator as private
      G4VITRestDiscreteProcess();
      G4VITRestDiscreteProcess & operator=(const G4VITRestDiscreteProcess &right);

};

// -----------------------------------------
//  inlined function members implementation
// -----------------------------------------
inline
 G4double G4VITRestDiscreteProcess::PostStepGetPhysicalInteractionLength(
                             const G4Track& track,
			     G4double   previousStepSize,
			     G4ForceCondition* condition
			    )
{
  if ( (previousStepSize < 0.0) || (fState->theNumberOfInteractionLengthLeft<=0.0)) {
    // beggining of tracking (or just after DoIt of this process)
    ResetNumberOfInteractionLengthLeft();
  } else if ( previousStepSize > 0.0) {
    // subtract NumberOfInteractionLengthLeft
    SubtractNumberOfInteractionLengthLeft(previousStepSize);
  } else {
    // zero step
    //  DO NOTHING
  }

  // condition is set to "Not Forced"
  *condition = NotForced;

  // get mean free path
  fState->currentInteractionLength = GetMeanFreePath(track, previousStepSize, condition);

  G4double value;
  if (fState->currentInteractionLength <DBL_MAX) {
    value = fState->theNumberOfInteractionLengthLeft * (fState->currentInteractionLength);
  } else {
    value = DBL_MAX;
  }
#ifdef G4VERBOSE
   if (verboseLevel>1){
    G4cout << "G4VITRestDiscreteProcess::PostStepGetPhysicalInteractionLength ";
    G4cout << "[ " << GetProcessName() << "]" <<G4endl;
    track.GetDynamicParticle()->DumpInfo();
    G4cout << " in Material  " <<  track.GetMaterial()->GetName() <<G4endl;
    G4cout << "InteractionLength= " << value/cm <<"[cm] " <<G4endl;
  }
#endif
  return value;
}

inline G4VParticleChange* G4VITRestDiscreteProcess::PostStepDoIt(
			     const G4Track& ,
			     const G4Step&
			    )
{
//  reset NumberOfInteractionLengthLeft
    ClearNumberOfInteractionLengthLeft();

    return pParticleChange;
}

inline G4double G4VITRestDiscreteProcess::AtRestGetPhysicalInteractionLength(
                             const G4Track& track,
			     G4ForceCondition* condition
			    )
{
  // beggining of tracking
  ResetNumberOfInteractionLengthLeft();

  // condition is set to "Not Forced"
  *condition = NotForced;

  // get mean life time
  fState->currentInteractionLength = GetMeanLifeTime(track, condition);

#ifdef G4VERBOSE
   if ((fState->currentInteractionLength <0.0) || (verboseLevel>2)){
    G4cout << "G4VITRestDiscreteProcess::AtRestGetPhysicalInteractionLength ";
    G4cout << "[ " << GetProcessName() << "]" <<G4endl;
    track.GetDynamicParticle()->DumpInfo();
    G4cout << " in Material  " << track.GetMaterial()->GetName() <<G4endl;
    G4cout << "MeanLifeTime = " << fState->currentInteractionLength/ns << "[ns]" <<G4endl;
  }
#endif

  return fState->theNumberOfInteractionLengthLeft * (fState->currentInteractionLength);
}


inline G4VParticleChange* G4VITRestDiscreteProcess::AtRestDoIt(
			     const G4Track&,
			     const G4Step&
			    )
{
//  clear NumberOfInteractionLengthLeft
    ClearNumberOfInteractionLengthLeft();

    return pParticleChange;
}



#endif