//
// ********************************************************************
// * 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.          *
// ********************************************************************
//
//
// $Id$
//
// $Id: 
// ------------------------------------------------------------
//	GEANT 4 class header file 
//
//
// Class Description  
//  Abstract class which defines the public behavior of
//  rest + discrete physics interactions.
//
// ------------------------------------------------------------
//   New Physics scheme           8  Mar. 1997  H.Kurahige
// ------------------------------------------------------------


#ifndef G4IVRestDiscreteProcess_h
#define G4IVRestDiscreteProcess_h 1

#include <CLHEP/Units/SystemOfUnits.h>

#include "globals.hh"
#include "G4ios.hh"
#include "Randomize.hh"              

#include "G4VProcess.hh"

#include "G4Step.hh"
#include "G4Track.hh"
#include "G4MaterialTable.hh"
#include "G4VParticleChange.hh"

class G4IVRestDiscreteProcess : public G4VProcess 
{
  //  Abstract class which defines the public behavior of
  //  rest + discrete physics interactions.

  public: // with description    

    // constructors 
     G4IVRestDiscreteProcess(const G4String& ,
			    G4ProcessType   aType = fNotDefined );
     G4IVRestDiscreteProcess(G4IVRestDiscreteProcess &);

  public:
     virtual ~G4IVRestDiscreteProcess();

  public: // with description    
     // GPIL and DoIt methods derived from G4VProcess
     virtual G4double PostStepGetPhysicalInteractionLength(
                             const G4Track& track,
			     G4double   previousStepSize,
			     G4ForceCondition* condition
			    );

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

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

     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 
      G4IVRestDiscreteProcess();
      G4IVRestDiscreteProcess & operator=(const G4IVRestDiscreteProcess &right);


   protected:
      G4PhysicsTable* theNlambdaTable ;
      G4PhysicsTable* theInverseNlambdaTable ;

      const G4double BIGSTEP;
};

// -----------------------------------------
//  inlined function members implementation
// -----------------------------------------

inline 
 void     G4IVRestDiscreteProcess::SubtractNumberOfInteractionLengthLeft(
                             G4double )
 {
  // dummy routine
   ;
 }    

inline G4VParticleChange* G4IVRestDiscreteProcess::PostStepDoIt(
			     const G4Track& ,
			     const G4Step& 
			    )
{ 
//  reset NumberOfInteractionLengthLeft
    ClearNumberOfInteractionLengthLeft();

    return pParticleChange;
}

inline G4double G4IVRestDiscreteProcess::AtRestGetPhysicalInteractionLength(
                             const G4Track& track,
			     G4ForceCondition* condition
			    )
{
  // beggining of tracking 
  ResetNumberOfInteractionLengthLeft();

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

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

#ifdef G4VERBOSE
  if ((currentInteractionLength <0.0) || (verboseLevel>2)){
    G4cout << "G4IVRestDiscreteProcess::AtRestGetPhysicalInteractionLength ";
    G4cout << "[ " << GetProcessName() << "]" <<G4endl;
    track.GetDynamicParticle()->DumpInfo();
    G4cout << " in Material  " << track.GetMaterial()->GetName() <<G4endl;
    G4cout << "MeanLifeTime = " << currentInteractionLength/CLHEP::ns << "[ns]" <<G4endl;
  }
#endif

  return theNumberOfInteractionLengthLeft * currentInteractionLength;
}


inline G4VParticleChange* G4IVRestDiscreteProcess::AtRestDoIt( 
			     const G4Track&,
			     const G4Step& 
			    )
{
//  clear NumberOfInteractionLengthLeft
    ClearNumberOfInteractionLengthLeft();

    return pParticleChange;
}

#endif