// M Hentz, 2016

#include "StepMax.hh"
#include "StepMaxMessenger.hh"

StepMax::StepMax( const G4String& processName )
    :G4VDiscreteProcess(processName),
     fMaxChargedStep(DBL_MAX),
     fMessenger(0)
{
  fMessenger = new StepMaxMessenger(this);
}

StepMax::~StepMax() { delete fMessenger; }

G4bool StepMax::IsApplicable( const G4ParticleDefinition& particle )
{
  return ( particle.GetPDGCharge() != 0. && !particle.IsShortLived() );
}

void StepMax::SetMaxStep( G4double step ) { fMaxChargedStep = step; }

G4double StepMax::PostStepGetPhysicalInteractionLength( const G4Track& aTrack,
                                                        G4double,
                                                        G4ForceCondition* condition )
{
  // condition is set to "Not Forced"
  *condition = NotForced;
  G4double proposedStep = DBL_MAX;

  G4String volName = aTrack.GetVolume()->GetName();

  // Remove last character from volume name
  G4String shortenedVolName = volName.remove( volName.length() - 1 );

  // Set the maximum step length depending on the volume
  if ( fMaxChargedStep > 0. && aTrack.GetVolume() != NULL && volName != "World" ) {
    proposedStep = fMaxChargedStep;
  }

  // Set the max step length to be no bigger than 5% of the volume's thickness
  if ( fMaxChargedStep > 0. && aTrack.GetVolume() != NULL ) {

    // Thickness of scatter foils: 25 um
    if (volName == "ScatterFoil") {
      proposedStep = 0.05 * 0.025*CLHEP::mm;
    }

    // Thickness of mylar layer: 5 um
    if (volName == "MonitorMylar") {
      proposedStep = 0.05 * 0.005*CLHEP::mm;
    }

    // Thicnkess of aluminium foil: 1 um
    if (volName == "MonitorAl") {
      proposedStep = (0.05)*(0.001*CLHEP::mm);
    }
  }

  return proposedStep;
}

G4VParticleChange* StepMax::PostStepDoIt( const G4Track& aTrack, const G4Step& )
{
  // do nothing

  aParticleChange.Initialize(aTrack);
  return &aParticleChange;
}