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//
//
//
// ------------------------------------------------------------
// GEANT 4 class implementation
//
//      ------- GVFlashShowerParameterisation -------
//
// Authors: Joanna Weng - 11.2005
// ------------------------------------------------------------

#include <cmath>

#include "GVFlashShowerParameterisation.hh"

#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "Randomize.hh"
#include "G4ios.hh"
#include "G4Material.hh"
#include "Gamma.hh" // @@@@
#include "G4MaterialTable.hh"

GVFlashShowerParameterisation::GVFlashShowerParameterisation()
  : thePar(0), density(0.), A(0.), Z(0.), X0(0.), Ec(0.), Rm(0.), NSpot(0.)
{
  fGamma = new MyGamma;
}

GVFlashShowerParameterisation::~GVFlashShowerParameterisation()
{
  delete fGamma;
}

G4double GVFlashShowerParameterisation::GetEffZ(const G4Material* mat)
{
  // Returns Z or effective Z=sum(pi*Zi) (if compound/mixture)
  // of given material
  //
  G4double z = 0.;
  G4int nofElements = (G4int)mat->GetNumberOfElements();
  if (nofElements > 1) {
    for (G4int i = 0; i < nofElements; ++i) {
      G4double zOfElement = mat->GetElement(i)->GetZ();
      G4double massFraction = mat->GetFractionVector()[i];
      // cout << mat->GetElement(i)->GetName()
      //      <<" Z= "<<zOfElement << " , Fraction= "<<massFraction <<endl;
      z += zOfElement * massFraction;
    }
  }
  else {
    z = mat->GetZ();
  }
  return z;
}

G4double GVFlashShowerParameterisation::GetEffA(const G4Material* mat)
{
  // Returns A or effective A=sum(pi*Ai) (if compound/mixture)
  // of given material
  //
  G4double a = 0.;
  G4int nofElements = (G4int)mat->GetNumberOfElements();
  if (nofElements > 1) {
    for (G4int i = 0; i < nofElements; ++i) {
      G4double aOfElement = mat->GetElement(i)->GetA() / (g / mole);
      G4double massFraction = mat->GetFractionVector()[i];
      a += aOfElement * massFraction;
    }
  }
  else {
    a = mat->GetA() / (g / mole);
  }
  return a;
}

void GVFlashShowerParameterisation::PrintMaterial(const G4Material* mat)
{
  G4cout << "/********************************************/ " << G4endl;
  G4cout << "  - GVFlashShowerParameterisation::Material -  " << G4endl;
  G4cout << "        Material : " << mat->GetName() << G4endl;
  G4cout << "   Z  = " << Z << G4endl;
  G4cout << "   A  = " << A << G4endl;
  G4cout << "   X0 = " << X0 / cm << " cm" << G4endl;
  G4cout << "   Rm = " << Rm / cm << " cm" << G4endl;
  G4cout << "   Ec = " << Ec / MeV << " MeV" << G4endl;
  G4cout << "/********************************************/ " << G4endl;
}

G4double GVFlashShowerParameterisation::GeneratePhi()
{
  G4double Phi = twopi*G4UniformRand() ;
  return Phi;
}

G4double GVFlashShowerParameterisation::gam(G4double x, G4double a) const
{
  return fGamma->Gamma(a, x);
}