// $Id: PamVMCPrimaryGenerator.cxx,v 1.0 2006/06/03 


#include <TVirtualMC.h>
#include <TVirtualMCStack.h>
#include <TPDGCode.h>
#include <TDatabasePDG.h>
#include <TParticlePDG.h>
#include <TVector3.h>
#include <TMath.h>
#include <Riostream.h>



#include "PamVMCPrimaryGenerator.h"

using namespace TMath;

ClassImp(PamVMCPrimary)


PamVMCPrimary & operator+=(PamVMCPrimary &a, const PamVMCPrimary &b)
{
  a.fID=b.fID;
  a.fPDG=b.fPDG;
  a.fX0=b.fX0;
  a.fY0=b.fY0;
  a.fZ0=b.fZ0;
  a.fTHETA=b.fTHETA;
  a.fPHI=b.fPHI;
  a.fP0=b.fP0;
  a.fGOOD=b.fGOOD;
  a.fXTOL=b.fXTOL;
  a.fYTOL=b.fYTOL;
  for (Int_t j = 0; j<14; j++){
    a.fCR_X[j] = b.fCR_X[j];	
    a.fCR_Y[j] = b.fCR_Y[j];		
  }	    

  return a;
}



ClassImp(PamVMCPrimaryGenerator)

PamVMCPrimaryGenerator::PamVMCPrimaryGenerator(TVirtualMCStack* stack) 
  : TObject(),
    fStack(stack),
    fevno(0),
    fngood(0),
    fmass(0.),
    fcharge(0.),
    fxprev(0.),
    fyprev(0.),
    fzprev(200.),
    frandom(0)
{
  //gObjectTable->Add(this);

// Standard constructor

  ftheta = new TF1("ftheta","sin(x)*cos(x)",0.,acos(-1.)/4.);
  ftheta->SetNpx(1000);

  fprimColl = new TClonesArray("PamVMCPrimary");
  fprim.fPDG=kProton;
  fprim.fX0=1.;
  fprim.fY0=1.;
  fprim.fZ0=130.;
  fprim.fTHETA=0.;
  fprim.fPHI=0.;
  fprim.fP0=1.; //1GV

  f2PiAux = new PamVMC2PiAux();
  fpgf = new PamVMCPrimaryGF();
} 

PamVMCPrimaryGenerator::PamVMCPrimaryGenerator()
  : TObject(),
    fStack(0),
    fevno(0),
    fngood(0),
    fmass(0.),
    fcharge(0.),
    fxprev(0.),
    fyprev(0.),
    fzprev(200.),
    fprimColl(0),
    frandom(0)
{    
 // Default constructor
  //Default primary proton

  //gObjectTable->Add(this);

  ftheta = new TF1("ftheta","sin(x)*cos(x)",0.,acos(-1.)/4.);
  ftheta->SetNpx(1000);

  fprim.fPDG=kProton;
  fprim.fX0=1.;
  fprim.fY0=1.;
  fprim.fZ0=130.;
  fprim.fTHETA=0.;
  fprim.fPHI=0.;
  fprim.fP0=1.; //1GV

  f2PiAux = new PamVMC2PiAux();
  fpgf = new PamVMCPrimaryGF();
}

PamVMCPrimaryGenerator::~PamVMCPrimaryGenerator() 
{
// Destructor
  delete fpgf;
  delete f2PiAux;
  delete ftheta;
  delete fprimColl;
  //gObjectTable->Remove(this);
}


// private methods


void PamVMCPrimaryGenerator::GeneratePrimary()
{    
// Add one primary particle to the user stack (derived from TVirtualMCStack).
  
  // Track ID (filled by stack)
  Int_t ntr;
 
  // Option: to be tracked
  Int_t toBeDone = 1; 
 
  // Particle type
  Int_t pdg  = fprim.fPDG;
  
  Double_t fvx, fvy, fvz;
  fvx=fprim.fX0;
  fvy=fprim.fY0;
  fvz=fprim.fZ0;

  // Position
  
  Double_t tof = 0.;

  // Energy (in GeV)
  //printf("generateprimary check fprimP0 = %f\n",fprim.fP0);
  Double_t kinEnergy = MomentumToKinE(fprim.fP0);     
  Double_t e  = fmass + kinEnergy;
 
  // Particle momentum
  Double_t  px, py, pz;
   
  px = TMath::Abs(fprim.fP0)*Sin(fprim.fTHETA)*Cos(fprim.fPHI);
  py = TMath::Abs(fprim.fP0)*Sin(fprim.fTHETA)*Sin(fprim.fPHI);
  pz = -TMath::Abs(fprim.fP0)*Cos(fprim.fTHETA);
 
  // Polarization
  TVector3 polar;

  // Add particle to stack 
  fStack->PushTrack(toBeDone, -1, pdg, px, py, pz, e, fvx, fvy, fvz, tof, 
                   polar.X(), polar.Y(), polar.Z(), 
                   kPPrimary, ntr, 1., 0);

  PamVMCPrimary * pc = (PamVMCPrimary *)fprimColl->New(fevno++);
 
  *pc = fprim;
}


void PamVMCPrimaryGenerator::SetParticle(Int_t pdg){
  fprim.fPDG=pdg;
  //TParticlePDG* particlePDG = TDatabasePDG::Instance()->GetParticle(fprim.fPDG);
  fmass = (TDatabasePDG::Instance()->GetParticle(fprim.fPDG))->Mass();
  fcharge = ((TDatabasePDG::Instance()->GetParticle(fprim.fPDG))->Charge())/3.;
}

void PamVMCPrimaryGenerator::SetMomentum(
                              Double_t px, Double_t py, Double_t pz) 
{
  fprim.fP0= Sqrt(px*px+py*py+pz*pz);
  fprim.fTHETA=ATan(Sqrt(px*px+py*py)/pz);
  fprim.fPHI=ATan(py/px);
}
   				     
void PamVMCPrimaryGenerator::GenSpe(Double_t PEmin, Double_t PEmax, Bool_t isEnergy)
{
  if(isEnergy) {
    fprim.fP0=frandom->Uniform(KinEToMomentum(PEmin),KinEToMomentum(PEmax));
  } else{
    fprim.fP0=frandom->Uniform(PEmin,PEmax);
  }

}

void PamVMCPrimaryGenerator::GenSpe(Double_t PEmin, Double_t PEmax, Double_t gamma, Bool_t isEnergy)
{
  Double_t alpha = 1.+gamma; //integral spectral index
  if(alpha==0.){
    fprim.fP0=Exp(Log(PEmin)+frandom->Uniform(0.,1.)*(Log(PEmax)-Log(PEmin)));
  } else {
    if(PEmin==0.) PEmin=1.E-10;
    fprim.fP0=Power((frandom->Uniform(0.,1.)*(Power(PEmax,alpha)-Power(PEmin,alpha))+Power(PEmin,alpha)),1./alpha);
  }
  //  cout<<"GenSpe fprim.fP0= "<<fprim.fP0<<endl;
  if(isEnergy) fprim.fP0=KinEToMomentum(fprim.fP0);

}


//Cecilia Pizzolotto: powerlaw spectrum 3 with the shape
// J(E) = 0.5*(E + b * exp(-c * sqrt(E)))^-a
// between PEmin and PEmax and with the input parameters a,b,c.
// Valeria di Felice fits parameter values are:
// protons:   a,b,c= 2.70, 2.15, 0.21
// electrons: a,b,c= 0.0638, 1.248e-16, -38.248  
void PamVMCPrimaryGenerator::GenSpe_3par(Double_t PEmin, Double_t PEmax, Double_t a, Double_t b, Double_t c)
{

  Bool_t found=0;
  Double_t funct_min, funct_max;
  funct_max = function3par(PEmin,a,b,c);
  funct_min = function3par(PEmax,a,b,c);
  //
  Double_t wurfP;
  Double_t wurfy ;
  //printf("in genspe3par^^^^%f ^^%f ^^^^^^^^%f ^^^^^%f^^^^^^^\n",PEmin,PEmax,funct_min,funct_max);
  //printf("in par^^ %f  %f  %f \n",a,b,c);
  while( found==0 )
    {
      wurfP = frandom->Uniform(PEmin,PEmax);
      wurfy = frandom->Uniform(funct_min,funct_max);
      if( wurfy<(function3par(wurfP,a,b,c) )) 
	{
	  // this is ok!
	  fprim.fP0=wurfP;
	  found=1;
	}
    }
  //printf("exit+++++++++++++++++++  %f   %f \n",wurfP,fprim.fP0);
}



// cecilia pizzolotto
void PamVMCPrimaryGenerator::GenSpe_Flat(Double_t PEmin, Double_t PEmax, Double_t gamma, Bool_t isEnergy)
{
  // Generates a flat spectrum from PEmin to PElim. Then a power law
  Double_t PElim = 1.;
  //Double_t alpha = 1.+gamma; //integral spectral index

  Bool_t   okflag=0.;
  Double_t throw_x =0.;
  Double_t throw_y =0.;
  
  while(okflag==0)
    {
      throw_x=frandom->Uniform(PEmin,PEmax);
      //	cout<<"        x "<<throw_x<<endl;
      if(throw_x<=PElim)
	{
	  okflag=1.;
	}
      else
	{
	  throw_y=frandom->Uniform(0.,1.);
	  if( throw_y<(1*pow(throw_x,gamma)))
	    {
	      okflag=1.;
	    }
	}
    }
  fprim.fP0=throw_x;
  //h->Fill(fprimf.P0);
  okflag=0.; // reset
  
  if(isEnergy) fprim.fP0=KinEToMomentum(fprim.fP0);

}

// Spherical distribution -- Test by Cecilia P july 2009 ----
// flusso isotropo su 2pi
void PamVMCPrimaryGenerator::GenSphericalPhiThe()
{
  // Generate phi theta
  Double_t theta=0.;
  Double_t phi=0.;
  
  Double_t xcos = sqrt( frandom->Uniform(0.,1.) );
  theta = acos(xcos);   //RAD
  
  phi = frandom->Uniform(0.,2.*Pi());
  
  SetDirection(theta, phi);
  return;
}





void PamVMCPrimaryGenerator::GenSphPhiThe(Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax, 
					  Double_t zmin, Double_t zmax)
{
  Bool_t trkGood = kFALSE;
  Double_t theta = 999.;
  Double_t phi = 0.;
  Double_t x2,y2,x3,y3;
  Double_t x0,y0,z0;

  //static const Double_t rad2deg = 57.2958;
  // S21 and S31 position/size taken as reference (z on top of det)
  // constraint: must pass throuth these planes
  static const Double_t s2_xmax=9.05, s2_ymax=7.55, s2_z=73.439; // z on top of det
  static const Double_t s3_xmax=9.05, s3_ymax=7.55, s3_z=26.093; // z on top of det

  //Double_t thetamax=3.14;
  //thetamax = atan((xmax+s3_xmax)/(zmax-s3_z));
  //cout<<" Quanto è il theta max? "<<thetamax<<" in deg "<<thetamax*(90./Pi())<<endl;

  while (trkGood!=kTRUE)
    {
       x0= frandom->Uniform(xmin,xmax);
       y0= frandom->Uniform(ymin,ymax);
       z0= frandom->Uniform(zmin,zmax);
  
      // Generate phi theta
      theta=999.; // init
      while (theta>=0.65) // take only theta smaller than 37deg=0.65rad
	{
	  Double_t xcos = sqrt( frandom->Uniform(0.,1.) );
	  theta = acos(xcos);   //RAD
	}
      phi = frandom->Uniform(0.,2.*Pi());
 
      // Calculate xy at the constraint
      Double_t fact2 = (s2_z-z0)/cos(theta);
      x2 = x0 + fabs(fact2) *  sin(theta) * cos(phi);
      y2 = y0 + fabs(fact2) *  sin(theta) * sin(phi);
      Double_t fact3 = (s3_z-z0)/cos(theta);
      x3 = x0 + fabs(fact3) *  sin(theta) * cos(phi);
      y3 = y0 + fabs(fact3) *  sin(theta) * sin(phi);
	 
      //cout<<" x/y0= "<<x0<<" "<<y0<<"  x/y2= "<<fact2*sin(theta)*cos(phi)<<" "<<x2<<"  xy3= "<<
      //  fact3*sin(theta)*cos(phi)<<" "<<x3<<"   phi/the "<<phi*(90./Pi())<<" "<<theta*(90./Pi())<<endl;

      // Test condition on the direction
      if ( Abs(x2) <= Abs(s2_xmax) && Abs(y2) <= Abs(s2_ymax) &&
	   Abs(x3) <= Abs(s3_xmax) && Abs(y3) <= Abs(s3_ymax) ) {
	trkGood = kTRUE;
	//cout<<" x/y0= "<<x0<<" "<<y0<<"  x/y2= "<<fact2*sin(theta)*cos(phi)<<" "<<x2<<"  xy3= "<<
	//  fact3*sin(theta)*cos(phi)<<" "<<x3<<endl;
      }      
    } 

  // Set direction and position:
  SetDirection(theta, phi);
  SetPosition(x0, y0, z0);
  
  return;
}