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#include "PrimaryGeneratorAction.hh"
#include "FileReader.hh"

#include "G4RunManager.hh"
#include "G4Event.hh"
#include "G4AutoLock.hh"
#include "G4ParticleTable.hh"
#include "G4ParticleDefinition.hh"

#include "Randomize.hh"

#include "G4GeneralParticleSource.hh"
#include "G4ParticleGun.hh"

#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "globals.hh"

namespace {G4Mutex PrimaryGeneratorActionMutex = G4MUTEX_INITIALIZER;}
FileReader* PrimaryGeneratorAction::fFileReader = 0;

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PrimaryGeneratorAction::PrimaryGeneratorAction():
fReadFromFile(0)
{
	G4cout << "### PrimaryGeneratorAction instantiated ###" << G4endl;

  	//Primary particles
    G4ParticleDefinition* particle = 
    	G4ParticleTable::GetParticleTable()->FindParticle("gamma");
	
	//defining a GPS (it is used in batch mode if fReadFromFile=0)
    fGPS = new G4GeneralParticleSource(); 
    fGPS->SetParticleDefinition(particle);    
    //Spatial distribution
    G4SPSPosDistribution* vPosDist = fGPS->GetCurrentSource()->GetPosDist();
    vPosDist->SetPosDisType("Plane");
    vPosDist->SetPosDisShape("Circle");
    vPosDist->SetRadius(50.*mm);   
    vPosDist->SetCentreCoords(G4ThreeVector(0.,0.,0.));
    //Angular distribution
    G4SPSAngDistribution* vAngDist = fGPS->GetCurrentSource()->GetAngDist();
    vAngDist->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));  
    //Energy distribution
    G4SPSEneDistribution* vEneDist = fGPS->GetCurrentSource()->GetEneDist();
    vEneDist->SetEnergyDisType("Mono");
    vEneDist->SetMonoEnergy(20.*keV);
   
	//defining a Particle Gun (to be used with file reader)
    fGun = new G4ParticleGun();
    fGun->SetParticleDefinition(particle);
    
    //options 
    fReadFromFile = false;
    fFileName = "input/rect_source_1E7_2.dat";
	IWantGPS = false;
	
	hLx = 50.;	//mm
	hLy = 50.;	//mm
	Nx = 100;
	Ny = 100;
	
	//root code for histogram of the generated points (it works only in single core)
	if (!fReadFromFile && !IWantGPS) {
		RGfile = new TFile("RGstats.root","recreate");	
		RGSpatialDistrib = new TH2D("RGSpatialDistrib","RGSpatialDistrib",
		                            Nx,-hLx,hLx,Ny,-hLy,hLy);
	}
}

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PrimaryGeneratorAction::~PrimaryGeneratorAction()
{
    G4AutoLock lock(&PrimaryGeneratorActionMutex);

    if (fFileReader) {
        delete fFileReader;
        fFileReader = 0;
    }

	delete fGPS;
    delete fGun;
    
    if (!fReadFromFile && !IWantGPS) {
      	RGfile->Write();
  		RGfile->Close();
  	}
}

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void PrimaryGeneratorAction::SetFileName(G4String vFileName) {fFileName = vFileName;}

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void PrimaryGeneratorAction::GeneratePrimaries(G4Event* anEvent)
{
    G4AutoLock lock(&PrimaryGeneratorActionMutex);
  
    if (!fFileReader) {
        fFileReader = new FileReader(fFileName);  
           
        if (fReadFromFile) {
            G4cout << G4endl << "Read file ..." << G4endl;
            fFileReader->StoreEvents();
            G4cout << "... file read" << G4endl << G4endl;
        }
    }
    
    if (fReadFromFile) {
        fGun->SetParticlePosition(fFileReader->GetAnEventPosition(anEvent->GetEventID()));
        //fGun->SetParticleMomentumDirection(fFileReader->GetAnEventMomentum(anEvent->GetEventID()));
        //fGun->SetParticleEnergy(fFileReader->GetAnEventEnergy(anEvent->GetEventID())); 
        fGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
        fGun->SetParticleEnergy(20.*keV);                
        fGun->GeneratePrimaryVertex(anEvent);
    } else {
    	if (IWantGPS) {
			fGPS->GeneratePrimaryVertex(anEvent);
		} else {				
			G4double xs = -hLx + 2*hLx*G4UniformRand();
			G4double ys = -hLy + 2*hLy*G4UniformRand();
			fGun->SetParticlePosition(G4ThreeVector(xs, ys, 0.)*mm);
	
			fGun->SetParticleMomentumDirection(G4ThreeVector(0., 0., 1.));
			fGun->SetParticleEnergy(20.*keV);
			
			RGSpatialDistrib->Fill(xs,ys,1);	//fill the histogram

			fGun->GeneratePrimaryVertex(anEvent);
		}   
    }
}

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