// -------------------------------------------------------------------------
// -----                PndDskFLGHitProducerIdeal source file             -----
// -----                 Created 23/04/10  by Yutie Liang              -----
// -----                                                               -----
// -----                                                               -----
// -------------------------------------------------------------------------
#include <fstream>
#include <iostream>
#include <math.h>
#include "stdio.h"

//#include "PndGeoDsk.h"
#include "PndDskFLGHitProducerIdeal.h"
#include "FairRootManager.h"
#include "PndMCTrack.h"
#include "PndDskParticle.h"
#include "PndDskFLGHit.h"
#include "TVector3.h"
#include "TRandom.h"
#include "FairRunAna.h"
#include "FairRuntimeDb.h"
#include "FairBaseParSet.h"
#include "FairGeoVolume.h"
#include "TString.h"
#include "FairGeoTransform.h"
#include "FairGeoVector.h"
#include "FairGeoMedium.h"
#include "FairGeoNode.h"
#include "TFormula.h"
#include "TMath.h"
#include "TParticlePDG.h"
#include "TDatabasePDG.h"
#include "TPDGCode.h"
#include "TGeoManager.h"


using std::endl;
using std::cout;

// -----   Default constructor   -------------------------------------------
PndDskFLGHitProducerIdeal::PndDskFLGHitProducerIdeal() 
:FairTask("PndDskFLGHitProducerIdeal")
{

  fGeo         = new PndGeoDskFLG();  
}
// -------------------------------------------------------------------------

// -----   Standard constructor with verbosity level  -------------------------------------------

PndDskFLGHitProducerIdeal::PndDskFLGHitProducerIdeal(Int_t verbose) 
  :FairTask("PndDskFLGHitProducerIdeal")
{
  fGeo         = new PndGeoDskFLG();
  fVerbose = verbose;  
}
// -------------------------------------------------------------------------


// -----   Destructor   ----------------------------------------------------
PndDskFLGHitProducerIdeal::~PndDskFLGHitProducerIdeal()
{
 
  if (fGeo) delete fGeo; 
}
// -------------------------------------------------------------------------


// -----   Initialization   -----------------------------------------------
// -------------------------------------------------------------------------
InitStatus PndDskFLGHitProducerIdeal::Init()
{
  cout << " ---------- INITIALIZATION ------------" << endl;
  nevents = 0;
  // Get RootManager
  FairRootManager* ioman = FairRootManager::Instance();
  if ( ! ioman ) {
    cout << "-E- PndDskFLGHitProducerIdeal::Init: "
         << "RootManager not instantiated!" << endl;
    return kFATAL;
  }

  // Get input array
  fDskParticleArray = (TClonesArray*) ioman->GetObject("DskParticle");
   if ( ! fDskParticleArray ) {
    cout << "-W- PndDskFLGHitProducerIdeal::Init: "
         << "No DskBarPoint array!" << endl;
    return kERROR;
  }

   // Create and register output array
   fHitArray = new TClonesArray("PndDskFLGHit");
   ioman->Register("PndDskFLGHit","Dsk",fHitArray, kTRUE);

   //initialize random for producing cherenkov photons
   rand = new TRandom();   
 
   //fVerbose = 2;
   cout << "-I- PndDskFLGHitProducerIdeal: Intialization successfull" << endl;

   return kSUCCESS;
   
}


// -----   Execution of Task   ---------------------------------------------
// -------------------------------------------------------------------------
void PndDskFLGHitProducerIdeal::Exec(Option_t*)
{
  if ( ! fHitArray ) Fatal("Exec", "No HitArray");
  fHitArray->Clear();


  PndDskParticle* pt=NULL;
  nevents++;
   
  if (fVerbose > 1) {
    cout << " ----------------- DSK Hit Producer --------------------" << endl;
    cout <<" Number of input MC points in the plate: "<<fDskParticleArray->GetEntries()<<endl;
  }

  // fNHits = 0;

  // Loop over PndDskPoints
  for(Int_t j=0; j<fDskParticleArray->GetEntriesFast(); j++) {
    if (fVerbose > 1) printf("\n\n=====> Event No. %d\n", nevents); 
    
    pt = (PndDskParticle*)fDskParticleArray->At(j);
  
    Double_t Px= pt->GetPx();
    Double_t Py= pt->GetPy();
    Double_t Pz= pt->GetPz();
    Double_t P = sqrt(Px*Px + Py*Py +Pz*Pz);
    Double_t mass = pt->GetMass();
    Double_t energy = TMath::Sqrt(P*P + mass*mass); 

    Double_t beta;
    if(energy != 0) {
      beta = P/energy;
    }
    else {
      beta = -1.;
      if (fVerbose >1) cout << "Beta not calculated " << endl; 
    }

    Double_t thetaC;
    if (fabs(1./(1.47*beta)) > 1. || P == 0. || energy == 0.){
      thetaC = -1.;
    }else{
      thetaC = acos(1/(1.47*beta));
    }

    if (thetaC != -1. && beta > 1/1.47){  

    //collect that need to be stored
    Int_t trackID = pt->GetTrackID(); 
    Int_t detectorID = 0;
    TVector3 position_store(pt->GetX(), pt->GetY(), pt->GetZ());
    TVector3 momentum_store(Px, Py, Pz);
    Double_t time = 0;
    Double_t angIn = pt->GetAngIn();
    Double_t thetaC_store = pt->GetThetaC();  
    
    //generate Cherenkov photons in a cone

    int N_cherenko_photon = pt->GetNPhot();

    TVector3 Cone_Pos(pt->GetX()*10, pt->GetY()*10, pt->GetZ()*10);
    TVector3 Cone_Axis(Px, Py, Pz);
    TVector3 Cherenkov_photon(1,0,0); //initialize
    Cherenkov_photon.SetTheta(Cone_Axis.Theta() + thetaC);
    Cherenkov_photon.SetPhi(Cone_Axis.Phi());
    for(int i_photon = 0; i_photon < N_cherenko_photon; i_photon++){
       Double_t rot_angle = 2*(TMath::Pi())*rand->Rndm();
       Cherenkov_photon.Rotate(rot_angle, Cone_Axis); 

       //cout<<"Cone_Axis: "<<Cone_Axis.X()<<" "<<Cone_Axis.Y()<<" "<<Cone_Axis.Z()<<endl;
       //cout<<"Cone_Pos: "<<Cone_Pos.X()<<" "<<Cone_Pos.Y()<<" "<<Cone_Pos.Z()<<endl;
       //cout<<"photon_dir: "<<Cherenkov_photon.X()<<" "<<Cherenkov_photon.Y()<<" "<<Cherenkov_photon.Z()<<"  theta: "<<Cherenkov_photon.Theta()<<"  phi: "<<Cherenkov_photon.Phi()<<endl;
       if(Cherenkov_photon.Theta()<0.8 || Cherenkov_photon.Z()<0) continue;

       f_light_guide = -99;
       f_pixel = -99; //fixme
       //Propagate(Cone_Pos, Cherenkov_photon);  

       if(Cherenkov_photon.Theta()>fGeo->reflect_threshold())  fGeo->Propagate(Cone_Pos, Cherenkov_photon, f_light_guide, f_pixel);

       if(f_light_guide != -99)
 	AddHit(trackID,detectorID,position_store,momentum_store,time,
		angIn,thetaC_store,Cherenkov_photon,f_light_guide,f_pixel);

    }


    }
  }
}




// -----   Add Hit to HitCollection   --------------------------------------
PndDskFLGHit* PndDskFLGHitProducerIdeal::AddHit(Int_t trackID, Int_t detectorID,
		TVector3 position_store, TVector3 momentum_store, Double_t time,
                Double_t angIn, Double_t thetaC_store, 
		TVector3 Cherenkov_photon, Int_t light_guide, Int_t pixel)
				     {
  TClonesArray& clref = *fHitArray;
  Int_t size = clref.GetEntriesFast();
  return new(clref[size]) PndDskFLGHit( trackID,detectorID,position_store,momentum_store,time,
                angIn,thetaC_store,Cherenkov_photon,light_guide,pixel);
}
// -------------------------------------------------------------------------


// -----   Finish Task   ---------------------------------------------------
void PndDskFLGHitProducerIdeal::Finish()
{

  cout << "-I- PndDskFLGHitProducerIdeal: Finish" << endl;
 }
// -------------------------------------------------------------------------


ClassImp(PndDskFLGHitProducerIdeal)