// -------------------------------------------------------------------------
// -----                CbmD0Candidates  header file                   -----
// -----               Created 09/02/07  by C. Dritsa                  -----
// -------------------------------------------------------------------------


/**  CbmD0Candidates.h
 *@author C.Dritsa <c.dritsa@gsi.de>
 *
 *  Selection of candidate pairs
 *  for D0 reconstruction
 *
 **/




#ifndef CBMD0CANDIDATES_H
#define CBMD0CANDIDATES_H

#include "FairTask.h"
#include "CbmMCTrack.h"
#include "TH1F.h"
#include "TH2F.h"
#include "TString.h"
#include "CbmD0TrackCandidate.h"
#include "TNtuple.h"
#include "FairField.h"

class TClonesArray;
class CbmStsKFSecondaryVertexFinder;
class CbmStsKFTrackFitter;
class CbmStsTrack;
class CbmVertex;
class FairTrackParam;



class CbmD0Candidates : public FairTask
{
 public:
  CbmD0Candidates();
  CbmD0Candidates(char* name, Int_t iVerbose, Double_t cutIPD, Double_t cutSVZ);
  virtual ~CbmD0Candidates();
  virtual InitStatus Init();
  virtual void Exec(Option_t* option);
  
  /*
  virtual void KminusReFit(CbmStsTrack* track);
  Double_t GetImpactParameterRadius(FairTrackParam *etrack);
  Double_t GetImpactParameterX(FairTrackParam *etrack);
  Double_t GetImpactParameterY(FairTrackParam *etrack);
  Double_t GetTransverseMom(FairTrackParam *etrack);
  Double_t GetMom(FairTrackParam *etrack);
  //void SetParContainers() {; };
  */
  void SetHistoFileName( TString name ){ fHistoFileName = name;  };
  Double_t SetKFParticle(Bool_t useKFparticle) { fUseKF = useKFparticle;};



private:
    Int_t fEventNumber;
    TClonesArray* fListRCD0;
    TClonesArray* fListMCTracks;
    TClonesArray* fListD0TrackCandidate;
    TClonesArray* fStsTrackArray;
    TClonesArray* fD0TrackArray;
    TClonesArray* fInfoArray;
    TClonesArray* fStsTrackMatches;
    TClonesArray* fPosStsTracks;
    TClonesArray* fNegStsTracks;
    CbmStsKFTrackFitter* fFit;
    CbmStsKFSecondaryVertexFinder* fSVF;
    CbmVertex* fPrimVtx;
    CbmVertex* fSecVtx;
    FairField* fMF;

    TString fHistoFileName;


    Double_t GetPairImpactParameterR( Double_t Pair_Tx, Double_t Pair_Ty, Double_t SvX, Double_t SvY, Double_t SvZ, Double_t PvZ );
    Double_t GetPairPt(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2);
    Double_t GetPairPz(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2);
    Double_t GetPairTx(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2);
    Double_t GetPairTy(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2);
    Double_t GetMomentum(CbmD0TrackCandidate* tr1);
    Double_t GetPairMomentum(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2);
    Double_t GetEnergy(CbmD0TrackCandidate* tr1);
    Double_t GetPairEnergy( CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2 );
    Double_t GetIM(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2);
    Double_t GetCos12(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2 );
    Double_t GetIPAngle(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2 );
    Double_t GetChi2Topo(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2 );
    Double_t GetAPalpha(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2 );
    Double_t GetAPptt(CbmD0TrackCandidate* tr1, CbmD0TrackCandidate* tr2 );
    TNtuple* fTrackPairNtuple;

    TH1F* test;


    Double_t fcutIPD0, fcutSVZ;
    Bool_t fUseKF;

    void SetCuts(Double_t ipD0, Double_t SVZ);

    /** Register the output arrays to the IOManager **/
    void Register();
    void Finish();

  ClassDef(CbmD0Candidates,1);
};

#endif