// Class for the representation of a track as helix (SC system)
//
// Authors: M. Al-Turany, A. Fontana, L. Lavezzi and A. Rotondi
//
//
// GEANE parameters (q/p, lambda, phi, y_perp, z_perp) of Helix track
// The Helix can be constructed using the Helix parameter (1/p, lambda, phi,y_perp,z_perp) in SC reference
// and the covariance matrix. Or using position and momentum in LAB referance.

#ifndef FAIRSTSTRACKPARH
#define FAIRSTSTRACKPARH 1

#include "FairTrackPar.h"
#include "FairTrackParP.h"

#include "TVector3.h"

class FairTrackParP;

class FairTrackParH : public FairTrackPar
{

  public:

    /** Constructor **/
    FairTrackParH();

    /** Constructor with track variables  (in SC) **/
    FairTrackParH(Double_t x,  Double_t y,  Double_t z,
                  Double_t lambda, Double_t phi, Double_t qp,
                  Double_t CovMatrix[15]);

    /** Constructor track parameters with position and momentum (in LAB)**/

    FairTrackParH(TVector3 pos, TVector3 Mom, TVector3 posErr, TVector3 MomErr, Int_t q);

    /** copy Constructor **/
    FairTrackParH(FairTrackPar& Trkbase);

    //FairTrackParH(FairTrackParH &Trk);

    FairTrackParH(FairTrackParP* parab, Int_t& ierr);

    /** Destructor **/
    virtual ~FairTrackParH();

    /** Output to screen **/
//   void Print();
    virtual void  Print(Option_t* option = "") const;

    /** Accessors **/
    Double_t GetLambda() { return fLm; };
    Double_t GetPhi() { return fPhi; };
    Double_t GetDLambda() ; /**Get Error in Lambda*/
    Double_t GetDPhi()  ;   /**Get Error in Phi*/
    /**Get the coveriant matrix*/
    void GetCov(Double_t* Cov) {for(Int_t i=0; i<15; i++) { Cov[i]=fCovMatrix[i]; }}
    void GetCovQ(Double_t* CovQ);
    // MARS
    void GetMARSCov(Double_t Cov66[6][6]) {for(Int_t i=0; i<6; i++) for(Int_t j=0; j<6; j++) { Cov66[i][j] = fCovMatrix66[i][j]; }  }
    Double_t GetDX_sc();  /**Get dx in SC*/
    Double_t GetDY_sc();  /**Get dy in SC*/
    Double_t GetDZ_sc();  /**Get dz in SC*/
    Double_t GetX_sc() {return fX_sc;} /**Get x in SC*/
    Double_t GetY_sc() {return fY_sc;} /**Get y in SC*/
    Double_t GetZ_sc() {return fZ_sc;} /**Get z in SC*/
// Double_t GetDPx() ;   /**Get error in Px (in SC frame)*/
// Double_t GetDPy() ;   /**Get error in Py (in SC frame)*/
// Double_t GetDPz() ;   /**Get error in Pz (in SC frame)*/
//  Double_t GetDQp() ;   /**Get error in Q/P*/
    Double_t GetX();  /**Get X in Lab*/
    Double_t GetY();  /**Get Y in Lab*/
    Double_t GetZ();  /**Get Z in Lab*/



    /** Modifiers **/
    void SetLambda(Double_t Lm ) { fLm = Lm; };
    void SetPhi(Double_t Phi) { fPhi = Phi; };

    void SetDLambda(Double_t DLm ) { fDLm = DLm; };
    void SetDPhi(Double_t DPhi) { fDPhi = DPhi; };

    void  SetX_sc(Double_t x) {fX_sc =x;} /**Set x in SC*/
    void  SetY_sc(Double_t y) {fY_sc =y;} /**Set y in SC*/
    void  SetZ_sc(Double_t z) {fZ_sc =z;} /**Set z in SC*/
    void  SetCov(Double_t* Cov) {for(Int_t i=0; i<15; i++) { fCovMatrix[i]=Cov[i]; }}
    void  SetTrackPar(Double_t x,  Double_t y,  Double_t z,
                      Double_t Px, Double_t Py, Double_t Pz, Int_t Q,
                      Double_t CovMatrix[15]);

    void  SetTrackPar(Double_t x,  Double_t y,  Double_t z,
                      Double_t pq, Double_t lm, Double_t phi,  Double_t CovMatrix[15]);
    void Reset();
    ClassDef(FairTrackParH,1);


  private:

    /** fLm = Dip angle **/
    Double_t fLm;
    /**fPhi = azimuthal angle **/
    Double_t fPhi;
    /** Error in Lambda*/
    Double_t fDLm;
    /** Error in Phi*/
    Double_t fDPhi;
    /** Points coordinates in SC system */
    Double_t fX_sc, fY_sc, fZ_sc;
    /** Errors for X,Y,Z  (in SC system) */
    Double_t fDX_sc, fDY_sc, fDZ_sc;
    /** Covariant matrix in SC*/
    Double_t fCovMatrix[15];
    // in MARS
    Double_t fCovMatrix66[6][6];

    /**Calculate the cov. mat. for this helix*/
    void CalCov();

    /** just to simplify a little bit typing the equations
       cLm  = Cos(Lambda),
       sLm  = Sin(Lambda),
       cphi = cos(Phi),
       sphi = Sin(Phi)
       //! do not streame this to the file
    */
    Double_t cLm,sLm, cphi ,sphi; //!

};


#endif