#ifndef TG4HitCheren_hxx_seen
#define TG4HitCheren_hxx_seen

#include <vector>

#include "IG4VHit.hxx"
#include "IG4Trajectory.hxx"
#include "IHandle.hxx"

namespace COMET { class IG4HitCheren; }

/// DO NOT USE THIS CLASS IN ANALYSIS CODE.
///
/// This is a base class used to save cherenkov counter hits into a ROOT file.
class COMET::IG4HitCheren: public IG4VHit {
public:
    IG4HitCheren();
    IG4HitCheren(const IG4HitCheren& rhs);
    virtual ~IG4HitCheren();

    /// Get the charge associated with this particle
    double GetCharge(void) const {return fCharge;}
    /// Get the beta factor of this particle
    double GetBeta(void) const {return fBeta;}

    /// The X position of the hit
    double GetStartX(void) const {return fStartPos.vX;}
    /// The Y position of the hit
    double GetStartY(void) const {return fStartPos.vY;}
    /// The Z position of the hit
    double GetStartZ(void) const {return fStartPos.vZ;}
    /// The time of the hit
    double GetStartT(void) const {return fStartPos.vT;}

    /// The X position of the hit
    double GetStopX(void) const {return fStopPos.vX;}
    /// The Y position of the hit
    double GetStopY(void) const {return fStopPos.vY;}
    /// The Z position of the hit
    double GetStopZ(void) const {return fStopPos.vZ;}
    /// The time of the hit
    double GetStopT(void) const {return fStopPos.vT;}

    // Get the length of the hit
    double GetHitLength(void) const;

    /// The X position of the hit
    double GetPosX(void) const {return (fStartPos.vX + fStopPos.vX)/2.;}
    /// The Y position of the hit
    double GetPosY(void) const {return (fStartPos.vY + fStopPos.vY)/2.;}
    /// The Z position of the hit
    double GetPosZ(void) const {return (fStartPos.vZ + fStopPos.vZ)/2.;}
    /// The time of the hit
    double GetPosT(void) const {return (fStartPos.vT + fStopPos.vT)/2.;}

    /// The X component of the momentum vector of the track
    double GetMomentumX(void) const {return fMomentum.vX;}
    /// The Y component of the momentum vector of the track
    double GetMomentumY(void) const {return fMomentum.vY;}
    /// The Z component of the momentum vector of the track
    double GetMomentumZ(void) const {return fMomentum.vZ;}
    /// The Z component of the momentum vector of the track
    double GetTotalEnergy(void) const {return fMomentum.vT;}
    /// The magnitude of the momentum
    double GetMomentumMag(void) const {return TVector3(fMomentum.vX,
                                                       fMomentum.vY,
                                                       fMomentum.vZ).Mag();}
    /// Print the hit information.
    virtual void ls(Option_t * = "") const;

    /// Light weight struct for storing 4-vectors values
    struct FourVector {
        Float_t vX;
        Float_t vY;
        Float_t vZ;
        Float_t vT;
        FourVector(): 
            vX(0), vY(0), vZ(0), vT(0) {};
        FourVector(double x, double y, double z, double t): 
            vX(x), vY(y), vZ(z), vT(t) {};
        FourVector(const FourVector& rhs): 
            vX(rhs.vX), vY(rhs.vY), vZ(rhs.vZ), vT(rhs.vT) {};
    };

protected:

    /// The charge of the associated particle in units of e/3
    Float_t fCharge;
    /// The beta factor of the particle, i.e. v/c
    Float_t fBeta;
    /// The start position of the cherenkov hit
    FourVector fStartPos;
    /// The end position of the cherenkov hit
    FourVector fStopPos;
    /// The four momentum at the start point
    FourVector fMomentum;

    ClassDef(IG4HitCheren,1);
};
#endif