// D0GTrackPropagator.hpp

#ifndef D0GTrackPropagator_H
#define D0GTrackPropagator_H

// This is just a facade for GTrackPropagator constructed using
// D0Propagator.

#include "gtrbase/GTrackPropagator.hpp"
#include "ref_count/RefCounter.hpp"

class D0GTrackPropagator : public RefCounter {
//class D0GTrackPropagator {

private:  // attributes

  // The underlying propagator.
  // We construct this and it does all the work.
  GTrackPropagator _gprop;

public:  // methods

  // Default constructor.
  explicit D0GTrackPropagator();

  // destructor
  ~D0GTrackPropagator();

  // Return the GTrack propagator pointer.
  const GTrackPropagator& get_gtrack_propagator() const;
 
  // Return the TRF++ propagator pointer.
  const trf::PropagatorPtr& get_propagator() const;

  // Propagate track to a surface over a specified s-range.
  // A reference to an invalid state is returned if the surface
  // cannot be reached.
  GTrackState
  propagate(const GTrack& gtr, const trf::SurfacePtr& srf,
            double s1 =GTrack::SMIN, double s2 =GTrack::SMAX) const;

};

// output stream
std::ostream& operator<<(std::ostream& stream, const D0GTrackPropagator& gtr);

// equality
bool operator==(const D0GTrackPropagator& lhs, const D0GTrackPropagator& rhs);

// inequality
inline
bool operator!=(const D0GTrackPropagator& lhs, const D0GTrackPropagator& rhs) {
  return ! (lhs == rhs);
}

#endif