// HitXYPlane2.h

#ifndef HitXYPlane2_H
#define HitXYPlane2_H

// Describes a (v,z) measurement on a XYPlane.
//
// This is a very simple hit.  It produces one prediction with fixed
// measurement which is simply the (v,z) of the track.

#include "trfbase/Hit.h"
#include "trfbase/McCluster.h"

#include "SurfXYPlane.h"

//**********************************************************************

namespace trf {

class ClusXYPlane2 : public McCluster {

public:  // static methods

  // Return the type name.
  static TypeName get_type_name() { return "ClusXYPlane2"; }

  // Return the creator.
  static ObjCreator get_creator();

  // Return the type.
  static Type get_static_type() { return get_creator(); }

public:   // cluster parameter indices

  enum { IV=0, IZ=1 };

private:  // attributes

  // the surface
  SurfXYPlane _sxyp;

  // measurement
  double _v,_z;

  // the error matrix for the measurement
  double _dv2,_dz2,_dvdz;

private:  // methods

  // output stream
  void ostr(std::ostream& stream) const;

  // equality
  bool equal(const Cluster& clus) const;

  // generate first (and only) track prediction
  HitList _predict(const ETrack& tre) const;

public:  // methods

  // constructor
  // Depricated , go and see figure#1 . 
  ClusXYPlane2(double dist, double phi, const HitVector& hm,
               const HitError& dhm );

  // Depricated , go and see figure#1 . 
  ClusXYPlane2(double dist,double phi, double v, double z, 
               const HitError& dhm );

  ClusXYPlane2(double dist,double phi, double v, double z, 
               double dv2, double dz2, double dvdz );

  // constructor
  // Depricated , go and see figure#1 . 
  ClusXYPlane2(double dist, double phi, const HitVector& hm,
                const HitError& dhm,const McIdList& mcids );

  // Depricated , go and see figure#1 . 
  ClusXYPlane2(double dist,double phi, double v, double z, 
                const HitError& dhm,const McIdList& mcids );

  ClusXYPlane2(double dist,double phi, double v, double z, 
               double dv2, double dz2, double dvdz,const McIdList& mcids );

  // copy constructor
  ClusXYPlane2(const ClusXYPlane2& rhs);

  // destructor
  ~ClusXYPlane2( );

  // return a unique address specifying the type
  Type get_type() const { return get_static_type();  };

  // Write the object data.
  ObjData write_data() const;


  // return the surface
  const Surface& get_surface() const { return _sxyp; };

  // Depricated , go and see figure#1 . 
  HitVector get_hm() const { return HitVector(_v,_z); };

  // Depricated , go and see figure#1 . 
  HitError get_dhm() const { return HitError(_dv2,_dvdz,_dz2); };

  inline double get_v() const { return _v; }
  inline double get_z() const { return _z; }
  inline double get_dv2() const { return _dv2; }
  inline double get_dz2() const { return _dz2; }
  inline double get_dvdz() const { return _dvdz; }

  // there are no more predictions.
  Hit* new_next_prediction() const { return 0; };

};

//**********************************************************************

class HitXYPlane2 : public Hit {

// Only ClusXYPlane2 is allowed to construct HitXYPlane2 objects.
friend class ClusXYPlane2;

public:
  // Return the type name.
  static TypeName get_type_name() { return "HitXYPlane2"; }

  // Return the creator.
  static ObjCreator get_creator();

  // Return the type.
  static Type get_static_type() { return get_creator(); }

private:

  // prediction for hm
  double _v,_z;

  // error matrix for hm
  double _dv2,_dz2,_dvdz;

private:

  // output stream
  void ostr(std::ostream& stream) const;

  // equality
  bool equal(const Hit& hit) const;

  // constructor
  HitXYPlane2(double v, double z, double dv2, double dz2, double dvdz);

public:

  // copy constructor
  HitXYPlane2(const HitXYPlane2& lhs);

  // destructor
  ~HitXYPlane2( );

  // return the dimension
  inline int size() const { return 2; };

  // return the measured hit vector
  HitVector measured_vector() const;

  // return the measured hit error
  HitError measured_error() const;

  // return the predicted hit vector
  HitVector predicted_vector() const;

  // return the predicted hit error
  HitError predicted_error() const;

  // return the derivative
  HitDerivative dhit_dtrack() const;

  // return the difference between prediction and measurement
  HitVector difference_vector() const;

  // update the prediction
  void update( const ETrack& tre);

  // return a ClusXYPlane2 reference to the cluster
  inline const ClusXYPlane2& get_full_cluster() const
    { return (const ClusXYPlane2&) *_pclus; };

  inline double get_v() const { return _v; }
  inline double get_z() const { return _z; }
  inline double get_dv2() const { return _dv2; }
  inline double get_dz2() const { return _dz2; }
  inline double get_dvdz() const { return _dvdz; }

  // return a unique address specifying the type
  Type get_type() const { return get_static_type();  };

  // Write the object data.
  ObjData write_data() const;

};

}  // end namespace trf

#endif