////////////////////////////////////////////////////////////////////////////////
/// \class RAT::DU::LightPathStraightFitter
///
/// \brief LightPath fitter using a simple straight line.
///
/// The geometry assumed here is that the AV is a sphere centred on a
/// notional origin.  Since it uses Point3D, however, this shouldn't matter.
////////////////////////////////////////////////////////////////////////////////
#ifndef __RAT_DU_LightPathStraightFitter__
#define __RAT_DU_LightPathStraightFitter__

#include <string>
#include <TVector3.h>
#include <RAT/DU/LightPath.hh>
#include <RAT/DU/LightPathFitter.hh>

namespace RAT
{

namespace DU
{

class LightPathStraightFitter : public LightPathFitter
{
public:

  /// Initialize geometry
  static void BeginOfRun();

  /// geometry
  static Double_t GetNeckInnerRadius() { return fNeckInnerRadius; }
  static Double_t GetNeckOuterRadius() { return fNeckOuterRadius; }
  static Double_t GetAVInnerRadius() { return fAVInnerRadius; }
  static Double_t GetAVOuterRadius() { return fAVOuterRadius; }
  static Double_t GetPMTRadius() { return fPMTRadius; }
  static Double_t GetFillZ() { return fFillZ; }

  static std::string Name() { return std::string("LightPathStraightFitter"); }

  LightPathStraightFitter() { }

  virtual LightPath& Fit(LightPath& startPath) const;

  virtual Double_t GetSolidAngle(const LightPath& lightPath, const TVector3& pmtNorm, UInt_t nVal, Double_t& cosThetaAvg) const;

  ClassDefNV( LightPathStraightFitter, 0 );

private:

  static Double_t fNeckInnerRadius;
  static Double_t fNeckOuterRadius;
  static Double_t fAVInnerRadius;
  static Double_t fAVOuterRadius;
  static Double_t fPMTRadius;
  static Double_t fFillZ;
  static size_t fAVSystemId;

  static LightPath::RegionType GetRegionType(const Point3D& point);
  static void Insert(LightPath& path,
                     std::vector<Double_t>& ts,
                     const Point3D& p,
                     Double_t t,
                     LightPath::RegionType rtype);

}; // class LightPathStraightFitter

} // namespace DU

} // namespace RAT

#endif