////////////////////////////////////////////////////////////////////////////////
/// \class RAT::LP::LightPathStraightScintWater
///
/// \brief LightPath fitter using straight lines through water and scintillator.
/// only. Esssentially assumes infinitesimally thin AV.
///
/// Code optimised for for specific situation of fitting straight lines in
/// partial fill. Public function GetPath can be called to bypass using Light
/// Paths and Point3Ds to give faster results.
////////////////////////////////////////////////////////////////////////////////
#ifndef __RAT_LP_LightPathStraightScintWater__
#define __RAT_LP_LightPathStraightScintWater__

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

namespace RAT
{

namespace LP
{

class LightPathStraightScintWater : public LightPathFitter
{
public:

  /// Initialize geometry
  static void BeginOfRun();

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

  LightPathStraightScintWater() { }

  virtual LightPath& Fit(LightPath& startPath) const;

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

  static void GetPath(TVector3 fPMTpos, TVector3 fVertex, double &distInWater, double &distInScint);

private:

  static Double_t fFillLevel;
  static std::vector <Double_t> fAV_offset;
  static Double_t fAV_offset_z;
  static TVector3 fFillLevelCentre;//center of fill level
  static Double_t fAVRadiusOuter; // outer radius, 6060 mm
  static Double_t fAVRadius; // inner radius, 6005 mm
  static Double_t fNeckRadiusOuter; // outer radius of neck
  static Double_t fNeckRadius; // inner radius of neck
  static Double_t fBoundary;
  static Double_t fPSUPRadius;
  static Double_t fZneckLo; // bottom of the neck in z position
  static Double_t fPMTRadius;
  static std::vector<RAT::DU::Point3D> pStart;
  static Double_t distInUpperTarget;
  static Double_t distInWater;
  static RAT::DU::Point3D startPoint;
  static RAT::DU::Point3D endPoint;
  static RAT::DU::Point3D interPoint;
  static TVector3 startVec;
  static TVector3 endVec;
  static TVector3 dirVec;
}; // class LightPathStraightScintWater

} // namespace LP

} // namespace RAT

#endif