#ifndef G__SOLTRK_H
#define G__SOLTRK_H

#include <TMath.h>
#include <TMatrixDSym.h>

class SolGeom;

// Class to store track information
// Assumes that the geometry has been initialized
class SolTrack{
  // Track handling class
  // Assume tracks originate from (0,0) for the time being
private:
  Int_t fNl;        // Actual number of layers
  SolGeom *fG;      // Geometry
  Double_t fp[3];   // px, py, pz momentum
  Double_t fx[3];   //  x,  y,  z track origin
  Double_t fpar[5]; // D, phi0, C, z0, cot(theta)

  TMatrixDSym fCov; // Full covariance matrix

public:
  // Constructors
  SolTrack(Double_t *x, Double_t *p, SolGeom *G);
  SolTrack(Double_t D, Double_t phi0, Double_t C, Double_t z0, Double_t ct, SolGeom *G);
  // Destructor
  ~SolTrack();
  // Accessors
  // Position (at minimum approach)
  Double_t x() { return fx[0]; }
  Double_t y() { return fx[1]; }
  Double_t z() { return fx[2]; }
  // Momentum  (at minimum approach)
  Double_t px() { return fp[0]; }
  Double_t py() { return fp[1]; }
  Double_t pz() { return fp[2]; }
  Double_t pt() { return TMath::Sqrt(fp[0] * fp[0] + fp[1] * fp[1]); }
  Double_t p()  { return TMath::Sqrt(fp[0] * fp[0] + fp[1] * fp[1] + fp[2] * fp[2]); }
  // Track parameters
  Double_t D()    { return fpar[0]; }
  Double_t phi0() { return fpar[1]; }
  Double_t C()    { return fpar[2]; }
  Double_t z0()   { return fpar[3]; }
  Double_t ct()   { return fpar[4]; }
  // Covariance
  TMatrixDSym Cov()   { return fCov; }
  // Track parameter covariance calculation
  void CovCalc(Bool_t Res, Bool_t MS);
  // Parameter errors
  Double_t s_D()    { return TMath::Sqrt(fCov(0, 0)); }
  Double_t s_phi0() { return TMath::Sqrt(fCov(1, 1)); }
  Double_t s_C()    { return TMath::Sqrt(fCov(2, 2)); }
  Double_t s_pt()   { return 2 * s_C()*pt() / (0.2998*fG->B()); } // Dpt/pt
  Double_t s_z0()   { return TMath::Sqrt(fCov(3, 3)); }
  Double_t s_ct()   { return TMath::Sqrt(fCov(4, 4)); }
  // Track hit management
  Int_t nHit();
  Bool_t HitLayer(Int_t Layer, Double_t &R, Double_t &phi, Double_t &zz);
  Int_t HitList(Int_t *&ihh, Double_t *&rhh, Double_t *&zhh);
  // Make normalized matrix positive definite
  TMatrixDSym MakePosDef(TMatrixDSym NormMat);
};
#endif