// -------------------------------------------------------------------------
// -------------------------------------------------------------------------

#ifndef PNDDCHSIMPLEFITTER_H
#define PNDDCHSIMPLEFITTER_H


#include "CbmTask.h"
#include "TVector3.h"

class TClonesArray;
class TH1F;
class TString;

class PndDchSimpleFitter : public CbmTask {
  
 public:
  
  PndDchSimpleFitter();
  
  ~PndDchSimpleFitter();
  
  // Virtual method Init
  virtual InitStatus Init();
  virtual void Finish();
  
  // Virtual method Exec
  virtual void Exec(Option_t* opt);
  
 private: 
  //fit circle by less square method
  Bool_t GetCircleParameters(TClonesArray *fPoints, TVector3& result);
  //fit line by less square method
  Bool_t GetLineParameters(TClonesArray *fPoints, TVector2& result);
  Bool_t GetMomentum(TVector3 circle, TVector2 lineXZ, TVector2 lineYZ, TVector3& momentum);
  
  // Input array of PndDchPoints
  TClonesArray* fPointArray;

  // array of hit points (TVector2) in XZ plane upstream the dipole (Chamber3 and Chamber4)  
  TClonesArray* fPointsBeforeXZ;
  // array of hit points (TVector2) in XZ plane downstream the dipole (Chamber7 and Chamber8)  
  TClonesArray* fPointsAfterXZ;
  // array of hit points (TVector2) in XZ plane for the region of dipole 
  // which are hits form (Chamber7 and Chamber8 plus 2 artificial points when the track 
  // is entering and exiting the field region)  
  TClonesArray* fPointsInXZ;
  // array of hit points (TVector2) in YZ plane (hits from Chamber3 to Chamber8)
  TClonesArray* fPointsYZ;

  //upstream z - coordinate of the field border
  Double_t fZFieldBegin; 
  //downstream z - coordinate of the field border
  Double_t fZFieldEnd;
  //effecitive field strength
  Double_t fField;

  //pull histos
  TH1F* fPullPx;
  TH1F* fPullPy;  
  TH1F* fPullPz;  
  TH1F* fPullP;

  TString fOutFile;
  
  ClassDef(PndDchSimpleFitter,1)
  
};

#endif