#ifndef MPDKALMANTRACK_H
#define MPDKALMANTRACK_H

/// \ingroup rec
/// \class MpdKalmanTrack
/// \brief Kalman track in MPD
///
/// \author Alexander Zinchenko, LHEP JINR Dubna

#include <TMath.h>
#include <TMatrixD.h>
#include <TMatrixDSym.h>
#include <TObjArray.h>
#include <TString.h>
#include <TVector3.h>
#include <map>

class MpdKalmanTrack : public TObject
{

 public:
  enum TrackDir {kInward, kOutward};
  enum TrackType {kBarrel, kEndcap};
  enum TrackFlag {kOk, kNoOut};
 public:
  
  MpdKalmanTrack(); ///< Default ctor
  MpdKalmanTrack(Double_t pos, TVector3 &vertex); ///< Ctor from position and vertex
  virtual ~MpdKalmanTrack(); ///< Destructor
  MpdKalmanTrack (const MpdKalmanTrack& track); ///< copy constructor
  MpdKalmanTrack& operator=(const MpdKalmanTrack& track); ///< assignment operator

  Int_t GetTrackID() const { return fID; } ///< get track ID
  TrackDir GetDirection() const { return fTrackDir; } ///< Get track direction
  TrackType GetType() const { return fTrackType; } ///< Get track type
  TrackFlag GetFlag() const { return fFlag; } ///< Get track flag
  Int_t GetLastLay() const { return fLastLay; } ///< get the outermost layer
  Int_t GetNofWrong() const { return fNofWrong; } ///< number of wrong hits
  TString GetNode() const { return fNode; } ///< node path
  TString GetNodeNew() const { return fNodeNew; } ///< node path
  Double_t GetPartID() const { return fPartID; } ///< get particle ID
  Double_t GetDedx(Double_t coef = 6.036e-3) const { return fPartID * coef; } ///< get particle ID (De/dx converted from ADC counts to keV)
  Double_t GetPos() const { return fPos; } ///< Get current position 
  Double_t GetPosNew() const { return fPosNew; } ///< Get propagated position 
  Double_t GetPosAtHit() const { return fPosAtHit; } ///< Get position of outermost hit 
  Double_t GetZ() const { return fTrackType == kEndcap ? fPos : GetParam(1); } ///< Z-position
  Double_t GetChi2() const { return fChi2; } ///< Get track Chi2
  Double_t GetChi2Vertex() const { return fChi2Vertex; } ///< Get Chi2 to vertex
  Double_t GetLength() const { return fLength; } ///< Get track length
  Double_t GetLengAtHit() const { return fLengAtHit; } ///< Get track length at last hit
  TMatrixD* GetParam() const { return fParam; } ///< get param. matrix
  TMatrixD* GetParamNew() const { return fParamNew; } ///< get new param. matrix
  TMatrixD* GetParamAtHit() const { return fParamAtHit; } ///< get param. matrix at last hit
  Double_t GetParam(Int_t i) const { return (*fParam)(i,0); } ///< get param. value
  Double_t GetParamNew(Int_t i) const { return (*fParamNew)(i,0); } ///< get new param. value
  TMatrixDSym* GetCovariance() const { return fCovar; } ///< Get covariance matrix
  TMatrixDSym* Weight2Cov(); ///< Get covariance matrix from weight matrix
  TMatrixDSym* GetWeight() const { return fWeight; } ///< Get weight matrix
  TMatrixDSym* GetWeightAtHit() const { return fWeightAtHit; } ///< Get weight matrix at last hit
  Int_t GetNofHits() const { return fHits ? fHits->GetEntriesFast() : fNhits; } ///< Get number of track hits
  TObjArray* GetHits() const { return fHits; } ///< Get track hits container
  TVector3& GetVertex() { return fVertex; } ///< AZ

  void SetTrackID(Int_t id) { fID = id; } ///< set track ID
  void SetNofHits(Int_t nHits) { fNhits = nHits; } ///< Set number of track hits
  void SetDirection(TrackDir dir) { fTrackDir = dir; } ///< set track direction
  void SetType(TrackType type) { fTrackType = type; } ///< set track type
  void SetFlag(TrackFlag flag) { fFlag = flag; } ///< set track flag
  void SetLastLay(Int_t lay) { fLastLay = lay; } ///< set last layer
  void SetNofWrong(Int_t nWrong) { fNofWrong = nWrong; } ///< set number of wrong hits 
  void SetNode(TString node) { fNode = node; } ///< set node path
  void SetNodeNew(TString node) { fNodeNew = node; } ///< set node path
  void SetPartID(Double_t id) { fPartID = id; } ///< set particle ID
  void SetPos(Double_t pos) { fPos = pos; } ///< set position 
  void SetPosNew(Double_t posNew) { fPosNew = posNew; } ///< set propagated position 
  void SetPosAtHit(Double_t posHit) { fPosAtHit = posHit; } ///< set position of outermost hit
  void SetChi2(Double_t chi2) { fChi2 = chi2; } ///< set chi2
  void SetChi2Vertex(Double_t chi2) { fChi2Vertex = chi2; } ///< set chi2 to vertex
  void SetLength(Double_t length) { fLength = length; } ///< set length
  void SetLengAtHit(Double_t length) { fLengAtHit = length; } ///< set length at last hit
  void UpdateLength(Double_t length) { fLength += length; } ///< update length
  void SetParam(TMatrixD &param) { *fParam = param; } ///< set param. matrix
  void SetParamNew(TMatrixD &param) { *fParamNew = param; } ///< set new param. matrix
  void SetParamAtHit(TMatrixD &param) { *fParamAtHit = param; } ///< set param. matrix at last hit
  void SetParam(Int_t i, Double_t val) { (*fParam)(i,0) = val; } ///< set param. value
  void SetCovariance(TMatrixDSym &cov) { *fCovar = cov; } ///< set covar. matrix
  void SetWeight(TMatrixD &weight) { fWeight->SetMatrixArray(weight.GetMatrixArray()); } ///< set weight matrix
  void SetWeight(TMatrixDSym &weight) { *fWeight = weight; } ///< set weight matrix
  void SetWeightAtHit(TMatrixDSym &weight) { *fWeightAtHit = weight; } ///< set weight matrix at last hit
  void ReSetWeight(); ///< set weight from covariance
  virtual void StartBack() {}; ///< prepare for back tracing
  virtual void Clear(); ///< reset track (similar to destructor)
  void PrintNode(Bool_t nNew = kFALSE) const; ///< printout node name 
  std::map<Int_t,Double_t>& GetSteps() { return fStepMap; } ///< steps between points

  // Getters of "physics" track parameters
  Double_t Pt() const { return TMath::Abs(GetParam(4)) > 0.01 ? 1. / TMath::Abs(GetParam(4)) : 100. ; }
  Double_t Phi() const { return GetParam(2); }
  Double_t Theta() const { return TMath::PiOver2() - GetParam(3); }
  Double_t Momentum() const { return TMath::Abs(Pt() / TMath::Cos(GetParam(3))); }
  Int_t Charge() const { return TMath::Nint(TMath::Sign(1., -GetParam(4))); }
  TVector3 Momentum3() const { return TVector3(Pt()*TMath::Cos(Phi()), Pt()*TMath::Sin(Phi()), Momentum()*TMath::Cos(Theta())); }
  Double_t DCA() const; ///< signed DCA
  //Bool_t IsSortable() const { return kTRUE; }
  //Int_t Compare(const TObject* track) const; ///< sort in descending order in Pt

  //private:
  protected:

  Int_t fID; ///< trackID
  Int_t fNhits; ///< number of hits (just for convenience of tree browsing)
  TrackDir fTrackDir; ///< track direction (inward/outward)
  TrackType fTrackType; ///< track type (kBarrel/kEndcap)
  Int_t fLastLay; ///< the outermost layer number achieved
  Int_t fNofWrong; ///< number of wrong hits (different from the track ID)
  TString fNode; ///< node path (for local track parameters)
  TString fNodeNew; ///< node path (for local track parameters)
  Double32_t fPartID; ///< particle ID
  Double32_t fPos; ///< current track radial position
  Double32_t fPosNew; ///< propagated track radial position
  Double32_t fPosAtHit; ///< radial position of outermost hit
  Double32_t fChi2; ///< track Chi2
  Double32_t fChi2Vertex; ///< track Chi2-distance to primary vertex
  Double32_t fLength; ///< track length
  Double32_t fLengAtHit; ///< track length at last hit
  TMatrixD *fParam; ///< pointer to track parameter matrix
  TMatrixD *fParamNew; ///<! pointer to track parameter matrix after propagation
  TMatrixD *fParamAtHit; ///< pointer to track parameter matrix at last hit
  TMatrixDSym *fCovar; ///< pointer to covariance matrix
  TMatrixDSym *fWeight; ///<! pointer to weight matrix
  TMatrixDSym *fWeightAtHit; ///< pointer to weight matrix at last hit
  TVector3 fVertex; ///< track vertex
  TObjArray *fHits; ///<! array of hit pointers assigned to the track
  std::map<Int_t,Double_t> fStepMap; ///<! steps between points on track
  TrackFlag fFlag; ///< track flag

  ClassDef(MpdKalmanTrack,5);
};
#endif