#ifndef ALIKALMANTRACK_H
#define ALIKALMANTRACK_H

/* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 * See cxx source for full Copyright notice                               */

/* $Id$ */

//-------------------------------------------------------------------------
//                          Class AliKalmanTrack
//      fixed the interface for the derived reconstructed track classes 
//            Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch 
//-------------------------------------------------------------------------

#include <TObject.h>
#include "AliLog.h"
#include "AliPID.h"
#include "AliMagF.h"

class AliCluster;

class AliKalmanTrack : public TObject {
public:
  AliKalmanTrack();
  AliKalmanTrack(const AliKalmanTrack &t);

  virtual ~AliKalmanTrack(){};
  void SetLabel(Int_t lab) {fLab=lab;}
  void SetFakeRatio(Float_t ratio) {fFakeRatio=ratio;}

  Bool_t   IsSortable() const {return kTRUE;}
  Int_t    GetLabel()   const {return fLab;}
  Float_t    GetFakeRatio()   const {return fFakeRatio;}
  Double_t GetChi2()    const {return fChi2;}
  Double_t GetMass()    const {return fMass;}
  Int_t    GetNumberOfClusters() const {return fN;}
  virtual Int_t GetClusterIndex(Int_t) const { //reserved for AliTracker
    AliWarning("Method must be overloaded !\n");
    return 0;
  } 
  virtual Double_t GetPIDsignal() const {
    AliWarning("Method must be overloaded !\n");
    return 0.;
  }

  virtual Double_t GetDCA(const AliKalmanTrack *p,Double_t &xthis,Double_t &xp) const; 
  virtual 
  Double_t PropagateToDCA(AliKalmanTrack *p, Double_t d=0., Double_t x0=0.); 
  virtual Double_t GetAlpha() const {
    AliWarning("Method must be overloaded !\n");
    return 0.;
  }
  virtual Double_t GetSigmaY2() const {
    AliWarning("Method must be overloaded !\n");
    return 0.;
  }
  virtual Double_t GetSigmaZ2() const {
    AliWarning("Method must be overloaded !\n");
    return 0.;
  }

  virtual Int_t Compare(const TObject *) const {return 0;} 

  virtual void GetExternalParameters(Double_t&/*xr*/,Double_t/*x*/[5]) const=0;
  virtual void GetExternalCovariance(Double_t /*cov*/[15]) const = 0;

  virtual Double_t GetPredictedChi2(const AliCluster *) const = 0;
  virtual Int_t PropagateTo(Double_t/*xr*/,Double_t/*x0*/,Double_t/*rho*/) = 0;
  //virtual Int_t PropagateToVertex(Double_t /*d*/=0., Double_t /*x0*/=0.) = 0; 
  virtual Int_t Update(const AliCluster*, Double_t /*chi2*/, UInt_t) = 0;

  static void SetFieldMap(const AliMagF *map) { fgkFieldMap=map; }
  static const AliMagF *GetFieldMap() { return fgkFieldMap; }

  static void SetUniformFieldTracking() {
     if (fgkFieldMap==0) {
        printf("AliKalmanTrack: Field map has not been set !\n"); 
        exit(1);
     } 
     fgConvConst=1000/0.299792458/(fgkFieldMap->SolenoidField()+1e-13);
  }
  static void SetNonuniformFieldTracking() { fgConvConst=0.; }

  static Double_t GetConvConst();
  static Double_t MeanMaterialBudget(Double_t *start, Double_t *end, Double_t *mparam);
 
  // Time integration (S.Radomski@gsi.de)
  void   StartTimeIntegral();
  void SetIntegratedLength(Double_t l) {fIntegratedLength=l;}
  void SetIntegratedTimes(const Double_t *times);

  Bool_t IsStartedTimeIntegral() const {return fStartTimeIntegral;}
  void     AddTimeStep(Double_t length);
  void GetIntegratedTimes(Double_t *times) const;
  Double_t GetIntegratedTime(Int_t pdg) const;
  Double_t GetIntegratedLength() const {return fIntegratedLength;}
  void PrintTime() const;

protected:
  virtual void GetXYZ(Float_t r[3]) const = 0;
  void     SaveLocalConvConst();
  Double_t GetLocalConvConst() const;

  void External2Helix(Double_t helix[6]) const;

  void SetChi2(Double_t chi2) {fChi2=chi2;} 
  void SetMass(Double_t mass) {fMass=mass;}
  void SetNumberOfClusters(Int_t n) {fN=n;} 

  Int_t fLab;             // track label
  Float_t fFakeRatio;     // fake ratio
  Double_t fChi2;         // total chi2 value for this track
  Double_t fMass;         // mass hypothesis
  Int_t fN;               // number of associated clusters

private:
  static const AliMagF *fgkFieldMap;//pointer to the magnetic field map
  static Double_t fgConvConst;      //conversion "curvature(1/cm) -> pt(GeV/c)"
  Double_t fLocalConvConst;   //local conversion "curvature(1/cm) -> pt(GeV/c)"

  // variables for time integration (S.Radomski@gsi.de)
  Bool_t  fStartTimeIntegral;       // indicator wether integrate time
  Double_t fIntegratedTime[AliPID::kSPECIES];       // integrated time
  Double_t fIntegratedLength;        // integrated length
  
  ClassDef(AliKalmanTrack,4)    // Reconstructed track
};

inline Double_t AliKalmanTrack::GetConvConst() {
//
//  For backward compatibility only !
//
    if (fgConvConst > 0 || fgConvConst < 0) return fgConvConst; 
    return 1000/0.299792458/(fgkFieldMap->SolenoidField()+1e-13);
}

inline void AliKalmanTrack::SaveLocalConvConst() {
  //---------------------------------------------------------------------
  // Saves local conversion constant "curvature (1/cm) -> pt (GeV/c)" 
  //---------------------------------------------------------------------
     if (fgConvConst > 0 || fgConvConst < 0) return; //uniform field tracking
     Float_t r[3]={0.,0.,0.}; GetXYZ(r);
     Float_t b[3]; fgkFieldMap->Field(r,b);
     fLocalConvConst=1000/0.299792458/(1e-13 - b[2]);
} 

inline Double_t AliKalmanTrack::GetLocalConvConst() const {
  //---------------------------------------------------------------------
  // Returns conversion constant "curvature (1/cm) -> pt (GeV/c)" 
  //---------------------------------------------------------------------
     if (fgConvConst > 0 || fgConvConst < 0) return fgConvConst; //uniform field tracking
     return fLocalConvConst;
} 

#endif