// @(#) $Id$
// Original: AliHLTConfMapPoint.cxx,v 1.10 2005/06/23 17:46:55 hristov 

/**************************************************************************
 * This file is property of and copyright by the ALICE HLT Project        * 
 * ALICE Experiment at CERN, All rights reserved.                         *
 *                                                                        *
 * Primary Authors: Anders Vestbo, maintained by                          *
 *                  Matthias Richter <Matthias.Richter@ift.uib.no>        *
 *                  for The ALICE HLT Project.                            *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/** @file   AliHLTTPCConfMapPoint.cxx
    @author Anders Vestbo, maintained by Matthias Richter
    @date   
    @brief  Hit class for conformal mapper
*/

#include <cassert>
#include "AliHLTTPCLogging.h"
#include "AliHLTTPCConfMapPoint.h"
#include "AliHLTTPCSpacePointData.h"
#include "AliHLTTPCVertex.h"
#include "AliHLTTPCConfMapTrack.h"

/**
<pre>
//_____________________________________________________________
// AliHLTTPCConfMapPoint
//
// Hit class for conformal mapper
</pre>
*/

/** ROOT macro for the implementation of ROOT specific class methods */
ClassImp(AliHLTTPCConfMapPoint);

Bool_t AliHLTTPCConfMapPoint::fgDontMap=kFALSE;

AliHLTTPCConfMapPoint::AliHLTTPCConfMapPoint()
  :
  fHitNumber(-1),
  fTrackNumber(0),
  fNextHitNumber(0),
  fUsed(kFALSE),
  fPadrow(0),
  fSector(0),
  fx(0),
  fy(0),
  fz(0),
  fxerr(0),
  fyerr(0),
  fzerr(0),
  fWxy(0),
  fWz(0),
  fs(0),
  fXt(0),
  fYt(0),
  fZt(0),
  fXterr(0),
  fYterr(0),
  fZterr(0),
  fXprime(0),
  fYprime(0),
  fXprimeerr(0),
  fYprimeerr(0),
  fXv(0),
  fYv(0),
  fZv(0),
  fXverr(0),
  fYverr(0),
  fZverr(0),
  fPhi(0),
  fEta(0),
  fNextVolumeHit(NULL),
  fNextRowHit(NULL),
  fNextTrackHit(NULL),
  fPhiIndex(0),
  fEtaIndex(0),
  fXYChi2(0),
  fSZChi2(0)
{
  //Constructor
  fMCTrackID[0]=-1;
  fMCTrackID[1]=-1;
  fMCTrackID[2]=-1;
}

AliHLTTPCConfMapPoint::AliHLTTPCConfMapPoint(const AliHLTTPCConfMapPoint& src)
  :
  fHitNumber(src.fHitNumber),
  fTrackNumber(src.fTrackNumber),
  fNextHitNumber(src.fNextHitNumber),
  fUsed(src.fUsed),
  fPadrow(src.fPadrow),
  fSector(src.fSector),
  fx(src.fx),
  fy(src.fy),
  fz(src.fz),
  fxerr(src.fxerr),
  fyerr(src.fyerr),
  fzerr(src.fzerr),
  fWxy(src.fWxy),
  fWz(src.fWz),
  fs(src.fs),
  fXt(src.fXt),
  fYt(src.fYt),
  fZt(src.fZt),
  fXterr(src.fXterr),
  fYterr(src.fYterr),
  fZterr(src.fZterr),
  fXprime(src.fXprime),
  fYprime(src.fYprime),
  fXprimeerr(src.fXprimeerr),
  fYprimeerr(src.fYprimeerr),
  fXv(src.fXv),
  fYv(src.fYv),
  fZv(src.fZv),
  fXverr(src.fXverr),
  fYverr(src.fYverr),
  fZverr(src.fZverr),
  fPhi(src.fPhi),
  fEta(src.fEta),
  fNextVolumeHit(src.fNextVolumeHit),
  fNextRowHit(src.fNextRowHit),
  fNextTrackHit(src.fNextTrackHit),
  fPhiIndex(src.fPhiIndex),
  fEtaIndex(src.fEtaIndex),
  fXYChi2(src.fXYChi2),
  fSZChi2(src.fSZChi2)
{
  //Copy Constructor
  fMCTrackID[0]=src.fMCTrackID[0];
  fMCTrackID[1]=src.fMCTrackID[1];
  fMCTrackID[2]=src.fMCTrackID[2];
}

AliHLTTPCConfMapPoint& AliHLTTPCConfMapPoint::operator=(const AliHLTTPCConfMapPoint& src)
{
  fHitNumber=src.fHitNumber;
  fTrackNumber=src.fTrackNumber;
  fNextHitNumber=src.fNextHitNumber;
  fUsed=src.fUsed;
  fPadrow=src.fPadrow;
  fSector=src.fSector;
  fx=src.fx;
  fy=src.fy;
  fz=src.fz;
  fxerr=src.fxerr;
  fyerr=src.fyerr;
  fzerr=src.fzerr;
  fWxy=src.fWxy;
  fWz=src.fWz;
  fs=src.fs;
  fXt=src.fXt;
  fYt=src.fYt;
  fZt=src.fZt;
  fXterr=src.fXterr;
  fYterr=src.fYterr;
  fZterr=src.fZterr;
  fXprime=src.fXprime;
  fYprime=src.fYprime;
  fXprimeerr=src.fXprimeerr;
  fYprimeerr=src.fYprimeerr;
  fXv=src.fXv;
  fYv=src.fYv;
  fZv=src.fZv;
  fXverr=src.fXverr;
  fYverr=src.fYverr;
  fZverr=src.fZverr;
  fPhi=src.fPhi;
  fEta=src.fEta;
  fNextVolumeHit=src.fNextVolumeHit;
  fNextRowHit=src.fNextRowHit;
  fNextTrackHit=src.fNextTrackHit;
  fPhiIndex=src.fPhiIndex;
  fEtaIndex=src.fEtaIndex;
  fXYChi2=src.fXYChi2;
  fSZChi2=src.fSZChi2;
  fMCTrackID[0]=src.fMCTrackID[0];
  fMCTrackID[1]=src.fMCTrackID[1];
  fMCTrackID[2]=src.fMCTrackID[2];

  return *this;
}

AliHLTTPCConfMapPoint::~AliHLTTPCConfMapPoint()
{
  // Destructor.
}

Bool_t AliHLTTPCConfMapPoint::Read(const AliHLTTPCSpacePointData& hit)
{
  //read the hits
  SetHitNumber(hit.fID);
  SetPadRow(hit.fPadRow);  
  SetSector(hit.GetSlice());
  SetX(hit.fX);
  SetY(hit.fY);
  SetZ(hit.fZ);
  SetXerr(sqrt(hit.fSigmaY2));
  SetYerr(sqrt(hit.fSigmaY2));
  SetZerr(sqrt(hit.fSigmaZ2));
  return kTRUE;
}

void AliHLTTPCConfMapPoint::Reset()
{
  //Reset this point.
  SetUsage(kFALSE);
  SetS(0);
  fNextRowHit = NULL;
  fNextVolumeHit=NULL;
  fNextTrackHit=NULL;
}

void AliHLTTPCConfMapPoint::Setup(AliHLTTPCVertex *vertex)
{
  //Setup. Sets the vertex, conformal coordinates, 
  //and phi and eta of each hit.
  
  SetIntPoint(vertex->GetX(),    vertex->GetY(),    vertex->GetZ(),
              vertex->GetXErr(), vertex->GetYErr(), vertex->GetZErr());
  SetShiftedCoord();
  SetConfCoord();
  // The angles are set properly if they are set after 
  // the interaction point and the shifted coordinates
  SetAngles();
  //SetDist(0., 0.);
  return;
}

void AliHLTTPCConfMapPoint::SetIntPoint(Double_t inx, Double_t iny, Double_t inz,
			            Double_t inxerr, Double_t inyerr, Double_t inzerr)
{
  // Defines a new interaction point. This point is needed to calculate
  // the conformal coordinates.

  SetXt(inx);
  SetYt(iny);
  SetZt(inz);
  SetXterr(inxerr);
  SetYterr(inyerr);
  SetZterr(inzerr);

  return;
}

void AliHLTTPCConfMapPoint::SetAllCoord(const AliHLTTPCConfMapPoint *precedinghit)
{
  // Sets the interaction point, the shifted coordinates, and the conformal mapping coordinates.
  // These values are calculated from the interaction point of the given cluster which should be a
  // already found cluster on the same track.

  if (this == precedinghit) {
    SetIntPoint(precedinghit->GetX(),    precedinghit->GetY(),    precedinghit->GetZ(),
                precedinghit->GetXerr(), precedinghit->GetYerr(), precedinghit->GetZerr());
  }

  else {
    SetIntPoint(precedinghit->GetXt(),    precedinghit->GetYt(),    precedinghit->GetZt(),
                precedinghit->GetXterr(), precedinghit->GetYterr(), precedinghit->GetZterr());
  }

  SetShiftedCoord();
  SetConfCoord();

  return;
}

void AliHLTTPCConfMapPoint::SetShiftedCoord()
{
  // Sets the coordinates with resepct to the given vertex point

  SetXv(GetX() - fXt);
  SetYv(GetY() - fYt);
  SetZv(GetZ() - fZt);
  /*
  SetXverr(TMath::Sqrt(GetXerr()*GetXerr() + fXterr*fXterr));
  SetYverr(TMath::Sqrt(GetYerr()*GetYerr() + fYterr*fYterr));
  SetZverr(TMath::Sqrt(GetZerr()*GetZerr() + fZterr*fZterr));
  */
  return;
}

void AliHLTTPCConfMapPoint::SetConfCoord()
{
  // Calculates the conformal coordinates of one cluster.
  // If the option "vertex_constraint" applies the interaction point is
  // assumed to be at (0, 0, 0). Otherwise the function will use the
  // interaction point specified by fXt and fYt.

  if(fgDontMap){
    fXprime = fx;
    fYprime = fy;
    fWxy = 0;
    fs = 0; //track trajectory
    fWz = 0;
    return;
  }

  Double_t r2;
  Double_t xyErrorScale = 1;
  Double_t szErrorScale = 1;

  if ((r2 = fXv*fXv + fYv*fYv)) 
    {
      fXprime =  fXv / r2;
      fYprime = -fYv / r2;
      
      //set weights:
      fWxy = r2*r2 / ((xyErrorScale*xyErrorScale)*((fxerr*fxerr)+(fyerr*fyerr)));
      fs = 0; //track trajectory
      fWz = (Double_t)(1./(szErrorScale*fzerr*fzerr));
    } else {
    fXprime    = 0.;
    fYprime    = 0.;
    fXprimeerr = 0.;
    fYprimeerr = 0.;
    fWxy = 0;
    fWz = 0;
    fs = 0;
  }

  return;
}

void AliHLTTPCConfMapPoint::SetAngles()
{
  // Calculates the angle phi and the pseudorapidity eta for each cluster.
  /*
  Double_t r = TMath::Sqrt(x*x + y*y);

  fPhi = TMath::ATan2(y,x);
  if(fPhi<0) fPhi = fPhi + 2*TMath::Pi();
  fEta = 3.*z/(TMath::Abs(z)+2.*r);
  return;
  */
  //  Double_t r3dim = TMath::Sqrt(fXv*fXv + fYv*fYv + fZv*fZv);
  Double_t r3dim = sqrt(fXv*fXv + fYv*fYv + fZv*fZv);
  //Double_t r2dim = TMath::Sqrt(fXv*fXv + fYv*fYv);

  /*if (r2dim == 0.) {
  // If r2dim == 0 the pseudorapidity eta cannot be calculated (division by zero)!
  // This can only happen if the point is lying on the z-axis and this should never be possible.
    cerr << "The pseudorapidity eta cannot be calculated (division by zero)! Set to 1.e-10." << endl;
    r2dim = 1.e-10;
  }

  if (fXv == 0.) {
    fPhi = (fYv > 0.) ? TMath::Pi() / 2. : - TMath::Pi() / 2.;
  }

  else {
    fPhi = (fXv > 0.) ? TMath::ASin(fYv/r2dim) : TMath::Pi() - TMath::ASin(fYv/r2dim);
  }

  if (fPhi < 0.) {
    fPhi += 2. * TMath::Pi();
  }
  */
  //fPhi = TMath::ATan2(y,x);
  fPhi = atan2(fy,fx);
  //if(fPhi<0) fPhi = fPhi + 2*TMath::Pi();
  
  //fEta = 0.5 * TMath::Log((r3dim + fZv)/(r3dim - fZv));
  fEta = 0.5 * log((r3dim + fZv)/(r3dim - fZv));
  return;
}

/*
AliHLTTPCConfMapTrack *AliHLTTPCConfMapPoint::GetTrack(TClonesArray *tracks) const
{
  // Returns the pointer to the track to which this hit belongs.
  
  return (AliHLTTPCConfMapTrack*)tracks->At(this->GetTrackNumber());
}
*/