//
// Class AliRsnAnalysisEffSE
//
// TODO
// TODO
//
// authors: Alberto Pulvirenti (alberto.pulvirenti@ct.infn.it)
//          Martin Vala (martin.vala@cern.ch)
//
#include <Riostream.h>
#include "AliStack.h"
#include "AliESDEvent.h"
#include "AliAODEvent.h"
#include "AliMCEvent.h"

#include "AliCFContainer.h"
#include "AliRsnCutManager.h"
#include "AliRsnValue.h"
#include "AliRsnAnalysisEffSE.h"
#include "AliRsnPairDef.h"
#include "AliRsnCutSet.h"

ClassImp(AliRsnAnalysisEffSE)

//_____________________________________________________________________________
AliRsnAnalysisEffSE::AliRsnAnalysisEffSE(const char *name) :
  AliRsnVAnalysisTaskSE(name),
  fUseITSSA(kTRUE),
  fUseGlobal(kTRUE),
  fStepListMC(0),
  fStepListESD(0),
  fAxisList("AliRsnValue", 0),
  fPairDefList(0),
  fContainerList(0x0),
  fOutList(0x0),
  fVar(0),
  fPair(),
  fEventCuts("eventCuts", AliRsnCut::kEvent)
{
//
// Default constructor.
//

  AliDebug(AliLog::kDebug+2,"<-");

  DefineOutput(2, TList::Class());

  AliDebug(AliLog::kDebug+2,"->");
}

//_____________________________________________________________________________
AliRsnAnalysisEffSE::AliRsnAnalysisEffSE(const AliRsnAnalysisEffSE& copy) :
  AliRsnVAnalysisTaskSE(copy),
  fUseITSSA(copy.fUseITSSA),
  fUseGlobal(copy.fUseGlobal),
  fStepListMC(copy.fStepListMC),
  fStepListESD(copy.fStepListESD),
  fAxisList(copy.fAxisList),
  fPairDefList(copy.fPairDefList),
  fContainerList(copy.fContainerList),
  fOutList(0x0),
  fVar(0),
  fPair(),
  fEventCuts(copy.fEventCuts)
{
//
// Copy constrtuctor
//
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::AddStepMC(AliRsnCutManager *mgr)
{
//
// Add a step on montecarlo
//

  fStepListMC.AddLast(mgr);
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::AddStepESD(AliRsnCutManager *mgr) 
{
//
// Add a step on ESD
//

  fStepListESD.AddLast(mgr);
}
    
//_____________________________________________________________________________
void AliRsnAnalysisEffSE::AddAxis(AliRsnValue *axis) 
{
//
// Add a new axis
//

  Int_t n = fAxisList.GetEntries();
  new (fAxisList[n]) AliRsnValue(*axis);
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::RsnUserCreateOutputObjects()
{
//
// Creation of output objects.
// These are created through the utility methods in the analysis manager,
// which produces a list of histograms for each specified set of pairs.
// Each of these lists is added to the main list of this task.
//

  AliDebug(AliLog::kDebug+2,"<-");

  // get number of steps and axes
  Int_t iaxis  = 0;
  Int_t nAxes  = fAxisList.GetEntries();
  Int_t nSteps = (Int_t)fStepListMC.GetEntries() + (Int_t)fStepListESD.GetEntries();

  if (!nSteps) {
    AliError("No steps defined");
    return;
  }
  if (!nAxes) {
    AliError("No axes defined");
    return;
  }

  // initialize variable list
  fVar.Set(nAxes);

  // retrieve number of bins for each axis
  Int_t *nBins = new Int_t[nAxes];
  for (iaxis = 0; iaxis < nAxes; iaxis++) 
  {
    AliRsnValue *fcnAxis = (AliRsnValue*)fAxisList.At(iaxis);
    nBins[iaxis] = fcnAxis->GetArray().GetSize() - 1;
  }

  // create ouput list of containers
  fContainerList = new TList;
  fContainerList->SetOwner();
  fContainerList->SetName(Form("%s_containers", GetName()));

  // initialize output list
  OpenFile(2);
  fOutList = new TList();
  fOutList->SetOwner();

  // create the containers
  Int_t i = 0, nDef = (Int_t)fPairDefList.GetEntries();
  for (i = 0; i < nDef; i++) 
  {
    AliRsnPairDef *def = (AliRsnPairDef*)fPairDefList[i];
    AliCFContainer *cont = new AliCFContainer(Form("%s", def->GetPairName()), "", nSteps, nAxes, nBins);
    // set the bin limits for each axis
    for (iaxis = 0; iaxis < nAxes; iaxis++) 
    {
      AliRsnValue *fcnAxis = (AliRsnValue*)fAxisList.At(iaxis);
      cont->SetBinLimits(iaxis, fcnAxis->GetArray().GetArray());
    }
    // add the container to output list
    fContainerList->Add(cont);
  }

  fOutList->Add(fContainerList);
  fOutList->Print();

  PostData(2, fOutList);
  
  // clear heap
  delete [] nBins;

  AliDebug(AliLog::kDebug+2,"->");
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::RsnUserExec(Option_t*)
{
//
// Execution of the analysis task.
// Recovers the input event and processes it with all included pair objects.
// In this case, we NEED to have ESD and MC, otherwise we cannod do anything.
//

  // process first MC steps and then ESD steps
  AliRsnPairDef *pairDef = 0;
  TObjArrayIter iter(&fPairDefList);
  while ( (pairDef = (AliRsnPairDef*)iter.Next()) )
  {
    if (fRsnEvent.IsESD()) ProcessEventESD(pairDef);
    if (fRsnEvent.IsAOD()) ProcessEventAOD(pairDef);
  }

  // Post the data
  PostData(2, fOutList);
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::ProcessEventESD(AliRsnPairDef *pairDef)
{
//
// Process current event with the definitions of the specified step in MC list
// and store results in the container slot defined in second argument.
// It is associated with the AliCFContainer with the name of the pair.
//

  AliStack      *stack = fRsnEvent.GetRefMCESD()->Stack();
  AliESDEvent   *esd   = fRsnEvent.GetRefESD();
  AliMCEvent    *mc    = fRsnEvent.GetRefMCESD();
  AliMCParticle *mother;

  if (!pairDef) return;
  AliCFContainer *cont = (AliCFContainer*)fContainerList->FindObject(pairDef->GetPairName());
  if (!cont) return;
  
  // get informations from pairDef
  Int_t   pdgM = 0;
  Int_t   pdgD[2] = {0, 0};
  Short_t chargeD[2] = {0, 0};
  pdgM       = pairDef->GetMotherPDG();
  pdgD   [0] = AliPID::ParticleCode(pairDef->GetPID(0));
  pdgD   [1] = AliPID::ParticleCode(pairDef->GetPID(1));
  chargeD[0] = pairDef->GetChargeShort(0);
  chargeD[1] = pairDef->GetChargeShort(1);

  // other utility variables
  Int_t      first, j, ipart;
  Int_t      label[2] = {-1, -1};
  Short_t    charge[2] = {0, 0};
  Short_t    pairDefMatch[2] = {-1, -1};
  Int_t      esdIndex[2] = {-1, -1};
  TParticle *part[2] = {0, 0};

  // in this case, we first take the resonance from MC
  // and then we find its daughters and compute cuts on them
  for (ipart = 0; ipart < stack->GetNprimary(); ipart++) 
  {
    // take a track from the MC event
    mother = (AliMCParticle*) fMCEvent->GetTrack(ipart);
    
    // check that it is a binary decay and the PDG code matches
    if (mother->Particle()->GetNDaughters() != 2) continue;
    if (mother->Particle()->GetPdgCode() != pdgM) continue;

    // store the labels of the two daughters
    label[0] = mother->Particle()->GetFirstDaughter();
    label[1] = mother->Particle()->GetLastDaughter();
    
    // retrieve the particles and other stuff
    // check if they match the order in the pairDef
    for (j = 0; j < 2; j++)
    {
      if (label[j] < 0) continue;
      part[j]   = stack->Particle(label[j]);
      pdgD[j]   = TMath::Abs(part[j]->GetPdgCode());
      charge[j] = (Short_t)(part[j]->GetPDG()->Charge() / 3);
      if (pdgD[j] == AliPID::ParticleCode(pairDef->GetPID(0)) && charge[j] == pairDef->GetChargeShort(0))
        pairDefMatch[j] = 0;
      else if (pdgD[j] == AliPID::ParticleCode(pairDef->GetPID(1)) && charge[j] == pairDef->GetChargeShort(1))
        pairDefMatch[j] = 1;
      else
        pairDefMatch[j] = -1;
        
      // find corresponding ESD particle: first try rejecting fakes,
      // and in case of failure, try accepting fakes
      esdIndex[j] = FindESDtrack(label[j], esd, kTRUE);
      //TArrayI idx = FindESDtracks(label[j], esd);
      //for (Int_t kk = 0; kk < idx.GetSize(); kk++) cout << "DAUGHTER " << j << " --> FOUND INDEX: " << idx[kk] << endl;
      if (esdIndex[j] < 0) esdIndex[j] = FindESDtrack(label[j], esd, kFALSE);
      //cout << "DAUGHTER " << j << " SINGLE FOUND INDEX = " << esdIndex[j] << endl;
    }
    
    // since each candidate good resonance is taken once, we must check
    // that it matches the pair definition in any order, and reject in case
    // in none of them the pair is OK
    // anyway, we must associate the correct daughter to the correct data member
    if (pairDefMatch[0] == 0 && pairDefMatch[1] == 1)
    {
      // 1st track --> 1st member of PairDef
      fDaughter[0].SetRef(mc->GetTrack(label[0]));
      fDaughter[0].SetRefMC((AliMCParticle*)mc->GetTrack(label[0]));
      fDaughter[0].SetGood();
      // 2nd track --> 2nd member of PairDef
      fDaughter[1].SetRef(mc->GetTrack(label[1]));
      fDaughter[1].SetRefMC((AliMCParticle*)mc->GetTrack(label[1]));
      fDaughter[1].SetGood();
    }
    else if ((pairDefMatch[0] == 1 && pairDefMatch[1] == 0))
    {
      // 1st track --> 2nd member of PairDef
      fDaughter[0].SetRef(mc->GetTrack(label[1]));
      fDaughter[0].SetRefMC((AliMCParticle*)mc->GetTrack(label[1]));
      fDaughter[0].SetGood();
      // 2nd track --> 1st member of PairDef
      fDaughter[1].SetRef(mc->GetTrack(label[0]));
      fDaughter[1].SetRefMC((AliMCParticle*)mc->GetTrack(label[0]));
      fDaughter[1].SetGood();
    }
    else
    {
      fDaughter[0].SetBad();
      fDaughter[1].SetBad();
    }
    
    // reject the pair if the matching was unsuccessful
    if (!fDaughter[0].IsOK() || !fDaughter[1].IsOK()) continue;
    
    // first, we set the internal AliRsnMother object to
    // the MC particles and then operate the selections on MC
    fPair.SetDaughters(&fDaughter[0], pairDef->GetMass(0), &fDaughter[1], pairDef->GetMass(1));
    FillContainer(cont, &fStepListMC, pairDef, 0);
    
    // then, if both particles found a good match in the ESD
    // reassociate the ESD tracks to the pair and fill ESD containers
    if (esdIndex[0] < 0 || esdIndex[1] < 0) continue;
    if (pairDefMatch[0] == 0 && pairDefMatch[1] == 1)
    {
      // 1st track --> 1st member of PairDef
      fDaughter[0].SetRef(esd->GetTrack(esdIndex[0]));
      // 2nd track --> 2nd member of PairDef
      fDaughter[1].SetRef(esd->GetTrack(esdIndex[1]));
      //cout << "****** MATCHING SCHEME 1" << endl;
    }
    else if ((pairDefMatch[0] == 1 && pairDefMatch[1] == 0))
    {
      // 1st track --> 2nd member of PairDef
      fDaughter[0].SetRef(esd->GetTrack(esdIndex[1]));
      // 2nd track --> 1st member of PairDef
      fDaughter[1].SetRef(esd->GetTrack(esdIndex[0]));
      //cout << "****** MATCHING SCHEME 2" << endl;
    }
    //cout << "****** IDs = " << fDaughter[0].GetID() << ' ' << fDaughter[1].GetID() << endl;
    // here we must remember how many steps were already filled
    first = (Int_t)fStepListMC.GetEntries();
    FillContainer(cont, &fStepListESD, pairDef, first);
  }
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::ProcessEventAOD(AliRsnPairDef *pairDef)
{
//
// Process current event with the definitions of the specified step in MC list
// and store results in the container slot defined in second argument.
// It is associated with the AliCFContainer with the name of the pair.
//

  AliAODEvent      *aod   = fRsnEvent.GetRefAOD();
  AliAODMCParticle *mother;
  TClonesArray     *mcArray = (TClonesArray*)aod->GetList()->FindObject(AliAODMCParticle::StdBranchName());
  if (!mcArray) return;

  if (!pairDef) return;
  AliCFContainer *cont = (AliCFContainer*)fContainerList->FindObject(pairDef->GetPairName());
  if (!cont) return;
  
  // get informations from pairDef
  Int_t   pdgM = 0;
  Int_t   pdgD[2] = {0, 0};
  Short_t chargeD[2] = {0, 0};
  pdgM       = pairDef->GetMotherPDG();
  pdgD   [0] = AliPID::ParticleCode(pairDef->GetPID(0));
  pdgD   [1] = AliPID::ParticleCode(pairDef->GetPID(1));
  chargeD[0] = pairDef->GetChargeShort(0);
  chargeD[1] = pairDef->GetChargeShort(1);

  // other utility variables
  Int_t             first, j;
  Int_t             label [2] = {-1, -1};
  Short_t           charge[2] = {0, 0};
  Short_t           pairDefMatch[2] = {-1, -1};
  Int_t             aodIndex[2] = {-1, -1};
  AliAODMCParticle *part[2] = {0, 0};
  
  // loop on MC particles
  TObjArrayIter next(mcArray);
  while ( (mother = (AliAODMCParticle*)next()) )
  {  
    // check that it is a binary decay and the PDG code matches
    if (mother->GetNDaughters() != 2) continue;
    if (mother->GetPdgCode() != pdgM) continue;

    // store the labels of the two daughters
    label[0] = mother->GetDaughter(0);
    label[1] = mother->GetDaughter(1);
    
    // retrieve the particles and other stuff
    // check if they match the order in the pairDef
    for (j = 0; j < 2; j++)
    {
      if (label[j] < 0) continue;
      part[j]   = (AliAODMCParticle*)mcArray->At(label[j]);
      pdgD[j]   = TMath::Abs(part[j]->GetPdgCode());
      charge[j] = (Short_t)(part[j]->Charge());
      if (pdgD[j] == AliPID::ParticleCode(pairDef->GetPID(0)) && charge[j] == pairDef->GetChargeShort(0))
        pairDefMatch[j] = 0;
      else if (pdgD[j] == AliPID::ParticleCode(pairDef->GetPID(1)) && charge[j] == pairDef->GetChargeShort(1))
        pairDefMatch[j] = 1;
      else
        pairDefMatch[j] = -1;
        
      // find corresponding ESD particle: first try rejecting fakes,
      // and in case of failure, try accepting fakes
      aodIndex[j] = FindAODtrack(label[j], aod, kTRUE);
      if (aodIndex[j] < 0) aodIndex[j] = FindAODtrack(label[j], aod, kFALSE);
    }
    
    // since each candidate good resonance is taken once, we must check
    // that it matches the pair definition in any order, and reject in case
    // in none of them the pair is OK
    // anyway, we must associate the correct daughter to the correct data member
    if (pairDefMatch[0] == 0 && pairDefMatch[1] == 1)
    {
      // 1st track --> 1st member of PairDef
      fDaughter[0].SetRef((AliAODMCParticle*)mcArray->At(label[0]));
      fDaughter[0].SetRefMC((AliAODMCParticle*)mcArray->At(label[0]));
      fDaughter[0].SetGood();
      // 2nd track --> 2nd member of PairDef
      fDaughter[1].SetRef((AliAODMCParticle*)mcArray->At(label[1]));
      fDaughter[1].SetRefMC((AliAODMCParticle*)mcArray->At(label[1]));
      fDaughter[1].SetGood();
    }
    else if ((pairDefMatch[0] == 1 && pairDefMatch[1] == 0))
    {
      // 1st track --> 2nd member of PairDef
      fDaughter[0].SetRef((AliAODMCParticle*)mcArray->At(label[1]));
      fDaughter[0].SetRefMC((AliAODMCParticle*)mcArray->At(label[1]));
      fDaughter[0].SetGood();
      // 2nd track --> 1st member of PairDef
      fDaughter[1].SetRef((AliAODMCParticle*)mcArray->At(label[0]));
      fDaughter[1].SetRefMC((AliAODMCParticle*)mcArray->At(label[0]));
      fDaughter[1].SetGood();
    }
    else
    {
      fDaughter[0].SetBad();
      fDaughter[1].SetBad();
    }
    
    // reject the pair if the matching was unsuccessful
    if (!fDaughter[0].IsOK() || !fDaughter[1].IsOK()) continue;
    
    // first, we set the internal AliRsnMother object to
    // the MC particles and then operate the selections on MC
    fPair.SetDaughters(&fDaughter[0], pairDef->GetMass(0), &fDaughter[1], pairDef->GetMass(1));
    FillContainer(cont, &fStepListMC, pairDef, 0);
    
    // then, if both particles found a good match in the AOD
    // reassociate the AOD tracks to the pair and fill AOD containers
    if (aodIndex[0] < 0 || aodIndex[1] < 0) continue;
    if (pairDefMatch[0] == 0 && pairDefMatch[1] == 1)
    {
      // 1st track --> 1st member of PairDef
      fDaughter[0].SetRef(aod->GetTrack(aodIndex[0]));
      // 2nd track --> 2nd member of PairDef
      fDaughter[1].SetRef(aod->GetTrack(aodIndex[1]));
      //cout << "****** MATCHING SCHEME 1" << endl;
    }
    else if ((pairDefMatch[0] == 1 && pairDefMatch[1] == 0))
    {
      // 1st track --> 2nd member of PairDef
      fDaughter[0].SetRef(aod->GetTrack(aodIndex[1]));
      // 2nd track --> 1st member of PairDef
      fDaughter[1].SetRef(aod->GetTrack(aodIndex[0]));
      //cout << "****** MATCHING SCHEME 2" << endl;
    }
    //cout << "****** IDs = " << fDaughter[0].GetID() << ' ' << fDaughter[1].GetID() << endl;
    // here we must remember how many steps were already filled
    first = (Int_t)fStepListMC.GetEntries();
    FillContainer(cont, &fStepListESD, pairDef, first);
  }
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::FillContainer(AliCFContainer *cont, const TObjArray *stepList, AliRsnPairDef *pd, Int_t firstOutStep)
{
//
// Fill the containers
//

  Int_t  iaxis, nAxes  = fAxisList.GetEntries();
  Int_t  istep, nSteps = stepList->GetEntries();
  Bool_t computeOK;
  
  // set daughters to pair
  fPair.SetDaughters(&fDaughter[0], pd->GetMass(0), &fDaughter[1], pd->GetMass(1));

  // compute values for all axes
  for (iaxis = 0; iaxis < nAxes; iaxis++) 
  {
    AliRsnValue *fcnAxis = (AliRsnValue*)fAxisList.At(iaxis);
    fVar[iaxis] = -1E10;
    switch (fcnAxis->GetTargetType())
    {
      case AliRsnTarget::kMother:
        fcnAxis->SetSupportObject(pd);
        computeOK = fcnAxis->Eval(&fPair);
        break;
      case AliRsnTarget::kEvent:
        computeOK = fcnAxis->Eval(&fRsnEvent);
        break;
      default:
        AliError(Form("Allowed targets are mothers and events; cannot use axis '%s' which has target '%s'", fcnAxis->GetName(), fcnAxis->GetTargetTypeName()));
        computeOK = kFALSE;
    }
    if (computeOK) fVar[iaxis] = ((Float_t)fcnAxis->GetComputedValue());
  }

  // fill all steps
  for (istep = 0; istep < nSteps; istep++) 
  {
    AliRsnCutManager *cutMgr = (AliRsnCutManager*)stepList->At(istep);
    AliRsnTarget::SwitchToFirst();
    if (!cutMgr->PassCommonDaughterCuts(&fDaughter[0])) break;
    if (!cutMgr->PassCommonDaughterCuts(&fDaughter[1])) break;
    if (!cutMgr->PassDaughter1Cuts(&fDaughter[0])) break;
    if (!cutMgr->PassDaughter2Cuts(&fDaughter[1])) break;
    if (!cutMgr->PassMotherCuts(&fPair)) break;
    //cout << "**************************************** FILLING STEP " << istep << endl;
    cont->Fill(fVar.GetArray(), istep + firstOutStep);
  }
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::RsnTerminate(Option_t*)
{
//
// Termination.
// Could be added some monitor histograms here.
//

  AliDebug(AliLog::kDebug+2,"<-");
  AliDebug(AliLog::kDebug+2,"->");
}

//_____________________________________________________________________________
void AliRsnAnalysisEffSE::AddPairDef(AliRsnPairDef* pairDef)
{
//
//  Adds pair definition
//
  fPairDefList.AddLast(pairDef);
}

//_____________________________________________________________________________
Int_t AliRsnAnalysisEffSE::FindESDtrack(Int_t label, AliESDEvent *esd, Bool_t rejectFakes)
{
//
// Finds in the ESD a track whose label corresponds to that in argument.
// When global tracks are enabled, tries first to find a global track 
// satisfying that requirement.
// If no global tracks are found, if ITS-SA are enable, tries to search among them
// otherwise return a negative number.
// If global tracks are disabled, search only among ITS SA
//

  Int_t   i = 0;
  Int_t   ntracks = esd->GetNumberOfTracks();
  ULong_t status;
  Bool_t  isTPC;
  Bool_t  isITSSA;
  
  // loop for global tracks
  if (fUseGlobal)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliESDtrack *track = esd->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isTPC   = ((status & AliESDtrack::kTPCin)  != 0);
      if (!isTPC) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
      
      // if required, reject fakes
      if (rejectFakes && track->GetLabel() < 0) continue;
      
      // if all checks are passed and we are searching among global
      // this means that thie track is a global one with the right label
      // then, the return value is set to this, and returned
      return i;
    }
  }
  
  // loop for ITS-SA tracks (this happens only if no global tracks were found
  // or searching among globals is disabled)
  if (fUseITSSA)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliESDtrack *track = esd->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isITSSA = ((status & AliESDtrack::kTPCin)  == 0 && (status & AliESDtrack::kITSrefit) != 0 && (status & AliESDtrack::kITSpureSA) == 0 && (status & AliESDtrack::kITSpid) != 0);
      if (!isITSSA) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
            
      // if required, reject fakes
      if (rejectFakes && track->GetLabel() < 0) continue;
      
      // if all checks are passed and we are searching among global
      // this means that thie track is a global one with the right label
      // then, the return value is set to this, and returned
      return i;
    }
  }
  
  // if we reach this point, no match were found
  return -1;
}

//_____________________________________________________________________________
TArrayI AliRsnAnalysisEffSE::FindESDtracks(Int_t label, AliESDEvent *esd)
{
//
// Finds in the ESD a track whose label corresponds to that in argument.
// When global tracks are enabled, tries first to find a global track 
// satisfying that requirement.
// If no global tracks are found, if ITS-SA are enable, tries to search among them
// otherwise return a negative number.
// If global tracks are disabled, search only among ITS SA
//

  Int_t   i = 0;
  Int_t   ntracks = esd->GetNumberOfTracks();
  ULong_t status;
  Bool_t  isTPC;
  Bool_t  isITSSA;
  TArrayI array(100);
  Int_t   nfound = 0;
  
  // loop for global tracks
  if (fUseGlobal)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliESDtrack *track = esd->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isTPC   = ((status & AliESDtrack::kTPCin)  != 0);
      if (!isTPC) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
      
      array[nfound++] = i;
    }
  }
  
  // loop for ITS-SA tracks (this happens only if no global tracks were found
  // or searching among globals is disabled)
  if (fUseITSSA)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliESDtrack *track = esd->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isITSSA = ((status & AliESDtrack::kTPCin)  == 0 && (status & AliESDtrack::kITSrefit) != 0 && (status & AliESDtrack::kITSpureSA) == 0 && (status & AliESDtrack::kITSpid) != 0);
      if (!isITSSA) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
            
      array[nfound++] = i;
    }
  }
  
  array.Set(nfound);
  return array;
}

//_____________________________________________________________________________
Int_t AliRsnAnalysisEffSE::FindAODtrack(Int_t label, AliAODEvent *aod, Bool_t rejectFakes)
{
//
// Finds in the ESD a track whose label corresponds to that in argument.
// When global tracks are enabled, tries first to find a global track 
// satisfying that requirement.
// If no global tracks are found, if ITS-SA are enable, tries to search among them
// otherwise return a negative number.
// If global tracks are disabled, search only among ITS SA
//

  Int_t   i = 0;
  Int_t   ntracks = aod->GetNumberOfTracks();
  ULong_t status;
  Bool_t  isTPC;
  Bool_t  isITSSA;
  
  // loop for global tracks
  if (fUseGlobal)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliAODTrack *track = aod->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isTPC   = ((status & AliESDtrack::kTPCin)  != 0);
      if (!isTPC) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
      
      // if required, reject fakes
      if (rejectFakes && track->GetLabel() < 0) continue;
      
      // if all checks are passed and we are searching among global
      // this means that thie track is a global one with the right label
      // then, the return value is set to this, and returned
      return i;
    }
  }
  
  // loop for ITS-SA tracks (this happens only if no global tracks were found
  // or searching among globals is disabled)
  if (fUseITSSA)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliAODTrack *track = aod->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isITSSA = ((status & AliESDtrack::kTPCin)  == 0 && (status & AliESDtrack::kITSrefit) != 0 && (status & AliESDtrack::kITSpureSA) == 0 && (status & AliESDtrack::kITSpid) != 0);
      if (!isITSSA) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
            
      // if required, reject fakes
      if (rejectFakes && track->GetLabel() < 0) continue;
      
      // if all checks are passed and we are searching among global
      // this means that thie track is a global one with the right label
      // then, the return value is set to this, and returned
      return i;
    }
  }
  
  // if we reach this point, no match were found
  return -1;
}

//_____________________________________________________________________________
TArrayI AliRsnAnalysisEffSE::FindAODtracks(Int_t label, AliAODEvent *aod)
{
//
// Finds in the ESD a track whose label corresponds to that in argument.
// When global tracks are enabled, tries first to find a global track 
// satisfying that requirement.
// If no global tracks are found, if ITS-SA are enable, tries to search among them
// otherwise return a negative number.
// If global tracks are disabled, search only among ITS SA
//

  Int_t   i = 0;
  Int_t   ntracks = aod->GetNumberOfTracks();
  ULong_t status;
  Bool_t  isTPC;
  Bool_t  isITSSA;
  TArrayI array(100);
  Int_t   nfound = 0;
  
  // loop for global tracks
  if (fUseGlobal)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliAODTrack *track = aod->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isTPC   = ((status & AliESDtrack::kTPCin)  != 0);
      if (!isTPC) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
      
      array[nfound++] = i;
    }
  }
  
  // loop for ITS-SA tracks (this happens only if no global tracks were found
  // or searching among globals is disabled)
  if (fUseITSSA)
  {
    for (i = 0; i < ntracks; i++)
    {
      AliAODTrack *track = aod->GetTrack(i);
      status  = (ULong_t)track->GetStatus();
      isITSSA = ((status & AliESDtrack::kTPCin)  == 0 && (status & AliESDtrack::kITSrefit) != 0 && (status & AliESDtrack::kITSpureSA) == 0 && (status & AliESDtrack::kITSpid) != 0);
      if (!isITSSA) continue;
      
      // check that label match
      if (TMath::Abs(track->GetLabel()) != label) continue;
            
      array[nfound++] = i;
    }
  }
  
  array.Set(nfound);
  return array;
}

//______________________________________________________________________________
Bool_t AliRsnAnalysisEffSE::EventProcess()
{
//
// Customized event pre-processing.
// First checks if the current event passes all cuts,
// and if it does, updates the informations and then
// call the operations which are already defined in the
// omonyme function in mother class
//

  // initially, an event is expected to be bad
  fTaskInfo.SetEventUsed(kFALSE);

  // check the event cuts and update the info data accordingly
  // events not passing the cuts must be rejected
  if (!fEventCuts.IsSelected(&fRsnEvent))
  {
    fTaskInfo.SetEventUsed(kFALSE);
    return kFALSE;
  }
  
  // if we reach this point, cuts were passed;
  // then additional operations can be done
  
  // find leading particle (without any PID/momentum restriction)
  fRsnEvent.SelectLeadingParticle(0);
  
  // final return value is positive
  // but call the mother class method which updates info object
  fTaskInfo.SetEventUsed(kTRUE);
  return AliRsnVAnalysisTaskSE::EventProcess();
}