//
// Class AliRsnCutPrimaryVertex
//
// This cut implementation checks the quality of event primary vertex.
// It currently works only with ESD events (not AOD).
//
// authors: Martin Vala (martin.vala@cern.ch)
//          Alberto Pulvirenti (alberto.pulvirenti@ct.infn.it)
//

#include "AliRsnCutPrimaryVertex.h"
#include "AliAnalysisUtils.h"

ClassImp(AliRsnCutPrimaryVertex)

//_________________________________________________________________________________________________
AliRsnCutPrimaryVertex::AliRsnCutPrimaryVertex
(const char *name, Double_t maxVz, Int_t nContributors, Bool_t acceptTPC) :
   AliRsnCut(name, AliRsnCut::kEvent, 0, nContributors - 1, -maxVz, maxVz + 1E-6),
   fAcceptTPC(acceptTPC),
   fCheckPileUp(kFALSE)
{
//
// Main constructor.
// Defines the cut range between 0 and
// the minimum required number of contributors.
// The cut will be passed when if the event has a
// primary vertex with number of contributors outside this interval.
// ---
// If the 'acceptTPC' argument is true, events with TPC
// primary vertex will be checked, otherwise they will be
// rejected by default.
// ---
// Since the range check uses the '>=' and '<=', the high edge
// must be decreased by 1 to get the right behaviour, since this is integer.
//
}

//_________________________________________________________________________________________________
Bool_t AliRsnCutPrimaryVertex::IsSelected(TObject *object)
{
//
// Cut checker
//
   // coherence check
   // which also fills data member objects
   if (!TargetOK(object)) return kFALSE;

   // retrieve ESD event
   AliESDEvent *esd = dynamic_cast<AliESDEvent *>(fEvent->GetRef());
   AliAODEvent *aod = dynamic_cast<AliAODEvent *>(fEvent->GetRef());
   AliVEvent *vevt = dynamic_cast<AliVEvent *>(fEvent->GetRef());
   // pile-up check
   if (fCheckPileUp) {
     AliAnalysisUtils * utils = new AliAnalysisUtils();
     if (utils->IsPileUpSPD(vevt)) return kFALSE;
   }
   
   if (esd) {
      // get the best primary vertex:
      // first try the one with tracks
      const AliESDVertex *vTrk  = esd->GetPrimaryVertexTracks();
      const AliESDVertex *vSPD  = esd->GetPrimaryVertexSPD();
      const AliESDVertex *vTPC  = esd->GetPrimaryVertexTPC();
      Int_t               ncTrk = -1;
      Int_t               ncSPD = -1;
      Int_t               ncTPC = -1;
      Double_t            vzTrk = 1000000.0;
      Double_t            vzSPD = 1000000.0;
      Double_t            vzTPC = 1000000.0;
      if (vTrk) vzTrk = TMath::Abs(vTrk->GetZv());
      if (vSPD) vzSPD = TMath::Abs(vSPD->GetZv());
      if (vTPC) vzTPC = TMath::Abs(vTPC->GetZv());
      if (vTrk) ncTrk = (Int_t)vTrk->GetNContributors();
      if (vSPD) ncSPD = (Int_t)vSPD->GetNContributors();
      if (vTPC) ncTPC = (Int_t)vTPC->GetNContributors();
      if (vTrk && ncTrk > 0) {
         fCutValueI = ncTrk;
         fCutValueD = vzTrk;
      } else if (vSPD && ncSPD > 0) {
         fCutValueI = ncSPD;
         fCutValueD = vzSPD;
      } else if (vTPC && ncTPC > 0) {
         if (!fAcceptTPC)
            return kFALSE;
         else {
            fCutValueI = ncTPC;
            fCutValueD = vzTPC;
         }
      } else
         return kFALSE;
   } else if (aod) {
      // in this case, as suggested by Andrea Dainese,
      // we first check if the SPD primary vertex is there
      // if it is not, then the only available is the TPC
      // stand-alone primary vertex, which is rejected
      AliAODVertex *aodv = aod->GetPrimaryVertexSPD();
      if (!aodv) {
         AliDebugClass(1, "Not found SPD vertex --> TPC only available, skipped");
         return kFALSE;
      }
      // now check primary vertex
      aodv = (AliAODVertex *)aod->GetPrimaryVertex();
      if (CheckVertex(aodv)) {
         AliDebugClass(1, "Vertex TRK is OK");
         fCutValueD = aodv->GetZ();
         fCutValueI = aodv->GetNDaughters(); //aodv->GetNContributors();
      }
      else {
         aodv = aod->GetPrimaryVertexSPD();
         if (CheckVertex(aodv)) {
            AliDebugClass(1, "Vertex TRK is BAD, but vertex SPD is OK");
            fCutValueD = aodv->GetZ();
            fCutValueI = aodv->GetNDaughters(); //aodv->GetNContributors();
         } else {
            AliDebugClass(1, "Vertex TRK is BAD, and vertex SPD is BAD");
            return kFALSE;
         }
      }
   } else
      return kFALSE;

   // output
   Bool_t result = ((!OkRangeI()) && OkRangeD());
   return result;
}

//_________________________________________________________________________________________________
void AliRsnCutPrimaryVertex::Print(const Option_t *) const
{
//
// Print information on this cut
//

   AliInfo(Form("Cut name                     : %s", GetName()));
   AliInfo(Form("Accepting TPC primary vertex : %s", (fAcceptTPC ? "YES" : "NO")));
   AliInfo(Form("Contributors range (outside) : %d - %d", fMinI, fMaxI));
   AliInfo(Form("Z-vertex     range (inside)  : %f - %f", fMinD, fMaxD));
}

//__________________________________________________________________________________________________
Bool_t AliRsnCutPrimaryVertex::CheckVertex(AliVVertex *vertex)
{
//
// Checks if a candidate primary vertex is good,
// which is true if it is not null and has at
// least one contributor
//

   if (!vertex) return kFALSE;
   if (vertex->GetNContributors() < 1) return kFALSE;
   return kTRUE;
}