#include "AliHBTReaderESD.h"

#include <TPDGCode.h>
#include <TString.h>
#include <TObjString.h>
#include <TTree.h>
#include <TFile.h>
#include <TParticle.h>

#include <AliRunLoader.h>
#include <AliStack.h>
#include <AliESDtrack.h>
#include <AliESD.h>

#include "AliHBTRun.h"
#include "AliHBTEvent.h"
#include "AliHBTParticle.h"
#include "AliHBTParticleCut.h"

ClassImp(AliHBTReaderESD)

AliHBTReaderESD::AliHBTReaderESD(const Char_t* esdfilename, const Char_t* galfilename):
 fESDFileName(esdfilename),
 fGAlFileName(galfilename),
 fFile(0x0),
 fRunLoader(0x0),
 fReadParticles(kFALSE)
{
  //cosntructor
  if ( ((Int_t)kNSpecies) != ((Int_t)AliESDtrack::kSPECIES))
    Fatal("AliHBTReaderESD","ESD defintions probobly changed. Ask Youra.");
}
/********************************************************************/
  
AliHBTReaderESD::AliHBTReaderESD(TObjArray* dirs,const Char_t* esdfilename, const Char_t* galfilename):
 AliHBTReader(dirs), 
 fESDFileName(esdfilename),
 fGAlFileName(galfilename),
 fFile(0x0),
 fRunLoader(0x0),
 fReadParticles(kFALSE)
{
  //cosntructor
  if ( ((Int_t)kNSpecies) != ((Int_t)AliESDtrack::kSPECIES))
    Fatal("AliHBTReaderESD","ESD defintions probobly changed. Ask Youra.");
}
/********************************************************************/

AliHBTReaderESD::~AliHBTReaderESD()
{
 //desctructor
  delete fFile;
  delete fRunLoader;
}
/**********************************************************/
Int_t AliHBTReaderESD::ReadNext()
{
//reads next event from fFile
  
  //****** Tentative particle type "concentrations"
  static const Double_t concentr[5]={0.05, 0., 0.85, 0.10, 0.05};
  
  Double_t pidtable[kNSpecies];//array used for reading pid probabilities from ESD track
  Double_t w[kNSpecies];
  Double_t mom[3];//momentum
  Double_t pos[3];//position
  
  if (AliHBTParticle::fgDebug)
    Info("ReadNext","Entered");
    
  TDatabasePDG* pdgdb = TDatabasePDG::Instance();
  if (pdgdb == 0x0)
   {
     Error("Next","Can not get PDG Database Instance.");
     return 1;
   }
  
  if (fParticlesEvent == 0x0)  fParticlesEvent = new AliHBTEvent();
  if (fTracksEvent == 0x0)  fTracksEvent = new AliHBTEvent();
  
  fParticlesEvent->Reset();
  fTracksEvent->Reset();
        
  do  //do{}while; is OK even if 0 dirs specified. In that case we try to read from "./"
   {
     if (fFile == 0x0)
      {
       fFile = OpenFile(fCurrentDir);//rl is opened here
       if (fFile == 0x0)
         {
           Error("ReadNext","Cannot get fFile for dir no. %d",fCurrentDir);
           fCurrentDir++;
           continue;
         }
       fCurrentEvent = 0;
      } 
      
     //try to read
     TString esdname;
     esdname+=fCurrentEvent;
     AliESD* esd = dynamic_cast<AliESD*>(fFile->Get(esdname));
     if (esd == 0x0)
      {
        if (AliHBTParticle::fgDebug > 2 )
          {
            Info("ReadNext","Can not find ESD object named %s.",esdname.Data());
          }
        fCurrentDir++;
        delete fFile;//we have to assume there is no more ESD objects in the fFile
        delete fRunLoader;
        fFile = 0x0;
        continue;
      }
     AliStack* stack = 0x0;
     if (fReadParticles && fRunLoader)
      {
        fRunLoader->GetEvent(fCurrentEvent);
        stack = fRunLoader->Stack();
      }
     Info("ReadNext","Reading Event %d",fCurrentEvent);
  
     Int_t ntr = esd->GetNumberOfTracks();
     Info("ReadNext","Found %d tracks.",ntr);
     for (Int_t i = 0;i<ntr; i++)
      {
        AliESDtrack *esdtrack = esd->GetTrack(i);
        if (esdtrack == 0x0)
         {
           Error("Next","Can not get track %d", i);
           continue;
         }
        if ((esdtrack->GetStatus()&AliESDtrack::kESDpid) == kFALSE) 
         {
           if (AliHBTParticle::fgDebug > 2) 
             Info("ReadNext","Particle skipped: PID BIT is not set.");
           continue;
         }

        esdtrack->GetESDpid(pidtable);
        esdtrack->GetPxPyPz(mom);
        esdtrack->GetXYZ(pos);
        
        Double_t extx;
        Double_t extp[5];
        esdtrack->GetExternalParameters(extx,extp);
        
        Int_t charge = (extp[4] > 0)?-1:1;//if curvature=-charg/Pt is positive charge is negative
        
        //Particle from kinematics
        AliHBTParticle* particle = 0;
        Bool_t keeppart = kFALSE;
        if ( fReadParticles && stack  )
         {
           if (esdtrack->GetLabel() < 0) continue;//this is fake -  we are not able to match any track 
           TParticle *p = stack->Particle(esdtrack->GetLabel());
           if (p==0x0) 
            {
              Error("ReadNext","Can not find track with such label.");
              continue;
            }
//           if(p->GetPdgCode()<0) charge = -1;
           particle = new AliHBTParticle(*p,i);
           
         }
         
        //Here we apply Bayes' formula
        Double_t rc=0.;
        for (Int_t s=0; s<AliESDtrack::kSPECIES; s++) rc+=concentr[s]*pidtable[s];
        if (rc==0.0) 
         {
           if (AliHBTParticle::fgDebug > 2) 
             Info("ReadNext","Particle rejected since total bayessian PID probab. is zero.");
           continue;
         }

        for (Int_t s=0; s<AliESDtrack::kSPECIES; s++) w[s]=concentr[s]*pidtable[s]/rc;

        if (AliHBTParticle::fgDebug > 4)
         { 
           Info("ReadNext","###########################################################################");
           Info("ReadNext","Momentum: %f %f %f",mom[0],mom[1],mom[2]);
           Info("ReadNext","Position: %f %f %f",pos[0],pos[1],pos[2]);
           TString msg("Pid list got from track:");
           for (Int_t s = 0;s<kNSpecies;s++)
            {
              msg+="\n    ";
              msg+=s;
              msg+="(";
              msg+=charge*GetSpeciesPdgCode((ESpecies)s);
              msg+="): ";
              msg+=w[s];
              msg+=" (";
              msg+=pidtable[s];
              msg+=")";
            }
           Info("ReadNext","%s",msg.Data());
         }//if (AliHBTParticle::fgDebug>4)

        for (Int_t s = 0; s<kNSpecies; s++)
         {
           if (w[s] == 0.0) continue;

           Int_t pdgcode = charge*GetSpeciesPdgCode((ESpecies)s);
           if(Pass(pdgcode)) continue; //check if we are intersted with particles of this type 

           Double_t mass = pdgdb->GetParticle(pdgcode)->Mass();
           Double_t tEtot = TMath::Sqrt( mom[0]*mom[0] + mom[1]*mom[1] + mom[2]*mom[2] + mass*mass);//total energy of the track

           AliHBTParticle* track = new AliHBTParticle(pdgcode, w[s],i, 
                                                      mom[0], mom[1], mom[2], tEtot,
                                                      pos[0], pos[1], pos[2], 0.);
           //copy probabilitis of other species (if not zero)
           for (Int_t k = 0; k<kNSpecies; k++)
            {
              if (k == s) continue;
              if (w[k] == 0.0) continue;
              track->SetPIDprobability(charge*GetSpeciesPdgCode( (ESpecies)k ),w[k]);
            }
           if(Pass(track))//check if meets all criteria of any of our cuts
                          //if it does not delete it and take next good track
            { 
              delete track;
              continue;
            }
           
           fTracksEvent->AddParticle(track);
           if (particle) fParticlesEvent->AddParticle(particle);
           keeppart = kTRUE;
               
           if (AliHBTParticle::fgDebug > 4 )
            {
              Info("ReadNext","\n\nAdding Particle with incarnation %d",pdgcode);
              track->Print();
            }
         }//for (Int_t s = 0; s<kNSpecies; s++)
         
        if (keeppart == kFALSE) delete particle;//particle was not stored in event
        
      }//for (Int_t i = 0;i<ntr; i++)  -- loop over tracks
     
     Info("ReadNext","Read %d tracks and %d particles from event %d (event %d in dir %d).",
            fParticlesEvent->GetNumberOfParticles(), fTracksEvent->GetNumberOfParticles(),
            fNEventsRead,fCurrentEvent,fCurrentDir);
      
     fCurrentEvent++;
     fNEventsRead++;
     delete esd;
     return 0;//success -> read one event
   }while(fCurrentDir < GetNumberOfDirs());//end of loop over directories specified in fDirs Obj Array  
   
  return 1; //no more directories to read
}
/**********************************************************/
void AliHBTReaderESD::Rewind()
{
  delete fFile;
  fFile = 0;
  delete fRunLoader;
  fCurrentDir = 0;
  fNEventsRead = 0;
  fCurrentEvent++;
  
}
/**********************************************************/

TFile* AliHBTReaderESD::OpenFile(Int_t n)
{
//opens fFile with kine tree

 const TString& dirname = GetDirName(n);
 if (dirname == "")
  {
   Error("OpenFiles","Can not get directory name");
   return 0x0;
  }
 TString filename = dirname +"/"+ fESDFileName;
 TFile *ret = TFile::Open(filename.Data()); 

 if ( ret == 0x0)
  {
    Error("OpenFiles","Can't open fFile %s",filename.Data());
    return 0x0;
  }
 if (!ret->IsOpen())
  {
    Error("OpenFiles","Can't open fFile  %s",filename.Data());
    return 0x0;
  }
 
 if (fReadParticles)
  {
   fRunLoader = AliRunLoader::Open(dirname +"/"+ fGAlFileName);
   if (fRunLoader == 0x0)
    {
      Error("OpenFiles","Can't get RunLoader for directory %s",dirname.Data());
      delete ret;
      return 0x0;
    }
   fRunLoader->LoadHeader();
   if (fRunLoader->LoadKinematics())
    {
      Error("Next","Error occured while loading kinematics.");
      delete fRunLoader;
      delete ret;
      return 0x0;
    }
  }
 return ret;
}
/**********************************************************/

Int_t AliHBTReaderESD::GetSpeciesPdgCode(ESpecies spec)//skowron
{
  //returns pdg code from the PID index
  //ask jura about charge
  switch (spec)
   {
     case kESDElectron:
       return kPositron;
       break;
     case kESDMuon:
       return kMuonPlus;
       break;
     case kESDPion:
       return kPiPlus;
       break;
     case kESDKaon:
       return kKPlus;
       break;
     case kESDProton:
       return kProton;
       break;
     default:
       ::Warning("GetSpeciesPdgCode","Specie with number %d is not defined.",(Int_t)spec);
       break;
   }
  return 0;
}