#include "AliHBTReader.h"

#include <TString.h>
#include <TObjString.h>
#include <TObjArray.h>
#include <TClass.h>
#include <TRandom.h>

#include "AliHBTParticleCut.h"
#include "AliHBTEvent.h"
#include "AliHBTRun.h"
 
ClassImp(AliHBTReader)
//pure virtual
    
/*************************************************************************************/

AliHBTReader::AliHBTReader():
 fCuts(new TObjArray()),
 fDirs(0x0),
 fCurrentEvent(0),
 fCurrentDir(0),
 fNEventsRead(0),
 fTracksEvent(0x0),
 fParticlesEvent(0x0),
 fParticles(0x0),
 fTracks(0x0),
 fIsRead(kFALSE),
 fBufferEvents(kFALSE),
 fBlend(kFALSE),
 fFirst(0),
 fLast(0)
{
//constructor
}
/*************************************************************************************/

AliHBTReader::AliHBTReader(TObjArray* dirs):
 fCuts(new TObjArray()),
 fDirs(dirs),
 fCurrentEvent(0),
 fCurrentDir(0),
 fNEventsRead(0),
 fTracksEvent(0x0),
 fParticlesEvent(0x0),
 fParticles(0x0),
 fTracks(0x0),
 fIsRead(kFALSE),
 fBufferEvents(kFALSE),
 fBlend(kFALSE),
 fFirst(0),
 fLast(0)
{
//ctor with array of directories to read as parameter
}
/*************************************************************************************/

AliHBTReader::~AliHBTReader()
{
//destructor
 if(fCuts)
  {
   fCuts->SetOwner();
   delete fCuts;
  }
 delete fParticlesEvent;
 delete fTracksEvent;
}
/*************************************************************************************/

Int_t AliHBTReader::Next()
{
//moves to next event
  if ((fNEventsRead > fLast) && (fLast > 0) )
   
  do
   {
    if ( ReadNext() == kTRUE)
      return kTRUE;
   }while (fNEventsRead < fFirst);
  
  if (fBlend) Blend();
  
  if (fBufferEvents)
   {
     if ( ReadsTracks() && fTracksEvent) 
       fTracks->SetEvent(fNEventsRead-1-fFirst,fTracksEvent);
     if ( ReadsParticles() && fParticlesEvent)
       fParticles->SetEvent(fNEventsRead-1-fFirst,fParticlesEvent);
   }
  return kFALSE;
}
/*************************************************************************************/

void AliHBTReader::AddParticleCut(AliHBTParticleCut* cut)
{
 //sets the new cut 
 
  if (!cut) //if cut is NULL return with error
   {
    Error("AddParticleType","NULL pointers are not accepted any more.\nIf You want to accept all particles of this type, set an empty cut ");
    return;
   }
  AliHBTParticleCut *c = (AliHBTParticleCut*)cut->Clone();
  fCuts->Add(c);
}
/********************************************************************/

AliHBTEvent* AliHBTReader::GetParticleEvent(Int_t n)
 {
 //returns Nth event with simulated particles
  if (ReadsParticles() == kFALSE)
   {
     Error("GetParticleEvent","This reader is not able to provide simulated particles.");
     return 0;
   } 
   
  if (!fIsRead) 
   { 
    if (ReadsParticles() && (fParticles == 0x0)) fParticles = new AliHBTRun();
    if (ReadsTracks() && (fTracks == 0x0)) fTracks = new AliHBTRun();
    
    if (Read(fParticles,fTracks))
     {
       Error("GetParticleEvent","Error in reading");
       return 0x0;
     }
    else fIsRead = kTRUE;
   }
  return fParticles->GetEvent(n);
 }
/********************************************************************/

AliHBTEvent* AliHBTReader::GetTrackEvent(Int_t n)
 {
 //returns Nth event with reconstructed tracks
  if (ReadsTracks() == kFALSE)
   {
     Error("GetTrackEvent","This reader is not able to provide recosntructed tracks.");
     return 0;
   } 
  if (!fIsRead) 
   {
    if (ReadsParticles() && (fParticles == 0x0)) fParticles = new AliHBTRun();
    if (ReadsTracks() && (fTracks == 0x0)) fTracks = new AliHBTRun();
    
    if(Read(fParticles,fTracks))
     {
       Error("GetTrackEvent","Error in reading");
       return 0x0;
     }
    else fIsRead = kTRUE;
   }
  return fTracks->GetEvent(n);
 }
/********************************************************************/

Int_t AliHBTReader::GetNumberOfPartEvents()
 {
 //returns number of events of particles
  if (ReadsParticles() == kFALSE)
   {
     Error("GetNumberOfPartEvents","This reader is not able to provide simulated particles.");
     return 0;
   } 
   
  if (!fIsRead) 
   {
    if (ReadsParticles() && (fParticles == 0x0)) fParticles = new AliHBTRun();
    if (ReadsTracks() && (fTracks == 0x0)) fTracks = new AliHBTRun();
    
    if (Read(fParticles,fTracks))
     {
       Error("GetNumberOfPartEvents","Error in reading");
       return 0;
     }
    else fIsRead = kTRUE;
   }
   return fParticles->GetNumberOfEvents();
 }
/********************************************************************/
 
Int_t AliHBTReader::GetNumberOfTrackEvents()
 {
 //returns number of events of tracks
  if (ReadsTracks() == kFALSE)
   {
     Error("GetNumberOfTrackEvents","This reader is not able to provide recosntructed tracks.");
     return 0;
   } 
  if (!fIsRead)
   {
     if (ReadsParticles() && (fParticles == 0x0)) fParticles = new AliHBTRun();
     if (ReadsTracks() && (fTracks == 0x0)) fTracks = new AliHBTRun();
     
     if(Read(fParticles,fTracks))
      {
        Error("GetNumberOfTrackEvents","Error in reading");
        return 0;
      }
     else fIsRead = kTRUE;
   }
  return fTracks->GetNumberOfEvents();
 }
/********************************************************************/

Int_t AliHBTReader::Read(AliHBTRun* particles, AliHBTRun *tracks)
{
 //reads data and puts put to the particles and tracks objects
 //reurns 0 if everything is OK
 //
  Info("Read","");
  
  if ( ReadsParticles() && (particles == 0x0) ) //check if an object is instatiated
   {
     Error("Read"," particles object must be instatiated before passing it to the reader");
     return 1;
   }
  if ( ReadsTracks() && (tracks == 0x0) )  //check if an object is instatiated
   {
     Error("Read"," tracks object must be instatiated before passing it to the reader");
     return 1;
   }
   
  if (ReadsParticles()) particles->Reset();//clear runs == delete all old events
  if (ReadsTracks()) tracks->Reset();
  
  Rewind();
  
  Int_t i = 0;
  while(Next() == kFALSE)
   {
     if (ReadsTracks()) tracks->SetEvent(i,fTracksEvent);
     if (ReadsParticles()) particles->SetEvent(i,fParticlesEvent);
     i++;
   }
  return 0;
}      
/*************************************************************************************/

Bool_t AliHBTReader::Pass(AliHBTParticle* p)
{
 //Method examines whether particle meets all cut and particle type criteria
  
   if(p==0x0)//of corse we not pass NULL pointers
    {
     Warning("Pass()","No Pasaran! We never accept NULL pointers");
     return kTRUE;
    }
   //if no particle is specified, we pass all particles
   //excluding NULL pointers, of course
  if ( fCuts->GetEntriesFast() == 0 ) return kFALSE; //if no cut specified accept all particles
  for(Int_t i=0; i<fCuts->GetEntriesFast(); i++)   
   {
     AliHBTParticleCut &cut = *((AliHBTParticleCut*)fCuts->At(i));
     if(!cut.Pass(p)) return kFALSE;  //accepted
   }
   
  return kTRUE;//not accepted
}
/*************************************************************************************/

Bool_t  AliHBTReader::Pass(Int_t pid)
{
//this method checks if any of existing cuts accepts this pid particles
//or any cuts accepts all particles

 if(pid == 0)
  return kTRUE;

 if ( fCuts->GetEntriesFast() == 0 ) return kFALSE; //if no cut specified accept all particles
  
 for(Int_t i=0; i<fCuts->GetEntriesFast(); i++)   
   {
     AliHBTParticleCut &cut = *((AliHBTParticleCut*)fCuts->At(i));
     //if some of cuts accepts all particles or some accepts particles of this type, accept
     if ( (cut.GetPID() == 0) || (cut.GetPID() == pid) ) return kFALSE; 
   }
 return kTRUE;
}
/*************************************************************************************/

TString& AliHBTReader::GetDirName(Int_t entry)
{
//returns directory name of next one to read
  TString* retval;//return value
  if (fDirs ==  0x0)
   {
     retval = new TString(".");
     return *retval;
   }

  if ( (entry>fDirs->GetEntries()) || (entry<0))//if out of bounds return empty string
   {                                            //note that entry==0 is accepted even if array is empty (size=0)
     Error("GetDirName","Name out of bounds");
     retval = new TString();
     return *retval;
   }

  if (fDirs->GetEntries() == 0)
   { 
     retval = new TString(".");
     return *retval;
   }

  TClass *objclass = fDirs->At(entry)->IsA();
  TClass *stringclass = TObjString::Class();

  TObjString *dir = (TObjString*)objclass->DynamicCast(stringclass,fDirs->At(entry));

  if(dir == 0x0)
   {
     Error("GetDirName","Object in TObjArray is not a TObjString or its descendant");
     retval = new TString();
     return *retval;
   }
  if (gDebug > 0) Info("GetDirName","Returned ok %s",dir->String().Data());
  return dir->String();
}
/*************************************************************************************/

void AliHBTReader::Blend()
{
  //randomly change positions of the particles after reading
  //is used to check if some distr depends on order of particles
  //(tracking gives particles Pt sorted)
  for (Int_t i = 2; i < fParticlesEvent->GetNumberOfParticles(); i++)
   {
     Int_t with = gRandom->Integer(i);
     fParticlesEvent->SwapParticles(i,with);
     if (fTracksEvent) fTracksEvent->SwapParticles(i,with);
   }
}