/*************************************************************************
* Copyright(c) 1998-2009, ALICE Experiment at CERN, All rights reserved. *
*                                                                        *
* Author: The ALICE Off-line Project.                                    *
* Contributors are mentioned in the code where appropriate.              *
*                                                                        *
* 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.                  *
**************************************************************************/

///////////////////////////////////////////////////////////////////////////
//                                                                       //
//                        Basic Analysis Task                            //
//                                                                       //
///////////////////////////////////////////////////////////////////////////

#include <TChain.h>
#include <TH1D.h>

#include <AliCFContainer.h>
#include <AliInputEventHandler.h>
#include <AliAnalysisManager.h>
#include <AliVEvent.h>

#include "AliDielectron.h"
#include "AliDielectronHistos.h"
#include "AliDielectronCF.h"
#include "AliDielectronMC.h"
#include "AliAnalysisTaskDielectronME.h"

ClassImp(AliAnalysisTaskDielectronME)

//_________________________________________________________________________________
AliAnalysisTaskDielectronME::AliAnalysisTaskDielectronME() :
  AliAnalysisTaskME(),
  fListDielectron(),
  fListHistos(),
  fListCF(),
  fPoolDepth(2),
  fSelectPhysics(kFALSE),
  fTriggerMask(AliVEvent::kMB),
  fEventStat(0x0)
{
  //
  // Constructor
  //
}

//_________________________________________________________________________________
AliAnalysisTaskDielectronME::AliAnalysisTaskDielectronME(const char *name) :
  AliAnalysisTaskME(name),
  fListDielectron(),
  fListHistos(),
  fListCF(),
  fPoolDepth(2),
  fSelectPhysics(kFALSE),
  fTriggerMask(AliVEvent::kMB),
  fEventStat(0x0)
{
  //
  // Constructor
  //
  DefineInput(0,TChain::Class());
  DefineOutput(1, TList::Class());
  DefineOutput(2, TList::Class());
  DefineOutput(3, TH1D::Class());
  fListHistos.SetName("Dielectron_Histos_Multi");
  fListCF.SetName("Dielectron_CF_Multi");
}


//_________________________________________________________________________________
void AliAnalysisTaskDielectronME::UserCreateOutputObjects()
{
  //
  // Add all histogram manager histogram lists to the output TList
  //

  if (!fListHistos.IsEmpty()||!fListCF.IsEmpty()) return; //already initialised

  TIter nextDie(&fListDielectron);
  AliDielectron *die=0;
  while ( (die=static_cast<AliDielectron*>(nextDie())) ){
    die->Init();
    if (die->GetHistogramList()) fListHistos.Add(const_cast<THashList*>(die->GetHistogramList()));
    if (die->GetCFManagerPair()) fListCF.Add(const_cast<AliCFContainer*>(die->GetCFManagerPair()->GetContainer()));
  }

  Int_t cuts=fListDielectron.GetEntries();
  Int_t nbins=2+2*cuts;
  if (!fEventStat){
    fEventStat=new TH1D("hEventStat","Event statistics",nbins,0,nbins);
    fEventStat->GetXaxis()->SetBinLabel(1,"Before Phys. Sel.");
    fEventStat->GetXaxis()->SetBinLabel(2,"After Phys. Sel.");
    for (Int_t i=0; i<cuts; ++i){
      fEventStat->GetXaxis()->SetBinLabel(3+2*i,Form("#splitline{1 candidate}{%s}",fListDielectron.At(i)->GetName()));
      fEventStat->GetXaxis()->SetBinLabel(4+2*i,Form("#splitline{With >1 candidate}{%s}",fListDielectron.At(i)->GetName()));
    }
  }
  
  PostData(1, &fListHistos);
  PostData(2, &fListCF);
  PostData(3, fEventStat);
}

//_________________________________________________________________________________
void AliAnalysisTaskDielectronME::UserExec(Option_t *)
{
  //
  // Main loop. Called for every event
  //

  if (fListHistos.IsEmpty()&&fListCF.IsEmpty()) return;

  AliAnalysisManager *man=AliAnalysisManager::GetAnalysisManager();
  AliInputEventHandler* inputHandler = (AliInputEventHandler*) (man->GetInputEventHandler());
  if (!inputHandler) return;

  if ( inputHandler->GetPIDResponse() ){
    AliDielectronVarManager::SetPIDResponse( inputHandler->GetPIDResponse() );
  } else {
    AliFatal("This task needs the PID response attached to the input event handler!");
  }

  // Was event selected ?
  UInt_t isSelected = AliVEvent::kAny;
  if( fSelectPhysics && inputHandler && inputHandler->GetEventSelection() ) {
    isSelected = inputHandler->IsEventSelected();
    isSelected&=fTriggerMask;
  }
  
  //Before physics selection
  fEventStat->Fill(0.);
  if (isSelected==0) {
    PostData(3,fEventStat);
    return;
  }
  //after physics selection
  fEventStat->Fill(1.);
  
  //bz for AliKF
  Double_t bz = GetEvent(0)->GetMagneticField();
  AliKFParticle::SetField( bz );

  //Process event in all AliDielectron instances
  TIter nextDie(&fListDielectron);
  AliDielectron *die=0;
  Int_t idie=0;
  while ( (die=static_cast<AliDielectron*>(nextDie())) ){
    for (Int_t evt1=0; evt1<fPoolDepth-1; evt1++){
      for (Int_t evt2=evt1+1; evt2<fPoolDepth; evt2++){
        die->Process((AliESDEvent*)GetEvent(evt1),(AliESDEvent*)GetEvent(evt2));
        if (die->HasCandidates()){
          Int_t ncandidates=die->GetPairArray(1)->GetEntriesFast();
          if (ncandidates==1) fEventStat->Fill(3+2*idie);
          else if (ncandidates>1) fEventStat->Fill(4+2*idie);
        }
      }
    }
    ++idie;
  }
  
  PostData(1, &fListHistos);
  PostData(2, &fListCF);
  PostData(3,fEventStat);
}

//_________________________________________________________________________________
void AliAnalysisTaskDielectronME::FinishTaskOutput()
{
  //
  // Write debug tree
  //
  TIter nextDie(&fListDielectron);
  AliDielectron *die=0;
  while ( (die=static_cast<AliDielectron*>(nextDie())) ){
    die->SaveDebugTree();
  }
}