/* $Id$ */

#include "AlidNdEtaCorrectionTask.h"

#include <TCanvas.h>
#include <TChain.h>
#include <TFile.h>
#include <TH1F.h>
#include <TParticle.h>

#include <AliLog.h>
#include <AliESDVertex.h>
#include <AliESDEvent.h>
#include <AliStack.h>
#include <AliHeader.h>
#include <AliGenEventHeader.h>
#include <AliMultiplicity.h>
#include <AliAnalysisManager.h>
#include <AliMCEventHandler.h>
#include <AliMCEvent.h>
#include <AliESDInputHandler.h>

#include "esdTrackCuts/AliESDtrackCuts.h"
#include "AliPWG0Helper.h"
//#include "AliCorrection.h"
//#include "AliCorrectionMatrix3D.h"
#include "dNdEta/dNdEtaAnalysis.h"
#include "dNdEta/AlidNdEtaCorrection.h"

ClassImp(AlidNdEtaCorrectionTask)

AlidNdEtaCorrectionTask::AlidNdEtaCorrectionTask(const char* opt) :
  AliAnalysisTask("AlidNdEtaCorrectionTask", ""),
  fESD(0),
  fOutput(0),
  fOption(opt),
  fAnalysisMode(kTPC),
  fSignMode(0),
  fEsdTrackCuts(0),
  fdNdEtaCorrection(0),
  fdNdEtaAnalysisMC(0),
  fdNdEtaAnalysisESD(0),
  fPIDParticles(0),
  fPIDTracks(0)
{
  //
  // Constructor. Initialization of pointers
  //

  // Define input and output slots here
  DefineInput(0, TChain::Class());
  DefineOutput(0, TList::Class());
}

AlidNdEtaCorrectionTask::~AlidNdEtaCorrectionTask()
{
  //
  // Destructor
  //

  // histograms are in the output list and deleted when the output
  // list is deleted by the TSelector dtor

  if (fOutput) {
    delete fOutput;
    fOutput = 0;
  }
}

//________________________________________________________________________
void AlidNdEtaCorrectionTask::ConnectInputData(Option_t *)
{
  // Connect ESD
  // Called once

  Printf("AlidNdEtaCorrectionTask::ConnectInputData called");

  TTree* tree = dynamic_cast<TTree*> (GetInputData(0));
  if (!tree) {
    Printf("ERROR: Could not read tree from input slot 0");
  } else {
    // Disable all branches and enable only the needed ones
    tree->SetBranchStatus("*", 0);

    tree->SetBranchStatus("fTriggerMask", 1);
    tree->SetBranchStatus("fSPDVertex*", 1);

    if (fAnalysisMode == kSPD)
      tree->SetBranchStatus("fSPDMult*", 1);

    if (fAnalysisMode == kTPC) {
      AliESDtrackCuts::EnableNeededBranches(tree);
      tree->SetBranchStatus("fTracks.fLabel", 1);
    }

    AliESDInputHandler *esdH = dynamic_cast<AliESDInputHandler*> (AliAnalysisManager::GetAnalysisManager()->GetInputEventHandler());

    if (!esdH) {
      Printf("ERROR: Could not get ESDInputHandler");
    } else
      fESD = esdH->GetEvent();
  }
}

void AlidNdEtaCorrectionTask::CreateOutputObjects()
{
  // create result objects and add to output list

  if (fOption.Contains("only-positive"))
  {
    Printf("INFO: Processing only positive particles.");
    fSignMode = 1;
  }
  else if (fOption.Contains("only-negative"))
  {
    Printf("INFO: Processing only negative particles.");
    fSignMode = -1;
  }

  TString detector;
  if (fAnalysisMode == kTPC)
  {
    detector = "TPC";
  }
  else if (fAnalysisMode == kSPD)
    detector = "SPD";

  fOutput = new TList;
  fOutput->SetOwner();

  fdNdEtaCorrection = new AlidNdEtaCorrection("dndeta_correction", "dndeta_correction", detector);
  fOutput->Add(fdNdEtaCorrection);

  fPIDParticles = new TH1F("pid_particles", "PID of generated primary particles", 10001, -5000.5, 5000.5);
  fOutput->Add(fPIDParticles);

  fPIDTracks = new TH1F("pid_tracks", "MC PID of reconstructed tracks", 10001, -5000.5, 5000.5);
  fOutput->Add(fPIDTracks);

  fdNdEtaAnalysisMC = new dNdEtaAnalysis("dndetaMC", "dndetaMC", detector);
  fOutput->Add(fdNdEtaAnalysisMC);

  fdNdEtaAnalysisESD = new dNdEtaAnalysis("dndetaESD", "dndetaESD", detector);
  fOutput->Add(fdNdEtaAnalysisESD);
}

void AlidNdEtaCorrectionTask::Exec(Option_t*)
{
  // process the event

  // Check prerequisites
  if (!fESD)
  {
    AliDebug(AliLog::kError, "ESD branch not available");
    return;
  }

  // trigger definition
  Bool_t eventTriggered = AliPWG0Helper::IsEventTriggered(fESD->GetTriggerMask(), AliPWG0Helper::kMB2);

  Bool_t eventVertex = AliPWG0Helper::IsVertexReconstructed(fESD->GetVertex());

  // post the data already here
  PostData(0, fOutput);

  // create list of (label, eta, pt) tuples
  Int_t inputCount = 0;
  Int_t* labelArr = 0;
  Float_t* etaArr = 0;
  Float_t* ptArr = 0;
  if (fAnalysisMode == kSPD)
  {
    // get tracklets
    const AliMultiplicity* mult = fESD->GetMultiplicity();
    if (!mult)
    {
      AliDebug(AliLog::kError, "AliMultiplicity not available");
      return;
    }

    labelArr = new Int_t[mult->GetNumberOfTracklets()];
    etaArr = new Float_t[mult->GetNumberOfTracklets()];
    ptArr = new Float_t[mult->GetNumberOfTracklets()];

    // get multiplicity from ITS tracklets
    for (Int_t i=0; i<mult->GetNumberOfTracklets(); ++i)
    {
      //printf("%d %f %f %f\n", i, mult->GetTheta(i), mult->GetPhi(i), mult->GetDeltaPhi(i));

      // This removes non-tracklets in PDC06 data. Very bad solution. New solution is implemented for newer data. Keeping this for compatibility.
      if (mult->GetDeltaPhi(i) < -1000)
        continue;

      etaArr[inputCount] = mult->GetEta(i);
      labelArr[inputCount] = mult->GetLabel(i);
      ptArr[inputCount] = 0; // no pt for tracklets
      ++inputCount;
    }
  }
  else if (fAnalysisMode == kTPC)
  {
    if (!fEsdTrackCuts)
    {
      AliDebug(AliLog::kError, "fESDTrackCuts not available");
      return;
    }

    // get multiplicity from ESD tracks
    TObjArray* list = fEsdTrackCuts->GetAcceptedTracks(fESD);
    Int_t nGoodTracks = list->GetEntries();

    labelArr = new Int_t[nGoodTracks];
    etaArr = new Float_t[nGoodTracks];
    ptArr = new Float_t[nGoodTracks];

    // loop over esd tracks
    for (Int_t i=0; i<nGoodTracks; i++)
    {
      AliESDtrack* esdTrack = dynamic_cast<AliESDtrack*> (list->At(i));
      if (!esdTrack)
      {
        AliDebug(AliLog::kError, Form("ERROR: Could not retrieve track %d.", i));
        continue;
      }

      etaArr[inputCount] = esdTrack->Eta();
      labelArr[inputCount] = TMath::Abs(esdTrack->GetLabel());
      ptArr[inputCount] = esdTrack->Pt();
      ++inputCount;
    }
  }
  else
    return;

  AliMCEventHandler* eventHandler = dynamic_cast<AliMCEventHandler*> (AliAnalysisManager::GetAnalysisManager()->GetMCtruthEventHandler());
  if (!eventHandler) {
    Printf("ERROR: Could not retrieve MC event handler");
    return;
  }

  AliMCEvent* mcEvent = eventHandler->MCEvent();
  if (!mcEvent) {
    Printf("ERROR: Could not retrieve MC event");
    return;
  }

  AliStack* stack = mcEvent->Stack();
  if (!stack)
  {
    AliDebug(AliLog::kError, "Stack not available");
    return;
  }

  AliHeader* header = mcEvent->Header();
  if (!header)
  {
    AliDebug(AliLog::kError, "Header not available");
    return;
  }

  // get process type
  Int_t processType = AliPWG0Helper::GetPythiaEventProcessType(header);
  AliDebug(AliLog::kDebug+1, Form("Found pythia procces type %d", processType));

  if (processType<0)
    AliDebug(AliLog::kError, Form("Unknown Pythia process type %d.", processType));

  // get the MC vertex
  AliGenEventHeader* genHeader = header->GenEventHeader();
  TArrayF vtxMC(3);
  genHeader->PrimaryVertex(vtxMC);

  // loop over mc particles
  Int_t nPrim  = stack->GetNprimary();

  for (Int_t iMc = 0; iMc < nPrim; ++iMc)
  {
    //Printf("Getting particle %d", iMc);
    TParticle* particle = stack->Particle(iMc);

    if (!particle)
      continue;

    if (AliPWG0Helper::IsPrimaryCharged(particle, nPrim) == kFALSE)
      continue;

    if (SignOK(particle->GetPDG()) == kFALSE)
      continue;

    Float_t eta = particle->Eta();
    Float_t pt = particle->Pt();

    fdNdEtaCorrection->FillMCParticle(vtxMC[2], eta, pt, eventTriggered, eventVertex, processType);

    if (eventTriggered)
      if (eventVertex)
        fdNdEtaAnalysisMC->FillTrack(vtxMC[2], eta, pt);
  }

  for (Int_t i=0; i<inputCount; ++i)
  {
    Int_t label = labelArr[i];

    if (label < 0)
    {
      AliDebug(AliLog::kWarning, Form("WARNING: cannot find corresponding mc part for track %d.", label));
      continue;
    }

    TParticle* particle = stack->Particle(label);
    if (!particle)
    {
      AliDebug(AliLog::kError, Form("UNEXPECTED: particle with label %d not found in stack (track loop).", label));
      continue;
    }

    if (SignOK(particle->GetPDG()) == kFALSE)
        continue;

    if (eventTriggered && eventVertex)
    {
      fdNdEtaCorrection->FillTrackedParticle(vtxMC[2], particle->Eta(), particle->Pt());
      fdNdEtaAnalysisESD->FillTrack(vtxMC[2], particle->Eta(), particle->Pt());
      if (particle->Pt() > 0.1 && particle->Pt() < 0.2)
      {
        fPIDTracks->Fill(particle->GetPdgCode());
      }
    }
  }

  if (eventTriggered && eventVertex)
    fdNdEtaAnalysisMC->FillEvent(vtxMC[2], inputCount);

  // stuff regarding the vertex reco correction and trigger bias correction
  fdNdEtaCorrection->FillEvent(vtxMC[2], inputCount, eventTriggered, eventVertex, processType);
  if (eventTriggered) {
    if (eventVertex)
    {
      fdNdEtaAnalysisESD->FillEvent(vtxMC[2], inputCount);
    }
  }

  delete[] etaArr;
  delete[] labelArr;
  delete[] ptArr;
}

void AlidNdEtaCorrectionTask::Terminate(Option_t *)
{
  // The Terminate() function is the last function to be called during
  // a query. It always runs on the client, it can be used to present
  // the results graphically or save the results to file.

  fOutput = dynamic_cast<TList*> (GetOutputData(0));
  if (!fOutput) {
    Printf("ERROR: fOutput not available");
    return;
  }

  fdNdEtaCorrection = dynamic_cast<AlidNdEtaCorrection*> (fOutput->FindObject("dndeta_correction"));
  fdNdEtaAnalysisMC = dynamic_cast<dNdEtaAnalysis*> (fOutput->FindObject("dndetaMC"));
  fdNdEtaAnalysisESD = dynamic_cast<dNdEtaAnalysis*> (fOutput->FindObject("dndetaESD"));
  if (!fdNdEtaCorrection || !fdNdEtaAnalysisMC || !fdNdEtaAnalysisESD)
  {
    AliDebug(AliLog::kError, "Could not read object from output list");
    return;
  }

  fdNdEtaCorrection->Finish();

  TString fileName;
  fileName.Form("correction_map%s.root", fOption.Data());
  TFile* fout = new TFile(fileName, "RECREATE");

  if (fEsdTrackCuts)
    fEsdTrackCuts->SaveHistograms("esd_track_cuts");
  fdNdEtaCorrection->SaveHistograms();
  fdNdEtaAnalysisMC->SaveHistograms();
  fdNdEtaAnalysisESD->SaveHistograms();

  fout->Write();
  fout->Close();

  fdNdEtaCorrection->DrawHistograms();

  if (fPIDParticles && fPIDTracks)
  {
    new TCanvas("pidcanvas", "pidcanvas", 500, 500);

    fPIDParticles->Draw();
    fPIDTracks->SetLineColor(2);
    fPIDTracks->Draw("SAME");

    TDatabasePDG* pdgDB = new TDatabasePDG;

    for (Int_t i=0; i <= fPIDParticles->GetNbinsX()+1; ++i)
      if (fPIDParticles->GetBinContent(i) > 0)
        printf("PDG = %d (%s): generated: %d, reconstructed: %d, ratio: %f\n", (Int_t) fPIDParticles->GetBinCenter(i), pdgDB->GetParticle((Int_t) fPIDParticles->GetBinCenter(i))->GetName(), (Int_t) fPIDParticles->GetBinContent(i), (Int_t) fPIDTracks->GetBinContent(i), ((fPIDTracks->GetBinContent(i) > 0) ? fPIDParticles->GetBinContent(i) / fPIDTracks->GetBinContent(i) : -1));

    delete pdgDB;
    pdgDB = 0;
  }

  Printf("Writting result to %s", fileName.Data());
}

Bool_t AlidNdEtaCorrectionTask::SignOK(TParticlePDG* particle)
{
  // returns if a particle with this sign should be counted
  // this is determined by the value of fSignMode, which should have the same sign
  // as the charge
  // if fSignMode is 0 all particles are counted

  if (fSignMode == 0)
    return kTRUE;

  if (!particle)
  {
    printf("WARNING: not counting a particle that does not have a pdg particle\n");
    return kFALSE;
  }

  Double_t charge = particle->Charge();

  if (fSignMode > 0)
    if (charge < 0)
      return kFALSE;

  if (fSignMode < 0)
    if (charge > 0)
      return kFALSE;

  return kTRUE;
}