/**************************************************************************
 * Copyright(c) 2004, 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.                  *
 **************************************************************************/

// Thil class computes background corrections for the FMD. The correction is computed 
// in eta,phi cells and the objects stored can be put into alien to use with analysis.
// It is based on the AliFMDInput class that is used to loop over hits and primaries.
//
// Author: Hans Hjersing Dalsgaard, NBI, hans.dalsgaard@cern.ch
//
//

#include "AliSimulation.h"
#include "TStopwatch.h"
#include "iostream"
#include "TGrid.h"
#include "AliRunLoader.h"
#include "AliGeomManager.h"
#include "AliFMDGeometry.h"
#include "AliStack.h"
#include "TParticle.h"
#include "TDatabasePDG.h"
#include "TParticlePDG.h"
#include "AliRun.h"
#include "AliFMDBackgroundCorrection.h"
#include "TSystem.h"
#include "AliCDBManager.h"
#include "TTree.h"
#include "TClonesArray.h"
#include "TBranch.h"
#include "AliFMDHit.h"
#include "AliLoader.h" 
#include "AliFMD.h"
#include "TH2F.h"
#include "AliGenEventHeader.h"
#include "AliHeader.h"
#include "TFile.h"
#include "TAxis.h"
#include "AliCDBId.h"
#include "AliCDBMetaData.h"
#include "TROOT.h"
#include "AliFMDParameters.h"
#include "AliLog.h"
#include "AliFMDAnaParameters.h"
#include "AliFMDAnaCalibBackgroundCorrection.h"

ClassImp(AliFMDBackgroundCorrection)
//_____________________________________________________________________
AliFMDBackgroundCorrection::AliFMDBackgroundCorrection() : 
  TNamed(),
  fCorrectionArray()
{} 

//_____________________________________________________________________
AliFMDBackgroundCorrection::AliFMDInputBG::AliFMDInputBG() : 
  AliFMDInput(),
  fPrimaryArray(),
  fHitArray(),
  fPrim(0),
  fHits(0),
  fZvtxCut(0),
  fNvtxBins(0),
  fPrevTrack(-1),
  fPrevDetector(-1),
  fPrevRing('Q'),
  fNbinsEta(100)
{
  AddLoad(kTracks); 
  AddLoad(kHits); 
  AddLoad(kKinematics); 
  AddLoad(kHeader);
}

//_____________________________________________________________________

void AliFMDBackgroundCorrection::GenerateBackgroundCorrection(Int_t nvtxbins,
							      Float_t zvtxcut, 
							      Int_t nBinsEta, 
							      Bool_t storeInAlien, 
							      Int_t runNo,
							      Int_t endRunNo, 
							      const Char_t* filename, 
							      Bool_t simulate,
							      Int_t nEvents) {
  
  TGrid::Connect("alien:",0,0,"t");
  if(simulate)
    Simulate(nEvents);
  else {
    AliCDBManager::Instance()->SetDefaultStorage("alien://Folder=/alice/data/2008/LHC08d/OCDB/");
    AliCDBManager::Instance()->SetRun(runNo);
    
#if defined(__CINT__)
    gSystem->Load("liblhapdf");
    gSystem->Load("libEGPythia6");
    gSystem->Load("libpythia6");
    gSystem->Load("libAliPythia6");
    gSystem->Load("libgeant321");
#endif
  }  
  
  //Setting up the geometry
  //-----------------------------------------------
  if (AliGeomManager::GetGeometry() == NULL)
    AliGeomManager::LoadGeometry();
  
  AliFMDGeometry* geo = AliFMDGeometry::Instance();
  geo->Init();
  geo->InitTransformations();
  
  
  
  AliInfo("Processing hits and primaries ");
  
  AliFMDInputBG input;
  input.SetVtxCutZ(zvtxcut);
  input.SetNvtxBins(nvtxbins);
  input.SetNbinsEta(nBinsEta);
  input.Run();
  
  AliInfo(Form("Found %d primaries and %d hits.", input.GetNprim(),input.GetNhits()));
  
  TObjArray* hitArray = input.GetHits();
  TObjArray* primaryArray = input.GetPrimaries();
  fCorrectionArray.SetName("FMD_bg_correction");
  fCorrectionArray.SetOwner();
  
  AliFMDAnaCalibBackgroundCorrection* background = new AliFMDAnaCalibBackgroundCorrection();
  
  for(Int_t det= 1; det <=3; det++) {
    Int_t nRings = (det==1 ? 1 : 2);
    
    TObjArray* detArrayCorrection = new TObjArray();
    detArrayCorrection->SetName(Form("FMD%d",det));
    fCorrectionArray.AddAtAndExpand(detArrayCorrection,det);
    
    
    for(Int_t iring = 0; iring<nRings; iring++) {
      TObjArray* primRingArray = (TObjArray*)primaryArray->At(iring);
      Char_t ringChar = (iring == 0 ? 'I' : 'O');
      TObjArray* vtxArrayCorrection = new TObjArray();
      vtxArrayCorrection->SetName(Form("FMD%d%c",det,ringChar));
      detArrayCorrection->AddAtAndExpand(vtxArrayCorrection,iring);
      
      for(Int_t vertexBin=0;vertexBin<nvtxbins;vertexBin++) {
	TObjArray* detArray  = (TObjArray*)hitArray->At(det);
	TObjArray* vtxArray  = (TObjArray*)detArray->At(iring);
	TH2F* hHits          = (TH2F*)vtxArray->At(vertexBin);
	TH2F* hPrimary  = (TH2F*)primRingArray->At(vertexBin);
	TH2F* hCorrection = (TH2F*)hHits->Clone(Form("FMD%d%c_vtxbin_%d_correction",det,ringChar,vertexBin));
	hCorrection->SetTitle(hCorrection->GetName());
	hCorrection->Divide(hPrimary);
	vtxArrayCorrection->AddAtAndExpand(hCorrection,vertexBin);
	background->SetBgCorrection(det,ringChar,vertexBin,hCorrection);
      }
      
    }
  }
  
  TAxis refAxis(nvtxbins,-1*zvtxcut,zvtxcut);
  
  background->SetRefAxis(&refAxis);
  
  TFile*  fout = new TFile(filename,"RECREATE");
  refAxis.Write("vertexbins");
  fout->mkdir("Hits");
  fout->cd("Hits");
  hitArray->Write();
  fout->mkdir("Primaries");
  fout->cd("Primaries");
  primaryArray->Write();
  fout->mkdir("Correction");
  fout->cd("Correction");
  fCorrectionArray.Write();
  
  TObjArray* container = new TObjArray();
  container->SetOwner();
  container->AddAtAndExpand(&refAxis,0);
  container->AddAtAndExpand(&fCorrectionArray,1);
  container->AddAtAndExpand(hitArray,2);
  container->AddAtAndExpand(primaryArray,3);
  
  
  if(storeInAlien) {
    AliCDBManager* cdb = AliCDBManager::Instance();
    cdb->SetDefaultStorage("local://$ALICE_ROOT");
    AliCDBId      id(AliFMDAnaParameters::GetBackgroundPath(),runNo,endRunNo);
    
    AliCDBMetaData* meta = new AliCDBMetaData;				
    meta->SetResponsible(gSystem->GetUserInfo()->fRealName.Data());	
    meta->SetAliRootVersion(gROOT->GetVersion());			
    meta->SetBeamPeriod(1);						
    meta->SetComment("Background Correction for FMD");
    meta->SetProperty("key1", background );
    cdb->Put(background, id, meta);
    
  }
  
  fout->Close();
 
  
}
//_____________________________________________________________________
void AliFMDBackgroundCorrection::Simulate(Int_t nEvents) {
  
  AliSimulation sim ; 
  sim.SetRunNumber(0);
  TGrid::Connect("alien:",0,0,"t");
  sim.SetDefaultStorage("alien://Folder=/alice/data/2008/LHC08d/OCDB/");
  sim.SetConfigFile("Config.C");
  sim.SetRunQA("FMD:");
  TStopwatch timer;
  timer.Start();
  sim.RunSimulation(nEvents);    
  timer.Stop();
  timer.Print();
  
}

//_____________________________________________________________________
Bool_t AliFMDBackgroundCorrection::AliFMDInputBG::ProcessTrack(Int_t i , TParticle* p, AliFMDHit* h) {
  
  AliGenEventHeader* genHeader = fLoader->GetHeader()->GenEventHeader();
  TArrayF vertex;
  genHeader->PrimaryVertex(vertex);
  
  if(TMath::Abs(vertex.At(2)) > fZvtxCut) 
    return kTRUE;
  
  Double_t delta = 2*fZvtxCut/fNvtxBins;
  Double_t vertexBinDouble = (vertex.At(2) + fZvtxCut) / delta;
  Int_t vertexBin = (Int_t)vertexBinDouble;
  
  if(h)
    if(h->Q() !=  0 && (i != fPrevTrack || h->Detector() != fPrevDetector || h->Ring() != fPrevRing)) {
      
      Int_t det = h->Detector();
      Char_t ring = h->Ring();
      //  if(h->Detector() == 3)
      //	std::cout<<"Detected a hit in " <<"FMD"<<det<<ring<<"    ! "<<std::endl;
     
      Int_t iring = (ring == 'I' ? 0 : 1);
      
      TObjArray* detArray  = (TObjArray*)fHitArray.At(det);
      TObjArray* vtxArray  = (TObjArray*)detArray->At(iring);
      TH2F* hHits          = (TH2F*)vtxArray->At(vertexBin);
      
      Float_t phi   = TMath::ATan2(h->Py(),h->Px());
      if(phi<0)
	phi = phi+2*TMath::Pi();
      Float_t theta = TMath::ATan2(TMath::Sqrt(TMath::Power(h->X(),2)+TMath::Power(h->Y(),2)),h->Z()+vertex.At(2));
      Float_t eta   = -1*TMath::Log(TMath::Tan(0.5*theta));
      hHits->Fill(eta,phi);
      fHits++;
      //fPrevTrack = i;
      fPrevDetector = det;
      fPrevRing     = ring;
    }
  if(p && i != fPrevTrack) {
    
    TDatabasePDG* pdgDB = TDatabasePDG::Instance();
    TParticlePDG* pdgPart = pdgDB->GetParticle(p->GetPdgCode());
    Float_t charge = (pdgPart ? pdgPart->Charge() : 0);
    Float_t phi = TMath::ATan2(p->Py(),p->Px());

    if(phi<0)
      phi = phi+2*TMath::Pi();
    
    
    Bool_t primary = (charge!=0)&&(TMath::Abs(p->Vx() - vertex.At(0))<0.1)&&(TMath::Abs(p->Vy() - vertex.At(1))<0.1)&&(TMath::Abs(p->Vz() - vertex.At(2))<0.1);
    if(primary) {
      fPrim++;
      TObjArray* innerArray = (TObjArray*)fPrimaryArray.At(0);
      TObjArray* outerArray = (TObjArray*)fPrimaryArray.At(1);
      
      TH2F* hPrimaryInner  = (TH2F*)innerArray->At(vertexBin);
      TH2F* hPrimaryOuter  = (TH2F*)outerArray->At(vertexBin);
      hPrimaryInner->Fill(p->Eta(),phi);
      hPrimaryOuter->Fill(p->Eta(),phi);
    }
  }
  
  
  fPrevTrack = i;
  return kTRUE;
}

//_____________________________________________________________________
Bool_t AliFMDBackgroundCorrection::AliFMDInputBG::Init() {
  
  fPrimaryArray.SetOwner();
  fPrimaryArray.SetName("FMD_primary");
  
  for(Int_t iring = 0; iring<2;iring++) {
    Char_t ringChar = (iring == 0 ? 'I' : 'O');
    TObjArray* ringArray = new TObjArray();
    ringArray->SetName(Form("FMD_%c",ringChar));
    fPrimaryArray.AddAtAndExpand(ringArray,iring);
    Int_t nSec = (iring == 1 ? 40 : 20);
    for(Int_t v=0; v<fNvtxBins;v++) {

      TH2F* hPrimary       = new TH2F(Form("hPrimary_FMD_%c_vtx%d",ringChar,v),
				      Form("hPrimary_FMD_%c_vtx%d",ringChar,v),
				      fNbinsEta, -6,6, nSec, 0,2*TMath::Pi());
      hPrimary->Sumw2();
      ringArray->AddAtAndExpand(hPrimary,v);
    }
  }
  
  
  fHitArray.SetOwner();
  fHitArray.SetName("FMD_hits");
   
  for(Int_t det =1; det<=3;det++)
    {
      TObjArray* detArrayHits = new TObjArray();
      detArrayHits->SetName(Form("FMD%d",det));
      fHitArray.AddAtAndExpand(detArrayHits,det);
      Int_t nRings = (det==1 ? 1 : 2);
      for(Int_t ring = 0;ring<nRings;ring++)
	{
	  Int_t nSec = (ring == 1 ? 40 : 20);
	  Char_t ringChar = (ring == 0 ? 'I' : 'O');
	  TObjArray* vtxArrayHits = new TObjArray();
	  vtxArrayHits->SetName(Form("FMD%d%c",det,ringChar));
	  detArrayHits->AddAtAndExpand(vtxArrayHits,ring);
	  for(Int_t v=0; v<fNvtxBins;v++)
	    {
	      
	      TH2F* hHits          = new TH2F(Form("hHits_FMD%d%c_vtx%d",det,ringChar,v),
					      Form("hHits_FMD%d%c_vtx%d",det,ringChar,v),
					      fNbinsEta, -6,6, nSec, 0, 2*TMath::Pi());
	      hHits->Sumw2();
	      vtxArrayHits->AddAtAndExpand(hHits,v);
	      	      
	    } 
	}
      
    }


  
  AliFMDInput::Init();
  
  
  return kTRUE;
}
// EOF