// $Id$

//**************************************************************************
//* This file is property of and copyright by the ALICE Project            * 
//* ALICE Experiment at CERN, All rights reserved.                         *
//*                                                                        *
//* Primary Authors: Matthias Richter <Matthias.Richter@ift.uib.no>        *
//*                  Hege Erdal       <hege.erdal@gmail.com>               *
//*                                                                        *
//* 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.                  *
//**************************************************************************

/// @file   AliDxHFEParticleSelectionMCD0.cxx
/// @author Hege Erdal, Matthias Richter
/// @date   2012-07-19
/// @brief  MC D0 selection for D0-HFE correlation
///

#include "AliDxHFEParticleSelectionMCD0.h"
#include "AliAODRecoDecayHF2Prong.h"
#include "AliAODTrack.h"
#include "AliAODMCParticle.h"
#include "AliVParticle.h"
#include <iostream>
#include <cerrno>
#include <memory>

using namespace std;

/// ROOT macro for the implementation of ROOT specific class methods
ClassImp(AliDxHFEParticleSelectionMCD0)

// TODO: can that be a common definition
const char* AliDxHFEParticleSelectionMCD0::fgkTrackControlBinNames[]={
"Pt",
"Phi",
"Ptbin", 
"D0InvMass", 
"Eta",
"Statistics D0",
"Mother of D0"
};

AliDxHFEParticleSelectionMCD0::AliDxHFEParticleSelectionMCD0(const char* opt)
  : AliDxHFEParticleSelectionD0(opt)
  , fMCTools()
  , fResultMC(0)
  , fOriginMother(0)
{
  // constructor
  // 
  // 
  // 
  // 

  // TODO: argument scan, pass only relevant arguments to tools
  fMCTools.~AliDxHFEToolsMC();
  TString toolopt("pdg=421 mc-last");
  new (&fMCTools) AliDxHFEToolsMC(toolopt);
}

AliDxHFEParticleSelectionMCD0::~AliDxHFEParticleSelectionMCD0()
{
  // destructor
}
THnSparse* AliDxHFEParticleSelectionMCD0::DefineTHnSparse() const
{
  //
  // Defines the THnSparse.
  // could/should remove Pt and leave Ptbin

  const int thnSize2 = 7;
  const double Pi=TMath::Pi();
  TString name;
  name.Form("%s info", GetName());

  // 			       0    1      2      3          4     5         6      
  // 	 	               Pt   Phi   Ptbin  D0InvMass  Eta  'stat D0'  mother 
  int    thnBins[thnSize2] = { 1000,  200, 21,     200,     500,     2,       10  };
  double thnMin [thnSize2] = {    0,    0,  0,    1.5648,   -1.,  -0.5,     -1.5  };
  double thnMax [thnSize2] = {  100, 2*Pi, 20,    2.1648,    1.,   1.5,      8.5  };

  return CreateControlTHnSparse(name,thnSize2,thnBins,thnMin,thnMax,fgkTrackControlBinNames);

}

int AliDxHFEParticleSelectionMCD0::DefineParticleProperties(AliVParticle* p, Double_t* data, int dimension) const
{
  // fill the data array from the particle data
  if (!data) return -EINVAL;
  AliAODTrack *track=(AliAODTrack*)p;
  if (!track) return -ENODATA;
  int i=0;
  // TODO: this corresponds to the THnSparse dimensions which is available in the same class
  // use this consistently
  const int requiredDimension=7;
  if (dimension!=requiredDimension) {
    // TODO: think about filling only the available data and throwing a warning
    return -ENOSPC;
  }
  data[i++]=track->Pt();
  data[i++]=track->Phi();
  data[i++]=AliDxHFEParticleSelectionMCD0::GetPtBin(); 
  data[i++]=AliDxHFEParticleSelectionMCD0::GetInvMass();
  data[i++]=track->Eta();
  data[i++]=fResultMC;     // stat electron (MC electron or not)
  data[i++]=fOriginMother; // at the moment not included background. Should expand

  return i;
}

int AliDxHFEParticleSelectionMCD0::IsSelected(AliVParticle* p, const AliVEvent* pEvent)
{
  /// overloaded from AliDxHFEParticleSelection: check particle
  /// H: Have changed function. Now doing particle selection first, then run MC over 
  /// selected tracks. Could configure it to be configurable, but not sure if it
  /// is needed.  
  /// result from normal track selection is returned, result from MC is stored in
  /// THnSparse. 

  int iResult=0;
  fOriginMother=-1;

  // step 1:
  // MC selection
  if (fMCTools.MCFirst() && (iResult=CheckMC(p, pEvent))==0) {
    // histograming?
    return iResult;
  }

  // step 2 or 1, depending on sequence:
  // normal particle selection
  iResult=AliDxHFEParticleSelectionD0::IsSelected(p, pEvent);
  if (fMCTools.MCFirst() || iResult==0) return iResult;

  // step 2, only executed if MC check is last
  // MC selection  - > Should maybe also distinguish between D0 and D0bar
  iResult=CheckMC(p, pEvent);
  // TODO: why do we need to store the result in a member?
  fResultMC=iResult;
 
  return iResult;
}

int AliDxHFEParticleSelectionMCD0::CheckMC(AliVParticle* p, const AliVEvent* pEvent)
{
  /// check if MC criteria are fulfilled
  // Check both D0 and D0bar (for now only D0)

  if (!p || !pEvent){
    return -EINVAL;
  }
  int iResult=0;

  if (!fMCTools.IsInitialized() && (iResult=fMCTools.InitMCParticles(pEvent))<0) {
    // TODO: message? but has to be filtered in order to avoid message flood
    return 0; // no meaningful filtering on mc possible
  }

  AliAODRecoDecayHF2Prong *particle = dynamic_cast<AliAODRecoDecayHF2Prong*>(p);

  if(!particle) return 0;

  Int_t pdgDgD0toKpi[2]={AliDxHFEToolsMC::kPDGkaon,AliDxHFEToolsMC::kPDGpion};

  TClonesArray* fMCArray = dynamic_cast<TClonesArray*>(fMCTools.GetMCArray());
  if(!fMCArray) {cout << "no array" << endl; return -1;}

  // find associated MC particle for D0->Kpi
  Int_t MClabel=-9999;

  //return MC particle label if the array corresponds to a D0, -1 if not (cf. AliAODRecoDecay.cxx). Checks both D0s and daughters
  MClabel=particle->MatchToMC(AliDxHFEToolsMC::kPDGD0,fMCArray,2,pdgDgD0toKpi); 
  
  if(MClabel<0){
    fOriginMother=-1;
    return 0;
  }

  fMCTools.SetMClabel(MClabel);
  fMCTools.FindMotherPDG(p,AliDxHFEToolsMC::kGetOriginMother);
  fOriginMother=fMCTools.GetOriginMother();

  return 1;
}

void AliDxHFEParticleSelectionMCD0::Clear(const char* option)
{
  /// clear internal memory
  fMCTools.Clear(option);
}