// The class definition in esdV0.h has been generated automatically
// by the ROOT utility TTree::MakeSelector(). This class is derived
// from the ROOT class TSelector. For more information on the TSelector
// framework see $ROOTSYS/README/README.SELECTOR or the ROOT User Manual.

// The following methods are defined in this file:
//    Begin():        called everytime a loop on the tree starts,
//                    a convenient place to create your histograms.
//    SlaveBegin():   called after Begin(), when on PROOF called only on the
//                    slave servers.
//    Process():      called for each event, in this function you decide what
//                    to read and fill your histograms.
//    SlaveTerminate: called at the end of the loop on the tree, when on PROOF
//                    called only on the slave servers.
//    Terminate():    called at the end of the loop on the tree,
//                    a convenient place to draw/fit your histograms.
//
// To use this file, try the following session on your Tree T:
//
// Root > T->Process("AliSelector.C")
// Root > T->Process("AliSelector.C","some options")
// Root > T->Process("AliSelector.C+")
//

#include "AliSelector.h"
#include <TStyle.h>
#include <TSystem.h>
#include <TCanvas.h>
#include <TRegexp.h>

#include <TFriendElement.h>

#include <iostream>
using namespace std;

ClassImp(AliSelector)

AliSelector::AliSelector(TTree *) :
  TSelector(),
  fChain(0),
  fESD(0),
  fHeader(0),
  fRunLoader(0),
  fKineFile(0)
{
  // Constructor. Initialization of pointers
}

AliSelector::~AliSelector()
{
  // Remove all pointers

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

void AliSelector::Begin(TTree *)
{
  // The Begin() function is called at the start of the query.
  // When running with PROOF Begin() is only called on the client.
  // The tree argument is deprecated (on PROOF 0 is passed).

  //TString option = GetOption();
}

void AliSelector::SlaveBegin(TTree * tree)
{
  // The SlaveBegin() function is called after the Begin() function.
  // When running with PROOF SlaveBegin() is called on each slave server.
  // The tree argument is deprecated (on PROOF 0 is passed).

  Init(tree);

  printf("=======SLAVEBEGIN========\n");
  gSystem->Exec("hostname");
  gSystem->Exec("date");
  TFile *f = fChain->GetCurrentFile();
  printf("%s\n",f->GetName());

  TString option = GetOption();
}

void AliSelector::Init(TTree *tree)
{
  // The Init() function is called when the selector needs to initialize
  // a new tree or chain. Typically here the branch addresses of the tree
  // will be set. It is normaly not necessary to make changes to the
  // generated code, but the routine can be extended by the user if needed.
  // Init() will be called many times when running with PROOF.

  printf("=========Init==========\n");

  // Set branch addresses
  if (tree == 0)
  {
    printf("ERROR: tree argument is 0.\n");
    return;
  }

  fChain = dynamic_cast<TChain*> (tree);
  if (fChain == 0)
  {
    printf("ERROR: tree argument could not be casted to TChain.\n");
    return;
  }

  fChain->SetBranchAddress("ESD", &fESD);
  if (fESD != 0)
    printf("INFO: Found ESD branch in chain.\n");

  fChain->SetBranchAddress("Header", &fHeader);
  if (fHeader != 0)
    printf("INFO: Found event header branch in chain.\n");

}

Bool_t AliSelector::Notify()
{
  // The Notify() function is called when a new file is opened. This
  // can be either for a new TTree in a TChain or when when a new TTree
  // is started when using PROOF. Typically here the branch pointers
  // will be retrieved. It is normaly not necessary to make changes
  // to the generated code, but the routine can be extended by the
  // user if needed.

  printf("=========NOTIFY==========\n");
  gSystem->Exec("hostname");
  gSystem->Exec("date");
  TFile *f = fChain->GetCurrentFile();
  TString fileName(f->GetName());
  printf("%s\n",fileName.Data());

  DeleteKinematicsFile();
  DeleteRunLoader();

  return kTRUE;
}

Bool_t AliSelector::Process(Long64_t entry)
{
  // The Process() function is called for each entry in the tree (or possibly
  // keyed object in the case of PROOF) to be processed. The entry argument
  // specifies which entry in the currently loaded tree is to be processed.
  // It can be passed to either TTree::GetEntry() or TBranch::GetEntry()
  // to read either all or the required parts of the data. When processing
  // keyed objects with PROOF, the object is already loaded and is available
  // via the fObject pointer.
  //
  // This function should contain the "body" of the analysis. It can contain
  // simple or elaborate selection criteria, run algorithms on the data
  // of the event and typically fill histograms.

  // WARNING when a selector is used with a TChain, you must use
  //  the pointer to the current TTree to call GetEntry(entry).
  //  The entry is always the local entry number in the current tree.
  //  Assuming that fChain is the pointer to the TChain being processed,
  //  use fChain->GetTree()->GetEntry(entry).

  printf("=========PROCESS========== Entry %lld\n", entry);

  if (!fChain)
  {
    printf("ERROR: fChain is 0.\n");
    return kFALSE;
  }

  fChain->GetTree()->GetEntry(entry);

  if (fESD)
    printf("ESD: We have %d tracks.\n", fESD->GetNumberOfTracks());

  if (fHeader)
    printf("Header: We have %d primaries.\n", fHeader->GetNprimary());

  TTree* kinematics = GetKinematics();
  if (kinematics)
    printf("Kinematics from folder: We have %lld particles.\n", kinematics->GetEntries());

  printf("\n");

  return kTRUE;
}

void AliSelector::SlaveTerminate()
{
  // The SlaveTerminate() function is called after all entries or objects
  // have been processed. When running with PROOF SlaveTerminate() is called
  // on each slave server.

  DeleteKinematicsFile();
  DeleteRunLoader();
}

void AliSelector::Terminate()
{
  // 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.

  printf("=========TERMINATE==========\n");
}

TTree* AliSelector::GetKinematics()
{
  if (!fKineFile)
  {
    if (!fChain->GetCurrentFile())
      return 0;

    TString fileName(fChain->GetCurrentFile()->GetName());
    fileName.ReplaceAll("AliESDs", "Kinematics");

    fKineFile = TFile::Open(fileName);
    if (!fKineFile)
      return 0;
  }

  return dynamic_cast<TTree*> (fKineFile->Get(Form("Event%d/TreeK", fChain->GetTree()->GetReadEntry())));

  /* this is if we want to get it from a TChain

  define it in the header:

    TChain*          fKineChain;

  this creates the chain:

    TChain* chainKine = new TChain("TreeK");
    for (Int_t i=0; i<20; ++i)
      chainKine->Add(Form("test/Kinematics.root/Event%d/TreeK", i));
    for (Int_t i=0; i<20; ++i)
      chainKine->Add(Form("test2/Kinematics.root/Event%d/TreeK", i));

    <mainChain>->GetUserInfo()->Add(chainKine);

  we retrieve it in init:

    fKineChain = dynamic_cast<TChain*> (fChain->GetUserInfo()->FindObject("TreeK"));

  and use it in process:

    if (fKineChain)
    {
      Long64_t entryK = fKineChain->GetTreeOffset()[fChain->GetChainEntryNumber(entry)];
      cout << "Entry in fKineChain: " << entryK << endl;
      fKineChain->LoadTree(entryK);
      TTree* kineTree = fKineChain->GetTree();

      printf("Kinematics from tree friend: We have %lld particles.\n", kineTree->GetEntries());
    }
  */
}

void AliSelector::DeleteKinematicsFile()
{
  if (fKineFile)
  {
    fKineFile->Close();
    delete fKineFile;
    fKineFile = 0;
  }
}

AliRun* AliSelector::GetAliRun()
{
  if (!fRunLoader)
  {
    if (!fChain->GetCurrentFile())
      return 0;

    TString fileName(fChain->GetCurrentFile()->GetName());
    fileName.ReplaceAll("AliESDs", "galice");

    fRunLoader = AliRunLoader::Open(fileName);
    if (!fRunLoader)
      return 0;

    fRunLoader->LoadgAlice();
  }

  return fRunLoader->GetAliRun();
}

void AliSelector::DeleteRunLoader()
{
  if (fRunLoader)
  {
    fRunLoader->Delete();
    fRunLoader = 0;
  }
}