#include "TH1.h"
#include "TFile.h"
#include "TChain.h"
#include "TTree.h"

#include <iostream>
#include <iomanip>
#include <vector>


//Need to declare as global the variables that will be used for the branches.
//Otherwise it will not compile
std::vector<double> *T_Muon_Px;

void analisis(TString signal){
  
  
  
  cout << ">> Creating the chain..." << endl;
  TChain *suma = new TChain("Tree");
  
  //Signal 
  
  if (signal=="TTbar7"){suma->Add("/hadoop/JF/TTreeWithPfLeptons/TTreeWithPfLeptons_TTbar_7TeV_Skim2MuPt2010/*");}
  
  
  //Find the number of entries in this dataset
  cout << ">> Calculating the number of events..." << endl;
  int nEvents = suma->GetEntries();
  cout << endl;
  cout << "------------------------------------------" << endl;
  cout << nEvents << " raw Events (no weighted)" << endl;
  cout << "------------------------------------------" << endl;
  
  
  //Read Branches from the MiniTree
  cout << ">> Setting the branches... " << endl;
  suma->SetBranchAddress("T_Muon_Px", &T_Muon_Px);  
  
  
  //Create the root file 
  cout << ">> Creating the output file ..." << endl;
  TString histoFileName("histo");
  histoFileName+=signal;
  histoFileName+=".root";
  TFile histoAnalisis(histoFileName, "RECREATE");
  if (histoAnalisis.IsOpen())
    cout << "   ... \"" << histoFileName << "\" created" << endl;
  else {
    cout << "   ... ERROR: \""<< histoFileName 
	 << "\" already exists. Remove it." << endl;
    return;
  }
  
  
  
  
  //Define histograms
  cout << ">> Creating histograms..." << endl;
  TH1F *histoPxmuon=new TH1F("histoPxmuon", "Px muon", 100, 0, 300);
  
  
  
  
  /////////////////////////////////////////////////////////////////////////
  //  
  // Event loop
  //
  //
  cout << ">> Looping over the events..." << endl;
  // Small trick for the output
  unsigned int ndigits=log10(abs(nEvents))+1;
  char* strdelete= new char[ndigits+1];
  for (unsigned int i=0; i<ndigits;i++)
    strdelete[i]='\b';
  strdelete[ndigits]='\0';

  //Let's loop
  int event = 0;
  for(event = 0; event<nEvents; event++){

    //Output number of events every 100 events... with a small trick
    if ((event % 100) == 0)
      cout << strdelete << setw(ndigits) << setfill('-') << event << flush;

    //Charge the entry values on the branch variables
    suma->GetEntry(event);

    //Loop over muons storing the Px
    for (unsigned int i=0; i < T_Muon_Px->size(); i++){
      histoPxmuon->Fill(T_Muon_Px->at(i));
    }
  }
  //Final loop output
  cout << strdelete << setw(ndigits) << setfill('-') << event << flush;
  
  
  
  cout << endl << ">> Writting and closing output file..." << endl;
  histoAnalisis.Write();
  histoAnalisis.Close();
  
  
  cout << "------------------------------------------" << endl;
  cout << endl;
  
  
  
}