#include "TLorentzVector.h"
#include <vector>


void oneDHist_(){
      TH1F *h1 = new TH1F("h1", "" ,100,0,1000);     
      TH1F *h2 = new TH1F("h2", "" ,100,0,1000);
     // TH1F *h3 = new TH1F("h3", "" ,100,0,1000);
      
      TFile *f1 = new TFile("/eos/user/s/sverma/www/WWTo2L2Nu_hadd_2.root ");
      TFile *f2 = new TFile("/afs/cern.ch/work/s/sverma/Framework/CMSSW_10_6_4/src/PhysicsTools/NanoAODTools/scripts/VBF_hadd_500.root");
     // TFile *f3 = new TFile("Cl1loose2018v7__MCCorr2018v7__l2loose__l2tightOR2018v7__AddLHE_MEs/nanoLatino_VBFHToWWTo2L2Nu_M500__part2.root");


     
      TTree *t1 = (TTree*)f1->Get("Events");
      TTree *t2 = (TTree*)f2->Get("Events");
     // TTree *t3 = (TTree*)f3->Get("Events");
    
    
     const int nParticlesMax = 1000;
     Float_t NeutrinoGen_pt[nParticlesMax], NeutrinoGen_eta[nParticlesMax],NeutrinoGen_phi[nParticlesMax];
     UInt_t  nNeutrinoGen;
      Float_t p_Gen_GG_SIG_kappaTopBot_1_ghz1_1_MCFM;
      Float_t p_Gen_CPStoBWPropRewgt;
      Float_t weight;

     TLorentzVector N1(0.,0.,0.,0.);
     TLorentzVector N2(0.,0.,0.,0.);
     TLorentzVector NN(0.,0.,0.,0.);
     Float_t mass_nn;
 

    t1->SetBranchAddress("NeutrinoGen_pt", &NeutrinoGen_pt);
    t1->SetBranchAddress("NeutrinoGen_eta", &NeutrinoGen_eta);
    t1->SetBranchAddress("NeutrinoGen_phi", &NeutrinoGen_phi);
    t1->SetBranchAddress("nNeutrinoGen", &nNeutrinoGen);
   
   //  unsigned  nNeu(*nNeutrinoGen->Get());
   //  unsigned nLep(*nLeptonGen->Get());
  // TTree->Print();
  // t1->Print();
  //   t1->Scan();
       
     t2->SetBranchAddress("NeutrinoGen_pt", &NeutrinoGen_pt);
     t2->SetBranchAddress("NeutrinoGen_eta", &NeutrinoGen_eta);
     t2->SetBranchAddress("NeutrinoGen_phi", &NeutrinoGen_phi);
    t2->SetBranchAddress("nNeutrinoGen", &nNeutrinoGen);
 
  
  //  t3->SetBranchAddress("NeutrinoGen_pt", &NeutrinoGen_pt);
  //  t3->SetBranchAddress("NeutrinoGen_eta", &NeutrinoGen_eta);
  //  t3->SetBranchAddress("NeutrinoGen_phi", &NeutrinoGen_phi);
  //  t3->SetBranchAddress("nNeutrinoGen", &nNeutrinoGen);

    t1->Print();
///1
    Int_t n1entries = (Int_t)t1->GetEntries();
    for (Int_t i=0; i<n1entries; i++) {
          t1->GetEntry(i);

    
         if (nNeutrinoGen>1) {

        N1.SetPtEtaPhiM(NeutrinoGen_pt[0],NeutrinoGen_eta[0], NeutrinoGen_phi[0],0.);
        N2.SetPtEtaPhiM(NeutrinoGen_pt[1],NeutrinoGen_eta[1],NeutrinoGen_phi[1],0.);
        //cout << N1[0] << endl;
        NN = N1 +N2;
     
      
       mass_nn = NN.M();

       //cout << NN[0] <<endl; 
       // just keep these two lines here for now:
       //float pz_nn = NN.Pz();     
       // cout << "inside"  << pz_nn <<endl;
      }
    
     
        h1->Fill(mass_nn,weight);


}



//////////////////////////////2
 Int_t n2entries = (Int_t)t2->GetEntries();
    for (Int_t i=0; i<n2entries; i++) {
          t2->GetEntry(i);

    
         if (nNeutrinoGen>1) {

        N1.SetPtEtaPhiM(NeutrinoGen_pt[0],NeutrinoGen_eta[0], NeutrinoGen_phi[0],0.);
        N2.SetPtEtaPhiM(NeutrinoGen_pt[1],NeutrinoGen_eta[1],NeutrinoGen_phi[1],0.);
        //cout << N1[0] << endl;
        NN = N1 +N2;
     
      
       mass_nn = NN.M();

       //cout << NN[0] <<endl; 
       // just keep these two lines here for now:
       //float pz_nn = NN.Pz();     
       // cout << "inside"  << pz_nn <<endl;
      }
    
     
        h2->Fill(mass_nn,weight );


}



////////////////////////////////////////////////3
/*
 Int_t n3entries = (Int_t)t3->GetEntries();
    for (Int_t i=0; i<n3entries; i++) {
          t3->GetEntry(i);

    
         if (nNeutrinoGen>1) {

        N1.SetPtEtaPhiM(NeutrinoGen_pt[0],NeutrinoGen_eta[0], NeutrinoGen_phi[0],0.);
        N2.SetPtEtaPhiM(NeutrinoGen_pt[1],NeutrinoGen_eta[1],NeutrinoGen_phi[1],0.);
        //cout << N1[0] << endl;
        NN = N1 +N2;
     
      
       mass_nn = NN.M();

       //cout << NN[0] <<endl; 
       // just keep these two lines here for now:
       //float pz_nn = NN.Pz();     
       // cout << "inside"  << pz_nn <<endl;
      }
    
     
        h3->Fill(mass_nn);


}

*/

//cout << "Trans mass of X"<< Mt_X<<endl;
       

///   Here the other things like TCanvas, TPad, TLegend, TLegendEntry just learn about all these:

h1->SetTitleSize(0.05,"X");
h1->SetTitleSize(0.05,"Y");
h1->SetXTitle("genvv_mass");
h1->SetYTitle("Events");
h1->SetLineColor(kRed);
TCanvas *c1 = new TCanvas("c1", "Transverse mass of X", 1000, 1000);
TPad *gpad = new TPad("gpad", "",0., 0.,1,1);
gpad->Draw();
gpad->cd();
h1->DrawNormalized();
h2->SetLineColor(kBlue);
h2->DrawNormalized("same");
//h3->SetLineColor(kOrange);
//h3->DrawNormalized("same");
//h3->SetLineColor(kGreen);
//h3->DrawNormalized("same");
gpad->Modified();

/////////// Do clear the TLegend Options...........


TLegend *pl = new TLegend(0.3,0.4,0.3,0.4);  //// For time being I have filled this Options bracket like this.
pl->SetTextSize(0.04);
pl->SetFillColor(kYellow);
TLegendEntry *pl1 = pl->AddEntry(h1, "WW","l");
TLegendEntry *pl2 = pl->AddEntry(h2, "h500","l");
//TLegendEntry *pl3 = pl->AddEntry(h2, "h500","l");
//TLegendEntry *pl4 = pl->AddEntry(h3, "Signal","l");
pl1->SetMarkerSize(2.0);
pl1->SetMarkerColor(kRed);
pl2->SetMarkerSize(2.0);
pl2->SetMarkerColor(kBlue);
//pl3->SetMarkerSize(2.0);
//pl3->SetMarkerColor(kOrange);

//pl4->SetMarkerSize(2.0);
//pl4->SetMarkerColor(kGreen);
pl->Draw();

c1->SaveAs("genvv_mass.png");


}