#include <TLatex.h>
#include <TString.h>
#include <iostream>
#include "TPad.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
#include "TTree.h"
#include "TCut.h"
#include "TMath.h"
#include "TFile.h"
#include "TCanvas.h"
#include "RooHist.h"
#include "TLegend.h"

#include "TH1.h"
#include "TVirtualPad.h"
#include "TStyle.h"

using namespace std;
using namespace RooFit;




void fit_fraction_ex(){
  gStyle->SetOptStat(0);
  gStyle->SetOptFit(1);
  TH1F* h00;
  TH1F* h01;
  TH1F* h02;
 string stot[2]={"0.08","0.2"};

  TFile *f = new TFile("Data_hist_2bdt_100_2016BF.root");
  int ch=1, k=0;
  TH1F *h0D =(TH1F*)f->Get(Form("Data_osmdr_ch%d_%d",ch,k));
  h00 =(TH1F*)f->Get(Form("MC_osmdr40_ch%d_%d",ch,k));
  h01 =(TH1F*)f->Get(Form("MC_osmdr41_ch%d_%d",ch,k));
  h02 =(TH1F*)f->Get(Form("MC_osmdr42_ch%d_%d",ch,k));
  
  int nentries_ = h0D->GetEntries();
  cout << "\n=> total entries in data = " << nentries_ << endl;

  TObjArray *mc = new TObjArray(3);
  mc->Add(h00);
  mc->Add(h01);
  mc->Add(h02);
  TFractionFitter* fit = new TFractionFitter(h0D, mc); 
  fit->Constrain(0,0.0,1.0);
  fit->Constrain(1,0.0,1.0);
  fit->Constrain(2,0.0,1.0);
  Int_t status = fit->Fit();
  cout << "fit status: " << status <<"\t chi2 "<<fit->GetChisquare()<<"\t ndf "<<fit->GetNDF()<< endl;
  h0D->SetMarkerStyle(20);

  TH1F* resultmc0 = (TH1F*) fit->GetMCPrediction(0);
  TH1F* resultmc1 = (TH1F*) fit->GetMCPrediction(1);
  TH1F* resultmc2 = (TH1F*) fit->GetMCPrediction(2);
  resultmc0->SetLineColor(2);
  resultmc0->SetMarkerColor(2);
  resultmc0->SetMarkerStyle(24);

  resultmc1->SetLineColor(3);
  resultmc1->SetMarkerColor(3);
  resultmc1->SetMarkerStyle(24);

  resultmc2->SetLineColor(4);
  resultmc2->SetMarkerColor(4);
  resultmc2->SetMarkerStyle(24);
  
  Double_t p0, p1, p2, errP0, errP1, errP2;
  TLatex l;
  l.SetTextSize(.02);
  Char_t texte[200];
  
  TH1F* result = (TH1F*) fit->GetPlot();
  fit->GetResult( 0, p0, errP0);
  printf(" Parameter %d:  estim. %.3f +/- %.3f\n", 0,  p0, errP0);
  fit->GetResult( 1, p1, errP1);
  printf(" Parameter %d:  estim. %.3f +/- %.3f\n", 1,  p1, errP1);
  fit->GetResult( 2, p2, errP2);
  printf(" Parameter %d:  estim. %.3f +/- %.3f\n", 2,  p2, errP2);
  h0D->SetTitle("Data distribution with fitted contributions");
  TCanvas c(Form("canv_ch%d_bdt_%d",ch,k), "FractionFitter example", 600, 600);
  
  h0D->SetTitle("Data distribution with true contributions");
  h0D->DrawClone("EP");      
  resultmc0->SetTitle("MC generated samples with fit predictions");
  resultmc0->Draw("same");
  resultmc1->Draw("same");
  resultmc2->Draw("same");
  result->Draw("same");
  
  sprintf( texte, "%d:  estimated %.3f +/- %.3f\n", 0,  p0, errP0);
  l.DrawTextNDC( .15, .87, texte);
  sprintf( texte, "%d:  estimated %.3f +/- %.3f\n", 1,  p1, errP1);
  l.DrawTextNDC( .15, .85, texte);
  sprintf( texte, "%d:  estimated %.3f +/- %.3f\n", 2,  p2, errP2);
  l.DrawTextNDC( .15, .83, texte);
  //sprintf( texte, "Channel_%d _bdt> %s \n", ch,stot[k].c_str());
  sprintf( texte, "Channel_0&1_bdt> %s \n", stot[k].c_str());
  l.DrawTextNDC( .15, .81, texte);

  
  TLegend* leg3 = new TLegend(0.7,0.7,0.89,0.89);
  leg3->AddEntry(resultmc0,"Gluon fusion","p");
  leg3->AddEntry(resultmc1,"Flavor excitation","p");
  leg3->AddEntry(resultmc2,"Gluon splitting","p");
  leg3->AddEntry(result,"Total MC","f");
  leg3->AddEntry(h0D,"Data","p");
  leg3->Draw();
  
  c.SaveAs(Form("fraction_100bin_combinechan_de_plotch%d_bdt_%s.pdf",ch,stot[k].c_str()));
  //*/  
}