#include "TFile.h"
#include "TCanvas.h"
#include "TH1D.h"
#include "TH1F.h"
#include "TROOT.h"
#include "TPad.h"
#include "TText.h"
#include "TStyle.h"
#include "TPaveStats.h"
#include <cstring>
#include <iostream>

using namespace std ;

inline void WriteStats( char* txt, Double_t s, Double_t posx, Double_t posy )
{
  char text[100] ;
  sprintf( text , "%s Entries %f" , txt, s ) ;
  cout << text << " " << posx << " " << posy<< endl ;

  TText t(posx,posy,text ) ;
  t.SetTextSize(0.5) ;
  t.Draw() ;
}
inline TH1D* GetHist( char* hname, char* str, char* HistFile )
{
  TFile f( HistFile ) ;
  cout << " Open File " << HistFile << endl ;
  gROOT->cd() ;
  char histName[100] ;
  strcpy( histName, hname ) ;
  std::strcat( histName,str ) ;
  cout << " Get Histogram " << histName << endl ;
  TH1D* h = dynamic_cast<TH1D*>( f.Get(histName)->Clone() ) ;
  f.Close();

  h->SetLineWidth( 2 ) ;
  h->SetMarkerSize( 0.75 ) ;
  //  if( strcmp( str,"p" ) >= 0 || strcmp( str,"p_sel") >0 )
  if( strcmp( str,"p" ) >= 0 )
    {
      h->SetMarkerStyle( 20 ) ;  
      h->SetMarkerColor( 36 ) ;
      h->SetLineColor( 36 ) ;
    }
  else
    {
      h->SetMarkerStyle( 20 ) ;  
      h->SetMarkerColor( 46 ) ;
      h->SetLineColor( 46 ) ;
    }
  return h ;
}
void PlotHisto( char* hname, char* RootFile ="" , bool LogScale=false )
{
  gStyle->SetOptStat(10) ;
  TCanvas *TC = new TCanvas("TC","Charged Tracks") ;
  TPad* p1 = new TPad("p1","No Cut",0.01,0.20,0.49,0.99) ;
  TPad* p2 = new TPad("p2","Selected",0.51,0.20,0.99,0.99) ;
  TPad* p3 = new TPad("p3","Ratio No Cut",0.01,0.01,0.49,0.19) ;
  TPad* p4 = new TPad("p4","Ratio Selected",0.51,0.01,0.99,0.19) ;

  p1->Draw() ;  p2->Draw() ;  p3->Draw() ;  p4->Draw() ;

  if( LogScale ) { p1->SetLogy()  ; p2->SetLogy() ; }
  p1->cd() ;
  TH1D* hm = GetHist( hname ,"m", RootFile ) ;
  if( hm == 0 ) 
    {
      cout << hname << " not found . Stop execution " << endl ;
      return ;
    }

  hm->Draw("error") ;
  // WriteStats( "-",hm->GetSum(), 0.5 , 0.90*hm->GetMaximum() ) ;

  TPaveStats *stt = (TPaveStats*) hm->GetListOfFunctions()->FindObject("stats") ;
  //  cout << stt->GetX1() << endl ;

  TH1D* hp = GetHist( hname ,"p", RootFile ) ;
  hp->DrawCopy("sameserror") ;
  // WriteStats( "+",hp->GetSum(), 0.5, 0.95*hp->GetMaximum() ) ;

  TH1D* r = (TH1D*) hp->Clone() ;
  r->Sumw2() ; r->SetStats( kFALSE ) ;
  r->Divide( hm ) ; r->SetMaximum(1.2) ; r->SetMinimum(0.8) ;
  p3->cd() ;
  r->SetMarkerSize(0.5) ;
  r->DrawCopy("error") ;

  p2->cd() ;
  TH1D* hms = GetHist( hname ,"m_sel", RootFile ) ;
  hms->DrawCopy("error") ;
  TH1D* hps = GetHist( hname ,"p_sel", RootFile ) ;
  hps->DrawCopy("sameserror") ;

  TH1D* rs = (TH1D*) hps->Clone("Ratio") ;
  rs->SetMarkerSize(0.5) ;
  rs->Sumw2() ; rs->SetStats( kFALSE ) ;
  rs->Divide( hms ) ; rs->SetMaximum(1.2) ; rs->SetMinimum(0.8) ;
  p4->cd() ;
  rs->DrawCopy("error") ;

}