#ifndef __CINT__
#include "RooGlobalFunc.h"
#include <vector>
#endif
#include <sstream>
#include <vector>
#include "RooRealVar.h"
#include "RooDataHist.h"
#include "RooHistPdf.h"
#include "RooArgList.h"
#include "RooAddPdf.h"
#include "RooFitResult.h"
#include "TH1D.h"

/* 
   Jim Henderson 03/06/14
   Problem - idea was to write a class that can take any number of template histograms and fit them to a data histo
           - it is observed that if we try to fill the vector of RooHistPdfs in the same loop as the RooDataHists we get a seg. fault
	   - This can be avoided by filling the RooHistPdfs vector in a separate, identical loop
			     
   To observed the seg fault, comment out lines 60-63
			     
*/
  
void badLoop()
{

  TH1D* data = new TH1D("data","data",3,-0.5,2.5);
  TH1D* mc1 = new TH1D("mc1","mc1",3,-0.5,2.5);
  TH1D* mc2 = new TH1D("mc2","mc2",3,-0.5,2.5);

  std::vector<TH1D*> mc_hists;
  mc_hists.push_back( mc1 );
  mc_hists.push_back( mc2 );

  data->Fill(1);
  mc1->Fill(1);
  mc2->Fill(2);
  
  RooRealVar  fit_variable("fit_variable","fit_variable", -0.5, 2.5);
  RooDataHist data_RooDataHist("data_RooDataHist", "data_RooDataHist", fit_variable, RooFit::Import(*data));
  std::vector< RooDataHist > mc_RooDataHists;
  std::vector< RooRealVar > mc_integrals;
  std::vector< RooHistPdf > mc_RooHistPdf;
  
  for ( int mc_it = 0; mc_it < mc_hists.size(); mc_it++ ){
    std::stringstream mc_component;
    mc_component << mc_it;
    mc_RooDataHists.push_back( RooDataHist( ( "RooDataHist_" + mc_component.str() ).c_str(), 
					    ( "RooDataHist_" + mc_component.str() ).c_str(), 
					    fit_variable, 
					    RooFit::Import( *(mc_hists.at(mc_it)) ) ) );

    mc_integrals.push_back( RooRealVar( ( "mc_integrals_" + mc_component.str() ).c_str(), 
					( "mc_integrals_" + mc_component.str() ).c_str(),
					mc_hists.at(mc_it)->Integral(),
					0.0,
					10.0 * mc_hists.at(mc_it)->Integral() ) );
    /*
  }                                                            // Comment me out - to see seg fault
  for ( int mc_it = 0; mc_it < mc_hists.size(); mc_it++ ){     // Comment me out
    std::stringstream mc_component;                            // Comment me out 
    mc_component << mc_it;                                     // Comment me out
    */
    mc_RooHistPdf.push_back( RooHistPdf( ( "mcRooHistPdf_" + mc_component.str() ).c_str(), 
					 ( "mcRooHistPdf_" + mc_component.str() ).c_str(), 
					 fit_variable, 
					 mc_RooDataHists.at(mc_it) ) );
  }

  RooArgList mc_RooHistPdfArgList( mc_RooHistPdf.at(0),  mc_RooHistPdf.at(1) );
  RooArgList mc_integralsArgList( mc_integrals.at(0), mc_integrals.at(1) );

  RooAddPdf model( "model", "model", mc_RooHistPdfArgList, mc_integralsArgList );
  RooFitResult* result =  model.fitTo( data_RooDataHist );

  delete data; delete mc1; delete mc2;
  delete result;
}