#include <string>
#include <iostream>

#include <TH1.h>
#include <TH2.h>

#include <RooMsgService.h>
#include <RooRealVar.h>
#include <RooDataHist.h>
#include <RooHistPdf.h>
#include <RooDataSet.h>

static inline void RemoveTopic(RooFit::MsgTopic pTopic) {
  RooMsgService::instance().getStream(0).removeTopic(pTopic);
  RooMsgService::instance().getStream(1).removeTopic(pTopic);
}

static inline double GenerateFromPdf(RooAbsPdf& pPdf, RooRealVar& pVar) {
  RooDataSet* data = pPdf.generate(
      RooArgSet(pVar), 1,
      RooFit::AutoBinned(kFALSE));  // this creates the correct distribution if
                                    // called often enough
  const RooArgSet* args = data->get(0);
  RooRealVar* var = dynamic_cast<RooRealVar*>(args->find(pVar));
  double value = var->getVal();
  delete data;
  return value;
}

struct HistogramWrapper {
  HistogramWrapper(TH1* pHistogram)
      : Histogram(pHistogram),
        Var((std::string("Var_") + pHistogram->GetName()).c_str(),
            pHistogram->GetTitle(), pHistogram->GetXaxis()->GetXmin(),
            pHistogram->GetXaxis()->GetXmax()),
        Data((std::string("Data_") + pHistogram->GetName()).c_str(),
             pHistogram->GetTitle(), RooArgList(Var), Histogram),
        Pdf((std::string("Pdf_") + pHistogram->GetName()).c_str(),
            pHistogram->GetTitle(), RooArgSet(Var), Data) {}

  double Get() { return GenerateFromPdf(Pdf, Var); }

  TH1* Histogram;
  RooRealVar Var;
  RooDataHist Data;
  RooHistPdf Pdf;
};

int main() {
  RemoveTopic(RooFit::DataHandling);
  for (std::size_t index = 0; index < 1e9; ++index) {
    if (index && index % 10000 == 0)
      std::cout << index << " of " << 1e9 << std::endl;
    TH1D hist("hist", "hist", 100, 0, 100);
    for (std::size_t bin = 1; bin < 101; ++bin) hist.SetBinContent(bin, bin);
    HistogramWrapper wrapper(&hist);
    wrapper.Get();
  }

  return 0;
}