// -*- C++ -*-
#include "Rivet/Analyses/MC_JetAnalysis.hh"
#include "Rivet/Projections/ZFinder.hh"
#include "Rivet/Projections/FastJets.hh"

namespace Rivet {


  /// @brief MC validation analysis for Higgs [-> tau tau] + jets events
  class MC_HJETS1 : public MC_JetAnalysis {
  public:

    /// Default constructor
    MC_HJETS1()
      : MC_JetAnalysis("MC_HJETS1", 4, "Jets")
    {    }


    /// @name Analysis methods
    //@{

    /// Book histograms
    void init() {
      IdentifiedFinalState hfinder(FinalState(), 25);
      declare(hfinder, "Hfinder");
      FastJets jetpro(VetoedFinalState(FinalState(),25), FastJets::ANTIKT, 0.4);
      declare(jetpro, "Jets");

      book(_h_H_jet1_deta ,"H_jet1_deta", 50, -5.0, 5.0);
      book(_h_H_jet1_dR ,"H_jet1_dR", 25, 0.5, 7.0);

      MC_JetAnalysis::init();
    }



    /// Do the analysis
    void analyze(const Event & e) {
      const FinalState& hfinder = apply<FinalState>(e, "Hfinder");
      if (hfinder.size() != 1) vetoEvent;

      FourMomentum hmom(hfinder.particles()[0].momentum());
      const Jets& jets = apply<FastJets>(e, "Jets").jetsByPt(_jetptcut);
      if (jets.size() > 0) {
        _h_H_jet1_deta->fill(hmom.eta()-jets[0].eta());
        _h_H_jet1_dR->fill(deltaR(hmom, jets[0].momentum()));
      }

      MC_JetAnalysis::analyze(e);
    }


    /// Finalize
    void finalize() {
      normalize(_h_H_jet1_deta, crossSection()/picobarn);
      normalize(_h_H_jet1_dR, crossSection()/picobarn);
      MC_JetAnalysis::finalize();
    }

    //@}


  private:

    /// @name Histograms
    //@{
    Histo1DPtr _h_H_jet1_deta;
    Histo1DPtr _h_H_jet1_dR;
    //@}

  };



  // The hook for the plugin system
  RIVET_DECLARE_PLUGIN(MC_HJETS1);

}