// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Tools/BinnedHistogram.hh"

namespace Rivet {


  /// Jet mass as a function of ystar
  class ATLAS_2014_I1325553 : public Analysis {
  public:

    /// Constructor
    ATLAS_2014_I1325553()
      : Analysis("ATLAS_2014_I1325553")
    {    }


    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {

      const FinalState fs;
      addProjection(fs,"FinalState");

      FastJets fj04(fs,  FastJets::ANTIKT, 0.4);
      fj04.useInvisibles();
      addProjection(fj04, "AntiKT04");

      FastJets fj06(fs,  FastJets::ANTIKT, 0.6);
      fj06.useInvisibles();
      addProjection(fj06, "AntiKT06");

      double ybins[] = {0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0};

      size_t ptDsOffset(0);
      for (size_t alg = 0; alg < 2; ++alg) {
        for (size_t i = 0; i < 6; ++i) {
          _pt[alg].addHistogram(ybins[i], ybins[i + 1], bookHisto1D(1 + ptDsOffset, 1, i + 1));
        }
        ptDsOffset += 1;
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      Jets jetAr[2];
      jetAr[AKT4] = applyProjection<FastJets>(event, "AntiKT04").jetsByPt(100*GeV);
      jetAr[AKT6] = applyProjection<FastJets>(event, "AntiKT06").jetsByPt(100*GeV);

      // Loop over jet "radii" used in analysis
      for (size_t alg = 0; alg < 2; ++alg) {

        // fill the 1D pt histograms with all the jets passing the cuts
        foreach (const Jet& jet, jetAr[alg]) {
          const double absrap = jet.absrap();
          if (absrap < 3.0) {
	          const double pt = jet.pT();
	          if (pt/GeV > 100*GeV) {
	            _pt[alg].fill(absrap, pt/GeV, event.weight());
	          }
          }
        }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {


      /// Print summary info
      const double xs_pb( crossSection() / picobarn );
      const double sumW( sumOfWeights() );
      const double xs_norm_factor( xs_pb / sumW );
      MSG_INFO( "Cross-Section/pb     : " << xs_pb       );
      MSG_INFO( "Sum of weights       : " << sumW        );
      MSG_INFO( "nEvents              : " << numEvents() );

      for (size_t alg = 0; alg < 2; ++alg) {
        _pt[alg].scale(xs_norm_factor, this);
      }
    }

    //@}


  private:

    // Data members like post-cuts event weight counters go here
    enum Alg { AKT4=0, AKT6=1 };

    /// The inclusive jet spectrum binned in rapidity for akt6 and akt4 jets (array index is jet type from enum above)
    BinnedHistogram<double> _pt[2];

  };


  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(ATLAS_2014_I1325553);

}