// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
/// @todo Include more projections as required, e.g. ChargedFinalState, FastJets, ZFinder...

namespace Rivet {


  class MC_STATUS3TEST : public Analysis {


    class StatusThreeParticles : public ParticleFinder {
      
    public:

      StatusThreeParticles(const Cut& c=Cuts::open()) {
        setName("StatusThreeParticles");
        const bool open = ( c == Cuts::open() );
        if (!open) addProjection(StatusThreeParticles(), "OpenStatusThreeParticles");
      }

      virtual const Projection* clone() const {
        return new StatusThreeParticles(*this);
      }

      virtual void project(const Event& e) {
        _theParticles.clear();

        if ( _cuts == Cuts::open() ) {
          foreach (const GenParticle* p, Rivet::particles(e.genEvent())) {
            if (p->status() == 3) _theParticles.push_back(Particle(*p));
          }
          return;
        }

        const Particles allstable = applyProjection<StatusThreeParticles>(e, "OpenStatusThreeParticles").particles();
        foreach (const Particle& p, allstable) {
          const bool passed = accept(p);
          if (passed) _theParticles.push_back(p);
        }
      }

      virtual int compare(const Projection& p) const {
        const StatusThreeParticles& other = dynamic_cast<const StatusThreeParticles&>(p);
        return _cuts == other._cuts ? EQUIVALENT : UNDEFINED;
      }

      virtual bool accept(const Particle& p) const {
        assert(p.genParticle() == NULL || p.genParticle()->status() == 3);
        return _cuts->accept(p);
      }
    };


    
  public:

    /// Constructor
    MC_STATUS3TEST()
      : Analysis("MC_STATUS3TEST")
    {    }


    /// @name Analysis methods
    //@{

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

      /// @todo Initialise and register projections here
      addProjection(StatusThreeParticles(), "status3");

      /// @todo Book histograms here, e.g.:
      // _h_XXXX = bookProfile1D(1, 1, 1);
      // _h_YYYY = bookHisto1D(2, 1, 1);

    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const double weight = event.weight();

      /// @todo Do the event by event analysis here

    }


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

      /// @todo Normalise, scale and otherwise manipulate histograms here

      // scale(_h_YYYY, crossSection()/sumOfWeights()); // norm to cross section
      // normalize(_h_YYYY); // normalize to unity

    }

    //@}


  private:

    // Data members like post-cuts event weight counters go here


    /// @name Histograms
    //@{
    Profile1DPtr _h_XXXX;
    Histo1DPtr _h_YYYY;
    //@}


  };



  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(MC_STATUS3TEST);


}