// -*- C++ -*-
#ifndef RIVET_AtlasCommon_HH
#define RIVET_AtlasCommon_HH

#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/SingleValueProjection.hh"
#include "Rivet/Projections/TriggerProjection.hh"

/// @file Common projections for RHIC experiments' trigger conditions and centrality.
namespace Rivet {


  class STAR_BES_Centrality : public SingleValueProjection {
  public:

    STAR_BES_Centrality() {
      declare(ChargedFinalState(Cuts::abseta < 0.5 &&
                                Cuts::absrap < 0.1 && Cuts::pT > 0.2 * GeV),
              "STAR_BES_Centrality");
    }

    // Destructor
    virtual ~STAR_BES_Centrality() {}

    /// Clone on the heap.
    DEFAULT_RIVET_PROJ_CLONE(STAR_BES_Centrality);

    /// Import to avoid warnings about overload-hiding
    using Projection::operator =;

  protected:

    void project(const Event& e) {
      clear();
      double estimate =
        apply<FinalState>(e, "STAR_BES_Centrality").particles().size();
      set(estimate);
    }

    /// Compare projections
    virtual CmpState compare(const Projection& p) const {
      return mkNamedPCmp(p, "STAR_BES_Centrality");
    }

  };


  /// @brief BRAHMS Centrality projection.
  class BRAHMSCentrality : public SingleValueProjection {
  public:

    // Constructor
    BRAHMSCentrality() : SingleValueProjection() {
      // Using here the BRAHMS reaction centrality from eg. 1602.01183, which
      // might not be correct.
      declare(ChargedFinalState(Cuts::pT > 0.1*GeV && Cuts::abseta < 2.2),
              "ChargedFinalState");
    }

    // Destructor
    virtual ~BRAHMSCentrality() {}

    // Clone on the heap.
    DEFAULT_RIVET_PROJ_CLONE(BRAHMSCentrality);

    /// Import to avoid warnings about overload-hiding
    using Projection::operator =;

  protected:

    // Do the projection. Count the number of charged particles in
    // the specified range.
    virtual void project(const Event& e) {
      clear();
      set(apply<ChargedFinalState>
          (e, "ChargedFinalState").particles().size());
    }

    // Compare to another projection.
    virtual CmpState compare(const Projection& p) const {
      return mkNamedPCmp(p, "BRAHMSCentrality");
    }

  };


}

#endif
