#ifndef __JAANET__JFLATFLUX__
#define __JAANET__JFLATFLUX__

#include "JAAnet/JEvtWeightFactorFunction.hh"


/**
 * \author bjung
 */

namespace JAANET {}
namespace JPP { using namespace JAANET; }

namespace JAANET {


  /**
   * Function object for constant fluxes.
   */
  struct JFlatFlux
  {
    /**
     * Default constructor.
     */
    JFlatFlux() :
      flux(0.0)
    {}
    
    
    /**
     * Constructor.
     *
     * \param                  flux         [GeV * m^-2 * sr^-1 * s^-1]
     */
    JFlatFlux(const double flux) :
      flux(flux)
    {}
    
    
    /**
     * Get flux of given event.
     *
     * \param  evt             event
     * \return                 flux         [GeV * m^-2 * sr^-1 * s^-1]
     */
    double operator()(const Evt& evt) const
    {
      return flux;
    }
    
    
    /**
     * Stream input.
     *
     * \param  in                     input stream
     * \param  object                 uniform flux
     * \return                        input stream
     */
    friend inline std::istream& operator>>(std::istream& in, JFlatFlux& object)
    {
      in >> object.flux;

      return in;
    }
    
    
    /**
     * Write flux to output stream.
     *
     * \param  out                    output stream
     * \param  object                 uniform
     * \return                        output stream
     */
    friend inline std::ostream& operator<<(std::ostream& out, const JFlatFlux& object)
    {
      const JFormat format(out);
      
      out << FIXED(5,3) << object.flux;
      
      return out;
    }
    
    double flux;    //!< flux         [GeV * m^-2 * sr^-1 * s^-1]
  };


  /**
   * Auxiliary method for creating an interface to a flat flux function.
   *
   * \param  flux                     flux [GeV * m^-2 * sr^-1 * s^-1]
   */
  inline JEvtWeightFactorFunction<JFlatFlux, JFlux> make_flatFluxFunction(const double flux) {

    const JFlatFlux flatFlux(flux);
    
    return make_fluxFunction(flatFlux);
  }
}

#endif