#ifndef __JAANET__JEVTWEIGHTFACTORFUNCTION__
#define __JAANET__JEVTWEIGHTFACTORFUNCTION__

#include "km3net-dataformat/offline/Evt.hh"

#include "flux/Flux.hh"

#include "JLang/JClonable.hh"

#include "JAAnet/JEvtWeightFactor.hh"
#include "JAAnet/JFlux.hh"
#include "JAAnet/JDiffuseFlux.hh"


/**
 * \author bjung
 */

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

namespace JAANET {
  
  using JLANG::JClonable;
  
  
  /**
   * Implementation of event-weight factor interface.
   *
   * The first template argument refers to a function of which the copy constuctor needs to be defined.
   * The second template argument corresponds to the desired event-weight factor interface class.
   */
  template<class JFunction_t,
	   class JEvtWeightFactor_t>
  struct JEvtWeightFactorFunction :
    public JClonable<JEvtWeightFactor_t, JEvtWeightFactorFunction<JFunction_t,
								  JEvtWeightFactor_t> >
  {
    /** 
     * Constructor.
     *
     * \param  function          function for event-weight factor
     */
    JEvtWeightFactorFunction(const JFunction_t& function) :
      function(function)
    {}

    
    /**
     * Get weight-factor for given event.
     *
     * \param  evt               event
     * \return                   event-weight factor
     */
    double getFactor(const Evt& evt) const override
    {
      return function(evt);
    }
    
  private:
    
    JFunction_t function; //!< event-weight factor object.
  };


  /**
   * Implementation of event-weight factor interface for diffuse flux objects.
   *
   * The template argument corresponds to a function of which the copy constructor needs to be defined.
   */
  template<class JDiffuseFluxFunction_t>
  struct JEvtWeightFactorFunction<JDiffuseFluxFunction_t, JDiffuseFlux> :
    public JClonable<JDiffuseFlux, JEvtWeightFactorFunction<JDiffuseFluxFunction_t,
							    JDiffuseFlux> >
  {
    /**
     * Constructor.
     *
     * \param  function          flux function
     */
    JEvtWeightFactorFunction(const JDiffuseFluxFunction_t& function) :
      function(function)
    {}


    /**
     * Get event-weight factor for given particle PDG-identifier, energy and zenith-angle.
     *
     * \param  type              PDG particle type
     * \param  log10E            logarithmic neutrino energy [GeV]
     * \param  costh             cosine zenith angle
     * \return                   event-weight factor
     */
    double dNdEdOmega(int    type,
		      double log10E,
		      double costh) const override
    {
      return function.dNdEdOmega(type, log10E, costh);
    }
    
  private:
    
    JDiffuseFluxFunction_t function; //!< diffuse flux function object
  };
  

  /** Type definition of event-weight factor pointer. */
  typedef double (*pEvtWeightFactor)(const Evt&);


  /** Type definition of flux function pointer. */
  using pFlux = pEvtWeightFactor;
  
  
  /**
   * Implementation of C-style event-weight factor.
   *
   * The template argument refers to the desired event-weight factor interface class.
   */
  template<class JEvtWeightFactor_t>
  struct JEvtWeightFactorFunction<pEvtWeightFactor, JEvtWeightFactor_t> :
    public JClonable<JEvtWeightFactor_t, JEvtWeightFactorFunction<pEvtWeightFactor,
								  JEvtWeightFactor_t> >
  {
    /** 
     * Constructor.
     *
     * \param  pFunction         pointer to event-weight factor
     */
    JEvtWeightFactorFunction(pEvtWeightFactor pFunction) :
      pFunction(pFunction)
    {}
    
    
    /**
     * Get weight-factor for given event.
     *
     * \param  evt               event
     * \return                   event-weight factor
     */
    double getFactor(const Evt& evt) const override
    {
      return (*pFunction)(evt);
    }
    
  private:    

    pEvtWeightFactor pFunction; //!< Event-weight factor pointer.
  };

  
  /** Type definition of pointer to diffuse flux function. */
  typedef double (*pDiffuseFlux)(int, double, double);

    
  /**
   * Implementation of C-style diffuse flux event-weight factor.
   */
  template<>
  struct JEvtWeightFactorFunction<pDiffuseFlux, JDiffuseFlux> :
    public JClonable<JDiffuseFlux, JEvtWeightFactorFunction<pDiffuseFlux,
							    JDiffuseFlux> >
  {
    /** 
     * Constructor.
     *
     * \param  pFunction         pointer to diffuse flux function
     */
    JEvtWeightFactorFunction(pDiffuseFlux pFunction) :
      pFunction(pFunction)
    {}
    
    /**
     * Get event-weight factor for given particle PDG-identifier, energy and zenith-angle.
     *
     * \param  type              PDG particle type
     * \param  log10E            logarithmic neutrino energy [GeV]
     * \param  costh             cosine zenith angle
     * \return                   event-weight factor
     */
    double dNdEdOmega(int    type,
		      double log10E,
		      double costh) const override
    {
      return (*pFunction)(type, log10E, costh);
    }
    
  private:    

    pDiffuseFlux pFunction; //!< Pointer to diffuse flux function.
  };
  


  /**
   * Auxiliary method for creating an interface to an event-weight factor.
   *
   * \param  function             function object
   * \return                      event-weight factor interface
   */
  template<class JFunction_t, class JEvtWeightFactor_t = JEvtWeightFactor>
  inline JEvtWeightFactorFunction<JFunction_t, JEvtWeightFactor_t> make_weightFactor(const JFunction_t& function) {
    return JEvtWeightFactorFunction<JFunction_t, JEvtWeightFactor_t>(function);
  }  


  /**
   * Auxiliary method for creating an interface to an event-weight factor.
   *
   * \param  function             function pointer
   * \return                      event-weight factor interface
   */
  template<class JEvtWeightFactor_t = JEvtWeightFactor>
  inline JEvtWeightFactorFunction<pEvtWeightFactor, JEvtWeightFactor_t> make_weightFactor(pEvtWeightFactor function) {
    return JEvtWeightFactorFunction<pEvtWeightFactor, JEvtWeightFactor_t>(function);
  }


  /**
   * Auxiliary method for creating an interface to a flux function.
   *
   * \param  flux                 flux function object
   * \return                      flux function interface
   */
  template<class JFunction_t>
  inline JEvtWeightFactorFunction<JFunction_t, JFlux> make_fluxFunction(const JFunction_t& flux) {
    return JEvtWeightFactorFunction<JFunction_t, JFlux>(flux);
  }


  /**
   * Auxiliary method for creating an interface to a flux function.
   *
   * \param  flux                 flux function pointer
   * \return                      flux function interface
   */
  inline JEvtWeightFactorFunction<pFlux, JFlux> make_fluxFunction(pFlux flux) {
    return JEvtWeightFactorFunction<pFlux, JFlux>(flux);
  }


  /**
   * Auxiliary method for creating an interface to a diffuse flux function.
   *
   * \param  flux                 diffuse flux function object
   * \return                      diffuse flux function interface
   */
  template<class JFunction_t>
  inline JEvtWeightFactorFunction<JFunction_t, JDiffuseFlux> make_diffuseFluxFunction(const JFunction_t& flux) {
    return JEvtWeightFactorFunction<JFunction_t, JDiffuseFlux>(flux);
  }


  /**
   * Auxiliary method for creating an interface to a diffuse flux function.
   *
   * \param  flux                 diffuse flux function pointer
   * \return                      diffuse flux function interface
   */
  inline JEvtWeightFactorFunction<pDiffuseFlux, JDiffuseFlux> make_diffuseFluxFunction(pDiffuseFlux flux) {
    return JEvtWeightFactorFunction<pDiffuseFlux, JDiffuseFlux>(flux);
  }
}

#endif