#ifndef __JAANET__JOSCFLUX__
#define __JAANET__JOSCFLUX__

#include "km3net-dataformat/definitions/w2list_gseagen.hh"

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

#include "JLang/JClonable.hh"

#include "JAAnet/JGENIETypes.hh"
#include "JAAnet/JParticleTypes.hh"
#include "JAAnet/JAAnetToolkit.hh"

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

#include "JOscProb/JOscChannel.hh"
#include "JOscProb/JOscProbHelper.hh"
#include "JOscProb/JOscProbInterface.hh"


/**
 * \author bjung
 */

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

namespace JAANET {

  using JLANG::JClonable;
  
  using JOSCPROB::JOscProbHelper;
  using JOSCPROB::JOscProbInterface;
  

  /**
   * Implementation of oscillated neutrino flux.
   */ 
  struct JOscFlux :
    public JClonable<JFlux, JOscFlux>
  {
    /**
     * Constructor.
     *
     * \param  diffuseFlux       diffuse flux function object
     * \param  oscProb           oscillation probability function object
     */
    JOscFlux(const JDiffuseFluxHelper& diffuseFlux,
	     const JOscProbHelper&     oscProb) :
      P(oscProb),
      F(diffuseFlux)
    {}
    
    
    /**
     * Check whether this oscillated neutrino flux object is valid.
     *
     * \return                 true if valid; else false
     */
    bool is_valid() const override final
    {
      return (F && F->is_valid() &&
	      P && P->getParameters().is_valid());
    }
    
    
    /**
     * Get flux for given event.
     *
     * Note that in this evaluation the zenith-angle is defined\n
     * with respect to the line of sight (i.e. a neutrino pointing straight at you\n
     * from the center of the Earth has \f$ cos(\theta) = -1.0 \f$).
     *
     * \param  evt               event
     * \return                   flux  \f$ \left[\mathrm{GeV}^{-1} \, \mathrm{m}^{-2} \, \mathrm{sr}^{-1} \, \mathrm{s}^{-1}\right] \f$
     */
    double getFactor(const Evt& evt) const override final    
    {
      using namespace JPP;

      double flux = 0.0;

      const Trk& neutrino = get_neutrino(evt);
      const double costh  = -neutrino.dir.z;

      const int interactionType = evt.w2list[W2LIST_GSEAGEN_CC];

      if        (interactionType == (int) JInteractionTypeGENIE_t::WEAK_CHARGED_CURRENT) {

	for (int i = 0; i != NUMBER_OF_OSCCHANNELS; ++i) {

	  const JOscChannel& channel = getOscChannel[i];

	  const int inType  = ((int) channel.Cparity) * ((int) channel.in);
	  const int outType = ((int) channel.Cparity) * ((int) channel.out);
	
	  if (outType == neutrino.type) {
	  
	    flux += ( F.getFlux(inType,  log10(neutrino.E), costh) *
		      P.getP   (channel, neutrino.E,        costh) );
	  }
	}
	
      } else if (interactionType == (int) JInteractionTypeGENIE_t::WEAK_NEUTRAL_CURRENT) { // For NC events, the neutrino flavour is irrelevant

	const int Cparity = (int) getChargeParity(neutrino);

	flux += (F.getFlux(Cparity * TRACK_TYPE_NUE,   log10(neutrino.E), costh) +
		 F.getFlux(Cparity * TRACK_TYPE_NUMU,  log10(neutrino.E), costh) +
		 F.getFlux(Cparity * TRACK_TYPE_NUTAU, log10(neutrino.E), costh));
      }
      
      return flux;
    }


    /**
     * Get properties of this class.
     *
     * \param  eqpars          equation parameters
     */
    JProperties getProperties(const JEquationParameters& eqpars = JEvtWeightFactor::getEquationParameters()) override final
    {
      return JOscFluxHelper(*this, eqpars);
    }


    /**
     * Get properties of this class.
     *
     * \param  eqpars          equation parameters
     */
    JProperties getProperties(const JEquationParameters& eqpars = JEvtWeightFactor::getEquationParameters()) const override final
    {
      return JOscFluxHelper(*this, eqpars);      
    }
    
    
    /**
     * Stream input.
     *
     * \param  in              input stream
     * \return                 input stream
     */
    std::istream& read(std::istream& in) override final
    {
      using namespace std;
      using namespace JPP;
      
      if (F) {
	F->read(in);
      }

      if (P) {
	in >> P->getParameters();
      }
      
      check_validity();

      return in;
    }
    
      
  protected:

    JOscProbHelper     P;
    JDiffuseFluxHelper F;


  private:

    /**
     * Auxiliary class for I/O of oscillated flux.
     */
    struct JOscFluxHelper :
      public JProperties
    {
      /**
       * Constructor.
       *
       * \param  oscflux       oscillated flux
       * \param  eqpars        equation parameters 
       */
      template<class JOscFlux_t>
      JOscFluxHelper(JOscFlux_t&                oscflux,
		     const JEquationParameters& eqpars) :
	JProperties(eqpars, 1)
      {
	using namespace JPP;
	
	const JDiffuseFluxHelper& flux    = oscflux.F;
	const JOscProbHelper&     oscprob = oscflux.P;
	
	if (flux)    { this->join(flux.getProperties()); }
	if (oscprob) { this->join(oscprob.getParameters().getProperties()); }
      }
    };
  };
}

#endif