#ifndef __JOSCPROB__JOSCPROBFUNCTION__
#define __JOSCPROB__JOSCPROBFUNCTION__

#include "JLang/JClonable.hh"

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


/**
 * \author bjung
 */

namespace JOSCPROB {

  using JLANG::JClonable;

  
  /**
   * Implementation of oscillation probability function interface.
   *
   * The template argument refers to a function of which the copy constuctor needs to be defined.
   */
  template<class JFunction_t>
  struct JOscProbFunction :
    public JClonable<JOscProb, JOscProbFunction<JFunction_t> >
  {
    /**
     * Constructor.
     * 
     * \param  function           oscillation probability function
     */
    JOscProbFunction(const JFunction_t& function) :
      function(function)
    {}


    /**
     * Get oscillation probability for given oscillation channel.
     *
     * \param  channel            oscillation channel
     * \param  energy             neutrino energy     [GeV]
     * \param  costh              cosine zenith angle
     * \return                    oscillation probability
     */
    double getOscProb(const JOscChannel& channel,
		      const double       energy,
		      const double       costh) const override
    {
      return function(channel, energy, costh);
    }

  private:

    JFunction_t function;    //!< oscillation probability function
  };

  
  /* Type definition of pointer to oscillation probability function. */
  typedef double (*pOscProb)(const JOscChannel&, const double, const double);

  
  /**
   * Implementation of C-style oscillation probability function.
   */
  template<>
  struct JOscProbFunction<pOscProb> :
    public JClonable< JOscProb, JOscProbFunction<pOscProb> >
  {
    /** 
     * Constructor.
     *
     * \param  pFunction         oscillation probability function
     */
    JOscProbFunction(pOscProb pFunction) :
      pFunction(pFunction)
    {}
    

    /**
     * Get oscillation probability for given oscillation channel.
     *
     * \param  channel            oscillation channel
     * \param  energy             neutrino energy     [GeV]
     * \param  costh              cosine zenith angle
     * \return                    oscillation probability
     */
    double getOscProb(const JOscChannel& channel,
		      const double       energy,
		      const double       costh) const override
    {
      return (*pFunction)(channel, energy, costh);
    }
    
  private:    

    pOscProb pFunction;
  };


  /**
   * Auxiliary method for creating an interface to an oscillation probability function.
   *
   * \param  function             oscillation probability function object
   * \return                      oscillation probability function interface
   */
  template<class JFunction_t>
  inline JOscProbFunction<JFunction_t> make_oscProbFunction(const JFunction_t& function) {
    return JOscProbFunction<JFunction_t>(function);
  }  


  /**
   * Auxiliary method for creating an interface to an oscillation probability function.
   *
   * \param  function             oscillation probability function pointer
   * \return                      oscillation probability function interface
   */
  inline JOscProbFunction<pOscProb> make_oscProbFunction(pOscProb function) {
    return JOscProbFunction<pOscProb>(function);
  }
}

#endif