#ifndef __JAANET__JEVTWEIGHTFACTOR__
#define __JAANET__JEVTWEIGHTFACTOR__

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

#include "JLang/JStringStream.hh"

#include "JSystem/JStat.hh"

#include "Jeep/JProperties.hh"

#include "JLang/JClonable.hh"


/**
 * \author bjung
 */

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

namespace JAANET {

  using JLANG::JClonable;

  
  /**
   * Abstract base class for specifiable event-weight factors.
   */
  struct JEvtWeightFactor :
    public JClonable<JEvtWeightFactor>
  {
    /**
     * Virtual destructor.
     */
    virtual ~JEvtWeightFactor()
    {}


    /**
     * Get type keyword.
     *
     * \return                 type keyword
     */
    static const char* const getTypeKey()
    {
      return "type";
    }
    
    
    /**
     * Get event-weight factor of given event.
     *
     * \param  evt               event
     * \return                   event-weight factor
     */
    virtual double getFactor(const Evt& evt) const = 0;


    /**
     * Get event-weight factor of given event.
     *
     * \param  evt               event
     * \return                   event-weight factor
     */
    double operator()(const Evt& evt) const
    {
      return getFactor(evt);
    }


    /**
     * Check whether this event-weight factor is valid.
     *
     * \return                 true if valid; else false
     */
    virtual bool is_valid() const
    {
      return true;
    }


    /**
     * Check validity of this event-weight factor.
     */
    void check_validity() const
    {
      using namespace JPP;
      
      if (!is_valid()) {
	THROW(JValueOutOfRange, "JEvtWeightFactor():check_validity(): Invalid event-weight factor " << *this);
      }
    }


    /**
     * Get equation parameters.
     *
     * \return                 equation parameters
     */
    static inline JEquationParameters& getEquationParameters()
    {
      static JEquationParameters equation("=", ",", "./", "#");
       
      return equation;
    }    


    /**
     * Set equation parameters.
     *
     * \param  eqpars          equation parameters
     */
    static inline void setEquationParameters(const JEquationParameters& eqpars)
    {
      getEquationParameters() = eqpars;
    }


    /**
     * Get properties of this class.
     *
     * \param  eqpars          equation parameters
     */
    virtual JProperties getProperties(const JEquationParameters& eqpars = JEvtWeightFactor::getEquationParameters())
    {
      return JProperties(eqpars,1);
    }
    

    /**
     * Get properties of this class.
     *
     * \param  eqpars          equation parameters
     */
    virtual JProperties getProperties(const JEquationParameters& eqpars = JEvtWeightFactor::getEquationParameters()) const
    {
      return JProperties(eqpars,1);
    }

    
    /**
     * Read event-weight factor from input.
     *
     * \param  in                 input stream
     * \return                    input stream
     */
    virtual std::istream& read(std::istream& in)
    {
      using namespace std;
      using namespace JPP;

      JStringStream is(in);

      if (getFileStatus(is.str().c_str())) {
        is.load();
      }

      JProperties properties = getProperties();
      is >> properties;

      check_validity();

      return in;      
    }


    /**
     * Write event-weight factor to output
     *
     * \param  out                output stream
     * \return                    output stream
     */
    virtual std::ostream& write(std::ostream& out) const
    {
      return out << getProperties();
    }

    
    /**
     * Read event category from input.
     *
     * \param  in                 input stream
     * \param  object             event category
     * \return                    input stream
     */
    friend inline std::istream& operator>>(std::istream& in, JEvtWeightFactor& object)
    {
      return object.read(in);
    }


    /** 
     * Write event category to output.
     *
     * \param  out                output stream
     * \param  object             event  category
     * \return                    output stream
     */
    friend inline std::ostream& operator<<(std::ostream& out, const JEvtWeightFactor& object)
    {
      return object.write(out);
    }
  };
}

#endif