#ifndef __JDETECTOR__JCALIBRATION__
#define __JDETECTOR__JCALIBRATION__

#include <istream>
#include <ostream>

#include "JIO/JSerialisable.hh"
#include "JLang/JClass.hh"
#include "JLang/JManip.hh"


/**
 * \file
 *
 * Time calibration (including definition of sign of time offset).
 * \author mdejong
 */
namespace JDETECTOR {}
namespace JPP { using namespace JDETECTOR; }

namespace JDETECTOR {

  using JIO::JReader;
  using JIO::JWriter;


  /**
   * Specification for time-over-threshold corresponding to a one photo-electron pulse.
   */
  const double TIME_OVER_THRESHOLD_NS = 25.08;  // [ns]

  /**
   * Specification for normalized gain corresponding to a one photo-electron pulse.
   */
  const double NOMINAL_GAIN           =  1.0;   // [--]


  /**
   * Data structure for time calibration.
   */
  class JCalibration
  {
  public:
    /**
     * Default constructor.
     */
    JCalibration() :
      t0(0.0)
    {}


    /**
     * Constructor.
     *
     * \param  __t0       time offset [ns]
     */
    JCalibration(const double __t0) :
      t0(__t0)
    {}


    /**
     * Get calibration.
     *
     * \return            calibration
     */
    const JCalibration& getCalibration() const
    {
      return *this;
    }


    /**
     * Get calibration.
     *
     * \return            calibration
     */
    JCalibration& getCalibration()
    {
      return *this;
    }


    /**
     * Set calibration.
     *
     * \param  cal        calibration
     */
    void setCalibration(const JCalibration& cal)
    {
      *this = cal;
    }


    /**
     * Get time offset.
     *
     * \return            time offset [ns]
     */
    double getT0() const 
    {
      return t0;
    }


    /**
     * Set time offset.
     *
     * \param  t0            time offset [ns]
     */
    void setT0(const double t0)
    {
      this->t0 = t0;
    }


    /**
     * Add time offset.
     *
     * \param  t0            time offset [ns]
     */
    void addT0(const double t0)
    {
      this->t0 += t0;
    }


    /**
     * Subtract time offset.
     *
     * \param  t0            time offset [ns]
     */
    void subT0(const double t0)
    {
      this->t0 -= t0;
    }


    /**
     * Read calibration from input.
     *
     * \param  in         input stream
     * \param  cal        calibration
     * \return            input stream
     */
    friend inline std::istream& operator>>(std::istream& in, JCalibration& cal)
    {
      in >> cal.t0;

      return in;
    }


    /**
     * Write calibration to output.
     *
     * \param  out        output stream
     * \param  cal        calibration
     * \return            output stream
     */
    friend inline std::ostream& operator<<(std::ostream& out, const JCalibration& cal)
    {
      const JFormat format(out, getFormat<JCalibration>(JFormat_t(9, 3, std::ios::fixed | std::ios::showpos)));

      out << format << cal.t0;

      return out;
    }


    /**
     * Read calibration from input.
     *
     * \param  in       reader
     * \param  cal      calibration
     * \return          reader
     */
    friend inline JReader& operator>>(JReader& in, JCalibration& cal)
    {
      in >> cal.t0;

      return in;
    }


    /**
     * Write calibration to output.
     *
     * \param  out      writer
     * \param  cal      calibration
     * \return          writer
     */
    friend inline JWriter& operator<<(JWriter& out, const JCalibration& cal)
    {
      out << cal.t0;

      return out;
    }


  protected:
    double t0;
  };

  
  
  /**
   * Auxiliary class to apply (de-)calibration to template hit.
   */
  template<class T, bool is_primitive = JLANG::JClass<T>::is_primitive>
  struct JCalibrator;


  /**
   * Get calibrated time.
   *
   * \param  t1         time [ns]
   * \param  cal        calibration
   * \return            time [ns]
   */
  template<class T>
  inline double getTime(const T& t1, const JCalibration& cal)
  {
    return JCalibrator<T>::getTime(t1, cal);
  }
    

  /**
   * Get de-calibrated time.
   *
   * \param  t1         time [ns]
   * \param  cal        calibration
   * \return            time [ns]
   */
  template<class T>
  inline double putTime(const T& t1, const JCalibration& cal)
  {
    return JCalibrator<T>::putTime(t1, cal);
  }
    

  /**
   * Get calibrated time-over-threshold of hit.
   *
   * \param  tot        time-over-threshold [ns]
   * \param  cal        calibration
   * \return            time-over-threshold [ns]
   */
  template<class T>
  inline double getToT(const T& tot, const JCalibration& cal)
  {
    return JCalibrator<T>::getToT(tot, cal);
  }
  
    
  /**
   * Get de-calibrated time-over-threshold of hit.
   *
   * \param  tot        time-over-threshold [ns]
   * \param  cal        calibration
   * \return            time-over-threshold [ns]
   */
  template<class T>
  inline double putToT(const T& tot, const JCalibration& cal)
  {
    return JCalibrator<T>::putToT(tot, cal);
  }


  /**
   * Template specialisation of JCalibrator for primitive data types.
   */
  template<class T>
  struct JCalibrator<T, true>
  {
    /**
     * Get calibrated time.
     *
     * \param  t1         time [ns]
     * \param  cal        calibration
     * \return            time [ns]
     */
    static inline double getTime(const T t1, const JCalibration& cal)
    {
      return t1 + cal.getT0();
    }
    

    /**
     * Get de-calibrated time.
     *
     * \param  t1         time [ns]
     * \param  cal        calibration
     * \return            time [ns]
     */
    static inline double putTime(const T t1, const JCalibration& cal)
    {
      return t1 - cal.getT0();
    }
    

    /**
     * Get calibrated time-over-threshold of hit.
     *
     * \param  tot        time-over-threshold [ns]
     * \param  cal        calibration
     * \return            time-over-threshold [ns]
     */
    static inline double getToT(const T tot, const JCalibration& cal)
    {
      return tot;
    }

    
    /**
     * Get de-calibrated time-over-threshold of hit.
     *
     * \param  tot        time-over-threshold [ns]
     * \param  cal        calibration
     * \return            time-over-threshold [ns]
     */
    static inline double putToT(const T tot, const JCalibration& cal)
    {
      return tot;
    }
  };
  

  /**
   * Template specialisation of JCalibrator for non-primitive data types.
   * It is assumed that the template class has the following methods:
   * <pre>
   *      %getT();
   *      %getToT();
   * </pre>
   * which should return the time (ns) and time-over-threshold (ns), respectively.
   */
  template<class JHit_t>
  struct JCalibrator<JHit_t, false> {
    /**
     * Get calibrated time of hit.
     *
     * \param  hit            hit
     * \param  cal            calibration
     * \return                time [ns]
     */
    static inline double getTime(const JHit_t& hit, const JCalibration& cal)
    {
      return JDETECTOR::getTime(hit.getT(), cal);
    }
    

    /**
     * Get de-calibrated time of hit.
     *
     * \param  hit        hit
     * \param  cal        calibration
     * \return            time [ns]
     */
    static inline double putTime(const JHit_t& hit, const JCalibration& cal)
    {
      return JDETECTOR::putTime(hit.getT(), cal);
    }
    
    
    /**
     * Get calibrated time-over-threshold of hit.
     *
     * \param  hit        hit
     * \param  cal        calibration
     * \return            time-over-threshold [ns]
     */
    static inline double getToT(const JHit_t& hit, const JCalibration& cal)
    {
      return JDETECTOR::getToT(hit.getToT(), cal);
    }
    

    /**
     * Get de-calibrated time-over-threshold of hit.
     *
     * \param  hit        hit
     * \param  cal        calibration
     * \return            time-over-threshold [ns]
     */
    inline double putToT(const JHit_t& hit, const JCalibration& cal)
    {
      return JDETECTOR::putToT(hit.getToT(), cal);
    }
  };
}

#endif