#ifndef __JMATCH3G__
#define __JMATCH3G__

#include "JTools/JConstants.hh"

#include "JTrigger/JMatch.hh"


namespace JTRIGGER {

  namespace {
    using JTOOLS::getInverseSpeedOfLight;
    using JTOOLS::getIndexOfRefraction;
  }


  /** 
   * 3G match criterion. 
   * This match algorithm is intented for shower signals.
   */
  template<class JHit_t>
  class JMatch3G :
    public JMatch<JHit_t>
  {
  public:
    /**
     * Constructor.
     *
     * \param  Dmax_m           maximal distance between PMTs [m]
     * \param  Tmax_ns          maximal extra time [ns]
     */
    JMatch3G(const double Dmax_m,
	     const double Tmax_ns = 0.0) :
      DMax_m      (Dmax_m),
      TMaxExtra_ns(Tmax_ns)
    {
      TMax_ns = DMax_m * getIndexOfRefraction() * getInverseSpeedOfLight()  +  TMaxExtra_ns;
    }


    /**
     * Clone object.
     *
     * \return          match result
     */
    JMatch<JHit_t>* clone() const
    {
      return new JMatch3G<JHit_t>(*this);
    }


    /**
     * Match operator.
     *
     * \param  first    hit
     * \param  second   hit
     * \return          match result
     */
    virtual bool operator()(const JHit_t& first, const JHit_t& second) const
    {
      t = fabs(first.getT() - second.getT());

      if (t > TMax_ns)
	return false;

      x = first.getX() - second.getX();
      y = first.getY() - second.getY();
      z = first.getZ() - second.getZ();
      d = sqrt(x*x + y*y + z*z);
      
      return d <= DMax_m && t <= d * getIndexOfRefraction() * getInverseSpeedOfLight()  +  TMaxExtra_ns;
    }


    double DMax_m;
    double TMax_ns;
    double TMaxExtra_ns;

  private:
    mutable double x;
    mutable double y;
    mutable double z;
    mutable double d;
    mutable double t;
  };
}

#endif