#ifndef __JTRIGGER__JMATCH__
#define __JTRIGGER__JMATCH__

#include "JLang/JClonable.hh"


/**
 * \file
 *
 * Base class for match operations for cluster and hit-preprocessing methods.
 * \author mdejong
 */
namespace JTRIGGER {}
namespace JPP { using namespace JTRIGGER; }

namespace JTRIGGER {

  using JLANG::JClonable;


  /**
   * Function object interface for hit matching.
   */
  template<class JHit_t>
  class JMatch : 
    public JClonable< JMatch<JHit_t> >
  {
  public:
    /** 
     * Virtual destructor.
     */
    virtual ~JMatch()
    {}

    
    /**
     * Match operator.
     *
     * \param  first    hit
     * \param  second   hit
     * \return          match result
     */
    virtual bool operator()(const JHit_t& first, const JHit_t& second) const = 0;


    /**
     * Get number of matches between given hit and data.
     *
     * \param  hit      hit
     * \param  __begin  begin of data
     * \param  __end    end   of data
     * \return          number of matches
     */
    template<class T>
    int count(const JHit_t& hit, T __begin, T __end) const
    {
      int n = 0;

      for (T i = __begin; i != __end; ++i) {
	if ((*this)(hit,*i)) {
	  ++n;
	}
      }

      return n;
    }
  };


  /**
   * Auxiliary class to handle pointer to match function.
   */
  template<class JHit_t>
  class JMatchHelper :
    public JClonable< JMatch<JHit_t> , JMatchHelper<JHit_t> >
  {
  public:

    typedef bool (*pFun)(const JHit_t&, const JHit_t&);    //!< pointer to match function

    /**
     * Constructor
     *
     * \param  match    pointer to match function
     */
    JMatchHelper(pFun match) :
      match(match)
    {}


    /**
     * Match operator.
     *
     * \param  first    hit
     * \param  second   hit
     * \return          match result
     */
    virtual bool operator()(const JHit_t& first, const JHit_t& second) const override 
    {
      return match(first, second);
    }

  protected:
    pFun match;
  };


  /**
   * Auxiliary method to make JMatch object based on pointer to match function.
   *
   * \param  match    pointer to match function
   * \return          match object
   */
  template<class JHit_t>
  JMatchHelper<JHit_t> make_match(bool (*match)(const JHit_t&, const JHit_t&))
  {
    return JMatchHelper<JHit_t>(match);
  }  
}

#endif