#ifndef __JTOOLS__JHASHMAPTOOLKIT__
#define __JTOOLS__JHASHMAPTOOLKIT__

#include <limits>

#include "JTools/JHashMap.hh"


/**
 * \file
 *
 * Arithmetic toolkit for hash maps.
 * \author mdejong
 */
namespace JTOOLS {}
namespace JPP { using namespace JTOOLS; }

namespace JTOOLS {

  /**
   * Toolkit for JHashMap.
   *
   * The various pointers to member functions refer to policy methods used in base class JMATH::JMath.
   */
  struct JHashMapToolkit {
    /** 
     * Reset buffer.
     *
     * \param  buffer                   buffer
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static void reset(JHashMap<JKey_t, JValue_t, JEvaluator_t>& buffer)
    {
      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::iterator i = buffer.begin(); i != buffer.end(); ++i) {
	i->second = JValue_t();
      }
    }


    /** 
     * Set values in target corresponding to keys in source.
     *
     * \param  target                   target buffer
     * \param  source                   source buffer
     * \param  value                    value
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static void set(JHashMap<JKey_t, JValue_t, JEvaluator_t>&       target,
		    const JHashMap<JKey_t, JValue_t, JEvaluator_t>& source,
		    const JValue_t&                                 value)
    {
      target.clear();

      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::const_iterator i = source.begin(); i != source.end(); ++i) {
	target[i->first] = value;
      }
    }


    /**
     * Evaluate arithmetic operation on buffer.
     *
     * \param  buffer                  buffer
     * \param  f1                      operation
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static void evaluate(JHashMap<JKey_t, JValue_t, JEvaluator_t>& buffer,
			 JValue_t& (JValue_t::*f1)())
    {
      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::iterator i = buffer.begin(); i != buffer.end(); ++i) {
	(i->second.*f1)();
      }
    }


    /**
     * Evaluate arithmetic operation on buffers.
     *
     * \param  first                   first  buffer
     * \param  second                  second buffer
     * \param  f1                      operation
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static void evaluate(JHashMap<JKey_t, JValue_t, JEvaluator_t>&       first,
			 const JHashMap<JKey_t, JValue_t, JEvaluator_t>& second,
			 JValue_t& (JValue_t::*f1)(const JValue_t&))
    {
      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::const_iterator i = second.begin(); i != second.end(); ++i) {
	(first[i->first].*f1)(i->second);
      }
    }


    /**
     * Evaluate arithmetic operation on buffer.
     *
     * \param  buffer                  buffer
     * \param  f1                      operation
     * \param  factor                  factor
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static void evaluate(JHashMap<JKey_t, JValue_t, JEvaluator_t>& buffer,
			 JValue_t& (JValue_t::*f1)(const double),
			 const double factor)
    {
      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::iterator i = buffer.begin(); i != buffer.end(); ++i) {
	(i->second.*f1)(factor);
      }
    }
      

    /**
     * Check equality of buffers.
     *
     * \param  first                    first  buffer
     * \param  second                   second buffer
     * \return                          true if buffers are equal; else false
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static bool equals(const JHashMap<JKey_t, JValue_t, JEvaluator_t>& first,
		       const JHashMap<JKey_t, JValue_t, JEvaluator_t>& second)
    {
      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::const_iterator 
	     p = first .begin(),
	     q = second.begin(); ; ++p, ++q) {

	if        (p != first.end() && q != second.end()) {

	  if (p->first != q->first || p->second != q->second) {
	    return false;
	  }

	} else if (p == first.end() && q == second.end()) {
	  
	  return true;

	} else {

	  return false;
	}
      }
    }
      

    /**
     * Check equality of buffers.
     *
     * \param  first                    first  buffer
     * \param  second                   second buffer
     * \param  precision                precision
     * \return                          true if buffers are equal; else false
     */
    template<class JKey_t, class JValue_t, class JEvaluator_t>
    static bool equals(const JHashMap<JKey_t, JValue_t, JEvaluator_t>& first,
		       const JHashMap<JKey_t, JValue_t, JEvaluator_t>& second,
		       const double precision)
    {
      for (typename JHashMap<JKey_t, JValue_t, JEvaluator_t>::const_iterator 
	     p = first .begin(),
	     q = second.begin(); ; ++p, ++q) {

	if        (p != first.end() && q != second.end()) {

	  if (p->first != q->first || !p->second.equals(q->second, precision)) {
	    return false;
	  }

	} else if (p == first.end() && q == second.end()) {
	  
	  return true;

	} else {

	  return false;
	}
      }
    }
  };
}

#endif