/* -*- C++ -*-

 * lemon/concept/matrix_maps.h - Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2006 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#ifndef LEMON_CONCEPT_MATRIX_MAPS_H

#define LEMON_CONCEPT_MATRIX_MAPS_H

#include <lemon/utility.h>

#include <lemon/concept_check.h>

///\ingroup concept

///\file

///\brief MatrixMap concepts checking classes for testing and documenting.

namespace lemon {

  namespace concept {

    /// \addtogroup concept

    /// @{

    /// Readable matrix map concept

    template <typename K1, typename K2, typename V>

    class ReadMatrixMap

    {

    public:

      /// Map's first key type.

      typedef K1 FirstKey;    

      /// Map's second key type.

      typedef K2 SecondKey;    

      /// \brief Map's value type. 

      /// (The type of objects associated with the pairs of keys).

      typedef V Value;

      // \bug Value don't need to be default constructible.

      /// Returns the value associated with a key.

      Value operator()(const FirstKey&, const SecondKey&) const {

	return Value();

      }

      template <typename _ReadMatrixMap>

      struct Constraints {

	void constraints() {

	  Value val = m(first_key, second_key);

	  val = m(first_key, second_key);

	  typename _ReadMatrixMap::Value own_val = 

	    m(own_first_key, own_second_key); 

	  own_val = m(own_first_key, own_second_key);

	  ignore_unused_variable_warning(val);

	  ignore_unused_variable_warning(own_val);

	}

	FirstKey& first_key;

	SecondKey& second_key;	

	typename _ReadMatrixMap::FirstKey& own_first_key;

	typename _ReadMatrixMap::SecondKey& own_second_key;

	_ReadMatrixMap& m;

      };

    };

    /// Writable map concept

    template <typename K1, typename K2, typename V>

    class WriteMatrixMap {

    public:

      /// Map's first key type.

      typedef K1 FirstKey;    

      /// Map's second key type.

      typedef K2 SecondKey;    

      /// \brief Map's value type. 

      /// (The type of objects associated with the pairs of keys).

      typedef V Value;

      /// Sets the value associated with the pair of keys.

      void set(const FirstKey&, const SecondKey& ,const Value&) {}

      template <typename _WriteMatrixMap>

      struct Constraints {

	void constraints() {

	  // No constraints for constructor.

	  m.set(first_key, second_key, val);

	  m.set(own_first_key, own_second_key, own_val);

	}

	Value& val;

	typename _WriteMatrixMap::Value own_val;

	FirstKey& first_key;

	SecondKey& second_key;

	typename _WriteMatrixMap::FirstKey& own_first_key;

	typename _WriteMatrixMap::SecondKey& own_second_key;

	_WriteMatrixMap& m;

      };

    };

    ///Read/Writable map concept

    template<typename K1, typename K2, typename V>

    class ReadWriteMatrixMap 

      : public ReadMatrixMap<K1, K2, V>, public WriteMatrixMap<K1, K2, V> {

    public:

      /// Map's first key type.

      typedef K1 FirstKey;    

      /// Map's second key type.

      typedef K2 SecondKey;    

      /// \brief Map's value type. 

      /// (The type of objects associated with the pairs of keys).

      typedef V Value;

      /// Returns the value associated with a pair of keys.

      Value operator()(const FirstKey&, const SecondKey&) const { 

	return Value(); 

      }

      /// Sets the value associated with the pair of keys.

      void set(const FirstKey&, const SecondKey& ,const Value&) {}

      template<typename _ReadWriteMatrixMap>

      struct Constraints {

	void constraints() {

	  checkConcept<ReadMatrixMap<K1, K2, V>, _ReadWriteMatrixMap >();

	  checkConcept<WriteMatrixMap<K1, K2, V>, _ReadWriteMatrixMap >();

	}

      };

    };

    ///Dereferable matrix map concept

    template<typename K1, typename K2, typename V, typename R, typename CR>

    class ReferenceMatrixMap : public ReadWriteMatrixMap<K1, K2, V>

    {

    public:

      /// Tag for reference maps.

      typedef True ReferenceMapTag;

      /// Map's first key type.

      typedef K1 FirstKey;    

      /// Map's second key type.

      typedef K1 SecondKey;    

      /// Map's value type. (The type of objects associated with the keys).

      typedef V Value;

      /// Map's reference type.

      typedef R Reference;

      /// Map's const reference type.

      typedef CR ConstReference;

    protected:

      Value tmp;

    public:

      ///Returns a reference to the value associated to a pair of keys.

      Reference operator()(const FirstKey&, const SecondKey&) { 

	return tmp; 

      }

      ///Returns a const reference to the value associated to a pair of keys.

      ConstReference operator()(const FirstKey&, const SecondKey&) const { 

	return tmp; 

      }

      /// Sets the value associated with the pair of keys.

      void set(const FirstKey&, const SecondKey& ,const Value&) {}

      // \todo rethink this concept

      template<typename _ReferenceMatrixMap>

      struct ReferenceMapConcept {

	void constraints() {

	  checkConcept<ReadWriteMatrixMap, _ReferenceMatrixMap >();

	  m(first_key, second_key) = val;

	  val  = m(first_key, second_key);

	  m(first_key, second_key) = ref;

	  ref = m(first_key, second_key);

	  m(own_first_key, own_second_key) = own_val;

	  own_val  = m(own_first_key, own_second_key);

	  m(own_first_key, own_second_key) = own_ref;

	  own_ref = m(own_first_key, own_second_key); 

	}

	typename _ReferenceMatrixMap::Key& own_first_key;

	typename _ReferenceMatrixMap::Key& own_second_key;

	typename _ReferenceMatrixMap::Value& own_val;

	typename _ReferenceMatrixMap::Reference& own_ref;

	FirstKey& first_key;

	SecondKey& second_key;

	Value& val;

	Reference& ref;

	_ReferenceMatrixMap& m;

      };

    };

    // @}

  } //namespace concept

} //namespace lemon

#endif // LEMON_CONCEPT_MATRIX_MAPS_H