/* -*- C++ -*-

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

 *

 * Copyright (C) 2005 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_GRAPH_H

#define LEMON_CONCEPT_GRAPH_H

///\ingroup graph_concepts

///\file

///\brief Declaration of Graph.

#include <lemon/invalid.h>

#include <lemon/utility.h>

#include <lemon/concept/maps.h>

#include <lemon/concept_check.h>

#include <lemon/concept/graph_component.h>

namespace lemon {

  namespace concept {

    /**************** The full-featured graph concepts ****************/

    /// \brief Modular static graph class.

    ///     

    /// It should be the same as the \c StaticGraph class.

    class _StaticGraph 

      :  virtual public BaseGraphComponent,

         public IterableGraphComponent, public MappableGraphComponent {

    public:

      ///\e

      ///\todo undocumented

      ///

      typedef False UndirTag;

      typedef BaseGraphComponent::Node Node;

      typedef BaseGraphComponent::Edge Edge;

      template <typename _Graph>

      struct Constraints {

        void constraints() {

          checkConcept<IterableGraphComponent, _Graph>();

          checkConcept<MappableGraphComponent, _Graph>();

        }

      };

    };

    /// \brief Modular extendable graph class.

    ///     

    /// It should be the same as the \c ExtendableGraph class.

    class _ExtendableGraph 

      :  virtual public BaseGraphComponent, public _StaticGraph,

         public ExtendableGraphComponent, public ClearableGraphComponent {

    public:

      typedef BaseGraphComponent::Node Node;

      typedef BaseGraphComponent::Edge Edge;

      template <typename _Graph>

      struct Constraints {

        void constraints() {

          checkConcept<_StaticGraph, _Graph >();

          checkConcept<ExtendableGraphComponent, _Graph >();

          checkConcept<ClearableGraphComponent, _Graph >();

        }

      };

    };

    /// \brief Modular erasable graph class.

    ///     

    /// It should be the same as the \c ErasableGraph class.

    class _ErasableGraph 

      :  virtual public BaseGraphComponent, public _ExtendableGraph,

         public ErasableGraphComponent {

    public:

      typedef BaseGraphComponent::Node Node;

      typedef BaseGraphComponent::Edge Edge;

      template <typename _Graph>

      struct Constraints {

        void constraints() {

          checkConcept<_ExtendableGraph, _Graph >();

          checkConcept<ErasableGraphComponent, _Graph >();

        }

      };

    };

    /// \addtogroup graph_concepts

    /// @{

    /// An empty static graph class.

    /// This class provides all the common features of a graph structure,

    /// however completely without implementations and real data structures

    /// behind the interface.

    /// All graph algorithms should compile with this class, but it will not

    /// run properly, of course.

    ///

    /// It can be used for checking the interface compatibility,

    /// or it can serve as a skeleton of a new graph structure.

    /// 

    /// Also, you will find here the full documentation of a certain graph

    /// feature, the documentation of a real graph imlementation

    /// like @ref ListGraph or

    /// @ref SmartGraph will just refer to this structure.

    ///

    /// \todo A pages describing the concept of concept description would

    /// be nice.

    class StaticGraph

    {

    public:

      ///\e

      ///\todo undocumented

      ///

      typedef False UndirTag;

      /// Defalult constructor.

      /// Defalult constructor.

      ///

      StaticGraph() { }

      ///Copy consructor.

//       ///\todo It is not clear, what we expect from a copy constructor.

//       ///E.g. How to assign the nodes/edges to each other? What about maps?

//       StaticGraph(const StaticGraph& g) { }

      /// The base type of node iterators, 

      /// or in other words, the trivial node iterator.

      /// This is the base type of each node iterator,

      /// thus each kind of node iterator converts to this.

      /// More precisely each kind of node iterator should be inherited 

      /// from the trivial node iterator.

      class Node {

      public:

        /// Default constructor

        /// @warning The default constructor sets the iterator

        /// to an undefined value.

        Node() { }

        /// Copy constructor.

        /// Copy constructor.

        ///

        Node(const Node&) { }

        /// Invalid constructor \& conversion.

        /// This constructor initializes the iterator to be invalid.

        /// \sa Invalid for more details.

        Node(Invalid) { }

        /// Equality operator

        /// Two iterators are equal if and only if they point to the

        /// same object or both are invalid.

        bool operator==(Node) const { return true; }

        /// Inequality operator

        /// \sa operator==(Node n)

        ///

        bool operator!=(Node) const { return true; }

	/// Artificial ordering operator.

	/// To allow the use of graph descriptors as key type in std::map or

	/// similar associative container we require this.

	///

	/// \note This operator only have to define some strict ordering of

	/// the items; this order has nothing to do with the iteration

	/// ordering of the items.

	///

	/// \bug This is a technical requirement. Do we really need this?

	bool operator<(Node) const { return false; }

      };

      /// This iterator goes through each node.

      /// This iterator goes through each node.

      /// Its usage is quite simple, for example you can count the number

      /// of nodes in graph \c g of type \c Graph like this:

      /// \code

      /// int count=0;

      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;

      /// \endcode

      class NodeIt : public Node {

      public:

        /// Default constructor

        /// @warning The default constructor sets the iterator

        /// to an undefined value.

        NodeIt() { }

        /// Copy constructor.

        /// Copy constructor.

        ///

        NodeIt(const NodeIt& n) : Node(n) { }

        /// Invalid constructor \& conversion.

        /// Initialize the iterator to be invalid.

        /// \sa Invalid for more details.

        NodeIt(Invalid) { }

        /// Sets the iterator to the first node.

        /// Sets the iterator to the first node of \c g.

        ///

        NodeIt(const StaticGraph&) { }

        /// Node -> NodeIt conversion.

        /// Sets the iterator to the node of \c the graph pointed by 

	/// the trivial iterator.

        /// This feature necessitates that each time we 

        /// iterate the edge-set, the iteration order is the same.

        NodeIt(const StaticGraph&, const Node&) { }

        /// Next node.

        /// Assign the iterator to the next node.

        ///

        NodeIt& operator++() { return *this; }

      };

      /// The base type of the edge iterators.

      /// The base type of the edge iterators.

      ///

      class Edge {

      public:

        /// Default constructor

        /// @warning The default constructor sets the iterator

        /// to an undefined value.

        Edge() { }

        /// Copy constructor.

        /// Copy constructor.

        ///

        Edge(const Edge&) { }

        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.

        ///

        Edge(Invalid) { }

        /// Equality operator

        /// Two iterators are equal if and only if they point to the

        /// same object or both are invalid.

        bool operator==(Edge) const { return true; }

        /// Inequality operator

        /// \sa operator==(Edge n)

        ///

        bool operator!=(Edge) const { return true; }

	/// Artificial ordering operator.

	/// To allow the use of graph descriptors as key type in std::map or

	/// similar associative container we require this.

	///

	/// \note This operator only have to define some strict ordering of

	/// the items; this order has nothing to do with the iteration

	/// ordering of the items.

	///

	/// \bug This is a technical requirement. Do we really need this?

	bool operator<(Edge) const { return false; }

      };

      /// This iterator goes trough the outgoing edges of a node.

      /// This iterator goes trough the \e outgoing edges of a certain node

      /// of a graph.

      /// Its usage is quite simple, for example you can count the number

      /// of outgoing edges of a node \c n

      /// in graph \c g of type \c Graph as follows.

      /// \code

      /// int count=0;

      /// for (Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) ++count;

      /// \endcode

      class OutEdgeIt : public Edge {

      public:

        /// Default constructor

        /// @warning The default constructor sets the iterator

        /// to an undefined value.

        OutEdgeIt() { }

        /// Copy constructor.

        /// Copy constructor.

        ///

        OutEdgeIt(const OutEdgeIt& e) : Edge(e) { }

        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.

        ///

        OutEdgeIt(Invalid) { }

        /// This constructor sets the iterator to the first outgoing edge.

        /// This constructor sets the iterator to the first outgoing edge of

        /// the node.

        ///@param n the node

        ///@param g the graph

        OutEdgeIt(const StaticGraph&, const Node&) { }

        /// Edge -> OutEdgeIt conversion

        /// Sets the iterator to the value of the trivial iterator.

	/// This feature necessitates that each time we 

        /// iterate the edge-set, the iteration order is the same.

        OutEdgeIt(const StaticGraph&, const Edge&) { }

        ///Next outgoing edge

        /// Assign the iterator to the next 

        /// outgoing edge of the corresponding node.

        OutEdgeIt& operator++() { return *this; }

      };

      /// This iterator goes trough the incoming edges of a node.

      /// This iterator goes trough the \e incoming edges of a certain node

      /// of a graph.

      /// Its usage is quite simple, for example you can count the number

      /// of outgoing edges of a node \c n

      /// in graph \c g of type \c Graph as follows.

      /// \code

      /// int count=0;

      /// for(Graph::InEdgeIt e(g, n); e!=INVALID; ++e) ++count;

      /// \endcode

      class InEdgeIt : public Edge {

      public:

        /// Default constructor

        /// @warning The default constructor sets the iterator

        /// to an undefined value.

        InEdgeIt() { }

        /// Copy constructor.

        /// Copy constructor.

        ///

        InEdgeIt(const InEdgeIt& e) : Edge(e) { }

        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.

        ///

        InEdgeIt(Invalid) { }

        /// This constructor sets the iterator to first incoming edge.

        /// This constructor set the iterator to the first incoming edge of

        /// the node.

        ///@param n the node

        ///@param g the graph

        InEdgeIt(const StaticGraph&, const Node&) { }

        /// Edge -> InEdgeIt conversion

        /// Sets the iterator to the value of the trivial iterator \c e.

        /// This feature necessitates that each time we 

        /// iterate the edge-set, the iteration order is the same.

        InEdgeIt(const StaticGraph&, const Edge&) { }

        /// Next incoming edge

        /// Assign the iterator to the next inedge of the corresponding node.

        ///

        InEdgeIt& operator++() { return *this; }

      };

      /// This iterator goes through each edge.

      /// This iterator goes through each edge of a graph.

      /// Its usage is quite simple, for example you can count the number

      /// of edges in a graph \c g of type \c Graph as follows:

      /// \code

      /// int count=0;

      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;

      /// \endcode

      class EdgeIt : public Edge {

      public:

        /// Default constructor

        /// @warning The default constructor sets the iterator

        /// to an undefined value.

        EdgeIt() { }

        /// Copy constructor.

        /// Copy constructor.

        ///

        EdgeIt(const EdgeIt& e) : Edge(e) { }

        /// Initialize the iterator to be invalid.

        /// Initialize the iterator to be invalid.

        ///

        EdgeIt(Invalid) { }

        /// This constructor sets the iterator to the first edge.

        /// This constructor sets the iterator to the first edge of \c g.

        ///@param g the graph

        EdgeIt(const StaticGraph&) { }

        /// Edge -> EdgeIt conversion

        /// Sets the iterator to the value of the trivial iterator \c e.

        /// This feature necessitates that each time we 

        /// iterate the edge-set, the iteration order is the same.

        EdgeIt(const StaticGraph&, const Edge&) { } 

        ///Next edge

        /// Assign the iterator to the next edge.

        EdgeIt& operator++() { return *this; }

      };

      ///Gives back the target node of an edge.

      ///Gives back the target node of an edge.

      ///

      Node target(Edge) const { return INVALID; }

      ///Gives back the source node of an edge.

      ///Gives back the source node of an edge.

      ///

      Node source(Edge) const { return INVALID; }

      /// Gives back the first Node in the iterating order.

      /// Gives back the first Node in the iterating order.

      ///     

      void first(Node&) const {}

      /// Gives back the next Node in the iterating order.

      /// Gives back the next Node in the iterating order.

      ///     

      void next(Node&) const {}

      /// Gives back the first Edge in the iterating order.

      /// Gives back the first Edge in the iterating order.

      ///     

      void first(Edge&) const {}

      /// Gives back the next Edge in the iterating order.

      /// Gives back the next Edge in the iterating order.

      ///     

      void next(Edge&) const {}

      /// Gives back the first of the Edges point to the given Node.

      /// Gives back the first of the Edges point to the given Node.

      ///     

      void firstIn(Edge&, const Node&) const {}

      /// Gives back the next of the Edges points to the given Node.

      /// Gives back the next of the Edges points to the given Node.

      ///

      void nextIn(Edge&) const {}

      /// Gives back the first of the Edges start from the given Node.

      /// Gives back the first of the Edges start from the given Node.

      ///     

      void firstOut(Edge&, const Node&) const {}

      /// Gives back the next of the Edges start from the given Node.

      /// Gives back the next of the Edges start from the given Node.

      ///     

      void nextOut(Edge&) const {}

      /// \brief The base node of the iterator.

      ///

      /// Gives back the base node of the iterator.

      Node baseNode(const InEdgeIt&) const { return INVALID; }

      /// \brief The running node of the iterator.

      ///

      /// Gives back the running node of the iterator.

      Node runningNode(const InEdgeIt&) const { return INVALID; }

      /// \brief The base node of the iterator.

      ///

      /// Gives back the base node of the iterator.

      Node baseNode(const OutEdgeIt&) const { return INVALID; }

      /// \brief The running node of the iterator.

      ///

      /// Gives back the running node of the iterator.

      Node runningNode(const OutEdgeIt&) const { return INVALID; }

      /// Read write map of the nodes to type \c T.

      /// \ingroup concept

      /// ReadWrite map of the nodes to type \c T.

      /// \sa Reference

      /// \warning Making maps that can handle bool type (NodeMap<bool>)

      /// needs some extra attention!

      template<class T> 

      class NodeMap : public ReadWriteMap< Node, T >

      {

      public:

        ///\e

        NodeMap(const StaticGraph&) { }

        ///\e

        NodeMap(const StaticGraph&, T) { }

        ///Copy constructor

        NodeMap(const NodeMap& nm) : ReadWriteMap< Node, T >(nm) { }

        ///Assignment operator

        NodeMap& operator=(const NodeMap&) { return *this; }

        // \todo fix this concept

      };

      /// Read write map of the edges to type \c T.

      /// \ingroup concept

      ///Reference map of the edges to type \c T.

      /// \sa Reference

      /// \warning Making maps that can handle bool type (EdgeMap<bool>)

      /// needs some extra attention!

      template<class T> 

      class EdgeMap : public ReadWriteMap<Edge,T>

      {

      public:

        ///\e

        EdgeMap(const StaticGraph&) { }

        ///\e

        EdgeMap(const StaticGraph&, T) { }

        ///Copy constructor

        EdgeMap(const EdgeMap& em) : ReadWriteMap<Edge,T>(em) { }

        ///Assignment operator

        EdgeMap& operator=(const EdgeMap&) { return *this; }

        // \todo fix this concept    

      };

      template <typename _Graph>

      struct Constraints : public _StaticGraph::Constraints<_Graph> {};

    };

    /// An empty non-static graph class.

    /// This class provides everything that \ref StaticGraph does.

    /// Additionally it enables building graphs from scratch.

    class ExtendableGraph : public StaticGraph

    {

    public:

      /// Defalult constructor.

      /// Defalult constructor.

      ///

      ExtendableGraph() { }

      ///Add a new node to the graph.

      /// \return the new node.

      ///

      Node addNode() { return INVALID; }

      ///Add a new edge to the graph.

      ///Add a new edge to the graph with source node \c s

      ///and target node \c t.

      ///\return the new edge.

      Edge addEdge(Node, Node) { return INVALID; }

      /// Resets the graph.

      /// This function deletes all edges and nodes of the graph.

      /// It also frees the memory allocated to store them.

      /// \todo It might belong to \ref ErasableGraph.

      void clear() { }

      template <typename _Graph>

      struct Constraints : public _ExtendableGraph::Constraints<_Graph> {};

    };

    /// An empty erasable graph class.

    /// This class is an extension of \ref ExtendableGraph. It makes it

    /// possible to erase edges or nodes.

    class ErasableGraph : public ExtendableGraph

    {

    public:

      /// Defalult constructor.

      /// Defalult constructor.

      ///

      ErasableGraph() { }

      /// Deletes a node.

      /// Deletes node \c n node.

      ///

      void erase(Node) { }

      /// Deletes an edge.

      /// Deletes edge \c e edge.

      ///

      void erase(Edge) { }

      template <typename _Graph>

      struct Constraints : public _ErasableGraph::Constraints<_Graph> {};

    };

    /************* New GraphBase stuff **************/

//     /// A minimal GraphBase concept

//     /// This class describes a minimal concept which can be extended to a

//     /// full-featured graph with \ref GraphFactory.

//     class GraphBase {

//     public:

//       GraphBase() {}

//       /// \bug Should we demand that Node and Edge be subclasses of the

//       /// Graph class???

//       typedef GraphItem<'n'> Node;

//       typedef GraphItem<'e'> Edge;

// //       class Node : public BaseGraphItem<'n'> {};

// //       class Edge : public BaseGraphItem<'e'> {};

//       // Graph operation

//       void firstNode(Node &n) const { }

//       void firstEdge(Edge &e) const { }

//       void firstOutEdge(Edge &e, Node) const { }

//       void firstInEdge(Edge &e, Node) const { }

//       void nextNode(Node &n) const { }

//       void nextEdge(Edge &e) const { }

//       // Question: isn't it reasonable if this methods have a Node

//       // parameter? Like this:

//       // Edge& nextOut(Edge &e, Node) const { return e; }

//       void nextOutEdge(Edge &e) const { }

//       void nextInEdge(Edge &e) const { }

//       Node target(Edge) const { return Node(); }

//       Node source(Edge) const { return Node(); }

//       // Do we need id, nodeNum, edgeNum and co. in this basic graphbase

//       // concept?

//       // Maps.

//       //

//       // We need a special slimer concept which does not provide maps (it

//       // wouldn't be strictly slimer, cause for map-factory id() & friends

//       // a required...)

//       template<typename T>

//       class NodeMap : public GraphMap<GraphBase, Node, T> {};

//       template<typename T>

//       class EdgeMap : public GraphMap<GraphBase, Node, T> {};

//     };

    // @}

  } //namespace concept  

} //namespace lemon

#endif // LEMON_CONCEPT_GRAPH_H