/* -*- C++ -*-

  * src/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/concept/maps.h>

 #include <lemon/concept_check.h>

 #include <lemon/concept/graph_component.h>

 namespace lemon {

   namespace concept {

     /// \addtogroup graph_concepts

     /// @{

     /**************** 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:

       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 >();

         }

       };

     };

     /// 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:

       /// 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; }

       };

       /// 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 g pointed by the trivial 

         /// iterator n.

         /// This feature necessitates that each time we 

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

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

         /// 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==(Node n)

         ///

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

       };

       /// 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 \c e.

         /// This feature necessitates that each time we 

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

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

         ///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; }

       /// 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