/* -*- C++ -*-

  *

  * src/lemon/concept/undir_graph_component.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.

  *

  */

 ///\ingroup graph_concepts

 ///\file

 ///\brief Undirected graphs and components of.

 #ifndef LEMON_CONCEPT_UNDIR_GRAPH_H

 #define LEMON_CONCEPT_UNDIR_GRAPH_H

 #include <lemon/concept/graph_component.h>

 namespace lemon {

   namespace concept {

     /// \addtogroup graph_concepts

     /// @{

     /// Skeleton class which describes an edge with direction in \ref

     /// UndirGraph "undirected graph".

     template <typename UndirGraph>

     class UndirGraphEdge : public UndirGraph::UndirEdge {

       typedef typename UndirGraph::UndirEdge UndirEdge;

       typedef typename UndirGraph::Node Node;

     public:

       /// \e

       UndirGraphEdge() {}

       /// \e

       UndirGraphEdge(const UndirGraphEdge& e) : UndirGraph::UndirEdge(e) {}

       /// \e

       UndirGraphEdge(Invalid) {}

       /// \brief Directed edge from undirected edge and a source node.

       ///

       /// Constructs a directed edge from undirected edge and a source node.

       ///

       /// \note You have to specify the graph for this constructor.

       UndirGraphEdge(const UndirGraph &g,

 		     UndirEdge undir_edge, Node n) {

 	ignore_unused_variable_warning(undir_edge);

 	ignore_unused_variable_warning(g);

 	ignore_unused_variable_warning(n);

       }

       /// \e

       UndirGraphEdge& operator=(UndirGraphEdge) { return *this; }

       /// \e

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

       /// \e

       bool operator!=(UndirGraphEdge) const { return false; }

       /// \e

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

       template <typename Edge>

       struct Constraints {

 	void constraints() {

 	  const_constraints();

 	}

 	void const_constraints() const {

 	  /// \bug This should be is_base_and_derived ...

 	  UndirEdge ue = e;

 	  ue = e;

 	  Edge e_with_source(graph,ue,n);

 	  ignore_unused_variable_warning(e_with_source);

 	}

 	Edge e;

 	UndirEdge ue;

 	UndirGraph graph;

 	Node n;

       };

     };

     struct BaseIterableUndirGraphConcept {

       template <typename Graph>

       struct Constraints {

 	typedef typename Graph::UndirEdge UndirEdge;

 	typedef typename Graph::Edge Edge;

 	typedef typename Graph::Node Node;

 	void constraints() {

 	  checkConcept<BaseIterableGraphComponent, Graph>();

 	  checkConcept<GraphItem<>, UndirEdge>();

 	  checkConcept<UndirGraphEdge<Graph>, Edge>();

 	  graph.first(ue);

 	  graph.next(ue);

 	  const_constraints();

 	}

 	void const_constraints() {

 	  Node n;

 	  n = graph.target(ue);

 	  n = graph.source(ue);

 	  n = graph.oppositeNode(n0, ue);

 	  bool b;

 	  b = graph.forward(e);

 	  ignore_unused_variable_warning(b);

 	}

 	Graph graph;

 	Edge e;

 	Node n0;

 	UndirEdge ue;

       };

     };

     struct IterableUndirGraphConcept {

       template <typename Graph>

       struct Constraints {

 	void constraints() {

 	  /// \todo we don't need the iterable component to be base iterable

 	  /// Don't we really???

 	  //checkConcept< BaseIterableUndirGraphConcept, Graph > ();

 	  checkConcept<IterableGraphComponent, Graph> ();

 	  typedef typename Graph::UndirEdge UndirEdge;

 	  typedef typename Graph::UndirEdgeIt UndirEdgeIt;

 	  typedef typename Graph::IncEdgeIt IncEdgeIt;

 	  checkConcept<GraphIterator<Graph, UndirEdge>, UndirEdgeIt>();

 	  checkConcept<GraphIncIterator<Graph, UndirEdge>, IncEdgeIt>();

 	}

       };

     };

     struct MappableUndirGraphConcept {

       template <typename Graph>

       struct Constraints {

 	struct Dummy {

 	  int value;

 	  Dummy() : value(0) {}

 	  Dummy(int _v) : value(_v) {}

 	};

 	void constraints() {

 	  checkConcept<MappableGraphComponent, Graph>();

 	  typedef typename Graph::template UndirEdgeMap<int> IntMap;

 	  checkConcept<GraphMap<Graph, typename Graph::UndirEdge, int>,

 	    IntMap >();

 	  typedef typename Graph::template UndirEdgeMap<bool> BoolMap;

 	  checkConcept<GraphMap<Graph, typename Graph::UndirEdge, bool>,

 	    BoolMap >();

 	  typedef typename Graph::template UndirEdgeMap<Dummy> DummyMap;

 	  checkConcept<GraphMap<Graph, typename Graph::UndirEdge, Dummy>,

 	    DummyMap >();

 	}

       };

     };

     struct ExtendableUndirGraphConcept {

       template <typename Graph>

       struct Constraints {

 	void constraints() {

 	  node_a = graph.addNode();

 	  uedge = graph.addEdge(node_a, node_b);

 	}

 	typename Graph::Node node_a, node_b;

 	typename Graph::UndirEdge uedge;

 	Graph graph;

       };

     };

     struct ErasableUndirGraphConcept {

       template <typename Graph>

       struct Constraints {

 	void constraints() {

 	  graph.erase(n);

 	  graph.erase(e);

 	}

 	Graph graph;

 	typename Graph::Node n;

 	typename Graph::UndirEdge e;

       };

     };

     /// Class describing the concept of Undirected Graphs.

     /// This class describes the common interface of all Undirected

     /// Graphs.

     ///

     /// As all concept describing classes it provides only interface

     /// without any sensible implementation. So any algorithm for

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

     /// run properly, of couse.

     ///

     /// In LEMON undirected graphs also fulfill the concept of directed

     /// graphs (\ref lemon::concept::Graph "Graph Concept"). For

     /// explanation of this and more see also the page \ref undir_graphs,

     /// a tutorial about undirected graphs.

     class UndirGraph {

     public:

       /// Type describing a node in the graph

       typedef GraphNode Node;

       /// Type describing an undirected edge

       typedef GraphItem<'u'> UndirEdge;

       /// Type describing an UndirEdge with direction

 #ifndef DOXYGEN

       typedef UndirGraphEdge<UndirGraph> Edge;

 #else

       typedef UndirGraphEdge Edge;

 #endif

       /// Iterator type which iterates over all nodes

 #ifndef DOXYGEN

       typedef GraphIterator<UndirGraph, Node> NodeIt;

 #else

       typedef GraphIterator NodeIt;

 #endif

       /// Iterator type which iterates over all undirected edges

 #ifndef DOXYGEN

       typedef GraphIterator<UndirGraph, UndirEdge> UndirEdgeIt;

 #else

       typedef GraphIterator UndirEdgeIt;

 #endif

       /// Iterator type which iterates over all directed edges.

       /// Iterator type which iterates over all edges (each undirected

       /// edge occurs twice with both directions.

 #ifndef DOXYGEN

       typedef GraphIterator<UndirGraph, Edge> EdgeIt;

 #else

       typedef GraphIterator EdgeIt;

 #endif

       /// Iterator of undirected edges incident to a node

 #ifndef DOXYGEN

       typedef GraphIncIterator<UndirGraph, UndirEdge, 'u'> IncEdgeIt;

 #else

       typedef GraphIncIterator IncEdgeIt;

 #endif

       /// Iterator of edges incoming to a node

 #ifndef DOXYGEN

       typedef GraphIncIterator<UndirGraph, Edge, 'i'> InEdgeIt;

 #else

       typedef GraphIncIterator InEdgeIt;

 #endif

       /// Iterator of edges outgoing from a node

 #ifndef DOXYGEN

       typedef GraphIncIterator<UndirGraph, Edge, 'o'> OutEdgeIt;

 #else

       typedef GraphIncIterator OutEdgeIt;

 #endif

       /// NodeMap template

 #ifdef DOXYGEN

       typedef GraphMap NodeMap<T>;

 #endif

       /// UndirEdgeMap template

 #ifdef DOXYGEN

       typedef GraphMap UndirEdgeMap<T>;

 #endif

       /// EdgeMap template

 #ifdef DOXYGEN

       typedef GraphMap EdgeMap<T>;

 #endif

       template <typename T>

       class NodeMap : public GraphMap<UndirGraph, Node, T> {

 	typedef GraphMap<UndirGraph, Node, T> Parent;

       public:

 	explicit NodeMap(const UndirGraph &g) : Parent(g) {}

 	NodeMap(const UndirGraph &g, T t) : Parent(g, t) {}

       };

       template <typename T>

       class UndirEdgeMap : public GraphMap<UndirGraph, UndirEdge, T> {

 	typedef GraphMap<UndirGraph, UndirEdge, T> Parent;

       public:

 	explicit UndirEdgeMap(const UndirGraph &g) : Parent(g) {}

 	UndirEdgeMap(const UndirGraph &g, T t) : Parent(g, t) {}

       };

       template <typename T>

       class EdgeMap : public GraphMap<UndirGraph, Edge, T> {

 	typedef GraphMap<UndirGraph, Edge, T> Parent;

       public:

 	explicit EdgeMap(const UndirGraph &g) : Parent(g) {}

 	EdgeMap(const UndirGraph &g, T t) : Parent(g, t) {}

       };

       /// Is the Edge oriented "forward"?

       /// Returns whether the given directed edge is same orientation as

       /// the corresponding undirected edge.

       ///

       /// \todo "What does the direction of an undirected edge mean?"

       bool forward(Edge) const { return true; }

       /// Opposite node on an edge

       /// \return the opposite of the given Node on the given Edge

       ///

       /// \todo What should we do if given Node and Edge are not incident?

       Node oppositeNode(Node, UndirEdge) const { return INVALID; }

       /// First node of the undirected edge.

       /// \return the first node of the given UndirEdge.

       ///

       /// Naturally undirectected edges don't have direction and thus

       /// don't have source and target node. But we use these two methods

       /// to query the two endnodes of the edge. The direction of the edge

       /// which arises this way is called the inherent direction of the

       /// undirected edge, and is used to define the "forward" direction

       /// of the directed versions of the edges.

       /// \sa forward

       Node source(UndirEdge) const { return INVALID; }

       /// Second node of the undirected edge.

       Node target(UndirEdge) const { return INVALID; }

       /// Source node of the directed edge.

       Node source(Edge) const { return INVALID; }

       /// Target node of the directed edge.

       Node target(Edge) const { return INVALID; }

       /// First node of the graph

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void first(Node&) const {}

       /// Next node of the graph

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void next(Node&) const {}

       /// First undirected edge of the graph

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void first(UndirEdge&) const {}

       /// Next undirected edge of the graph

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void next(UndirEdge&) const {}

       /// First directed edge of the graph

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void first(Edge&) const {}

       /// Next directed edge of the graph

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void next(Edge&) const {}

       /// First outgoing edge from a given node

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void firstOut(Edge&, Node) const {}

       /// Next outgoing edge to a node

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void nextOut(Edge&) const {}

       /// First incoming edge to a given node

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void firstIn(Edge&, Node) const {}

       /// Next incoming edge to a node

       /// \note This method is part of so called \ref

       /// developpers_interface "Developpers' interface", so it shouldn't

       /// be used in an end-user program.

       void nextIn(Edge&) const {}

       /// Base node of the iterator

       ///

       /// Returns the base node (the source in this case) of the iterator

       Node baseNode(OutEdgeIt e) const {

 	return source(e);

       }

       /// Running node of the iterator

       ///

       /// Returns the running node (the target in this case) of the

       /// iterator

       Node runningNode(OutEdgeIt e) const {

 	return target(e);

       }

       /// Base node of the iterator

       ///

       /// Returns the base node (the target in this case) of the iterator

       Node baseNode(InEdgeIt e) const {

 	return target(e);

       }

       /// Running node of the iterator

       ///

       /// Returns the running node (the source in this case) of the

       /// iterator

       Node runningNode(InEdgeIt e) const {

 	return source(e);

       }

       /// Base node of the iterator

       ///

       /// Returns the base node of the iterator

       Node baseNode(IncEdgeIt) const {

 	return INVALID;

       }

       /// Running node of the iterator

       ///

       /// Returns the running node of the iterator

       Node runningNode(IncEdgeIt) const {

 	return INVALID;

       }

       template <typename Graph>

       struct Constraints {

 	void constraints() {

 	  checkConcept<BaseIterableUndirGraphConcept, Graph>();

 	  checkConcept<IterableUndirGraphConcept, Graph>();

 	  checkConcept<MappableUndirGraphConcept, Graph>();

 	}

       };

     };

     class ExtendableUndirGraph : public UndirGraph {

     public:

       template <typename Graph>

       struct Constraints {

 	void constraints() {

 	  checkConcept<BaseIterableUndirGraphConcept, Graph>();

 	  checkConcept<IterableUndirGraphConcept, Graph>();

 	  checkConcept<MappableUndirGraphConcept, Graph>();

 	  checkConcept<UndirGraph, Graph>();

 	  checkConcept<ExtendableUndirGraphConcept, Graph>();

 	  checkConcept<ClearableGraphComponent, Graph>();

 	}

       };

     };

     class ErasableUndirGraph : public ExtendableUndirGraph {

     public:

       template <typename Graph>

       struct Constraints {

 	void constraints() {

 	  checkConcept<ExtendableUndirGraph, Graph>();

 	  checkConcept<ErasableUndirGraphConcept, Graph>();

 	}

       };

     };

     /// @}

   }

 }

 #endif