/* -*- C++ -*-

 *

 * src/lemon/concept/undir_graph_component.h - Part of LEMON, a generic

 * C++ optimization library

 *

 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi

 * Kutatocsoport (Egervary Combinatorial Optimization Research Group,

 * 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 UndirEdge>

    class UndirGraphEdge : public UndirEdge {

    public:

      /// \e

      UndirGraphEdge() {}

      /// \e

      UndirGraphEdge(const UndirGraphEdge&) {}

      /// \e

      UndirGraphEdge(Invalid) {}

      /// \brief Constructs a directed version of an undirected edge

      ///

      /// \param forward If \c true the direction of the contructed edge

      /// is the same as the inherent direction of the \c undir_edge; if

      /// \c false --- the opposite.

      UndirGraphEdge(UndirEdge undir_edge, bool forward) {

	ignore_unused_variable_warning(undir_edge);

	ignore_unused_variable_warning(forward);

      }

      /// \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() {

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

	  UndirEdge ue = e;

	  ue = e;

	  Edge forward(ue, true);

	  Edge backward(ue, false);

	  ignore_unused_variable_warning(forward);

	  ignore_unused_variable_warning(backward);

	}

	Edge e;

      };

    };

    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<UndirEdge>, 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<UndirEdge> 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 {}

      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