/* -*- C++ -*-

 * src/lemon/skeletons/graph.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.

 *

 */

#ifndef LEMON_SKELETON_GRAPH_H

#define LEMON_SKELETON_GRAPH_H

///\ingroup skeletons

///\file

///\brief Declaration of Graph.

#include <lemon/invalid.h>

#include <lemon/skeletons/maps.h>

namespace lemon {

  namespace skeleton {

    /// \addtogroup skeletons

    /// @{

    /// 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; }

 	///Comparison operator.

	///This is a strict ordering between the nodes.

	///

	///This ordering can be different from the order in which NodeIt

	///goes through the nodes.

	///\todo Possibly we don't need it.

	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&) { }

	/// 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& g) { }

	/// 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; }

 	///Comparison operator.

	///This is a strict ordering between the nodes.

	///

	///This ordering can be different from the order in which NodeIt

	///goes through the nodes.

	///\todo Possibly we don't need it.

 	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&) { }

	/// Initialize the iterator to be invalid.

	/// Initialize the iterator to be invalid.

	///

	OutEdgeIt(Invalid) { }

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

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

	/// node

	///@param n the node

	///@param g the graph

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

	/// 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&) { }

	/// 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

	/// node

	///@param n the node

	///@param g the graph

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

	/// 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& g, const Edge& n) { }

	/// 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&) { }

	/// Initialize the iterator to be invalid.

	/// Initialize the iterator to be invalid.

	///

	EdgeIt(Invalid) { }

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

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

	/// node

	///@param g the graph

	EdgeIt(const StaticGraph& g) { }

	/// 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 of the corresponding node.

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

      };

      /// First node of the graph.

      /// \retval i the first node.

      /// \return the first node.

      ///

      NodeIt& first(NodeIt& i) const { return i; }

      /// The first incoming edge.

      /// The first incoming edge.

      ///

      InEdgeIt& first(InEdgeIt &i, Node) const { return i; }

      /// The first outgoing edge.

      /// The first outgoing edge.

      ///

      OutEdgeIt& first(OutEdgeIt& i, Node) const { return i; }

      /// The first edge of the Graph.

      /// The first edge of the Graph.

      ///

      EdgeIt& first(EdgeIt& i) const { return i; }

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

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

      ///

      Node head(Edge) const { return INVALID; }

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

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

      ///

      Node tail(Edge) const { return INVALID; }

      ///Gives back the \e id of a node.

      ///\warning Not all graph structures provide this feature.

      ///

      ///\todo Should each graph provide \c id?

      int id(const Node&) const { return 0; }

      ///Gives back the \e id of an edge.

      ///\warning Not all graph structures provide this feature.

      ///

      ///\todo Should each graph provide \c id?

      int id(const Edge&) const { return 0; }

      ///\e

      ///\todo Should it be in the concept?

      ///

      int nodeNum() const { return 0; }

      ///\e

      ///\todo Should it be in the concept?

      ///

      int edgeNum() const { return 0; }

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

      /// \ingroup skeletons

      ///Reference 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 ReferenceMap< Node, T >

      {

      public:

	///\e

	NodeMap(const StaticGraph&) { }

	///\e

	NodeMap(const StaticGraph&, T) { }

	///Copy constructor

	template<typename TT> NodeMap(const NodeMap<TT>&) { }

	///Assignment operator

	template<typename TT> NodeMap& operator=(const NodeMap<TT>&)

	{ return *this; }

      };

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

      /// \ingroup skeletons

      ///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 ReferenceMap<Edge,T>

      {

      public:

	///\e

	EdgeMap(const StaticGraph&) { }

	///\e

	EdgeMap(const StaticGraph&, T) { }

	///Copy constructor

	template<typename TT> EdgeMap(const EdgeMap<TT>&) { }

	///Assignment operator

	template<typename TT> EdgeMap &operator=(const EdgeMap<TT>&)

	{ return *this; }

      };

    };

    struct DummyType {

      int value;

      DummyType() {}

      DummyType(int p) : value(p) {}

      DummyType& operator=(int p) { value = p; return *this;}

    };

    ///\brief Checks whether \c G meets the

    ///\ref lemon::skeleton::StaticGraph "StaticGraph" concept

    template<class Graph> void checkCompileStaticGraph(Graph &G) 

    {

      typedef typename Graph::Node Node;

      typedef typename Graph::NodeIt NodeIt;

      typedef typename Graph::Edge Edge;

      typedef typename Graph::EdgeIt EdgeIt;

      typedef typename Graph::InEdgeIt InEdgeIt;

      typedef typename Graph::OutEdgeIt OutEdgeIt;

      {

	Node i; Node j(i); Node k(INVALID);

	i=j;

	bool b; b=true;

	b=(i==INVALID); b=(i!=INVALID);

	b=(i==j); b=(i!=j); b=(i<j);

      }

      {

	NodeIt i; NodeIt j(i); NodeIt k(INVALID); NodeIt l(G);

	i=j;

	j=G.first(i);

	j=++i;

	bool b; b=true;

	b=(i==INVALID); b=(i!=INVALID);

	Node n(i);

	n=i;

	b=(i==j); b=(i!=j); b=(i<j);

	//Node ->NodeIt conversion

	NodeIt ni(G,n);

      }

      {

	Edge i; Edge j(i); Edge k(INVALID);

	i=j;

	bool b; b=true;

	b=(i==INVALID); b=(i!=INVALID);

	b=(i==j); b=(i!=j); b=(i<j);

      }

      {

	EdgeIt i; EdgeIt j(i); EdgeIt k(INVALID); EdgeIt l(G);

	i=j;

	j=G.first(i);

	j=++i;

	bool b; b=true;

	b=(i==INVALID); b=(i!=INVALID);

	Edge e(i);

	e=i;

	b=(i==j); b=(i!=j); b=(i<j);

	//Edge ->EdgeIt conversion

	EdgeIt ei(G,e);

      }

      {

	Node n;

	InEdgeIt i; InEdgeIt j(i); InEdgeIt k(INVALID); InEdgeIt l(G,n);

	i=j;

	j=G.first(i,n);

	j=++i;

	bool b; b=true;

	b=(i==INVALID); b=(i!=INVALID);

	Edge e(i);

	e=i;

	b=(i==j); b=(i!=j); b=(i<j);

	//Edge ->InEdgeIt conversion

	InEdgeIt ei(G,e);

      }

      {

	Node n;

	OutEdgeIt i; OutEdgeIt j(i); OutEdgeIt k(INVALID); OutEdgeIt l(G,n);

	i=j;

	j=G.first(i,n);

	j=++i;

	bool b; b=true;

	b=(i==INVALID); b=(i!=INVALID);

	Edge e(i);

	e=i;

	b=(i==j); b=(i!=j); b=(i<j);

	//Edge ->OutEdgeIt conversion

	OutEdgeIt ei(G,e);

      }

      {

	Node n,m;

	n=m=INVALID;

	Edge e;

	e=INVALID;

	n=G.tail(e);

	n=G.head(e);

      }

      // id tests

      { Node n; int i=G.id(n); i=i; }

      { Edge e; int i=G.id(e); i=i; }

      //NodeMap tests

      {

	Node k;

	typename Graph::template NodeMap<int> m(G);

	//Const map

	typename Graph::template NodeMap<int> const &cm = m;

	//Inicialize with default value

	typename Graph::template NodeMap<int> mdef(G,12);

	//Copy

	typename Graph::template NodeMap<int> mm(cm);

	//Copy from another type

	typename Graph::template NodeMap<double> dm(cm);

	//Copy to more complex type

	typename Graph::template NodeMap<DummyType> em(cm);

	int v;

	v=m[k]; m[k]=v; m.set(k,v);

	v=cm[k];

	m=cm;  

	dm=cm; //Copy from another type  

	em=cm; //Copy to more complex type

	{

	  //Check the typedef's

	  typename Graph::template NodeMap<int>::ValueType val;

	  val=1;

	  typename Graph::template NodeMap<int>::KeyType key;

	  key = typename Graph::NodeIt(G);

	}

      }  

      { //bool NodeMap

	Node k;

	typename Graph::template NodeMap<bool> m(G);

	typename Graph::template NodeMap<bool> const &cm = m;  //Const map

	//Inicialize with default value

	typename Graph::template NodeMap<bool> mdef(G,12);

	typename Graph::template NodeMap<bool> mm(cm);   //Copy

	typename Graph::template NodeMap<int> dm(cm); //Copy from another type

	bool v;

	v=m[k]; m[k]=v; m.set(k,v);

	v=cm[k];

	m=cm;  

	dm=cm; //Copy from another type

	m=dm; //Copy to another type

	{

	  //Check the typedef's

	  typename Graph::template NodeMap<bool>::ValueType val;

	  val=true;

	  typename Graph::template NodeMap<bool>::KeyType key;

	  key= typename Graph::NodeIt(G);

	}

      }

      //EdgeMap tests

      {

	Edge k;

	typename Graph::template EdgeMap<int> m(G);

	typename Graph::template EdgeMap<int> const &cm = m;  //Const map

	//Inicialize with default value

	typename Graph::template EdgeMap<int> mdef(G,12);

	typename Graph::template EdgeMap<int> mm(cm);   //Copy

	typename Graph::template EdgeMap<double> dm(cm);//Copy from another type

	int v;

	v=m[k]; m[k]=v; m.set(k,v);

	v=cm[k];

	m=cm;  

	dm=cm; //Copy from another type

	{

	  //Check the typedef's

	  typename Graph::template EdgeMap<int>::ValueType val;

	  val=1;

	  typename Graph::template EdgeMap<int>::KeyType key;

	  key= typename Graph::EdgeIt(G);

	}

      }  

      { //bool EdgeMap

	Edge k;

	typename Graph::template EdgeMap<bool> m(G);

	typename Graph::template EdgeMap<bool> const &cm = m;  //Const map

	//Inicialize with default value

	typename Graph::template EdgeMap<bool> mdef(G,12);

	typename Graph::template EdgeMap<bool> mm(cm);   //Copy

	typename Graph::template EdgeMap<int> dm(cm); //Copy from another type

	bool v;

	v=m[k]; m[k]=v; m.set(k,v);

	v=cm[k];

	m=cm;  

	dm=cm; //Copy from another type

	m=dm; //Copy to another type

	{

	  //Check the typedef's

	  typename Graph::template EdgeMap<bool>::ValueType val;

	  val=true;

	  typename Graph::template EdgeMap<bool>::KeyType key;

	  key= typename Graph::EdgeIt(G);

	}

      }

    }

    /// An empty non-static graph class.

    /// This class provides everything that \ref StaticGraph

    /// with additional functionality which enables to build a

    /// graph 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 tail node \c t

      ///and head node \c h.

      ///\return the new edge.

      Edge addEdge(Node h, Node t) { 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() { }

    };

    ///\brief Checks whether \c G meets the

    ///\ref lemon::skeleton::ExtendableGraph "ExtendableGraph" concept

    template<class Graph> void checkCompileExtendableGraph(Graph &G) 

    {

      checkCompileStaticGraph(G);

      typedef typename Graph::Node Node;

      typedef typename Graph::NodeIt NodeIt;

      typedef typename Graph::Edge Edge;

      typedef typename Graph::EdgeIt EdgeIt;

      typedef typename Graph::InEdgeIt InEdgeIt;

      typedef typename Graph::OutEdgeIt OutEdgeIt;

      Node n,m;

      n=G.addNode();

      m=G.addNode();

      Edge e;

      e=G.addEdge(n,m); 

      //  G.clear();

    }

    /// An empty erasable graph class.

    /// This class is an extension of \ref ExtendableGraph. It also 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 n) { }

      /// Deletes an edge.

      /// Deletes edge \c e edge.

      ///

      void erase(Edge e) { }

    };

    template<class Graph> void checkCompileGraphEraseEdge(Graph &G) 

    {

      typename Graph::Edge e;

      G.erase(e);

    }

    template<class Graph> void checkCompileGraphEraseNode(Graph &G) 

    {

      typename Graph::Node n;

      G.erase(n);

    }

    ///\brief Checks whether \c G meets the

    ///\ref lemon::skeleton::EresableGraph "EresableGraph" concept

    template<class Graph> void checkCompileErasableGraph(Graph &G) 

    {

      checkCompileExtendableGraph(G);

      checkCompileGraphEraseNode(G);

      checkCompileGraphEraseEdge(G);

    }

    ///Checks whether a graph has findEdge() member function.

    ///\todo findEdge() might be a global function.

    ///

    template<class Graph> void checkCompileGraphFindEdge(Graph &G) 

    {

      typedef typename Graph::NodeIt Node;

      typedef typename Graph::NodeIt NodeIt;

      G.findEdge(NodeIt(G),++NodeIt(G),G.findEdge(NodeIt(G),++NodeIt(G)));

      G.findEdge(Node(),Node(),G.findEdge(Node(),Node()));  

    }

    // @}

  } //namespace skeleton  

} //namespace lemon

#endif // LEMON_SKELETON_GRAPH_H