/* -*- C++ -*-

  * src/lemon/concept/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 concept

 ///\file

 ///\brief The graph components.

 #ifndef LEMON_CONCEPT_GRAPH_COMPONENT_H

 #define LEMON_CONCEPT_GRAPH_COMPONENT_H

 #include <lemon/invalid.h>

 #include <lemon/concept/maps.h>

 namespace lemon {

   namespace concept {

     /****************   Graph iterator concepts   ****************/

     /// Skeleton class for graph Node and Edge

     /// \note Because Node and Edge are forbidden to inherit from the same

     /// base class, this is a template. For Node you should instantiate it

     /// with character 'n' and for Edge with 'e'.

     template<char Ch>

     class GraphItem {

     public:

       GraphItem() {}

       GraphItem(Invalid) {}

       // We explicitely list these:

       GraphItem(GraphItem const&) {}

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

       bool operator==(GraphItem) const { return false; }

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

       // Technical requirement. Do we really need this?

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

     };

     template<typename GI>

     struct GraphItemConcept {

       void constraints() {

 	GI i1;

 	GI i2 = i1;

 	GI i3 = INVALID;

 	i1 = i2 = i3;

 	bool b;

 	b = (ia == ib) && (ia != ib) && (ia < ib);

 	b = (ia == INVALID) && (ib != INVALID);

       }

       const GI &ia;

       const GI &ib;

     };

     template<typename Iter, typename Graph, typename BaseItem>

     struct GraphIteratorConcept {

       void constraints() {

 	function_requires< GraphItemConcept<Iter> >();

 	Iter it1(g);

 	/// \todo Do we need NodeIt(Node) kind of constructor?

 	//	Iter it2(bj);

 	Iter it2;

 	it2 = ++it1;

 	++it2 = it1;

 	++(++it1);

 	/// \bug This should be: is_base_and_derived<BaseItem, Iter>

 	BaseItem bi = it1;

 	bi = it2;

       }

       BaseItem bj;

       Graph g;

     };

     template<typename Iter, typename Graph>

     struct GraphIncIteratorConcept {

       typedef typename Graph::Node Node;

       typedef typename Graph::Edge Edge;

       void constraints() {

 	function_requires< GraphItemConcept<Iter> >();

 	Iter it1(graph, node);

 	/// \todo Do we need OutEdgeIt(Edge) kind of constructor?

 	//	Iter it2(edge);

 	Iter it2;

 	it2 = ++it1;

 	++it2 = it1;

 	++(++it1);

 	Edge e = it1;

 	e = it2;

       }

       Edge edge;

       Node node;

       Graph graph;

     };

     /// An empty base graph class.

     /// This class provides the minimal set of features needed for a graph

     /// structure. All graph concepts have to be conform to this base

     /// graph.

     ///

     /// \bug This is not true. The minimal graph concept is the

     /// BaseIterableGraphComponent.

     class BaseGraphComponent {

     public:

       typedef BaseGraphComponent Graph;

       /// Node class of the graph.

       /// This class represents the Nodes of the graph. 

       ///

       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) {}

 	/// Assign operator for nodes.

 	/// The nodes are assignable. 

 	///

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

 	/// Equality operator.

 	/// Two iterators are equal if and only if they represents the

 	/// same node in the graph or both are invalid.

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

 	/// Inequality operator.

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

 	///

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

  	/// Comparison operator.

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

 	///

 	/// This ordering can be different from the iterating order of nodes.

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

 	bool operator<(const Node&) const { return true;}

       };

       /// Edge class of the graph.

       /// This class represents the Edges of the graph. 

       ///

       class Edge {

       public:

 	/// Default constructor.

 	/// @warning The default constructor sets the iterator

 	/// to an undefined value.

 	Edge() {}

 	/// Copy constructor.

 	/// Copy constructor.

 	///

 	Edge(const Edge&) {}

 	/// Invalid constructor \& conversion.

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

 	/// \sa Invalid for more details.

 	Edge(Invalid) {}

 	/// Assign operator for edges.

 	/// The edges are assignable. 

 	///

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

 	/// Equality operator.

 	/// Two iterators are equal if and only if they represents the

 	/// same edge in the graph or both are invalid.

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

 	/// Inequality operator.

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

 	///

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

  	/// Comparison operator.

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

 	///

 	/// This ordering can be different from the iterating order of edges.

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

 	bool operator<(const Edge&) const { return true;}

       };

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

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

       ///

       Node head(const Edge&) const { return INVALID;}

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

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

       ///

       Node tail(const Edge&) const { return INVALID;}

     };

     /// Concept check structure for BaseGraph.

     /// Concept check structure for BaseGraph.

     ///

     template <typename Graph>

     struct BaseGraphComponentConcept {

       typedef typename Graph::Node Node;

       typedef typename Graph::Edge Edge;

       void constraints() {

 	function_requires< GraphItemConcept<Node> >();

 	function_requires< GraphItemConcept<Edge> >();

 	{

 	  Node n;

 	  Edge e;

 	  n = graph.tail(e);

 	  n = graph.head(e);

 	}      

       }

       const Graph& graph;

     };

     /// An empty iterable base graph class.

     /// This class provides beside the core graph features

     /// core iterable interface for the graph structure.

     /// Most of the base graphs should be conform to this concept.

     class BaseIterableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       /// 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 {}

     };

     /// Concept check structure for IterableBaseGraph.

     /// Concept check structure for IterableBaseGraph.

     ///

     template <typename Graph>

     struct BaseIterableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	typename Graph::Node node;      

 	typename Graph::Edge edge;

 	{

 	  graph.first(node);

 	  graph.next(node);

 	}

 	{

 	  graph.first(edge);

 	  graph.next(edge);

 	}

 	{

 	  graph.firstIn(edge, node);

 	  graph.nextIn(edge);

 	}

 	{

 	  graph.firstOut(edge, node);

 	  graph.nextOut(edge);

 	}

       }

       const Graph& graph;

     };

     /// An empty idable base graph class.

     /// This class provides beside the core graph features

     /// core id functions for the graph structure.

     /// The most of the base graphs should be conform to this concept.

     /// The id's are unique and immutable.

     class IDableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       /// Gives back an unique integer id for the Node. 

       /// Gives back an unique integer id for the Node. 

       ///

       int id(const Node&) const { return -1;}

       /// Gives back an unique integer id for the Edge. 

       /// Gives back an unique integer id for the Edge. 

       ///

       int id(const Edge&) const { return -1;}

     };

     /// Concept check structure for IdableBaseGraph.

     /// Concept check structure for IdableBaseGraph.

     ///

     template <typename Graph>

     struct IDableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	typename Graph::Node node;

 	int nid = graph.id(node);

 	nid = graph.id(node);

 	typename Graph::Edge edge;

 	int eid = graph.id(edge);

 	eid = graph.id(edge);

       }

       const Graph& graph;

     };

     /// An empty max-idable base graph class.

     /// This class provides beside the core graph features

     /// core max id functions for the graph structure.

     /// The most of the base graphs should be conform to this concept.

     /// The id's are unique and immutable.

     class MaxIDableGraphComponent : virtual public BaseGraphComponent {

     public:

       /// Gives back an integer greater or equal to the maximum Node id. 

       /// Gives back an integer greater or equal to the maximum Node id. 

       ///

       int maxId(Node = INVALID) const { return -1;}

       /// Gives back an integer greater or equal to the maximum Edge id. 

       /// Gives back an integer greater or equal to the maximum Edge id. 

       ///

       int maxId(Edge = INVALID) const { return -1;}

     };

     /// Concept check structure for MaxIdableBaseGraph.

     /// Concept check structure for MaxIdableBaseGraph.

     ///

     template <typename Graph>

     struct MaxIDableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	int nid = graph.maxId(typename Graph::Node());

 	ignore_unused_variable_warning(nid);

 	int eid = graph.maxId(typename Graph::Edge());

 	ignore_unused_variable_warning(eid);

       }

       const Graph& graph;

     };

     /// An empty extendable base graph class.

     /// This class provides beside the core graph features

     /// core graph extend interface for the graph structure.

     /// The most of the base graphs should be conform to this concept.

     class BaseExtendableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       /// Adds a new Node to the graph.

       /// Adds a new Node to the graph.

       ///

       Node addNode() {

 	return INVALID;

       }

       /// Adds a new Edge connects the two Nodes to the graph.

       /// Adds a new Edge connects the two Nodes to the graph.

       ///

       Edge addEdge(const Node& from, const Node& to) {

 	return INVALID;

       }

     };

     /// Concept check structure for ExtendableBaseGraph.

     /// Concept check structure for ExtendableBaseGraph.

     ///

     template <typename Graph>

     struct BaseExtendableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	typename Graph::Node node_a, node_b;

 	node_a = graph.addNode();

 	typename Graph::Edge edge;

 	edge = graph.addEdge(node_a, node_b);

       }

       Graph& graph;

     };

     /// An empty erasable base graph class.

     /// This class provides beside the core graph features

     /// core erase functions for the graph structure.

     /// The most of the base graphs should be conform to this concept.

     class BaseErasableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       /// Erase a Node from the graph.

       /// Erase a Node from the graph. This function should not

       /// erase edges connecting to the Node.

       void erase(const Node&) {}    

       /// Erase an Edge from the graph.

       /// Erase an Edge from the graph.

       ///

       void erase(const Edge&) {}

     };

     /// Concept check structure for ErasableBaseGraph.

     /// Concept check structure for ErasableBaseGraph.

     ///

     template <typename Graph>

     struct BaseErasableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	typename Graph::Node node;

 	graph.erase(node);

 	typename Graph::Edge edge;

 	graph.erase(edge);

       }

       Graph& graph;

     };

     /// An empty clearable base graph class.

     /// This class provides beside the core graph features

     /// core clear functions for the graph structure.

     /// The most of the base graphs should be conform to this concept.

     class BaseClearableGraphComponent : virtual public BaseGraphComponent {

     public:

       /// Erase all the Nodes and Edges from the graph.

       /// Erase all the Nodes and Edges from the graph.

       ///

       void clear() {}    

     };

     /// Concept check function for ErasableBaseGraph.

     /// Concept check function for ErasableBaseGraph.

     ///

     template <typename Graph>

     struct BaseClearableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	graph.clear();

       }

       Graph& graph;

     };

     class IterableGraphComponent :

       virtual public BaseIterableGraphComponent {

     public:

       typedef IterableGraphComponent Graph;

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       class NodeIt : public Node {

       public:

 	NodeIt() {}

 	NodeIt(Invalid) {}

 	// explicit NodeIt(Node) {}

 	explicit NodeIt(const Graph&) {}

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

 	//	Node operator*() const { return INVALID; }

 	bool operator==(const NodeIt&) const { return true;}

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

       };

       class EdgeIt : public Edge {

       public:

 	EdgeIt() {}

 	EdgeIt(Invalid) {}

 	// explicit EdgeIt(Edge) {}

 	explicit EdgeIt(const Graph&) {}

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

 	//	Edge operator*() const { return INVALID; }

 	bool operator==(const EdgeIt&) const { return true;}

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

       };

       class InEdgeIt : public Edge {

       public:

 	InEdgeIt() {}

 	InEdgeIt(Invalid) {}

 	// explicit InEdgeIt(Edge) {}

 	explicit InEdgeIt(const Graph&, const Node&) {}

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

 	//	Edge operator*() const { return INVALID; }

 	bool operator==(const InEdgeIt&) const { return true;}

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

       };

       class OutEdgeIt : public Edge {

       public:

 	OutEdgeIt() {}

 	OutEdgeIt(Invalid) {}

 	// explicit OutEdgeIt(Edge) {}

 	explicit OutEdgeIt(const Graph&, const Node&) {}

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

 	//	Edge operator*() const { return INVALID; }

 	bool operator==(const OutEdgeIt&) const { return true;}

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

       };

     };

     template <typename Graph> 

     struct IterableGraphComponentConcept {

       void constraints() {

   	function_requires< BaseIterableGraphComponentConcept<Graph> >();

 	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;

 	function_requires< GraphIteratorConcept<NodeIt, Graph, Node> >();

 	function_requires< GraphIteratorConcept<EdgeIt, Graph, Edge> >();

 	function_requires< GraphIncIteratorConcept<OutEdgeIt, Graph> >();

 	function_requires< GraphIncIteratorConcept<InEdgeIt, Graph> >();

       }

     };

     class MappableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef MappableGraphComponent Graph;

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       template <typename Value>

       class NodeMap : public ReferenceMap<Node, Value> {

       public:

 	NodeMap(const Graph&) {}

 	NodeMap(const Graph&, const Value&) {}

 	NodeMap(const NodeMap&) {}

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

       };

       template <typename Value>

       class EdgeMap : public ReferenceMap<Edge, Value> {

       public:

 	EdgeMap(const Graph&) {}

 	EdgeMap(const Graph&, const Value&) {}

 	EdgeMap(const EdgeMap&) {}

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

       };

     };

     template <typename Graph>

     struct MappableGraphComponentConcept {

       struct Type {

 	int value;

 	Type() : value(0) {}

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

       };

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	{ // int map test

 	  typedef typename Graph::template NodeMap<int> IntNodeMap;

 	  function_requires<GraphMapConcept<IntNodeMap,Graph> >();

 	} { // bool map test

 	  typedef typename Graph::template NodeMap<bool> BoolNodeMap;

 	  function_requires<GraphMapConcept<BoolNodeMap,Graph> >();

 	} { // Type map test

 	  typedef typename Graph::template NodeMap<Type> TypeNodeMap;

 	  function_requires<GraphMapConcept<TypeNodeMap,Graph> >();

 	} 

 	{ // int map test

 	  typedef typename Graph::template EdgeMap<int> IntEdgeMap;

 	  function_requires<GraphMapConcept<IntEdgeMap,Graph> >();

 	} { // bool map test

 	  typedef typename Graph::template EdgeMap<bool> BoolEdgeMap;

 	  function_requires<GraphMapConcept<BoolEdgeMap,Graph> >();

 	} { // Type map test

 	  typedef typename Graph::template EdgeMap<Type> TypeEdgeMap;

 	  function_requires<GraphMapConcept<TypeEdgeMap,Graph> >();

 	} 

       }

       Graph& graph;

     };

     class ExtendableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef ExtendableGraphComponent Graph;

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       Node addNode() {

 	return INVALID;

       }

       Edge addEdge(const Node& from, const Node& to) {

 	return INVALID;

       }

     };

     template <typename Graph>

     struct ExtendableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	typename Graph::Node node_a, node_b;

 	node_a = graph.addNode();

 	typename Graph::Edge edge;

 	edge = graph.addEdge(node_a, node_b);      

       }

       Graph& graph;

     };

     class ErasableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef ErasableGraphComponent Graph;

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       void erase(const Node&) {}    

       void erase(const Edge&) {}

     };

     template <typename Graph>

     struct ErasableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	typename Graph::Node node;

 	graph.erase(node);

 	typename Graph::Edge edge;

 	graph.erase(edge);      

       }

       Graph& graph;

     };

     class ClearableGraphComponent : virtual public BaseGraphComponent {

     public:

       typedef ClearableGraphComponent Graph;

       typedef BaseGraphComponent::Node Node;

       typedef BaseGraphComponent::Edge Edge;

       void clear() {}    

     };

     template <typename Graph>

     struct ClearableGraphComponentConcept {

       void constraints() {

 	function_requires< BaseGraphComponentConcept<Graph> >();

 	graph.clear();

       }

       Graph& graph;

     };

   }

 }

 #endif