/* -*- 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