// -*- c++ -*-

#ifndef LEMON_ITERABLE_GRAPH_EXTENDER_H

#define LEMON_ITERABLE_GRAPH_EXTENDER_H

#include <lemon/invalid.h>

#include <lemon/utility.h>

namespace lemon {

  template <typename _Base>

  class IterableGraphExtender : public _Base {

  public:

    /// Indicates that the graph is undirected.

    ///\todo Better name?

    ///

    ///\bug Should it be here?

    typedef False UTag;

    typedef _Base Parent;

    typedef IterableGraphExtender<_Base> Graph;

    typedef typename Parent::Node Node;

    typedef typename Parent::Edge Edge;

    class NodeIt : public Node { 

      const Graph* graph;

    public:

      NodeIt() {}

      NodeIt(Invalid i) : Node(i) { }

      explicit NodeIt(const Graph& _graph) : graph(&_graph) {

	_graph.first(*static_cast<Node*>(this));

      }

      NodeIt(const Graph& _graph, const Node& node) 

	: Node(node), graph(&_graph) {}

      NodeIt& operator++() { 

	graph->next(*this);

	return *this; 

      }

    };

    class EdgeIt : public Edge { 

      const Graph* graph;

    public:

      EdgeIt() { }

      EdgeIt(Invalid i) : Edge(i) { }

      explicit EdgeIt(const Graph& _graph) : graph(&_graph) {

	_graph.first(*static_cast<Edge*>(this));

      }

      EdgeIt(const Graph& _graph, const Edge& e) : 

	Edge(e), graph(&_graph) { }

      EdgeIt& operator++() { 

	graph->next(*this);

	return *this; 

      }

    };

    class OutEdgeIt : public Edge { 

      const Graph* graph;

    public:

      OutEdgeIt() { }

      OutEdgeIt(Invalid i) : Edge(i) { }

      OutEdgeIt(const Graph& _graph, const Node& node) 

	: graph(&_graph) {

	_graph.firstOut(*this, node);

      }

      OutEdgeIt(const Graph& _graph, const Edge& edge) 

	: Edge(edge), graph(&_graph) {}

      OutEdgeIt& operator++() { 

	graph->nextOut(*this);

	return *this; 

      }

    };

    class InEdgeIt : public Edge { 

      const Graph* graph;

    public:

      InEdgeIt() { }

      InEdgeIt(Invalid i) : Edge(i) { }

      InEdgeIt(const Graph& _graph, const Node& node) 

	: graph(&_graph) {

	_graph.firstIn(*this, node);

      }

      InEdgeIt(const Graph& _graph, const Edge& edge) : 

	Edge(edge), graph(&_graph) {}

      InEdgeIt& operator++() { 

	graph->nextIn(*this);

	return *this; 

      }

    };

    /// \brief Base node of the iterator

    ///

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

    Node baseNode(const OutEdgeIt &e) const {

      return Parent::source((Edge)e);

    }

    /// \brief Running node of the iterator

    ///

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

    /// iterator

    Node runningNode(const OutEdgeIt &e) const {

      return Parent::target((Edge)e);

    }

    /// \brief Base node of the iterator

    ///

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

    Node baseNode(const InEdgeIt &e) const {

      return Parent::target((Edge)e);

    }

    /// \brief Running node of the iterator

    ///

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

    /// iterator

    Node runningNode(const InEdgeIt &e) const {

      return Parent::source((Edge)e);

    }

    using Parent::first;

    /// \brief The opposite node on the given edge.

    ///

    /// Gives back the opposite on the given edge.

    Node oppositeNode(const Node& n, const Edge& e) const {

      if (Parent::source(e) == n) {

	return Parent::target(e);

      } else {

	return Parent::source(e);

      }

    }

  private:

    // void first(NodeIt &) const;

    // void first(EdgeIt &) const;

    // void first(OutEdgeIt &) const;

    // void first(InEdgeIt &) const;

  };

  template <typename _Base>

  class IterableUGraphExtender : public IterableGraphExtender<_Base> {

  public:

    /// Indicates that the graph is undirected.

    ///\todo Better name?

    ///

    ///\bug Should it be here?

    ///\bug Should be tested in the concept checker whether it is defined

    ///correctly.

    typedef True UTag;

    typedef IterableGraphExtender<_Base> Parent;

    typedef IterableUGraphExtender<_Base> Graph;

    typedef typename Parent::Node Node;

    typedef typename Parent::Edge Edge;

    typedef typename Parent::UEdge UEdge;

    class UEdgeIt : public Parent::UEdge { 

      const Graph* graph;

    public:

      UEdgeIt() { }

      UEdgeIt(Invalid i) : UEdge(i) { }

      explicit UEdgeIt(const Graph& _graph) : graph(&_graph) {

	_graph.first(*static_cast<UEdge*>(this));

      }

      UEdgeIt(const Graph& _graph, const UEdge& e) : 

	UEdge(e), graph(&_graph) { }

      UEdgeIt& operator++() { 

	graph->next(*this);

	return *this; 

      }

    };

    class IncEdgeIt : public Parent::UEdge { 

      const Graph* graph;

      bool direction;

      friend class IterableUGraphExtender;

    public:

      IncEdgeIt() { }

      IncEdgeIt(Invalid i) : UEdge(i), direction(false) { }

      IncEdgeIt(const Graph& _graph, const Node &n) : graph(&_graph) {

	_graph.firstInc(*this, direction, n);

      }

      IncEdgeIt(const Graph& _graph, const UEdge &ue, const Node &n)

	: graph(&_graph), UEdge(ue) {

	direction = (_graph.source(ue) == n);

      }

      IncEdgeIt& operator++() {

	graph->nextInc(*this, direction);

	return *this; 

      }

    };

    using Parent::baseNode;

    using Parent::runningNode;

    /// Base node of the iterator

    ///

    /// Returns the base node of the iterator

    Node baseNode(const IncEdgeIt &e) const {

      return e.direction ? source(e) : target(e);

    }

    /// Running node of the iterator

    ///

    /// Returns the running node of the iterator

    Node runningNode(const IncEdgeIt &e) const {

      return e.direction ? target(e) : source(e);

    }

    /// \brief The opposite node on the given undirected edge.

    ///

    /// Gives back the opposite on the given undirected edge.

    Node oppositeNode(const Node& n, const UEdge& e) const {

      if (Parent::source(e) == n) {

	return Parent::target(e);

      } else {

	return Parent::source(e);

      }

    }

  };

  template <typename _Base>

  class IterableBpUGraphExtender : public _Base {

  public:

    typedef _Base Parent;

    typedef IterableBpUGraphExtender Graph;

    typedef typename Parent::Node Node;

    typedef typename Parent::ANode ANode;

    typedef typename Parent::BNode BNode;

    typedef typename Parent::Edge Edge;

    typedef typename Parent::UEdge UEdge;

    class NodeIt : public Node { 

      const Graph* graph;

    public:

      NodeIt() { }

      NodeIt(Invalid i) : Node(INVALID) { }

      explicit NodeIt(const Graph& _graph) : graph(&_graph) {

	graph->first(static_cast<Node&>(*this));

      }

      NodeIt(const Graph& _graph, const Node& node) 

	: Node(node), graph(&_graph) { }

      NodeIt& operator++() { 

	graph->next(*this);

	return *this; 

      }

    };

    class ANodeIt : public Node { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

    public:

      ANodeIt() { }

      ANodeIt(Invalid i) : Node(INVALID) { }

      explicit ANodeIt(const Graph& _graph) : graph(&_graph) {

	graph->firstANode(static_cast<Node&>(*this));

      }

      ANodeIt(const Graph& _graph, const Node& node) 

	: Node(node), graph(&_graph) {}

      ANodeIt& operator++() { 

	graph->nextANode(*this);

	return *this; 

      }

    };

    class BNodeIt : public Node { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

    public:

      BNodeIt() { }

      BNodeIt(Invalid i) : Node(INVALID) { }

      explicit BNodeIt(const Graph& _graph) : graph(&_graph) {

	graph->firstBNode(static_cast<Node&>(*this));

      }

      BNodeIt(const Graph& _graph, const Node& node) 

	: Node(node), graph(&_graph) {}

      BNodeIt& operator++() { 

	graph->nextBNode(*this);

	return *this; 

      }

    };

    class EdgeIt : public Edge { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

    public:

      EdgeIt() { }

      EdgeIt(Invalid i) : Edge(INVALID) { }

      explicit EdgeIt(const Graph& _graph) : graph(&_graph) {

	graph->first(static_cast<Edge&>(*this));

      }

      EdgeIt(const Graph& _graph, const Edge& edge) 

	: Edge(edge), graph(&_graph) { }

      EdgeIt& operator++() { 

	graph->next(*this);

	return *this; 

      }

    };

    class UEdgeIt : public UEdge { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

    public:

      UEdgeIt() { }

      UEdgeIt(Invalid i) : UEdge(INVALID) { }

      explicit UEdgeIt(const Graph& _graph) : graph(&_graph) {

	graph->first(static_cast<UEdge&>(*this));

      }

      UEdgeIt(const Graph& _graph, const UEdge& edge) 

	: UEdge(edge), graph(&_graph) { }

      UEdgeIt& operator++() { 

	graph->next(*this);

	return *this; 

      }

    };

    class OutEdgeIt : public Edge { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

    public:

      OutEdgeIt() { }

      OutEdgeIt(Invalid i) : Edge(i) { }

      OutEdgeIt(const Graph& _graph, const Node& node) 

	: graph(&_graph) {

	graph->firstOut(*this, node);

      }

      OutEdgeIt(const Graph& _graph, const Edge& edge) 

	: Edge(edge), graph(&_graph) {}

      OutEdgeIt& operator++() { 

	graph->nextOut(*this);

	return *this; 

      }

    };

    class InEdgeIt : public Edge { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

    public:

      InEdgeIt() { }

      InEdgeIt(Invalid i) : Edge(i) { }

      InEdgeIt(const Graph& _graph, const Node& node) 

	: graph(&_graph) {

	graph->firstIn(*this, node);

      }

      InEdgeIt(const Graph& _graph, const Edge& edge) : 

	Edge(edge), graph(&_graph) {}

      InEdgeIt& operator++() { 

	graph->nextIn(*this);

	return *this; 

      }

    };

    /// \brief Base node of the iterator

    ///

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

    Node baseNode(const OutEdgeIt &e) const {

      return Parent::source((Edge&)e);

    }

    /// \brief Running node of the iterator

    ///

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

    /// iterator

    Node runningNode(const OutEdgeIt &e) const {

      return Parent::target((Edge&)e);

    }

    /// \brief Base node of the iterator

    ///

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

    Node baseNode(const InEdgeIt &e) const {

      return Parent::target((Edge&)e);

    }

    /// \brief Running node of the iterator

    ///

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

    /// iterator

    Node runningNode(const InEdgeIt &e) const {

      return Parent::source((Edge&)e);

    }

    class IncEdgeIt : public Parent::UEdge { 

      friend class IterableBpUGraphExtender;

      const Graph* graph;

      bool direction;

    public:

      IncEdgeIt() { }

      IncEdgeIt(Invalid i) : UEdge(i), direction(true) { }

      IncEdgeIt(const Graph& _graph, const Node &n) : graph(&_graph) {

	graph->firstInc(*this, direction, n);

      }

      IncEdgeIt(const Graph& _graph, const UEdge &ue, const Node &n)

	: graph(&_graph), UEdge(ue) {

	direction = (graph->source(ue) == n);

      }

      IncEdgeIt& operator++() {

	graph->nextInc(*this, direction);

	return *this; 

      }

    };

    /// Base node of the iterator

    ///

    /// Returns the base node of the iterator

    Node baseNode(const IncEdgeIt &e) const {

      return e.direction ? source(e) : target(e);

    }

    /// Running node of the iterator

    ///

    /// Returns the running node of the iterator

    Node runningNode(const IncEdgeIt &e) const {

      return e.direction ? target(e) : source(e);

    }

  };

}

#endif // LEMON_GRAPH_EXTENDER_H