// -*- 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 IterableUBipartiteGraphExtender : public _Base {
  public:
    typedef _Base Parent;
    typedef IterableUBipartiteGraphExtender Graph;
   
    typedef typename Parent::Node Node;
    typedef typename Parent::UpperNode UpperNode;
    typedef typename Parent::LowerNode LowerNode;
    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 UpperNodeIt : public Node { 
      friend class IterableUBipartiteGraphExtender;
      const Graph* graph;
    public:
    
      UpperNodeIt() { }
    
      UpperNodeIt(Invalid i) : Node(INVALID) { }
    
      explicit UpperNodeIt(const Graph& _graph) : graph(&_graph) {
	graph->firstUpper(static_cast<Node&>(*this));
      }

      UpperNodeIt(const Graph& _graph, const Node& node) 
	: Node(node), graph(&_graph) {}
    
      UpperNodeIt& operator++() { 
	graph->nextUpper(*this);
	return *this; 
      }
    };

    class LowerNodeIt : public Node { 
      friend class IterableUBipartiteGraphExtender;
      const Graph* graph;
    public:
    
      LowerNodeIt() { }
    
      LowerNodeIt(Invalid i) : Node(INVALID) { }
    
      explicit LowerNodeIt(const Graph& _graph) : graph(&_graph) {
	graph->firstLower(static_cast<Node&>(*this));
      }

      LowerNodeIt(const Graph& _graph, const Node& node) 
	: Node(node), graph(&_graph) {}
    
      LowerNodeIt& operator++() { 
	graph->nextLower(*this);
	return *this; 
      }
    };

    class EdgeIt : public Edge { 
      friend class IterableUBipartiteGraphExtender;
      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 IterableUBipartiteGraphExtender;
      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 IterableUBipartiteGraphExtender;
      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 IterableUBipartiteGraphExtender;
      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 IterableUBipartiteGraphExtender;
      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