/* -*- C++ -*-

 * lemon/graph_extender.h - Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2006 Egervary Jeno Kombinatorikus Optimalizalasi

 * Kutatocsoport (Egervary Research Groin on Combinatorial Optimization,

 * 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_GRAPH_EXTENDER_H

#define LEMON_GRAPH_EXTENDER_H

#include <lemon/invalid.h>

#include <lemon/error.h>

namespace lemon {

  template <typename _Base>

  class GraphExtender : public _Base {

  public:

    typedef _Base Parent;

    typedef GraphExtender Graph;

    typedef typename Parent::Node Node;

    typedef typename Parent::Edge Edge;

    int maxId(Node) const {

      return Parent::maxNodeId();

    }

    int maxId(Edge) const {

      return Parent::maxEdgeId();

    }

    Node fromId(int id, Node) const {

      return Parent::nodeFromId(id);

    }

    Edge fromId(int id, Edge) const {

      return Parent::edgeFromId(id);

    }

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

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

	return Parent::target(e);

      else if(n==Parent::target(e))

	return Parent::source(e);

      else

	return INVALID;

    }

  };

  template <typename _Base>

  class UGraphExtender : public _Base {

    typedef _Base Parent;

    typedef UGraphExtender Graph;

  public:

    typedef typename Parent::Edge UEdge;

    typedef typename Parent::Node Node;

    class Edge : public UEdge {

      friend class UGraphExtender;

    protected:

      // FIXME: Marci use opposite logic in his graph adaptors. It would

      // be reasonable to syncronize...

      bool forward;

      Edge(const UEdge &ue, bool _forward) :

        UEdge(ue), forward(_forward) {}

    public:

      Edge() {}

      /// Invalid edge constructor

      Edge(Invalid i) : UEdge(i), forward(true) {}

      bool operator==(const Edge &that) const {

	return forward==that.forward && UEdge(*this)==UEdge(that);

      }

      bool operator!=(const Edge &that) const {

	return forward!=that.forward || UEdge(*this)!=UEdge(that);

      }

      bool operator<(const Edge &that) const {

	return forward<that.forward ||

	  (!(that.forward<forward) && UEdge(*this)<UEdge(that));

      }

    };

    /// \brief Edge of opposite direction.

    ///

    /// Returns the Edge of opposite direction.

    Edge oppositeEdge(const Edge &e) const {

      return Edge(e,!e.forward);

    }

  public:

    /// \todo Shouldn't the "source" of an undirected edge be called "aNode"

    /// or something???

    using Parent::source;

    /// Source of the given Edge.

    Node source(const Edge &e) const {

      return e.forward ? Parent::source(e) : Parent::target(e);

    }

    /// \todo Shouldn't the "target" of an undirected edge be called "bNode"

    /// or something???

    using Parent::target;

    /// Target of the given Edge.

    Node target(const Edge &e) const {

      return e.forward ? Parent::target(e) : Parent::source(e);

    }

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

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

	return Parent::target(e);

      else if( n == Parent::target(e))

	return Parent::source(e);

      else

	return INVALID;

    }

    /// \brief Directed edge from an undirected edge and a source node.

    ///

    /// Returns a (directed) Edge corresponding to the specified UEdge

    /// and source Node.

    ///

    Edge direct(const UEdge &ue, const Node &s) const {

      return Edge(ue, s == source(ue));

    }

    /// \brief Directed edge from an undirected edge.

    ///

    /// Returns a directed edge corresponding to the specified UEdge.

    /// If the given bool is true the given undirected edge and the

    /// returned edge have the same source node.

    Edge direct(const UEdge &ue, bool d) const {

      return Edge(ue, d);

    }

    /// Returns whether the given directed edge is same orientation as the

    /// corresponding undirected edge.

    ///

    /// \todo reference to the corresponding point of the undirected graph

    /// concept. "What does the direction of an undirected edge mean?"

    bool direction(const Edge &e) const { return e.forward; }

    using Parent::first;

    void first(Edge &e) const {

      Parent::first(e);

      e.forward=true;

    }

    using Parent::next;

    void next(Edge &e) const {

      if( e.forward ) {

	e.forward = false;

      }

      else {

	Parent::next(e);

	e.forward = true;

      }

    }

  public:

    void firstOut(Edge &e, const Node &n) const {

      Parent::firstIn(e,n);

      if( UEdge(e) != INVALID ) {

	e.forward = false;

      }

      else {

	Parent::firstOut(e,n);

	e.forward = true;

      }

    }

    void nextOut(Edge &e) const {

      if( ! e.forward ) {

	Node n = Parent::target(e);

	Parent::nextIn(e);

	if( UEdge(e) == INVALID ) {

	  Parent::firstOut(e, n);

	  e.forward = true;

	}

      }

      else {

	Parent::nextOut(e);

      }

    }

    void firstIn(Edge &e, const Node &n) const {

      Parent::firstOut(e,n);

      if( UEdge(e) != INVALID ) {

	e.forward = false;

      }

      else {

	Parent::firstIn(e,n);

	e.forward = true;

      }

    }

    void nextIn(Edge &e) const {

      if( ! e.forward ) {

	Node n = Parent::source(e);

	Parent::nextOut(e);

	if( UEdge(e) == INVALID ) {

	  Parent::firstIn(e, n);

	  e.forward = true;

	}

      }

      else {

	Parent::nextIn(e);

      }

    }

    void firstInc(UEdge &e, const Node &n) const {

      Parent::firstOut(e, n);

      if (e != INVALID) return;

      Parent::firstIn(e, n);

    }

    void nextInc(UEdge &e, const Node &n) const {

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

	Parent::nextOut(e);

	if (e != INVALID) return;

	Parent::firstIn(e, n);

      } else {

	Parent::nextIn(e);

      }

    }

    void firstInc(UEdge &e, bool &d, const Node &n) const {

      d = true;

      Parent::firstOut(e, n);

      if (e != INVALID) return;

      d = false;

      Parent::firstIn(e, n);

    }

    void nextInc(UEdge &e, bool &d) const {

      if (d) {

	Node s = Parent::source(e);

	Parent::nextOut(e);

	if (e != INVALID) return;

	d = false;

	Parent::firstIn(e, s);

      } else {

	Parent::nextIn(e);

      }

    }

    // Miscellaneous stuff:

    /// \todo these methods (id, maxEdgeId) should be moved into separate

    /// Extender

    // using Parent::id;

    // Using "using" is not a good idea, cause it could be that there is

    // no "id" in Parent...

    int id(const Node &n) const {

      return Parent::id(n);

    }

    int id(const UEdge &e) const {

      return Parent::id(e);

    }

    int id(const Edge &e) const {

      return 2 * Parent::id(e) + int(e.forward);

    }

    int maxNodeId() const {

      return Parent::maxNodeId();

    }

    int maxEdgeId() const {

      return 2 * Parent::maxEdgeId() + 1;

    }

    int maxUEdgeId() const {

      return Parent::maxEdgeId();

    }

    int maxId(Node) const {

      return maxNodeId();

    }

    int maxId(Edge) const {

      return maxEdgeId();

    }

    int maxId(UEdge) const {

      return maxUEdgeId();

    }

    int edgeNum() const {

      return 2 * Parent::edgeNum();

    }

    int uEdgeNum() const {

      return Parent::edgeNum();

    }

    Node nodeFromId(int id) const {

      return Parent::nodeFromId(id);

    }

    Edge edgeFromId(int id) const {

      return direct(Parent::edgeFromId(id >> 1), bool(id & 1));

    }

    UEdge uEdgeFromId(int id) const {

      return Parent::edgeFromId(id >> 1);

    }

    Node fromId(int id, Node) const {

      return nodeFromId(id);

    }

    Edge fromId(int id, Edge) const {

      return edgeFromId(id);

    }

    UEdge fromId(int id, UEdge) const {

      return uEdgeFromId(id);

    }

    Edge findEdge(Node source, Node target, Edge prev) const {

      if (prev == INVALID) {

	UEdge edge = Parent::findEdge(source, target);

	if (edge != INVALID) return direct(edge, true);

	edge = Parent::findEdge(target, source);

	if (edge != INVALID) return direct(edge, false);

      } else if (direction(prev)) {

	UEdge edge = Parent::findEdge(source, target, prev);

	if (edge != INVALID) return direct(edge, true);

	edge = Parent::findEdge(target, source);

	if (edge != INVALID) return direct(edge, false);	

      } else {

	UEdge edge = Parent::findEdge(target, source, prev);

	if (edge != INVALID) return direct(edge, false);	      

      }

      return INVALID;

    }

    UEdge findUEdge(Node source, Node target, UEdge prev) const {

      if (prev == INVALID) {

	UEdge edge = Parent::findEdge(source, target);

	if (edge != INVALID) return edge;

	edge = Parent::findEdge(target, source);

	if (edge != INVALID) return edge;

      } else if (Parent::source(prev) == source) {

	UEdge edge = Parent::findEdge(source, target, prev);

	if (edge != INVALID) return edge;

	edge = Parent::findEdge(target, source);

	if (edge != INVALID) return edge;	

      } else {

	UEdge edge = Parent::findEdge(target, source, prev);

	if (edge != INVALID) return edge;	      

      }

      return INVALID;

    }

  };

  template <typename _Base>

  class BpUGraphExtender : public _Base {

  public:

    typedef _Base Parent;

    typedef BpUGraphExtender Graph;

    typedef typename Parent::Node Node;

    typedef typename Parent::Edge UEdge;

    using Parent::first;

    using Parent::next;

    using Parent::id;

    Node source(const UEdge& edge) const {

      return aNode(edge);

    }

    Node target(const UEdge& edge) const {

      return bNode(edge);

    }

    void firstInc(UEdge& edge, bool& direction, const Node& node) const {

      if (Parent::aNode(node)) {

	Parent::firstOut(edge, node);

	direction = true;

      } else {

	Parent::firstIn(edge, node);

	direction = static_cast<UEdge&>(edge) == INVALID;

      }

    }

    void nextInc(UEdge& edge, bool& direction) const {

      if (direction) {

	Parent::nextOut(edge);

      } else {

	Parent::nextIn(edge);

	if (edge == INVALID) direction = true;

      }

    }

    int maxUEdgeId() const {

      return Parent::maxEdgeId();

    }

    UEdge uEdgeFromId(int id) const {

      return Parent::edgeFromId(id);

    }

    class Edge : public UEdge {

      friend class BpUGraphExtender;

    protected:

      bool forward;

      Edge(const UEdge& edge, bool _forward)

	: UEdge(edge), forward(_forward) {}

    public:

      Edge() {}

      Edge (Invalid) : UEdge(INVALID), forward(true) {}

      bool operator==(const Edge& i) const {

	return UEdge::operator==(i) && forward == i.forward;

      }

      bool operator!=(const Edge& i) const {

	return UEdge::operator!=(i) || forward != i.forward;

      }

      bool operator<(const Edge& i) const {

	return UEdge::operator<(i) || 

	  (!(i.forward<forward) && UEdge(*this)<UEdge(i));

      }

    };

    void first(Edge& edge) const {

      Parent::first(static_cast<UEdge&>(edge));

      edge.forward = true;

    }

    void next(Edge& edge) const {

      if (!edge.forward) {

	Parent::next(static_cast<UEdge&>(edge));

      }

      edge.forward = !edge.forward;

    }

    void firstOut(Edge& edge, const Node& node) const {

      if (Parent::aNode(node)) {

	Parent::firstOut(edge, node);

	edge.forward = true;

      } else {

	Parent::firstIn(edge, node);

	edge.forward = static_cast<UEdge&>(edge) == INVALID;

      }

    }

    void nextOut(Edge& edge) const {

      if (edge.forward) {

	Parent::nextOut(edge);

      } else {

	Parent::nextIn(edge);

        edge.forward = static_cast<UEdge&>(edge) == INVALID;

      }

    }

    void firstIn(Edge& edge, const Node& node) const {

      if (Parent::bNode(node)) {

	Parent::firstIn(edge, node);

	edge.forward = true;	

      } else {

	Parent::firstOut(edge, node);

	edge.forward = static_cast<UEdge&>(edge) == INVALID;

      }

    }

    void nextIn(Edge& edge) const {

      if (edge.forward) {

	Parent::nextIn(edge);

      } else {

	Parent::nextOut(edge);

	edge.forward = static_cast<UEdge&>(edge) == INVALID;

      }

    }

    Node source(const Edge& edge) const {

      return edge.forward ? Parent::aNode(edge) : Parent::bNode(edge);

    }

    Node target(const Edge& edge) const {

      return edge.forward ? Parent::bNode(edge) : Parent::aNode(edge);

    }

    bool direction(const Edge& edge) const {

      return edge.forward;

    }

    Edge direct(const UEdge& edge, const Node& node) const {

      return Edge(edge, node == Parent::source(edge));

    }

    Edge direct(const UEdge& edge, bool direction) const {

      return Edge(edge, direction);

    }

    Node oppositeNode(const UEdge& edge, const Node& node) const {

      return source(edge) == node ? 

	target(edge) : source(edge);

    }

    Edge oppositeEdge(const Edge& edge) const {

      return Edge(edge, !edge.forward);

    }

    int id(const Edge& edge) const {

      return (Parent::id(edge) << 1) + (edge.forward ? 0 : 1);

    }

    Edge edgeFromId(int id) const {

      return Edge(Parent::fromId(id >> 1, UEdge()), (id & 1) == 0);

    }

    int maxEdgeId() const {

      return (Parent::maxId(UEdge()) << 1) + 1;

    }

    class ANode : public Node {

      friend class BpUGraphExtender;

    public:

      ANode() {}

      ANode(const Node& node) : Node(node) {

	LEMON_ASSERT(Parent::aNode(node) || node == INVALID, 

		     typename Parent::NodeSetError());

      }

      ANode(Invalid) : Node(INVALID) {}

    };

    void first(ANode& node) const {

      Parent::firstANode(static_cast<Node&>(node));

    }

    void next(ANode& node) const {

      Parent::nextANode(static_cast<Node&>(node));

    }

    int id(const ANode& node) const {

      return Parent::aNodeId(node);

    }

    class BNode : public Node {

      friend class BpUGraphExtender;

    public:

      BNode() {}

      BNode(const Node& node) : Node(node) {

	LEMON_ASSERT(Parent::bNode(node) || node == INVALID,

		     typename Parent::NodeSetError());

      }

      BNode(Invalid) : Node(INVALID) {}

    };

    void first(BNode& node) const {

      Parent::firstBNode(static_cast<Node&>(node));

    }

    void next(BNode& node) const {

      Parent::nextBNode(static_cast<Node&>(node));

    }

    int id(const BNode& node) const {

      return Parent::aNodeId(node);

    }

    int maxId(Node) const {

      return Parent::maxNodeId();

    }

    int maxId(BNode) const {

      return Parent::maxBNodeId();

    }

    int maxId(ANode) const {

      return Parent::maxANodeId();

    }

    int maxId(Edge) const {

      return maxEdgeId();

    }

    int maxId(UEdge) const {

      return maxUEdgeId();

    }

    Node fromId(int id, Node) const {

      return Parent::nodeFromId(id);

    }

    ANode fromId(int id, ANode) const {

      return Parent::fromANodeId(id);

    }

    BNode fromId(int id, BNode) const {

      return Parent::fromBNodeId(id);

    }

    Edge fromId(int id, Edge) const {

      return edgeFromId(id);

    }

    UEdge fromId(int id, UEdge) const {

      return uEdgeFromId(id);

    }

  };

}

#endif // LEMON_UNDIR_GRAPH_EXTENDER_H