/* -*- C++ -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2003-2008

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group 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_BITS_BASE_EXTENDER_H

#define LEMON_BITS_BASE_EXTENDER_H

#include <lemon/bits/invalid.h>

#include <lemon/error.h>

#include <lemon/bits/map_extender.h>

#include <lemon/bits/default_map.h>

#include <lemon/concept_check.h>

#include <lemon/concepts/maps.h>

///\ingroup digraphbits

///\file

///\brief Extenders for the digraph types

namespace lemon {

  /// \ingroup digraphbits

  ///

  /// \brief BaseDigraph to BaseGraph extender

  template <typename Base>

  class UndirDigraphExtender : public Base {

  public:

    typedef Base Parent;

    typedef typename Parent::Arc Edge;

    typedef typename Parent::Node Node;

    typedef True UndirectedTag;

    class Arc : public Edge {

      friend class UndirDigraphExtender;

    protected:

      bool forward;

      Arc(const Edge &ue, bool _forward) :

        Edge(ue), forward(_forward) {}

    public:

      Arc() {}

      /// Invalid arc constructor

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

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

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

      }

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

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

      }

      bool operator<(const Arc &that) const {

	return forward<that.forward ||

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

      }

    };

    using Parent::source;

    /// Source of the given Arc.

    Node source(const Arc &e) const {

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

    }

    using Parent::target;

    /// Target of the given Arc.

    Node target(const Arc &e) const {

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

    }

    /// \brief Directed arc from an edge.

    ///

    /// Returns a directed arc corresponding to the specified Edge.

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

    /// returned arc have the same source node.

    static Arc direct(const Edge &ue, bool d) {

      return Arc(ue, d);

    }

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

    /// corresponding edge.

    ///

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

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

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

    using Parent::first;

    using Parent::next;

    void first(Arc &e) const {

      Parent::first(e);

      e.forward=true;

    }

    void next(Arc &e) const {

      if( e.forward ) {

	e.forward = false;

      }

      else {

	Parent::next(e);

	e.forward = true;

      }

    }

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

      Parent::firstIn(e,n);

      if( Edge(e) != INVALID ) {

	e.forward = false;

      }

      else {

	Parent::firstOut(e,n);

	e.forward = true;

      }

    }

    void nextOut(Arc &e) const {

      if( ! e.forward ) {

	Node n = Parent::target(e);

	Parent::nextIn(e);

	if( Edge(e) == INVALID ) {

	  Parent::firstOut(e, n);

	  e.forward = true;

	}

      }

      else {

	Parent::nextOut(e);

      }

    }

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

      Parent::firstOut(e,n);

      if( Edge(e) != INVALID ) {

	e.forward = false;

      }

      else {

	Parent::firstIn(e,n);

	e.forward = true;

      }

    }

    void nextIn(Arc &e) const {

      if( ! e.forward ) {

	Node n = Parent::source(e);

	Parent::nextOut(e);

	if( Edge(e) == INVALID ) {

	  Parent::firstIn(e, n);

	  e.forward = true;

	}

      }

      else {

	Parent::nextIn(e);

      }

    }

    void firstInc(Edge &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(Edge &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);

      }

    }

    Node nodeFromId(int ix) const {

      return Parent::nodeFromId(ix);

    }

    Arc arcFromId(int ix) const {

      return direct(Parent::arcFromId(ix >> 1), bool(ix & 1));

    }

    Edge edgeFromId(int ix) const {

      return Parent::arcFromId(ix);

    }

    int id(const Node &n) const {

      return Parent::id(n);

    }

    int id(const Edge &e) const {

      return Parent::id(e);

    }

    int id(const Arc &e) const {

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

    }

    int maxNodeId() const {

      return Parent::maxNodeId();

    }

    int maxArcId() const {

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

    }

    int maxEdgeId() const {

      return Parent::maxArcId();

    }

    int arcNum() const {

      return 2 * Parent::arcNum();

    }

    int edgeNum() const {

      return Parent::arcNum();

    }

    Arc findArc(Node s, Node t, Arc p = INVALID) const {

      if (p == INVALID) {

	Edge arc = Parent::findArc(s, t);

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

	arc = Parent::findArc(t, s);

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

      } else if (direction(p)) {

	Edge arc = Parent::findArc(s, t, p);

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

	arc = Parent::findArc(t, s);

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

      } else {

	Edge arc = Parent::findArc(t, s, p);

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

      }

      return INVALID;

    }

    Edge findEdge(Node s, Node t, Edge p = INVALID) const {

      if (s != t) {

        if (p == INVALID) {

          Edge arc = Parent::findArc(s, t);

          if (arc != INVALID) return arc;

          arc = Parent::findArc(t, s);

          if (arc != INVALID) return arc;

        } else if (Parent::s(p) == s) {

          Edge arc = Parent::findArc(s, t, p);

          if (arc != INVALID) return arc;

          arc = Parent::findArc(t, s);

          if (arc != INVALID) return arc;	

        } else {

          Edge arc = Parent::findArc(t, s, p);

          if (arc != INVALID) return arc;	      

        }

      } else {

        return Parent::findArc(s, t, p);

      }

      return INVALID;

    }

  };

  template <typename Base>

  class BidirBpGraphExtender : public Base {

  public:

    typedef Base Parent;

    typedef BidirBpGraphExtender Digraph;

    typedef typename Parent::Node Node;

    typedef typename Parent::Edge Edge;

    using Parent::first;

    using Parent::next;

    using Parent::id;

    class Red : public Node {

      friend class BidirBpGraphExtender;

    public:

      Red() {}

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

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

		     typename Parent::NodeSetError());

      }

      Red& operator=(const Node& node) {

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

		     typename Parent::NodeSetError());

        Node::operator=(node);

        return *this;

      }

      Red(Invalid) : Node(INVALID) {}

      Red& operator=(Invalid) {

        Node::operator=(INVALID);

        return *this;

      }

    };

    void first(Red& node) const {

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

    }

    void next(Red& node) const {

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

    }

    int id(const Red& node) const {

      return Parent::redId(node);

    }

    class Blue : public Node {

      friend class BidirBpGraphExtender;

    public:

      Blue() {}

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

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

		     typename Parent::NodeSetError());

      }

      Blue& operator=(const Node& node) {

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

		     typename Parent::NodeSetError());

        Node::operator=(node);

        return *this;

      }

      Blue(Invalid) : Node(INVALID) {}

      Blue& operator=(Invalid) {

        Node::operator=(INVALID);

        return *this;

      }

    };

    void first(Blue& node) const {

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

    }

    void next(Blue& node) const {

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

    }

    int id(const Blue& node) const {

      return Parent::redId(node);

    }

    Node source(const Edge& arc) const {

      return red(arc);

    }

    Node target(const Edge& arc) const {

      return blue(arc);

    }

    void firstInc(Edge& arc, bool& dir, const Node& node) const {

      if (Parent::red(node)) {

	Parent::firstFromRed(arc, node);

	dir = true;

      } else {

	Parent::firstFromBlue(arc, node);

	dir = static_cast<Edge&>(arc) == INVALID;

      }

    }

    void nextInc(Edge& arc, bool& dir) const {

      if (dir) {

	Parent::nextFromRed(arc);

      } else {

	Parent::nextFromBlue(arc);

	if (arc == INVALID) dir = true;

      }

    }

    class Arc : public Edge {

      friend class BidirBpGraphExtender;

    protected:

      bool forward;

      Arc(const Edge& arc, bool _forward)

	: Edge(arc), forward(_forward) {}

    public:

      Arc() {}

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

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

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

      }

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

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

      }

      bool operator<(const Arc& i) const {

	return Edge::operator<(i) || 

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

      }

    };

    void first(Arc& arc) const {

      Parent::first(static_cast<Edge&>(arc));

      arc.forward = true;

    }

    void next(Arc& arc) const {

      if (!arc.forward) {

	Parent::next(static_cast<Edge&>(arc));

      }

      arc.forward = !arc.forward;

    }

    void firstOut(Arc& arc, const Node& node) const {

      if (Parent::red(node)) {

	Parent::firstFromRed(arc, node);

	arc.forward = true;

      } else {

	Parent::firstFromBlue(arc, node);

	arc.forward = static_cast<Edge&>(arc) == INVALID;

      }

    }

    void nextOut(Arc& arc) const {

      if (arc.forward) {

	Parent::nextFromRed(arc);

      } else {

	Parent::nextFromBlue(arc);

        arc.forward = static_cast<Edge&>(arc) == INVALID;

      }

    }

    void firstIn(Arc& arc, const Node& node) const {

      if (Parent::blue(node)) {

	Parent::firstFromBlue(arc, node);

	arc.forward = true;	

      } else {

	Parent::firstFromRed(arc, node);

	arc.forward = static_cast<Edge&>(arc) == INVALID;

      }

    }

    void nextIn(Arc& arc) const {

      if (arc.forward) {

	Parent::nextFromBlue(arc);

      } else {

	Parent::nextFromRed(arc);

	arc.forward = static_cast<Edge&>(arc) == INVALID;

      }

    }

    Node source(const Arc& arc) const {

      return arc.forward ? Parent::red(arc) : Parent::blue(arc);

    }

    Node target(const Arc& arc) const {

      return arc.forward ? Parent::blue(arc) : Parent::red(arc);

    }

    int id(const Arc& arc) const {

      return (Parent::id(static_cast<const Edge&>(arc)) << 1) + 

        (arc.forward ? 0 : 1);

    }

    Arc arcFromId(int ix) const {

      return Arc(Parent::fromEdgeId(ix >> 1), (ix & 1) == 0);

    }

    int maxArcId() const {

      return (Parent::maxEdgeId() << 1) + 1;

    }

    bool direction(const Arc& arc) const {

      return arc.forward;

    }

    Arc direct(const Edge& arc, bool dir) const {

      return Arc(arc, dir);

    }

    int arcNum() const {

      return 2 * Parent::edgeNum();

    }

    int edgeNum() const {

      return Parent::edgeNum();

    }

  };

}

#endif