/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

  * 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