/* -*- C++ -*-

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

  *

  * Copyright (C) 2005 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_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 UndirGraphExtender : public _Base {

     typedef _Base Parent;

     typedef UndirGraphExtender Graph;

   public:

     typedef typename Parent::Edge UndirEdge;

     typedef typename Parent::Node Node;

     class Edge : public UndirEdge {

       friend class UndirGraphExtender;

     protected:

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

       // be reasonable to syncronize...

       bool forward;

       Edge(const UndirEdge &ue, bool _forward) :

         UndirEdge(ue), forward(_forward) {}

     public:

       Edge() {}

       /// Invalid edge constructor

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

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

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

       }

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

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

       }

       bool operator<(const Edge &that) const {

 	return forward<that.forward ||

 	  (!(that.forward<forward) && UndirEdge(*this)<UndirEdge(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 UndirEdge &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 UndirEdge

     /// and source Node.

     ///

     Edge direct(const UndirEdge &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 UndirEdge.

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

     /// returned edge have the same source node.

     Edge direct(const UndirEdge &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( UndirEdge(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( UndirEdge(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( UndirEdge(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( UndirEdge(e) == INVALID ) {

 	  Parent::firstIn(e, n);

 	  e.forward = true;

 	}

       }

       else {

 	Parent::nextIn(e);

       }

     }

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

       Parent::firstOut(e, n);

       if (e != INVALID) return;

       Parent::firstIn(e, n);

     }

     void nextInc(UndirEdge &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(UndirEdge &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(UndirEdge &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 UndirEdge &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 maxUndirEdgeId() const {

       return Parent::maxEdgeId();

     }

     int maxId(Node) const {

       return maxNodeId();

     }

     int maxId(Edge) const {

       return maxEdgeId();

     }

     int maxId(UndirEdge) const {

       return maxUndirEdgeId();

     }

     int edgeNum() const {

       return 2 * Parent::edgeNum();

     }

     int undirEdgeNum() 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));

     }

     UndirEdge undirEdgeFromId(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);

     }

     UndirEdge fromId(int id, UndirEdge) const {

       return undirEdgeFromId(id);

     }

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

       if (prev == INVALID) {

 	UndirEdge 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)) {

 	UndirEdge 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 {

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

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

       }

       return INVALID;

     }

     UndirEdge findUndirEdge(Node source, Node target, UndirEdge prev) const {

       if (prev == INVALID) {

 	UndirEdge 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) {

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

 	if (edge != INVALID) return edge;

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

 	if (edge != INVALID) return edge;	

       } else {

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

 	if (edge != INVALID) return edge;	      

       }

       return INVALID;

     }

   };

   template <typename _Base>

   class UndirBipartiteGraphExtender : public _Base {

   public:

     typedef _Base Parent;

     typedef UndirBipartiteGraphExtender Graph;

     typedef typename Parent::Node Node;

     typedef typename Parent::Edge UndirEdge;

     using Parent::first;

     using Parent::next;

     using Parent::id;

     Node source(const UndirEdge& edge) const {

       return upperNode(edge);

     }

     Node target(const UndirEdge& edge) const {

       return lowerNode(edge);

     }

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

       if (Parent::upper(node)) {

 	Parent::firstDown(edge, node);

 	direction = true;

       } else {

 	Parent::firstUp(edge, node);

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

       }

     }

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

       if (direction) {

 	Parent::nextDown(edge);

       } else {

 	Parent::nextUp(edge);

 	if (edge == INVALID) direction = true;

       }

     }

     int maxUndirEdgeId() const {

       return Parent::maxEdgeId();

     }

     UndirEdge undirEdgeFromId(int id) const {

       return Parent::edgeFromId(id);

     }

     class Edge : public UndirEdge {

       friend class UndirBipartiteGraphExtender;

     protected:

       bool forward;

       Edge(const UndirEdge& edge, bool _forward)

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

     public:

       Edge() {}

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

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

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

       }

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

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

       }

       bool operator<(const Edge& i) const {

 	return UndirEdge::operator<(i) || 

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

       }

     };

     void first(Edge& edge) const {

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

       edge.forward = true;

     }

     void next(Edge& edge) const {

       if (!edge.forward) {

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

       }

       edge.forward = !edge.forward;

     }

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

       if (Parent::upper(node)) {

 	Parent::firstDown(edge, node);

 	edge.forward = true;

       } else {

 	Parent::firstUp(edge, node);

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

       }

     }

     void nextOut(Edge& edge) const {

       if (edge.forward) {

 	Parent::nextDown(edge);

       } else {

 	Parent::nextUp(edge);

 	if (edge == INVALID) {

 	  edge.forward = true;

 	}	

       }

     }

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

       if (Parent::lower(node)) {

 	Parent::firstUp(edge, node);

 	edge.forward = true;	

       } else {

 	Parent::firstDown(edge, node);

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

       }

     }

     void nextIn(Edge& edge) const {

       if (edge.forward) {

 	Parent::nextUp(edge);

       } else {

 	Parent::nextDown(edge);

 	if (edge == INVALID) {

 	  edge.forward = true;

 	}	

       }

     }

     Node source(const Edge& edge) const {

       return edge.forward ? Parent::upperNode(edge) : Parent::lowerNode(edge);

     }

     Node target(const Edge& edge) const {

       return edge.forward ? Parent::lowerNode(edge) : Parent::upperNode(edge);

     }

     bool direction(const Edge& edge) const {

       return edge.forward;

     }

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

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

     }

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

       return Edge(edge, direction);

     }

     Node oppositeNode(const UndirEdge& 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, UndirEdge()), (id & 1) == 0);

     }

     int maxEdgeId() const {

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

     }

     class UpperNode : public Node {

       friend class UndirBipartiteGraphExtender;

     public:

       UpperNode() {}

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

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

 		     typename Parent::NodeSetError());

       }

       UpperNode(Invalid) : Node(INVALID) {}

     };

     void first(UpperNode& node) const {

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

     }

     void next(UpperNode& node) const {

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

     }

     int id(const UpperNode& node) const {

       return Parent::upperId(node);

     }

     class LowerNode : public Node {

       friend class UndirBipartiteGraphExtender;

     public:

       LowerNode() {}

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

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

 		     typename Parent::NodeSetError());

       }

       LowerNode(Invalid) : Node(INVALID) {}

     };

     void first(LowerNode& node) const {

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

     }

     void next(LowerNode& node) const {

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

     }

     int id(const LowerNode& node) const {

       return Parent::upperId(node);

     }

     int maxId(Node) const {

       return Parent::maxNodeId();

     }

     int maxId(LowerNode) const {

       return Parent::maxLowerId();

     }

     int maxId(UpperNode) const {

       return Parent::maxUpperId();

     }

     int maxId(Edge) const {

       return maxEdgeId();

     }

     int maxId(UndirEdge) const {

       return maxUndirEdgeId();

     }

     Node fromId(int id, Node) const {

       return Parent::nodeFromId(id);

     }

     UpperNode fromId(int id, UpperNode) const {

       return Parent::fromUpperId(id);

     }

     LowerNode fromId(int id, LowerNode) const {

       return Parent::fromLowerId(id);

     }

     Edge fromId(int id, Edge) const {

       return edgeFromId(id);

     }

     UndirEdge fromId(int id, UndirEdge) const {

       return undirEdgeFromId(id);

     }

   };

 }

 #endif // LEMON_UNDIR_GRAPH_EXTENDER_H