// -*- c++ -*-

#ifndef LEMON_SAGE_GRAPH_H

#define LEMON_SAGE_GRAPH_H

#include <iostream>

#include <vector>

#include <lemon/invalid.h>

namespace lemon {

//   template <typename It>

//   int count(It it) { 

//     int i=0;

//     for( ; it.valid(); ++it) { ++i; } 

//     return i;

//   }

  class SageGraph {

    struct node_item;

    struct edge_item;

  public:

    class Node;

    class NodeIt;

    class Edge;

    class EdgeIt;

    class OutEdgeIt;

    class InEdgeIt;

    class SymEdgeIt;

    template <typename T> class NodeMap;

    template <typename T> class EdgeMap;

//  private:

    template <typename T> friend class NodeMap;

    template <typename T> friend class EdgeMap;

    template <typename T>

    class NodeMap {

      const SageGraph& G; 

      std::vector<T> container;

    public:

      typedef T Value;

      typedef Node Key;

      NodeMap(const SageGraph& _G) : G(_G), container(G.node_id) { }

      NodeMap(const SageGraph& _G, T a) : 

	G(_G), container(G.node_id, a) { }

      void set(Node n, T a) { container[/*G.id(n)*/n.node->id]=a; }

//      T get(Node n) const { return container[/*G.id(n)*/n.node->id]; }

      typename std::vector<T>::reference operator[](Node n) { 

	return container[/*G.id(n)*/n.node->id]; }

      typename std::vector<T>::const_reference operator[](Node n) const { 

	return container[/*G.id(n)*/n.node->id]; 

      }

      void update() { container.resize(G.node_id); }

      void update(T a) { container.resize(G.node_id, a); }

    };

    template <typename T>

    class EdgeMap {

      const SageGraph& G; 

      std::vector<T> container;

    public:

      typedef T Value;

      typedef Edge Key;

      EdgeMap(const SageGraph& _G) : G(_G), container(G.edge_id) { }

      EdgeMap(const SageGraph& _G, T a) : 

	G(_G), container(G.edge_id, a) { }

      void set(Edge e, T a) { container[/*G.id(e)*/e.edge->id]=a; }

//      T get(Edge e) const { return container[/*G.id(e)*/e.edge->id]; }

      typename std::vector<T>::reference operator[](Edge e) { 

	return container[/*G.id(e)*/e.edge->id]; } 

      typename std::vector<T>::const_reference operator[](Edge e) const { 

	return container[/*G.id(e)*/e.edge->id]; 

      } 

      void update() { container.resize(G.edge_id); }

      void update(T a) { container.resize(G.edge_id, a); }

    };

  private:

    int node_id;

    int edge_id;

    int _node_num;

    int _edge_num;

    node_item* _first_node;

    node_item* _last_node;

    struct node_item {

      int id;

      edge_item* _first_out_edge;

      edge_item* _last_out_edge;

      edge_item* _first_in_edge;

      edge_item* _last_in_edge;

      node_item* _next_node;

      node_item* _prev_node;

    };

    struct edge_item {

      int id;

      node_item* _source;

      node_item* _target;

      edge_item* _next_out;

      edge_item* _prev_out;

      edge_item* _next_in;

      edge_item* _prev_in;

    };

    node_item* _add_node() { 

      node_item* p=new node_item;

      p->id=node_id++;

      p->_first_out_edge=0;

      p->_last_out_edge=0;

      p->_first_in_edge=0;

      p->_last_in_edge=0;

      p->_prev_node=_last_node;

      p->_next_node=0;

      if (_last_node) _last_node->_next_node=p;

      _last_node=p;

      if (!_first_node) _first_node=p;

      ++_node_num;

      return p;

    }

    edge_item* _add_edge(node_item* _source, node_item* _target) {

      edge_item* e=new edge_item;

      e->id=edge_id++;

      e->_source=_source;

      e->_target=_target;

      e->_prev_out=_source->_last_out_edge;

      if (_source->_last_out_edge) (_source->_last_out_edge)->_next_out=e;

      _source->_last_out_edge=e;

      if (!_source->_first_out_edge) _source->_first_out_edge=e; 

      e->_next_out=0;

      e->_prev_in=_target->_last_in_edge;

      if (_target->_last_in_edge) (_target->_last_in_edge)->_next_in=e;

      _target->_last_in_edge=e;

      if (!_target->_first_in_edge) { _target->_first_in_edge=e; } 

      e->_next_in=0;

      ++_edge_num;

      return e;

    }

    //deletes a node which has no out edge and no in edge

    void _delete_node(node_item* v) {

      if (v->_next_node) (v->_next_node)->_prev_node=v->_prev_node; else 

	_last_node=v->_prev_node;

      if (v->_prev_node) (v->_prev_node)->_next_node=v->_next_node; else 

	_first_node=v->_next_node;

      delete v;

      --_node_num;

    }

    void _delete_edge(edge_item* e) {

      if (e->_next_out) (e->_next_out)->_prev_out=e->_prev_out; else 

	(e->_source)->_last_out_edge=e->_prev_out;

      if (e->_prev_out) (e->_prev_out)->_next_out=e->_next_out; else 

	(e->_source)->_first_out_edge=e->_next_out;

      if (e->_next_in) (e->_next_in)->_prev_in=e->_prev_in; else 

	(e->_target)->_last_in_edge=e->_prev_in;

      if (e->_prev_in) (e->_prev_in)->_next_in=e->_next_in; else 

	(e->_target)->_first_in_edge=e->_next_in;

      delete e;

      --_edge_num;

    }

    void _set_source(edge_item* e, node_item* _source) {

      if (e->_next_out) (e->_next_out)->_prev_out=e->_prev_out; else 

	(e->_source)->_last_out_edge=e->_prev_out;

      if (e->_prev_out) (e->_prev_out)->_next_out=e->_next_out; else 

	(e->_source)->_first_out_edge=e->_next_out;

      e->_source=_source;

      e->_prev_out=_source->_last_out_edge;

      if (_source->_last_out_edge) (_source->_last_out_edge)->_next_out=e;

      _source->_last_out_edge=e;

      if (!_source->_first_out_edge) _source->_first_out_edge=e; 

      e->_next_out=0;

    }

    void _set_target(edge_item* e, node_item* _target) {

      if (e->_next_in) (e->_next_in)->_prev_in=e->_prev_in; else 

	(e->_target)->_last_in_edge=e->_prev_in;

      if (e->_prev_in) (e->_prev_in)->_next_in=e->_next_in; else 

	(e->_target)->_first_in_edge=e->_next_in;

      e->_target=_target;

      e->_prev_in=_target->_last_in_edge;

      if (_target->_last_in_edge) (_target->_last_in_edge)->_next_in=e;

      _target->_last_in_edge=e;

      if (!_target->_first_in_edge) { _target->_first_in_edge=e; } 

      e->_next_in=0;

    }

  public:

    /* default constructor */

    SageGraph() : node_id(0), edge_id(0), _node_num(0), _edge_num(0), _first_node(0), _last_node(0) { }

    ~SageGraph() { 

      NodeIt n;

      while (this->valid(first(n))) erase(n);

      //while (first<NodeIt>().valid()) erase(first<NodeIt>());

    }

    int nodeNum() const { return _node_num; }

    int edgeNum() const { return _edge_num; }

    /* functions to construct iterators from the graph, or from each other */

    //NodeIt firstNode() const { return NodeIt(*this); }

    //EdgeIt firstEdge() const { return EdgeIt(*this); }

    //OutEdgeIt firstOutEdge(const Node v) const { return OutEdgeIt(v); }

    //InEdgeIt firstInEdge(const Node v) const { return InEdgeIt(v); }

    //SymEdgeIt firstSymEdge(const Node v) const { return SymEdgeIt(v); }

    Node source(Edge e) const { return e.sourceNode(); }

    Node target(Edge e) const { return e.targetNode(); }

    Node aNode(const OutEdgeIt& e) const { return e.aNode(); }

    Node aNode(const InEdgeIt& e) const { return e.aNode(); }

    Node aNode(const SymEdgeIt& e) const { return e.aNode(); }

    Node bNode(const OutEdgeIt& e) const { return e.bNode(); }

    Node bNode(const InEdgeIt& e) const { return e.bNode(); }

    Node bNode(const SymEdgeIt& e) const { return e.bNode(); }

    //Node invalid_node() { return Node(); }

    //Edge invalid_edge() { return Edge(); }

    //OutEdgeIt invalid_out_edge() { return OutEdgeIt(); }

    //InEdgeIt invalid_in_edge() { return InEdgeIt(); }

    //SymEdgeIt invalid_sym_edge() { return SymEdgeIt(); }

    /* same methods in other style */

    /* for experimental purpose */

    NodeIt& first(NodeIt& v) const { 

      v=NodeIt(*this); return v; }

    EdgeIt& first(EdgeIt& e) const { 

      e=EdgeIt(*this); return e; }

    OutEdgeIt& first(OutEdgeIt& e, Node v) const { 

      e=OutEdgeIt(*this, v); return e; }

    InEdgeIt& first(InEdgeIt& e, Node v) const { 

      e=InEdgeIt(*this, v); return e; }

    SymEdgeIt& first(SymEdgeIt& e, Node v) const { 

      e=SymEdgeIt(*this, v); return e; }

    //void getSource(Node& n, const Edge& e) const { n=source(e); }

    //void getTarget(Node& n, const Edge& e) const { n=target(e); }

    //void getANode(Node& n, const OutEdgeIt& e) const { n=e.aNode(); }

    //void getANode(Node& n, const InEdgeIt& e) const { n=e.aNode(); }

    //void getANode(Node& n, const SymEdgeIt& e) const { n=e.aNode(); }

    //void getBNode(Node& n, const OutEdgeIt& e) const { n=e.bNode(); }

    //void getBNode(Node& n, const InEdgeIt& e) const { n=e.bNode(); }

    //void getBNode(Node& n, const SymEdgeIt& e) const { n=e.bNode(); }

    //void get_invalid(Node& n) { n=Node(); }

    //void get_invalid(Edge& e) { e=Edge(); }

    //void get_invalid(OutEdgeIt& e) { e=OutEdgeIt(); }

    //void get_invalid(InEdgeIt& e) { e=InEdgeIt(); }

    //void get_invalid(SymEdgeIt& e) { e=SymEdgeIt(); }

//     template< typename It >

//     It first() const { 

//       It e;

//       first(e);

//       return e; 

//     }

//     template< typename It >

//     It first(Node v) const { 

//       It e;

//       first(e, v);

//       return e; 

//     }

    bool valid(Node n) const { return n.valid(); }

    bool valid(Edge e) const { return e.valid(); }

//    template <typename It> It getNext(It it) const { 

//      It tmp(it); next(tmp); return tmp; }

//     NodeIt& next(NodeIt& it) const { return ++it; }

//     EdgeIt& next(EdgeIt& it) const { return ++it; }

//     OutEdgeIt& next(OutEdgeIt& it) const { return ++it; }

//     InEdgeIt& next(InEdgeIt& it) const { return ++it; }

//     SymEdgeIt& next(SymEdgeIt& it) const { return ++it; }

//    template <typename It> It& next(It& it) const { return ++it; }

    template <typename It> It& next(It& it) const { ++it; return it; }

    /* for getting id's of graph objects */

    /* these are important for the implementation of property vectors */

    int id(Node v) const { return v.node->id; }

    int id(Edge e) const { return e.edge->id; }

    /* adding nodes and edges */

    Node addNode() { return Node(_add_node()); }

    Edge addEdge(Node u, Node v) {

      return Edge(_add_edge(u.node, v.node)); 

    }

    void erase(Node i) { 

      { 

	OutEdgeIt e;

	while (this->valid(first(e, i))) erase(e);

      }

      {

	InEdgeIt e;

	while (this->valid(first(e, i))) erase(e);

      }

      //while (first<OutEdgeIt>(i).valid()) erase(first<OutEdgeIt>(i));

      //while (first<InEdgeIt>(i).valid()) erase(first<InEdgeIt>(i));

      _delete_node(i.node); 

    }

    void erase(Edge e) { _delete_edge(e.edge); }

    void clear() { 

      NodeIt e;

      while (this->valid(first(e))) erase(e); 

      //while (first<NodeIt>().valid()) erase(first<NodeIt>());

    }

    void setSource(Edge e, Node source) {

      _set_source(e.edge, source.node); 

    }

    void setTarget(Edge e, Node target) {

      _set_target(e.edge, target.node); 

    }

    /* stream operations, for testing purpose */

//     friend std::ostream& operator<<(std::ostream& os, const Node& i) { 

//       if (i.valid())

// 	os << i.node->id; 

//       else

// 	os << "invalid";

//       return os; 

//     }

//     friend std::ostream& operator<<(std::ostream& os, const Edge& i) { 

//       if (i.valid()) 

// 	os << "(" << i.edge->_source->id << "--" << i.edge->id << "->" << i.edge->_target->id << ")"; 

//       else 

// 	os << "invalid";

//       return os; 

//     }

    class Node {

      friend class SageGraph;

      template <typename T> friend class NodeMap;

      friend class Edge;

      friend class OutEdgeIt;

      friend class InEdgeIt;

      friend class SymEdgeIt;

      //public:  //FIXME: It is required by op= of NodeIt

    protected:

      node_item* node;

    protected:

      friend int SageGraph::id(Node v) const; 

    public:

      Node() /*: node(0)*/ { }

      Node(const Invalid&) : node(0) { }

    protected:

      Node(node_item* _node) : node(_node) { }

      bool valid() const { return (node); }

    public:

      //void makeInvalid() { node=0; }

      friend bool operator==(Node u, Node v) { return v.node==u.node; } 

      friend bool operator!=(Node u, Node v) { return v.node!=u.node; } 

      friend std::ostream& operator<<(std::ostream& os, const Node& i);

    };

    class NodeIt : public Node {

      friend class SageGraph;

      //protected:

    public: //for everybody but marci

      NodeIt(const SageGraph& G) : Node(G._first_node) { }

      NodeIt(const SageGraph& G, const Node& n) : Node(n) { } 

    public:

      NodeIt() : Node() { }

      NodeIt(const Invalid& i) : Node(i) { }

    protected:

      NodeIt(node_item* v) : Node(v) { }

    public:

      NodeIt& operator++() { node=node->_next_node; return *this; }

      //FIXME::

      //      NodeIt& operator=(const Node& e)

      //      { node=e.node; return *this; }

    };

    class Edge {

      friend class SageGraph;

      template <typename T> friend class EdgeMap;

      friend class Node;

      friend class NodeIt;

    protected:

      edge_item* edge;

      friend int SageGraph::id(Edge e) const;

    public:

      Edge() /*: edge(0)*/ { }

      Edge(const Invalid&) : edge(0) { }

      //Edge() { }

    protected:

      Edge(edge_item* _edge) : edge(_edge) { }

      bool valid() const { return (edge); }

    public:

      //void makeInvalid() { edge=0; }

      friend bool operator==(Edge u, Edge v) { return v.edge==u.edge; } 

      friend bool operator!=(Edge u, Edge v) { return v.edge!=u.edge; } 

    protected:

      Node sourceNode() const { return Node(edge->_source); }

      Node targetNode() const { return Node(edge->_target); }

    public:

      friend std::ostream& operator<<(std::ostream& os, const Edge& i);

    };

    class EdgeIt : public Edge {

      friend class SageGraph;

    public:

      EdgeIt() : Edge() { }

      EdgeIt(const Invalid& i) : Edge(i) { }

      EdgeIt(const SageGraph& G) {

	node_item* v=G._first_node;

	if (v) edge=v->_first_out_edge; else edge=0;

	while (v && !edge) { v=v->_next_node; if (v) edge=v->_first_out_edge; }

      }

      EdgeIt(const SageGraph& G, const Edge& e) : Edge(e) { }

//     protected:

//       EdgeIt(edge_item* _e) : Edge(_e) { }

    public:

      EdgeIt& operator++() { 

	node_item* v=edge->_source;

	edge=edge->_next_out; 

	while (v && !edge) { v=v->_next_node; if (v) edge=v->_first_out_edge; }

	return *this;

      }

    };

    class OutEdgeIt : public Edge {

      friend class SageGraph;

    public:

      OutEdgeIt() : Edge() { }

      OutEdgeIt(const Invalid& i) : Edge(i) { }

      OutEdgeIt(const SageGraph&, Node _v) : Edge(_v.node->_first_out_edge) { }

      OutEdgeIt(const SageGraph&, const Edge& e) : Edge(e) { }

      OutEdgeIt& operator++() { edge=edge->_next_out; return *this; }

    protected:

      Node aNode() const { return Node(edge->_source); }

      Node bNode() const { return Node(edge->_target); }

    };

    class InEdgeIt : public Edge {

      friend class SageGraph;

    public:

      InEdgeIt() : Edge() { }

      InEdgeIt(Invalid i) : Edge(i) { }

      InEdgeIt(const SageGraph&, Node _v) : Edge(_v.node->_first_in_edge) { }

      InEdgeIt(const SageGraph&, const Edge& e) : Edge(e) { }

      InEdgeIt& operator++() { edge=edge->_next_in; return *this; }

    protected:

      Node aNode() const { return Node(edge->_target); }

      Node bNode() const { return Node(edge->_source); }

    };

    class SymEdgeIt : public Edge {

      friend class SageGraph;

      bool out_or_in; //1 iff out, 0 iff in

      //node_item* v;

      //protected:

    protected: //for alpar

      SymEdgeIt(const Node& _v) /*: v(_v.node)*/ { 

	out_or_in=1;

	edge=_v.node->_first_out_edge; 

	if (!edge) { edge=_v.node->_first_in_edge; out_or_in=0; }

      }

    public:

      SymEdgeIt() : Edge() /*, v(0)*/ { }

      SymEdgeIt(const Invalid& i) : Edge(i) { }

      SymEdgeIt(const SageGraph&, Node _v) /*: v(_v.node)*/ { 

	out_or_in=1;

	edge=_v.node->_first_out_edge; 

	if (!edge) { edge=_v.node->_first_in_edge; out_or_in=0; }

      }

    protected:

      SymEdgeIt& operator++() { 

	if (out_or_in) { 

	  node_item* v=edge->_source;

	  edge=edge->_next_out; 

	  if (!edge) { out_or_in=0; edge=v->_first_in_edge; }

	} else {

	  edge=edge->_next_in; 

	}

	return *this;

      }

    protected:

      Node aNode() const { 

	return (out_or_in) ? Node(edge->_source) : Node(edge->_target); }

      Node bNode() const { 

	return (out_or_in) ? Node(edge->_target) : Node(edge->_source); }

    };

  };

  inline

  std::ostream& operator<<(std::ostream& os, const SageGraph::Node& i) { 

    if (i.valid())

      os << i.node->id;

    else

      os << "invalid";

    return os; 

  }

  inline

  std::ostream& operator<<(std::ostream& os, const SageGraph::Edge& i) { 

    if (i.valid()) 

      os << "(" << i.sourceNode() << "--" << i.edge->id << "->" 

	 << i.targetNode() << ")"; 

    else 

      os << "invalid";

    return os; 

  }

  class UndirSageGraph : public SageGraph {

  public:

    typedef SymEdgeIt OutEdgeIt;

    typedef SymEdgeIt InEdgeIt;

  };

} //namespace lemon

#endif //LEMON_SAGE_GRAPH_H