// -*- c++ -*-

#ifndef HUGO_LIST_GRAPH_H

#define HUGO_LIST_GRAPH_H

#include <iostream>

#include <vector>

#include "invalid.h"

#include "vector_map_factory.h"

namespace hugo {

  template <typename It>

  int count(It it) { 

    int i=0;

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

    return i;

  }

  class ListGraph {

    class node_item;

    class 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;

  private:

  public:

    typedef MapRegistry<ListGraph, Node, NodeIt> NodeMapRegistry;

    typedef VectorMapFactory<NodeMapRegistry> NodeMapFactory;

    NodeMapRegistry node_maps;

    typedef MapRegistry<ListGraph, Edge, EdgeIt> EdgeMapRegistry;

    typedef VectorMapFactory<EdgeMapRegistry> EdgeMapFactory;

    EdgeMapRegistry edge_maps;

    int node_id;

    int edge_id;

    int _node_num;

    int _edge_num;

    node_item* _first_node;

    node_item* _last_node;

    class node_item {

      friend class ListGraph;

      template <typename T> friend class NodeMap;

      friend class Node;

      friend class NodeIt;

      friend class Edge;

      friend class EdgeIt;

      friend class OutEdgeIt;

      friend class InEdgeIt;

      friend class SymEdgeIt;

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

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

      //ListGraph* G;

      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;

    public:

      node_item() { }

    };

    class edge_item {

      friend class ListGraph;

      template <typename T> friend class EdgeMap;

      friend class Node;

      friend class NodeIt;

      friend class Edge;

      friend class EdgeIt;

      friend class OutEdgeIt;

      friend class InEdgeIt;

      friend class SymEdgeIt;

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

      //ListGraph* G;

      int id;

      node_item* _tail;

      node_item* _head;

      edge_item* _next_out;

      edge_item* _prev_out;

      edge_item* _next_in;

      edge_item* _prev_in;

    public:

      edge_item() { }

    };

    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* _tail, node_item* _head) {

      edge_item* e=new edge_item;

      e->id=edge_id++;

      e->_tail=_tail;

      e->_head=_head;

      e->_prev_out=_tail->_last_out_edge;

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

      _tail->_last_out_edge=e;

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

      e->_next_out=0;

      e->_prev_in=_head->_last_in_edge;

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

      _head->_last_in_edge=e;

      if (!_head->_first_in_edge) { _head->_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->_tail)->_last_out_edge=e->_prev_out;

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

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

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

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

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

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

      delete e;

      --_edge_num;

    }

    void _set_tail(edge_item* e, node_item* _tail) {

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

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

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

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

      e->_tail=_tail;

      e->_prev_out=_tail->_last_out_edge;

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

      _tail->_last_out_edge=e;

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

      e->_next_out=0;

    }

    void _set_head(edge_item* e, node_item* _head) {

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

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

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

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

      e->_head=_head;

      e->_prev_in=_head->_last_in_edge;

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

      _head->_last_in_edge=e;

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

      e->_next_in=0;

    }

  public:

    /* default constructor */

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

    ~ListGraph() { 

      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 tail(Edge e) const { return e.tailNode(); }

    Node head(Edge e) const { return e.headNode(); }

    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& /*getF*/first(NodeIt& v) const { 

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

    EdgeIt& /*getF*/first(EdgeIt& e) const { 

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

    OutEdgeIt& /*getF*/first(OutEdgeIt& e, Node v) const { 

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

    InEdgeIt& /*getF*/first(InEdgeIt& e, Node v) const { 

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

    SymEdgeIt& /*getF*/first(SymEdgeIt& e, Node v) const { 

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

    //void getTail(Node& n, const Edge& e) const { n=tail(e); }

    //void getHead(Node& n, const Edge& e) const { n=head(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;

      /*getF*/first(e);

      return e; 

    }

    template< typename It >

    It first(Node v) const { 

      It e;

      /*getF*/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); return next(tmp); }

    template <typename It> It& next(It& it) const { 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() { 

      Node n = _add_node();

      node_maps.add(n);

      return n; 

    }

    Edge addEdge(Node u, Node v) {

      Edge e = _add_edge(u.node, v.node);

      edge_maps.add(e);

      return e; 

    }

    void erase(Node i) { 

      node_maps.erase(i);

      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) { 

      edge_maps.erase(e);

      _delete_edge(e.edge); 

    }

    void clear() { 

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

    }

    void setTail(Edge e, Node tail) {

      _set_tail(e.edge, tail.node); 

    }

    void setHead(Edge e, Node head) {

      _set_head(e.edge, head.node); 

    }

    /* stream operations, for testing purpose */

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

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

    }

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

      os << "(" << i.edge->_tail->id << "--" << i.edge->id << "->" << i.edge->_head->id << ")"; 

      return os; 

    }

    class Node {

      friend class ListGraph;

      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 ListGraph::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 ListGraph;

      //protected:

    public: //for everybody but marci

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

    public:

      NodeIt() : Node() { }

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

    protected:

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

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

      //FIXME::

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

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

    };

    class Edge {

      friend class ListGraph;

      template <typename T> friend class EdgeMap;

      friend class Node;

      friend class NodeIt;

    protected:

      edge_item* edge;

      friend int ListGraph::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 tailNode() const { return Node(edge->_tail); }

      Node headNode() const { return Node(edge->_head); }

    public:

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

    };

    class EdgeIt : public Edge {

      friend class ListGraph;

      //protected: 

    public: //for alpar

      EdgeIt(const ListGraph& 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; }

      }

    public:

      EdgeIt() : Edge() { }

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

    protected:

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

      EdgeIt& operator++() { 

	node_item* v=edge->_tail;

	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 ListGraph;

      //node_item* v;

      //protected: 

    protected: //for alpar

      OutEdgeIt(const Node& _v) /*: v(_v.node)*/ { edge=_v.node->_first_out_edge; }

    public:

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

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

      OutEdgeIt(const ListGraph&, Node _v) /*: v(_v.node)*/ { edge=_v.node->_first_out_edge; }

    protected:

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

    protected:

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

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

    };

    class InEdgeIt : public Edge {

      friend class ListGraph;

      //node_item* v;

      //protected:

    protected: //for alpar

      InEdgeIt(const Node& _v) /*: v(_v.node)*/ { edge=_v.node->_first_in_edge; }

    public:

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

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

      InEdgeIt(const ListGraph&, Node _v) /*: v(_v.node)*/ { edge=_v.node->_first_in_edge; }

    protected:

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

    protected:

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

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

    };

    class SymEdgeIt : public Edge {

      friend class ListGraph;

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

      //node_item* v;

      //protected:

    public: //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 ListGraph&, 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->_tail;

	  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->_tail) : Node(edge->_head); }

      Node bNode() const { 

	return (out_or_in) ? Node(edge->_head) : Node(edge->_tail); }

    };

  };

  //   template< typename T >

  //   T ListGraph::first() const { 

  //     std::cerr << "Invalid use of template<typemane T> T ListGraph::first<T>();" << std::endl; 

  //     return T(); 

  //   }

  //   template<>

  //   ListGraph::NodeIt ListGraph::first<ListGraph::NodeIt>() const { 

  //     return firstNode(); 

  //   }

  //   template<>

  //   ListGraph::EdgeIt ListGraph::first<ListGraph::EdgeIt>() const { 

  //     return firstEdge(); 

  //   }

  //   template< typename T >

  //   T ListGraph::first(ListGraph::Node v) const {

  //     std::cerr << "Invalid use of template<typemane T> T ListGraph::first<T>(ListGRaph::Node);" << std::endl; 

  //     return T(); 

  //   } 

  //   template<>

  //   ListGraph::OutEdgeIt ListGraph::first<ListGraph::OutEdgeIt>(const ListGraph::Node v) const { 

  //     return firstOutEdge(v); 

  //   }

  //   template<>

  //   ListGraph::InEdgeIt ListGraph::first<ListGraph::InEdgeIt>(const ListGraph::Node v) const { 

  //     return firstInEdge(v); 

  //   }

  //   template<>

  //   ListGraph::SymEdgeIt ListGraph::first<ListGraph::SymEdgeIt>(const ListGraph::Node v) const { 

  //     return firstSymEdge(v); 

  //   }

} //namespace hugo

#endif //HUGO_LIST_GRAPH_H