// -*- mode:C++ -*-

#ifndef SMART_GRAPH_H

#define SMART_GRAPH_H

#include <iostream>

#include <vector>

namespace hugo {

  class SmartGraph {

    static const int INVALID=-1;

    struct NodeT 

    {

      int first_in,first_out;      

      NodeT() : first_in(INVALID), first_out(INVALID) {}

    };

    struct EdgeT 

    {

      int head, tail, next_in, next_out;      

      //FIXME: is this necessary?

      EdgeT() : next_in(INVALID), next_out(INVALID) {}  

    };

    std::vector<NodeT> nodes;

    std::vector<EdgeT> edges;

  public:

    class NodeIt;

    class EachNodeIt;

    class EdgeIt;

    class EachEdgeIt;

    class OutEdgeIt;

    class InEdgeIt;

    //      class NodeIt { int n; };

    //     class EachNodeIt : public NodeIt { };

    //     class EdgeIt { int n; };

    //     class EachEdgeIt : public EdgeIt {};

    //     class OutEdgeIt : public EdgeIt {};

    //     class InEdgeIt : public EdgeIt {};

    //    class SymEdgeIt;

    template <typename T> class NodeMap;

    template <typename T> class EdgeMap;

  public:

    /* default constructor */

    SmartGraph() : nodes(), edges() { }

    ~SmartGraph() {}

    int nodeNum() const { return nodes.size(); }  //FIXME: What is this?

    int edgeNum() const { return edges.size(); }  //FIXME: What is this?

    NodeIt tail(EdgeIt e) const { return edges[e.n].tail; }

    NodeIt head(EdgeIt e) const { return edges[e.n].head; }

    NodeIt aNode(const OutEdgeIt& e) const { return tail(e); }

    NodeIt aNode(const InEdgeIt& e) const { return head(e); }

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

    NodeIt bNode(const OutEdgeIt& e) const { return head(e); }

    NodeIt bNode(const InEdgeIt& e) const { return tail(e); }

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

    EachNodeIt& getFirst(EachNodeIt& v) const { 

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

    EachEdgeIt& getFirst(EachEdgeIt& e) const { 

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

    OutEdgeIt& getFirst(OutEdgeIt& e, const NodeIt v) const { 

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

    InEdgeIt& getFirst(InEdgeIt& e, const NodeIt v) const { 

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

    template< typename It >

    It first() const { 

      It e;

      getFirst(e);

      return e; 

    }

    template< typename It >

    It first(NodeIt v) const { 

      It e;

      getFirst(e, v);

      return e; 

    }

    bool valid(EdgeIt e) const { return e.n!=INVALID; }

    bool valid(EachEdgeIt e) const { return e.n<int(edges.size()); }

    bool valid(NodeIt n) const { return n.n<int(nodes.size()); }

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

      //    { It tmp(it); return goNext(tmp); }

    { It tmp; tmp.n=it.n+1; return tmp; }

    NodeIt& goNext(NodeIt& it) const { ++it.n; return it; }

    OutEdgeIt& goNext(OutEdgeIt& it) const

    { it.n=edges[it.n].next_out; return it; }

    InEdgeIt& goNext(InEdgeIt& it) const

    { it.n=edges[it.n].next_in; return it; }

    EachEdgeIt& goNext(EachEdgeIt& it) const { ++it.n; return it; }

    int id(NodeIt v) const { return v.n; }

    int id(EdgeIt e) const { return e.n; }

    NodeIt addNode() {

      NodeIt n; n.n=nodes.size();

      nodes.push_back(NodeT()); //FIXME: Hmmm...

      return n;

    }

    EdgeIt addEdge(NodeIt u, NodeIt v) {

      EdgeIt e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...

      edges[e.n].tail=u.n; edges[e.n].head=v.n;

      edges[e.n].next_out=nodes[u.n].first_out;

      edges[e.n].next_in=nodes[v.n].first_in;

      nodes[u.n].first_out=nodes[v.n].first_in=e.n;

      return e;

    }

    void clear() {nodes.clear();edges.clear();}

    class NodeIt {

      friend class SmartGraph;

      template <typename T> friend class NodeMap;

      friend class EdgeIt;

      friend class OutEdgeIt;

      friend class InEdgeIt;

      friend class SymEdgeIt;

    protected:

      int n;

      friend int SmartGraph::id(NodeIt v) const; 

    public:

      NodeIt() {}

      NodeIt(int nn) {n=nn;}

      bool operator==(const NodeIt i) const {return n==i.n;}

      bool operator!=(const NodeIt i) const {return n!=i.n;}

    };

    class EachNodeIt : public NodeIt {

      friend class SmartGraph;

    public:

      EachNodeIt(const SmartGraph& G) : NodeIt(0) { }

      EachNodeIt() : NodeIt() { }

    };

    class EdgeIt {

      friend class SmartGraph;

      template <typename T> friend class EdgeMap;

      friend class NodeIt;

      friend class EachNodeIt;

    protected:

      int n;

      friend int SmartGraph::id(EdgeIt e) const;

    public:

      EdgeIt() { }

      EdgeIt(int nn) {n=nn;}

      bool operator==(const EdgeIt i) const {return n==i.n;}

      bool operator!=(const EdgeIt i) const {return n!=i.n;}

    };

    class EachEdgeIt : public EdgeIt {

      friend class SmartGraph;

    public:

      EachEdgeIt(const SmartGraph& G) : EdgeIt(0) { }

      EachEdgeIt() : EdgeIt() { }

    };

    class OutEdgeIt : public EdgeIt {

      friend class SmartGraph;

    public: 

      OutEdgeIt() : EdgeIt() { }

      OutEdgeIt(const SmartGraph& G,const NodeIt v)

	: EdgeIt(G.nodes[v.n].first_out) {}

    };

    class InEdgeIt : public EdgeIt {

      friend class SmartGraph;

    public: 

      InEdgeIt() : EdgeIt() { }

      InEdgeIt(const SmartGraph& G,NodeIt v) :EdgeIt(G.nodes[v.n].first_in){}

    };

    // Map types

    template <typename T>

    class NodeMap {

      const SmartGraph& G; 

      std::vector<T> container;

    public:

      typedef T ValueType;

      typedef NodeIt KeyType;

      NodeMap(const SmartGraph& _G) : G(_G), container(G.nodeNum()) { }

      NodeMap(const SmartGraph& _G, T a) : 

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

      void set(NodeIt n, T a) { container[n.n]=a; }

      T get(NodeIt n) const { return container[n.n]; }

      T& operator[](NodeIt n) { return container[n.n]; }

      const T& operator[](NodeIt n) const { return container[n.n]; }

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

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

    };

    template <typename T>

    class EdgeMap {

      const SmartGraph& G; 

      std::vector<T> container;

    public:

      typedef T ValueType;

      typedef EdgeIt KeyType;

      EdgeMap(const SmartGraph& _G) : G(_G), container(G.edgeNum()) { }

      EdgeMap(const SmartGraph& _G, T a) : 

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

      void set(EdgeIt e, T a) { container[e.n]=a; }

      T get(EdgeIt e) const { return container[e.n]; }

      T& operator[](EdgeIt e) { return container[e.n]; } 

      const T& operator[](EdgeIt e) const { return container[e.n]; } 

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

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

    };

  };

} //namespace hugo

#endif //SMART_GRAPH_H