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

#ifndef SMART_GRAPH_H
#define SMART_GRAPH_H

#include <vector>
#include <limits.h>

struct _Invalid {} Invalid;

namespace hugo {

  class SmartGraph {

//     static const int INVALID=-1;
//     static const int INVALID_NODE=INT_MAX;

    struct NodeT 
    {
      int first_in,first_out;      
      NodeT() : first_in(-1), first_out(-1) {}
    };
    struct EdgeT 
    {
      int head, tail, next_in, next_out;      
      //FIXME: is this necessary?
      EdgeT() : next_in(-1), next_out(-1) {}  
    };

    std::vector<NodeT> nodes;

    std::vector<EdgeT> edges;
    
    template <typename Key> class DynMapBase
    {
    protected:
      SmartGraph* G; 
    public:
      virtual void add(const Key k) = NULL;
      virtual void erase(const Key k) = NULL;
      DynMapBase(const SmartGraph &_G) : G(&_G) {}
      virtual ~DynMapBase() {}
      friend class SmartGraph;
    };
  public:
    template <typename T> class DynEdgeMap;
    template <typename T> class DynEdgeMap;

    class NodeIt;
    class EdgeIt;

  protected:
    mutable std::vector<DynMapBase<NodeIt> * > dyn_node_maps;
    mutable std::vector<DynMapBase<EdgeIt> * > dyn_edge_maps;
    
  public:

    class EachNodeIt;
    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(const SmartGraph &_g) : nodes(_g.nodes), edges(_g.edges) { }
    
    ~SmartGraph()
    {
      for(std::vector<DynMapBase<NodeIt> * >::iterator i=dyn_node_maps.begin();
	  i!=dyn_node_maps.end(); ++i) (**i).G=NULL;
      for(std::vector<DynMapBase<EdgeIt> * >::iterator i=dyn_edge_maps.begin();
	  i!=dyn_edge_maps.end(); ++i) (**i).G=NULL;
    }

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

    int maxNodeId() const { return nodes.size(); }  //FIXME: What is this?
    int maxEdgeId() 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!=-1; }
    //    bool valid(EachEdgeIt e) const { return e.n<int(edges.size()); }
    bool valid(NodeIt n) const { return n.n!=-1; }
    
    void setInvalid(EdgeIt &e) { e.n=-1; }
    void setInvalid(NodeIt &n) { n.n=-1; }
    
    template <typename It> It getNext(It it) const
    { It tmp(it); return next(tmp); }
    //{ It tmp; tmp.n=it.n+1; return tmp; }

    NodeIt& next(NodeIt& it) const { it.n=(it.n+2)%nodes.size()-1; return it; }
    OutEdgeIt& next(OutEdgeIt& it) const
    { it.n=edges[it.n].next_out; return it; }
    InEdgeIt& next(InEdgeIt& it) const
    { it.n=edges[it.n].next_in; return it; }
    EachEdgeIt& next(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...

      for(std::vector<DynMapBase<NodeIt> * >::iterator i=dyn_node_maps.begin();
	  i!=dyn_node_maps.end(); ++i) (**i).add(n.n);

      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;

      for(std::vector<DynMapBase<EdgeIt> * >::iterator i=dyn_edge_maps.begin();
	  i!=dyn_edge_maps.end(); ++i) (**i).add(e);

      return e;
    }

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

    class NodeIt {
      friend class SmartGraph;
      template <typename T> friend class NodeMap;
      template <typename T> friend class DynNodeMap;
      
      friend class EdgeIt;
      friend class OutEdgeIt;
      friend class InEdgeIt;
      friend class SymEdgeIt;

    protected:
      int n;
      friend int SmartGraph::id(NodeIt v) const; 
      NodeIt(int nn) {n=nn;}
    public:
      NodeIt() {}
      NodeIt (_Invalid i) { n=-1; }
      bool operator==(const NodeIt i) const {return n==i.n;}
      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(G.nodes.size()?0:-1) { }
      EachNodeIt() : NodeIt() { }
    };

    class EdgeIt {
      friend class SmartGraph;
      template <typename T> friend class EdgeMap;
      template <typename T> friend class DynEdgeMap;
      
      friend class NodeIt;
      friend class EachNodeIt;
    protected:
      int n;
      friend int SmartGraph::id(EdgeIt e) const;

      EdgeIt(int nn) {n=nn;}
    public:
      EdgeIt() { }
      EdgeIt (_Invalid i) { n=-1; }
      bool operator==(const EdgeIt i) const {return n==i.n;}
      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(G.edges.size()-1) { }
      EachEdgeIt (_Invalid i) : EdgeIt(i) { }
      EachEdgeIt() : EdgeIt() { }
    };
    
    class OutEdgeIt : public EdgeIt {
      friend class SmartGraph;
    public: 
      OutEdgeIt() : EdgeIt() { }
      OutEdgeIt (_Invalid i) : EdgeIt(i) { }

      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 (_Invalid i) : EdgeIt(i) { }
      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.maxNodeId()) { }
      NodeMap(const SmartGraph& _G, T a) : 
	G(_G), container(G.maxNodeId(), 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.maxNodeId()); }
      void update(T a) { container.resize(G.maxNodeId(), 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.maxEdgeId()) { }
      EdgeMap(const SmartGraph& _G, T a) : 
	G(_G), container(G.maxEdgeId(), 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.maxEdgeId()); }
      void update(T a) { container.resize(G.maxEdgeId(), a); }
    };

    template <typename T> class DynNodeMap : public DynMapBase<NodeIt>
    {
      std::vector<T> container;

    public:
      typedef T ValueType;
      typedef NodeIt KeyType;

      DynNodeMap(const SmartGraph &_G) :
	DynMapBase<NodeIt>(_G), container(_G.maxNodeId())
      {
	//FIXME: What if there are empty Id's?
	//FIXME: Can I use 'this' in a constructor?
	G->dyn_node_maps.push_back(this);
      }
      ~DynNodeMap()
      {
	if(G) {
	  std::vector<DynMapBase<NodeIt>* >::iterator i;
	  for(i=G->dyn_node_maps.begin();
	      i!=G->dyn_node_maps.end() && *i!=this; ++i) ;
	  //if(*i==this) G->dyn_node_maps.erase(i); //FIXME: Way too slow...
	  //A better way to do that: (Is this really important?)
	  if(*i==this) {
	    *i=G->dyn_node_maps.back();
	    G->dyn_node_maps.pop_back();
	  }
	}
      }

      void add(const NodeIt k) 
      {
	if(k.n>=container.size()) container.resize(k.n+1);
      }
//       void erase(const NodeIt k)
//       {
// 	//FIXME: Please implement me.
//       }
//       void erase(const EdgeIt k)
//       {
// 	//FIXME: Please implement me.
//       }
      
      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() {}    //Useless for DynMaps
      void update(T a) {}  //Useless for DynMaps
    };
    
    template <typename T> class DynEdgeMap : public DynMapBase<EdgeIt>
    {
      std::vector<T> container;

    public:
      typedef T ValueType;
      typedef EdgeIt KeyType;

      DynEdgeMap(const SmartGraph &_G) :
	DynMapBase<EdgeIt>(_G), container(_G.maxEdgeId())
      {
	//FIXME: What if there are empty Id's?
	//FIXME: Can I use 'this' in a constructor?
	G->dyn_edge_maps.push_back(this);
      }
      ~DynEdgeMap()
      {
	if(G) {
	  std::vector<DynMapBase<EdgeIt>* >::iterator i;
	  for(i=G->dyn_edge_maps.begin();
	      i!=G->dyn_edge_maps.end() && *i!=this; ++i) ;
	  //if(*i==this) G->dyn_edge_maps.erase(i); //Way too slow...
	  //A better way to do that: (Is this really important?)
	  if(*i==this) {
	    *i=G->dyn_edge_maps.back();
	    G->dyn_edge_maps.pop_back();
	  }
	}
      }
      
      void add(const EdgeIt k) 
      {
	if(k.n>=int(container.size())) container.resize(k.n+1);
      }
      void erase(const EdgeIt k)
      {
	//FIXME: Please implement me.
      }
      
      void set(EdgeIt n, T a) { container[n.n]=a; }
      T get(EdgeIt n) const { return container[n.n]; }
      T& operator[](EdgeIt n) { return container[n.n]; }
      const T& operator[](EdgeIt n) const { return container[n.n]; }

      void update() {}    //Useless for DynMaps
      void update(T a) {}  //Useless for DynMaps
    };
        
  };
} //namespace hugo




#endif //SMART_GRAPH_H