// Copyright (c) 2007  GeometryFactory (France).  All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 3 of the License,
// or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
// 
//
// Author(s)     : Andreas Fabri, Fernando Cacciola

#ifndef CGAL_GRAPH_TRAITS_DELAUNAY_TRIANGULATION_2_H
#define CGAL_GRAPH_TRAITS_DELAUNAY_TRIANGULATION_2_H

#include <CGAL/license/Triangulation_2.h>


// include this to avoid a VC15 warning
#include <CGAL/boost/graph/named_function_params.h>

#include <boost/config.hpp>
#include <boost/iterator_adaptors.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/properties.hpp>
#include <CGAL/boost/graph/graph_traits_Triangulation_2.h>
#include <CGAL/Delaunay_triangulation_2.h>

// The functions and classes in this file allows the user to
// treat a CGAL Delaunay_triangulation_2 object as a boost graph "as is". No
// wrapper is needed for the Delaunay_triangulation_2 object.



namespace boost { 

  template <class GT, class TDS>
  struct graph_traits< CGAL::Delaunay_triangulation_2<GT,TDS> > {

    struct DT2_graph_traversal_category : 
      public virtual bidirectional_graph_tag,
      public virtual adjacency_graph_tag,        
      public virtual edge_list_graph_tag,
      public virtual vertex_list_graph_tag { };

    typedef CGAL::Delaunay_triangulation_2<GT,TDS> Delaunay_triangulation;

    typedef typename CGAL::Delaunay_triangulation_2<GT,TDS>::Vertex_handle vertex_descriptor;
    typedef typename CGAL::Triangulation_2<GT,TDS>::Face_handle face_descriptor;
    typedef CGAL::detail::Edge<CGAL::Delaunay_triangulation_2<GT,TDS>, typename CGAL::Delaunay_triangulation_2<GT,TDS>::Edge>  edge_descriptor;
    typedef typename CGAL::Delaunay_triangulation_2<GT,TDS>::All_edges_iterator  edge_iterator;

    typedef CGAL::detail::T2_halfedge_descriptor<typename Delaunay_triangulation::Triangulation> halfedge_descriptor;

    typedef typename Delaunay_triangulation::All_halfedges_iterator  halfedge_iterator;

    typedef CGAL::Prevent_deref<typename Delaunay_triangulation::All_vertices_iterator> vertex_iterator;
    typedef CGAL::Prevent_deref<typename Delaunay_triangulation::All_faces_iterator> face_iterator;
    typedef CGAL::Counting_iterator<CGAL::detail::Out_edge_circulator<typename Delaunay_triangulation::Edge_circulator, edge_descriptor>, edge_descriptor > out_edge_iterator;
    typedef CGAL::Counting_iterator<CGAL::detail::In_edge_circulator<typename Delaunay_triangulation::Edge_circulator, edge_descriptor>, edge_descriptor > in_edge_iterator;
    typedef CGAL::Counting_iterator<typename Delaunay_triangulation::Vertex_circulator> Incident_vertices_iterator;
    typedef Incident_vertices_iterator adjacency_iterator;

    typedef undirected_tag directed_category;
    typedef disallow_parallel_edge_tag edge_parallel_category; 
    typedef DT2_graph_traversal_category traversal_category;
    typedef typename Delaunay_triangulation::size_type size_type;
    typedef size_type vertices_size_type;
    typedef size_type edges_size_type;
    typedef size_type degree_size_type;

    // nulls
    static vertex_descriptor   null_vertex() { return vertex_descriptor(); }
    static face_descriptor     null_face()   { return face_descriptor(); }
    static halfedge_descriptor     null_halfedge()   { return halfedge_descriptor(); }
  };


} // namespace boost

namespace CGAL {



  template <class Gt, class Tds>
  typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::vertex_descriptor
  source(typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::edge_descriptor e,
         const CGAL::Delaunay_triangulation_2<Gt,Tds>& g)
  {
    return e.first->vertex(g.ccw(e.second));
  }

  template <class Gt, class Tds>
  typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::vertex_descriptor
  target(typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::edge_descriptor e,
         const CGAL::Delaunay_triangulation_2<Gt,Tds>& g)
  {
    return e.first->vertex(g.cw(e.second));
  }


  template <class Gt, class Tds>
  inline std::pair<
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::out_edge_iterator,
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::out_edge_iterator >  
  out_edges(
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::vertex_descriptor u, 
    const CGAL::Delaunay_triangulation_2<Gt,Tds>& g)
  {
    typename CGAL::Delaunay_triangulation_2<Gt,Tds>::Edge_circulator ec(u,u->face());
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::degree_size_type out_deg = out_degree(u,g);
    typedef typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >
      ::out_edge_iterator Iter;
    
    return std::make_pair( Iter(ec), Iter(ec,out_deg) );
  }

  template <class Gt, class Tds>
  inline std::pair<
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::in_edge_iterator,
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::in_edge_iterator >  
  in_edges(
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::vertex_descriptor u, 
    const CGAL::Delaunay_triangulation_2<Gt,Tds>& g)
  {
    typename CGAL::Delaunay_triangulation_2<Gt,Tds>::Edge_circulator ec(u,u->face());
    typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >::degree_size_type out_deg = out_degree(u,g);
    typedef typename boost::graph_traits< CGAL::Delaunay_triangulation_2<Gt,Tds> >
      ::in_edge_iterator Iter;
    return std::make_pair( Iter(ec), Iter(ec,out_deg) );
  }

} // namespace CGAL

namespace boost {

  // g++ 'enumeral_type' in template unification not implemented workaround
  template <class Gt, class Tds, class Tag>
  struct property_map<CGAL::Delaunay_triangulation_2<Gt,Tds>, Tag> {
    typedef typename 
    CGAL::T2_property_map<Tag>::template bind_<Gt,Tds> map_gen;
    typedef typename map_gen::type type;
    typedef typename map_gen::const_type const_type;
  };

  // see struct property_map in Polyhedron for an explanation
  template <class Gt, class Tds, class Tag>
  struct property_map<const CGAL::Delaunay_triangulation_2<Gt,Tds>, Tag> {
    typedef typename 
    CGAL::T2_property_map<Tag>::template bind_<Gt,Tds> map_gen;
    typedef typename map_gen::type type;
    typedef typename map_gen::const_type const_type;
  };


  // What are those needed for ???
  template <typename Gt, typename Tds>
  struct edge_property_type<CGAL::Delaunay_triangulation_2<Gt,Tds> > {
    typedef void type;
  };  

  template <typename Gt, typename Tds>
  struct vertex_property_type<CGAL::Delaunay_triangulation_2<Gt,Tds> > {
    typedef void type;
  };
} // namespace boost


#endif // CGAL_GRAPH_TRAITS_DELAUNAY_TRIANGULATION_2_H
