// Copyright (c) 1997  INRIA Sophia-Antipolis (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v6.1.1/TDS_2/include/CGAL/Triangulation_ds_vertex_2.h $
// $Id: include/CGAL/Triangulation_ds_vertex_2.h 08b27d3db14 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Mariette Yvinec

#ifndef CGAL_TRIANGULATION_DS_VERTEX_2_H
#define CGAL_TRIANGULATION_DS_VERTEX_2_H

#include <CGAL/license/TDS_2.h>


#include <CGAL/basic.h>
#include <CGAL/assertions.h>

namespace CGAL {

template <class Vb>
class  Triangulation_ds_vertex_2
  : public Vb
{
  typedef typename Vb::Triangulation_data_structure Tds;
public:
  typedef typename Tds::size_type          size_type;
  typedef typename Tds::difference_type    difference_type;
  typedef typename Tds::Vertex             Vertex;
  typedef typename Tds::Vertex_handle      Vertex_handle;
  typedef typename Tds::Face_handle        Face_handle;
  typedef typename Tds::Vertex_circulator  Vertex_circulator;
  typedef typename Tds::Face_circulator    Face_circulator;
  typedef typename Tds::Edge_circulator    Edge_circulator;

  //CREATORS
  Triangulation_ds_vertex_2() : Vb() {}

  //ACCESS
  size_type degree(); //should be const

  //Deprecated access to circulators - for backward compatibility
  // the following should be const
  // when Face_circulator, Vertex_circulator and Edge_circulator
  // are created from
  // Face_const_handle and Face_const_vertex
  Vertex_circulator incident_vertices()
    {return Vertex_circulator(handle());}

  Vertex_circulator incident_vertices( Face_handle f)
    {return Vertex_circulator(handle(),f);}

  Face_circulator incident_faces()
    { return Face_circulator(handle()) ;}

  Face_circulator incident_faces( Face_handle f)
    { return Face_circulator(handle(), f);}

  Edge_circulator incident_edges()
    { return Edge_circulator(handle());}

  Edge_circulator incident_edges( Face_handle f)
    { return Edge_circulator(handle(), f);}

  bool is_valid(bool verbose = false, int level = 0);

private:
  // used to implement deprecated access to circulators
  Vertex_handle handle();
};

template <class Tds>
typename Triangulation_ds_vertex_2 <Tds>::size_type
Triangulation_ds_vertex_2 <Tds>::
degree() //const
{
  int count = 0;
  Vertex_circulator vc = incident_vertices(), done(vc);
  if ( ! vc.is_empty()) {
    do {
      count += 1;
    } while (++vc != done);
  }
  return count;
}

template <class Tds>
typename Triangulation_ds_vertex_2<Tds>::Vertex_handle
Triangulation_ds_vertex_2 <Tds> ::
handle()
{
  Face_handle fh = this->face();
  for(int i = 0 ; i < 3 ; ++i){
    if ( &*fh->vertex(i) == this) return fh->vertex(i);
  }
  return Vertex_handle();
}

template <class Vb>
bool
Triangulation_ds_vertex_2<Vb> ::
is_valid(bool verbose, int level)
{
  bool result = Vb::is_valid(verbose, level);
  CGAL_assertion(result);
  if (this->face() != Face_handle()) { // face==nullptr if dim <0
    result = result && ( &*this->face()->vertex(0) == this ||
                         &*this->face()->vertex(1) == this ||
                         &*this->face()->vertex(2) == this );
  }
  CGAL_assertion(result);
  return result;
}

} //namespace CGAL

#endif //CGAL_TRIANGULATION_DS_VERTEX_2_H
