// Copyright (c) 2006 Foundation for Research and Technology-Hellas (Greece).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v6.1/Voronoi_diagram_2/include/CGAL/Voronoi_diagram_2/Default_site_removers.h $
// $Id: include/CGAL/Voronoi_diagram_2/Default_site_removers.h b26b07a1242 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Menelaos Karavelas <mkaravel@iacm.forth.gr>

#ifndef CGAL_VORONOI_DIAGRAM_2_SITE_REMOVERS_H
#define CGAL_VORONOI_DIAGRAM_2_SITE_REMOVERS_H 1

#include <CGAL/license/Voronoi_diagram_2.h>


#include <CGAL/Voronoi_diagram_2/basic.h>
#include <CGAL/Voronoi_diagram_2/Adaptation_traits_functors.h>
#include <CGAL/Triangulation_utils_2.h>

namespace CGAL {

namespace VoronoiDiagram_2 { namespace Internal {

//===========================================================================
//===========================================================================

template<class DG>
struct Default_site_remover
{
  typedef DG                                        Delaunay_graph;
  typedef typename Delaunay_graph::Vertex_handle    Vertex_handle;
  typedef void                                      result_type;

  Default_site_remover() {}

  result_type operator()(Delaunay_graph& dg, const Vertex_handle& v) const {
    // this should return a boolean that indicates whether the removal
    // was successful.
    dg.remove(v);
  }
};

//===========================================================================

template<class AT, class SR>
class Default_caching_site_remover
{
private:
  typedef AT  Adaptation_traits;
  typedef SR  Site_remover;

  typedef Triangulation_cw_ccw_2                    CW_CCW_2;

public:
  typedef typename Adaptation_traits::Delaunay_graph   Delaunay_graph;
  typedef typename Site_remover::Vertex_handle         Vertex_handle;
  typedef typename Site_remover::result_type           result_type;

public:
  Default_caching_site_remover(const Adaptation_traits* at = nullptr) : at_(at) {}

  result_type operator()(Delaunay_graph& dg, const Vertex_handle& v) const
  {
    typedef typename Delaunay_graph::Edge               Edge;
    typedef typename Delaunay_graph::Face_circulator    Face_circulator;
    typedef typename Delaunay_graph::Vertex_circulator  Vertex_circulator;

    if ( dg.dimension() != 2 ) { dg.remove(v); }

    Face_circulator fc_start = dg.incident_faces(v);
    Face_circulator fc = fc_start;
    do {
      int id = fc->index(v);
      Edge e_opp(fc, id);
      Edge e_other(fc, CW_CCW_2::ccw(id));
      at_->edge_rejector_object().erase(e_opp);
      at_->edge_rejector_object().erase(e_other);
    } while ( ++fc != fc_start );

    Vertex_circulator vc_start = dg.incident_vertices(v);
    Vertex_circulator vc = vc_start;
    do {
      at_->face_rejector_object().erase(vc);
    } while ( ++fc != fc_start );

    Site_remover()(dg, v);
  }

private:
  const Adaptation_traits* at_;
};

//===========================================================================

template<class AT>
class Default_caching_site_remover<AT,Null_functor>
{
public:
  Default_caching_site_remover() {}
  template<typename T> Default_caching_site_remover(T /*t*/) {}
};

//===========================================================================
//===========================================================================

} } //namespace VoronoiDiagram_2::Internal

} //namespace CGAL

#endif // CGAL_VORONOI_DIAGRAM_2_SITE_REMOVERS_H

