// Copyright (c) 1997
// Utrecht University (The Netherlands),
// ETH Zurich (Switzerland),
// INRIA Sophia-Antipolis (France),
// Max-Planck-Institute Saarbruecken (Germany),
// and Tel-Aviv University (Israel).  All rights reserved.
//
// This file is part of CGAL (www.cgal.org)
//
// $URL$
// $Id$
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Guillaume Damiand <guillaume.damiand@liris.cnrs.fr>
//                 Mostafa Ashraf <mostaphaashraf1996@gmail.com>

#ifndef CGAL_DRAW_POLYGON_WITH_HOLES_2_H
#define CGAL_DRAW_POLYGON_WITH_HOLES_2_H

#include <CGAL/Qt/Basic_viewer.h>
#include <CGAL/Graphics_scene.h>
#include <CGAL/Graphics_scene_options.h>
#include <CGAL/Polygon_with_holes_2.h>

#ifdef DOXYGEN_RUNNING
namespace CGAL {

/*!
  \ingroup PkgDrawPolygonWithHoles2

opens a new window and draws a 2D polygon with holes. Parameters of the drawing are taken from the optional graphics scene options parameter.

A call to this function blocks the execution of the program until the drawing window is closed. This function requires `CGAL_Qt6`, and is only available if the macro `CGAL_USE_BASIC_VIEWER` is defined.
Linking with the cmake target `CGAL::CGAL_Basic_viewer` will link with `CGAL_Qt6` and add the definition `CGAL_USE_BASIC_VIEWER`.

\cgalAdvancedBegin
The real declaration of this function template is:

<code>
 template<class T, class C, class GSOptions>

 void CGAL::draw(const CGAL::Polygon_with_holes_2<T, C>& ph, const GSOptions& gso);
</code>
\cgalAdvancedEnd

\tparam PH which must be an instanciation of a `CGAL::Polygon_with_holes_2<...>`.
\tparam GSOptions a model of `GraphicsSceneOptions` concept.

\param ph the polygon with holes to draw.
\param gso the graphics scene options parameter.
 */
template <typename PH, class GSOptions>
void draw(const PH& ph, const GSOptions& gso);

/*!
\ingroup PkgDrawPolygonWithHoles2

A shortcut to `CGAL::draw(ph, Graphics_scene_options{})`.
*/
  template<class PH>
  void draw(const PH& ph);

/*!
\ingroup PkgDrawPolygonWithHoles2

adds the vertices, edges and faces of `ph` into the given graphic scene `gs`. Parameters of the cells are taken from the optional graphics scene options parameter `gso` . Note that `gs` is not cleared before being filled (to enable to draw several data structures in the same basic viewer).

\cgalAdvancedBegin
The real declaration of this function template is:

<code>
 template<class T, class C, class GSOptions>

 void CGAL::add_to_graphics_scene(const CGAL::Polygon_with_holes_2<T, C>& ph, CGAL::Graphics_scene& gs, const GSOptions& gso);
</code>
\cgalAdvancedEnd

\tparam PH which must be an instanciation of a `CGAL::Polygon_with_holes_2<...>`.
\tparam GSOptions a model of `GraphicsSceneOptions` concept.

\param ph the polygon with holes to draw.
\param gs the graphic scene to fill.
\param gso the graphics scene options parameter.
*/
template<class PH, class GSOptions>
void add_to_graphics_scene(const PH& ph,
                           CGAL::Graphics_scene& gs,
                           const GSOptions& gso);

/*!
\ingroup PkgDrawPolygonWithHoles2

A shortcut to `CGAL::add_to_graphics_scene(ph, gs, Graphics_scene_options{})`.
*/
template<class PH>
void add_to_graphics_scene(const PH& ph,
                           CGAL::Graphics_scene& gs);

} /* namespace CGAL */

#endif

namespace CGAL
{

namespace draw_function_for_ph2_with_holes {

template <class P2, class GSOptions>
void compute_one_loop_elements(const P2& ap2,
                               const typename P2::General_polygon_2& aloop,
                               Graphics_scene &graphics_scene,
                               bool hole,
                               const GSOptions& gs_options)
{
  if (hole && gs_options.are_faces_enabled())
  { graphics_scene.add_point_in_face(aloop.vertex(aloop.size()-1)); }

  typename P2::General_polygon_2::Vertex_const_iterator prev;
  for(typename P2::General_polygon_2::Vertex_const_iterator i=aloop.vertices_begin();
      i!=aloop.vertices_end(); ++i)
  {
    if(gs_options.are_vertices_enabled() &&
       gs_options.draw_vertex(ap2, i))
    { // Add vertex
      if(gs_options.colored_vertex(ap2, i))
      { graphics_scene.add_point(*i, gs_options.vertex_color(ap2, i)); }
      else
      { graphics_scene.add_point(*i); }
    }

    if(i!=aloop.vertices_begin() &&
       gs_options.are_edges_enabled() && gs_options.draw_edge(ap2, prev))
    { // Add segment with previous point
      if(gs_options.colored_edge(ap2, prev))
      { graphics_scene.add_segment(*prev, *i, gs_options.edge_color(ap2, prev)); }
      else
      { graphics_scene.add_segment(*prev, *i); }
    }

    if(gs_options.are_faces_enabled())
    { graphics_scene.add_point_in_face(*i); } // Add point in face

    prev=i;
  }

  // Add the last segment between the last point and the first one
  if(gs_options.are_edges_enabled() &&
     gs_options.draw_edge(ap2, aloop.vertices_begin()))
  {
    if(gs_options.colored_edge(ap2, prev))
    { graphics_scene.add_segment(*prev, *(aloop.vertices_begin()),
                                 gs_options.edge_color(ap2, prev)); }
    else
    { graphics_scene.add_segment(*prev, *(aloop.vertices_begin())); }
  }
}

template <class P2, class GSOptions>
void compute_elements(const P2& p2, Graphics_scene &graphics_scene,
                      const GSOptions& gs_options)
{
  if (p2.outer_boundary().is_empty()) return;

  if (gs_options.are_faces_enabled())
  {
    if(gs_options.colored_face(p2, nullptr))
    { graphics_scene.face_begin(gs_options.face_color(p2, nullptr)); }
    else
    { graphics_scene.face_begin(); }
  }

  compute_one_loop_elements<P2>(p2, p2.outer_boundary(), graphics_scene,
                                false, gs_options);

  for (typename P2::Hole_const_iterator it=p2.holes_begin(); it!=p2.holes_end(); ++it)
  {
    compute_one_loop_elements<P2>(p2, *it, graphics_scene,
                                  true, gs_options);
    if (gs_options.are_faces_enabled())
    { graphics_scene.add_point_in_face(p2.outer_boundary().vertex
                                       (p2.outer_boundary().size()-1));
    }
  }

 if (gs_options.are_faces_enabled())
 { graphics_scene.face_end(); }
}

} // draw_function_for_ph2

#define CGAL_P2_WITH_HOLES_TYPE CGAL::Polygon_with_holes_2<T, C>

template <class T, class C, class GSOptions>
void add_to_graphics_scene(const CGAL_P2_WITH_HOLES_TYPE& p2,
                           CGAL::Graphics_scene& graphics_scene,
                           const GSOptions &gs_options)
{
  draw_function_for_ph2_with_holes::compute_elements(p2, graphics_scene,
                                                     gs_options);
}

template <class T, class C>
void add_to_graphics_scene(const CGAL_P2_WITH_HOLES_TYPE& p2,
                           CGAL::Graphics_scene& graphics_scene)
{
  Graphics_scene_options<CGAL_P2_WITH_HOLES_TYPE,
                  typename CGAL_P2_WITH_HOLES_TYPE::General_polygon_2::Vertex_const_iterator,
                  typename CGAL_P2_WITH_HOLES_TYPE::General_polygon_2::Vertex_const_iterator,
                  void*> gs_options;

  add_to_graphics_scene(p2, graphics_scene, gs_options);
}

#ifdef CGAL_USE_BASIC_VIEWER

// Specialization of draw function.
template<class T, class C, class GSOptions>
void draw(const CGAL_P2_WITH_HOLES_TYPE& ap2, const GSOptions &gs_options,
          const char* title="Polygon with Holes Basic Viewer")
{
  CGAL::Graphics_scene buffer;
  add_to_graphics_scene(ap2, buffer, gs_options);
  draw_graphics_scene(buffer, title);
}

template<class T, class C>
void draw(const CGAL_P2_WITH_HOLES_TYPE& ap2,
          const char* title="Polygon with Holes Basic Viewer")
{
  CGAL::Graphics_scene buffer;
  add_to_graphics_scene(ap2, buffer);
  draw_graphics_scene(buffer, title);
}

#endif // CGAL_USE_BASIC_VIEWER

#undef CGAL_P2_WITH_HOLES_TYPE

} // End namespace CGAL

#endif // CGAL_DRAW_POLYGON_WITH_HOLES_2_H