// Copyright (c) 2008  INRIA Sophia-Antipolis (France), ETH Zurich (Switzerland).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org)
//
// $URL: https://github.com/CGAL/cgal/blob/v6.1/Intersections_3/include/CGAL/Intersections_3/internal/Iso_cuboid_3_Plane_3_do_intersect.h $
// $Id: include/CGAL/Intersections_3/internal/Iso_cuboid_3_Plane_3_do_intersect.h b26b07a1242 $
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Camille Wormser, Jane Tournois, Pierre Alliez


#ifndef CGAL_INTERNAL_INTERSECTIONS_3_ISO_CUBOID_3_PLANE_3_DO_INTERSECT_H
#define CGAL_INTERNAL_INTERSECTIONS_3_ISO_CUBOID_3_PLANE_3_DO_INTERSECT_H

#include <CGAL/enum.h>
#include <CGAL/Uncertain.h>

namespace CGAL {
namespace Intersections {
namespace internal {

template <class K, class Box3> // Iso_cuboid_3 or Bbox_3
Uncertain<bool> get_min_max(const typename K::Vector_3& p,
                            const Box3& bbox,
                            typename K::Point_3& p_min,
                            typename K::Point_3& p_max)
{
  if(certainly(p.x() > 0)) {
    if(certainly(p.y() > 0)) {
      if(certainly(p.z() > 0)) {
        p_min = typename K::Point_3(bbox.xmin(), bbox.ymin(),bbox.zmin());
        p_max = typename K::Point_3(bbox.xmax(), bbox.ymax(),bbox.zmax());
        return true;
      } else if(certainly(p.z() <= 0)) {
        p_min = typename K::Point_3(bbox.xmin(), bbox.ymin(),bbox.zmax());
        p_max = typename K::Point_3(bbox.xmax(), bbox.ymax(),bbox.zmin());
        return true;
      }
    } else if(certainly(p.y() <= 0)) {
      if(certainly(p.z() > 0)) {
        p_min = typename K::Point_3(bbox.xmin(), bbox.ymax(),bbox.zmin());
        p_max = typename K::Point_3(bbox.xmax(), bbox.ymin(),bbox.zmax());
        return true;
      } else if(certainly(p.z() <= 0)) {
        p_min = typename K::Point_3(bbox.xmin(), bbox.ymax(),bbox.zmax());
        p_max = typename K::Point_3(bbox.xmax(), bbox.ymin(),bbox.zmin());
        return true;
      }
    }
  }
  else if(certainly(p.x() <= 0)) {
    if(certainly(p.y() > 0)) {
      if(certainly(p.z() > 0)) {
        p_min = typename K::Point_3(bbox.xmax(), bbox.ymin(),bbox.zmin());
        p_max = typename K::Point_3(bbox.xmin(), bbox.ymax(),bbox.zmax());
        return true;
      } else if(certainly(p.z() <= 0)) {
        p_min = typename K::Point_3(bbox.xmax(), bbox.ymin(),bbox.zmax());
        p_max = typename K::Point_3(bbox.xmin(), bbox.ymax(),bbox.zmin());
        return true;
      }
    }
    else if(certainly(p.y() <= 0)) {
      if(certainly(p.z() > 0)) {
        p_min = typename K::Point_3(bbox.xmax(), bbox.ymax(),bbox.zmin());
        p_max = typename K::Point_3(bbox.xmin(), bbox.ymin(),bbox.zmax());
        return true;
      } else if(certainly(p.z() <= 0)) {
        p_min = typename K::Point_3(bbox.xmax(), bbox.ymax(),bbox.zmax());
        p_max = typename K::Point_3(bbox.xmin(), bbox.ymin(),bbox.zmin());
        return true;
      }
    }
  }

  return  Uncertain<bool>::indeterminate();
}

template <class K, class Box3> // Iso_cuboid_3 or Bbox_3
typename K::Boolean do_intersect_plane_box(const typename K::Plane_3& plane,
                                           const Box3& bbox,
                                           const K&)
{
  typedef typename K::Point_3 Point_3;

  Point_3 p_max, p_min;
  Uncertain<bool> b = get_min_max<K>(plane.orthogonal_vector(), bbox, p_min, p_max);
  if(is_certain(b))
  {
    return ! (plane.oriented_side(p_max) == ON_NEGATIVE_SIDE ||
              plane.oriented_side(p_min) == ON_POSITIVE_SIDE);
  }

  CGAL::Oriented_side side = plane.oriented_side(Point_3(bbox.xmin(), bbox.ymin(),bbox.zmin()));
  if(side == ON_ORIENTED_BOUNDARY) return true;

  CGAL::Oriented_side s = plane.oriented_side(Point_3(bbox.xmax(), bbox.ymax(),bbox.zmax()));
  if(s != side) return true;
  s = plane.oriented_side(Point_3(bbox.xmin(), bbox.ymin(),bbox.zmax()));
  if(s != side) return true;
  s = plane.oriented_side(Point_3(bbox.xmax(), bbox.ymax(),bbox.zmin()));
  if(s != side) return true;
  s = plane.oriented_side(Point_3(bbox.xmin(), bbox.ymax(),bbox.zmin()));
  if(s != side) return true;
  s = plane.oriented_side(Point_3(bbox.xmax(), bbox.ymin(),bbox.zmax()));
  if(s != side) return true;
  s = plane.oriented_side(Point_3(bbox.xmin(), bbox.ymax(),bbox.zmax()));
  if(s != side) return true;
  s = plane.oriented_side(Point_3(bbox.xmax(), bbox.ymin(),bbox.zmin()));
  if(s != side) return true;

  return false;
}

template <class K>
typename K::Boolean
do_intersect(const typename K::Plane_3& plane,
             const typename K::Iso_cuboid_3& bbox,
             const K& k)
{
  return do_intersect_plane_box(plane, bbox, k);
}

template <class K>
typename K::Boolean
do_intersect(const typename K::Iso_cuboid_3& bbox,
             const typename K::Plane_3& plane,
             const K& k)
{
  return do_intersect_plane_box(plane, bbox, k);
}

} // namespace internal
} // namespace Intersections
} // namespace CGAL

#endif // CGAL_INTERNAL_INTERSECTIONS_3_ISO_CUBOID_3_PLANE_3_DO_INTERSECT_H

