// Copyright (c) 2014
// INRIA Saclay-Ile de France (France)
//
// This file is part of CGAL (www.cgal.org)
//
// $URL: https://github.com/CGAL/cgal/blob/v6.2/NewKernel_d/include/CGAL/NewKernel_d/Types/Sphere.h $
// $Id: include/CGAL/NewKernel_d/Types/Sphere.h cac3e9d75e2 $
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s)     : Marc Glisse

#ifndef CGAL_KD_TYPE_SPHERE_H
#define CGAL_KD_TYPE_SPHERE_H
#include <CGAL/NewKernel_d/store_kernel.h>
#include <CGAL/boost/iterator/counting_iterator.hpp>
namespace CGAL {
template <class R_> class Sphere {
        typedef typename Get_type<R_, FT_tag>::type FT_;
        typedef typename Get_type<R_, Point_tag>::type        Point_;
        Point_ c_;
        FT_ r2_;

        public:
        Sphere(){}
        Sphere(Point_ const&p, FT_ const&r2): c_(p), r2_(r2) {}
        // TODO: Add a piecewise constructor?

        Point_ const& center()const{return c_;}
        FT_ const& squared_radius()const{return r2_;}
};

namespace CartesianDKernelFunctors {
template <class R_> struct Construct_sphere : Store_kernel<R_> {
  CGAL_FUNCTOR_INIT_STORE(Construct_sphere)
  typedef typename Get_type<R_, Sphere_tag>::type        result_type;
  typedef typename Get_type<R_, Point_tag>::type        Point;
  typedef typename Get_type<R_, FT_tag>::type FT;
  result_type operator()(Point const&a, FT const&b)const{
    return result_type(a,b);
  }
  // Not really needed
  result_type operator()()const{
    typename Get_functor<R_, Construct_ttag<Point_tag> >::type cp(this->kernel());
#if defined(BOOST_MSVC) && (BOOST_MSVC == 1900)
#  pragma warning(push)
#  pragma warning(disable: 4309)
#endif
    return result_type(cp(),0);
#if defined(BOOST_MSVC) && (BOOST_MSVC == 1900)
#  pragma warning(pop)
#endif
  }
  template <class Iter>
  result_type operator()(Iter f, Iter e)const{
    typename Get_functor<R_, Construct_circumcenter_tag>::type cc(this->kernel());
    typename Get_functor<R_, Squared_distance_tag>::type sd(this->kernel());

    // It should be possible to avoid copying the center by moving this code to a constructor.
    Point center = cc(f, e);
    FT const& r2 = sd(center, *f);
    return this->operator()(std::move(center), r2);
  }
};

template <class R_> struct Center_of_sphere : private Store_kernel<R_> {
  CGAL_FUNCTOR_INIT_STORE(Center_of_sphere)
  typedef typename Get_type<R_, Sphere_tag>::type        Sphere;
  // No reference because of the second overload
  typedef typename Get_type<R_, Point_tag>::type        result_type;

  result_type const& operator()(Sphere const&s)const{
    return s.center();
  }

  template<class Iter>
  result_type operator()(Iter b, Iter e)const{
    typename Get_functor<R_, Construct_ttag<Sphere_tag> >::type        cs(this->kernel());
    return operator()(cs(b,e)); // computes the radius needlessly
  }
};

template <class R_> struct Squared_radius {
  CGAL_FUNCTOR_INIT_IGNORE(Squared_radius)
  typedef typename Get_type<R_, Sphere_tag>::type        Sphere;
  typedef typename Get_type<R_, FT_tag>::type const&        result_type;
  // TODO: Uses_no_arithmetic?
  result_type operator()(Sphere const&s)const{
    return s.squared_radius();
  }
};

// FIXME: Move it to the generic functors, using the two above and conditional to the existence of sqrt(FT)
template<class R_> struct Point_of_sphere : private Store_kernel<R_> {
  CGAL_FUNCTOR_INIT_STORE(Point_of_sphere)
  typedef R_ R;
  typedef typename Get_type<R, FT_tag>::type FT;
  typedef typename Get_type<R, RT_tag>::type RT;
  typedef typename Get_type<R, Point_tag>::type Point;
  typedef typename Get_type<R, Sphere_tag>::type Sphere;
  typedef typename Get_functor<R, Construct_ttag<Point_tag> >::type CP;
  typedef typename Get_functor<R, Construct_ttag<Point_cartesian_const_iterator_tag> >::type CI;
  typedef typename Get_functor<R, Point_dimension_tag>::type PD;
  typedef Point result_type;
  typedef Sphere first_argument_type;
  typedef int second_argument_type;
  struct Trans : CGAL::cpp98::binary_function<FT,int,FT> {
    FT const& r_; int idx; bool sgn;
    Trans (int n, FT const& r, bool b) : r_(r), idx(n), sgn(b) {}
    FT operator()(FT const&x, int i)const{
      return (i == idx) ? sgn ? x + r_ : x - r_ : x;
    }
  };
  result_type operator()(Sphere const&s, int i)const{
    CI ci(this->kernel());
    PD pd(this->kernel());
    typedef boost::counting_iterator<int,std::random_access_iterator_tag> Count;
    Point const&c = s.center();
    int d=pd(c);
    bool last = (i == d);
    FT r = sqrt(s.squared_radius());
    Trans t(last ? 0 : i, r, !last);
    return CP(this->kernel())(make_transforming_pair_iterator(ci(c,Begin_tag()),Count(0),t),make_transforming_pair_iterator(ci(c,End_tag()),Count(d),t));
  }
};
}
CGAL_KD_DEFAULT_TYPE(Sphere_tag,(CGAL::Sphere<K>),(Point_tag),());
CGAL_KD_DEFAULT_FUNCTOR(Construct_ttag<Sphere_tag>,(CartesianDKernelFunctors::Construct_sphere<K>),(Sphere_tag,Point_tag),(Construct_ttag<Point_tag>,Compute_point_cartesian_coordinate_tag,Squared_distance_tag,Squared_distance_to_origin_tag,Point_dimension_tag));
CGAL_KD_DEFAULT_FUNCTOR(Center_of_sphere_tag,(CartesianDKernelFunctors::Center_of_sphere<K>),(Sphere_tag,Point_tag),(Construct_ttag<Sphere_tag>));
CGAL_KD_DEFAULT_FUNCTOR(Squared_radius_tag,(CartesianDKernelFunctors::Squared_radius<K>),(Sphere_tag),());
CGAL_KD_DEFAULT_FUNCTOR(Point_of_sphere_tag,(CartesianDKernelFunctors::Point_of_sphere<K>),(Sphere_tag,Point_tag),(Construct_ttag<Point_tag>, Construct_ttag<Point_cartesian_const_iterator_tag>));
} // namespace CGAL
#endif
