// 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/v6.1/NewKernel_d/include/CGAL/NewKernel_d/Types/Segment.h $
// $Id: include/CGAL/NewKernel_d/Types/Segment.h b26b07a1242 $
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s)     : Marc Glisse

#ifndef CGAL_KERNELD_SEGMENTD_H
#define CGAL_KERNELD_SEGMENTD_H
#include <CGAL/config.h>
#include <utility>
#include <CGAL/NewKernel_d/functor_tags.h>
namespace CGAL {
template <class R_> class Segment {
        typedef typename Get_type<R_, FT_tag>::type FT_;
        typedef typename Get_type<R_, Point_tag>::type        Point_;
        //typedef typename R_::Vector Vector_;
        //typedef typename Get_functor<R_, Construct_ttag<Vector_tag> >::type Cv_;
//        typedef typename R_::Squared_distance Csd_;
        typedef std::pair<Point_,Point_> Data_;
        Data_ data;
        public:
        //typedef Segmentd<R_> Segment;
        //FIXME: don't forward directly, piecewise_construct should call the point construction functor (I guess? or is it unnecessary?)
        template<class...U,class=std::enable_if_t<!std::is_same<std::tuple<typename std::decay<U>::type...>,std::tuple<Segment>>::value>>
        Segment(U&&...u):data(std::forward<U>(u)...){}
        Point_ source()const{return data.first;}
        Point_ target()const{return data.second;}
        Point_ operator[](int i)const{
                if((i%2)==0)
                        return source();
                else
                        return target();
        }
        Segment opposite()const{
                return Segment(target(),source());
        }
        //Vector_ vector()const{
        //        return Cv_()(data.first,data.second);
        //}
//        FT_ squared_length()const{
//                return Csd_()(data.first,data.second);
//        }
};

namespace CartesianDKernelFunctors {

template<class R_> struct Construct_segment : Store_kernel<R_> {
        CGAL_FUNCTOR_INIT_STORE(Construct_segment)
        typedef R_ R;
        typedef typename Get_type<R_, Point_tag>::type        Point;
        typedef typename Get_type<R_, Segment_tag>::type        Segment;
        typedef typename Get_functor<R_, Construct_ttag<Point_tag> >::type CP;
        typedef Segment result_type;
        result_type operator()(Point const&a, Point const&b)const{
                return result_type(a,b);
        }
        // Not really needed, especially since it forces us to store the kernel
        result_type operator()()const{
#if defined(BOOST_MSVC) && (BOOST_MSVC == 1900)
#  pragma warning(push)
#  pragma warning(disable: 4309)
#endif
                Point p = typename Get_functor<R_, Construct_ttag<Point_tag> >::type (this->kernel()) ();
                return result_type (p, p);
#if defined(BOOST_MSVC) && (BOOST_MSVC == 1900)
#  pragma warning(pop)
#endif
        }
        // T should only be std::piecewise_construct_t, but we shouldn't fail if it doesn't exist.
        template<class T,class U,class V>
        result_type operator()(T&&, U&& u, V&& v)const{
                CP cp(this->kernel());
                result_type r = {{
                        call_on_tuple_elements(cp, std::forward<U>(u)),
                        call_on_tuple_elements(cp, std::forward<V>(v)) }};
                return r;
        }
};

// This should be part of Construct_point, according to Kernel_23 conventions
template<class R_> struct Segment_extremity {
        CGAL_FUNCTOR_INIT_IGNORE(Segment_extremity)
        typedef R_ R;
        typedef typename Get_type<R_, Point_tag>::type        Point;
        typedef typename Get_type<R_, Segment_tag>::type        Segment;
        typedef Point result_type;
        result_type operator()(Segment const&s, int i)const{
                if(i==0) return s.source();
                CGAL_assertion(i==1);
                return s.target();
        }
        result_type operator()(Segment &&s, int i)const{
                if(i==0) return std::move(s.source());
                CGAL_assertion(i==1);
                return std::move(s.target());
        }
};
} // CartesianDKernelFunctors

CGAL_KD_DEFAULT_TYPE(Segment_tag,(CGAL::Segment<K>),(Point_tag),());
CGAL_KD_DEFAULT_FUNCTOR(Construct_ttag<Segment_tag>,(CartesianDKernelFunctors::Construct_segment<K>),(Segment_tag,Point_tag),(Construct_ttag<Point_tag>));
CGAL_KD_DEFAULT_FUNCTOR(Segment_extremity_tag,(CartesianDKernelFunctors::Segment_extremity<K>),(Segment_tag,Point_tag),());

} // namespace CGAL

#endif // CGAL_KERNELD_SEGMENTD_H

