// Copyright (c) 2008 Max-Planck-Institute Saarbruecken (Germany)
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; version 2.1 of the License.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.6-branch/Polynomial/include/CGAL/Polynomial/Real_embeddable_traits.h $
// $Id: Real_embeddable_traits.h 51456 2009-08-24 17:10:04Z spion $
//
//
// Author(s)     : Arno Eigenwillig <arno@mpi-inf.mpg.de>
//                 Michael Hemmer <hemmer@informatik.uni-mainz.de> 
//
// ============================================================================

// TODO: The comments are all original EXACUS comments and aren't adapted. So
//         they may be wrong now.


#ifndef CGAL_POLYNOMIAL_REAL_EMBEDDABLE_TRAITS_H
#define CGAL_POLYNOMIAL_REAL_EMBEDDABLE_TRAITS_H

#include <CGAL/basic.h>

CGAL_BEGIN_NAMESPACE

namespace internal {
template< class Polynomial , class TAG> class Real_embeddable_traits_poly_base;

template< class NT , class TAG> class Real_embeddable_traits_poly_base< Polynomial<NT>, TAG > 
  : public INTERN_RET::Real_embeddable_traits_base< Polynomial<NT> , CGAL::Tag_false > {};
  
// Real embeddable traits
// TODO: Polynomials aren't Real_embeddable! But for debugging and testing
//       reasons, the real embeddable functors are provided.
template< class NT > class Real_embeddable_traits_poly_base< Polynomial<NT>, CGAL::Tag_true > 
  : public INTERN_RET::Real_embeddable_traits_base< Polynomial<NT> , CGAL::Tag_false > {
public:
  
    typedef Tag_false Is_real_embeddable;
    
    class Abs {
    public:
        typedef Polynomial<NT> argument_type;
        typedef Polynomial<NT> result_type;
        Polynomial<NT> operator()( const Polynomial<NT>& x ) const {
            return x.abs(); 
        }
    };

    class Sgn {
    public:
        typedef Polynomial<NT>              argument_type;
        typedef CGAL::Sign        result_type;
        CGAL::Sign operator()( const Polynomial<NT>& x ) const {
            return x.sign();
        }
    };
    
    class Compare {
    public:
        typedef Polynomial<NT>                    first_argument_type;
        typedef Polynomial<NT>                    second_argument_type;
        typedef CGAL::Comparison_result result_type;
        
        CGAL::Comparison_result operator()( 
                const Polynomial<NT>& x, 
                const Polynomial<NT>& y ) const {
            return x.compare(y);
        }
        
        CGAL_IMPLICIT_INTEROPERABLE_BINARY_OPERATOR_WITH_RT( Polynomial<NT>,
                CGAL::Comparison_result )
    };

    class To_double {
    public:
        typedef typename Real_embeddable_traits<NT>::To_double NT_to_double;
        typedef Polynomial<typename NT_to_double::result_type> result_type;
        typedef Polynomial<NT> argument_type;
        result_type operator()( const Polynomial<NT>& x ) const {
            CGAL_precondition(x.degree() >= 0);
            NT_to_double to_double;
            return result_type(
                    ::boost::make_transform_iterator(x.begin(),to_double),
                    ::boost::make_transform_iterator(x.end()  ,to_double));
        }
    };

    class To_interval {
    public:
        typedef typename Real_embeddable_traits<NT>::To_interval NT_to_interval;
        typedef Polynomial<typename NT_to_interval::result_type> result_type;
        typedef Polynomial<NT> argument_type;
        result_type operator()( const Polynomial<NT>& x ) const {
            CGAL_precondition( x.degree() >= 0 );
            NT_to_interval to_interval;  
            return result_type(
                    ::boost::make_transform_iterator(x.begin(),to_interval),
                    ::boost::make_transform_iterator(x.end()  ,to_interval));
        }
    };
};
} // namespace internal

template <typename NT>
struct Real_embeddable_traits<Polynomial<NT> > 
  :public internal::Real_embeddable_traits_poly_base<
  Polynomial<NT>,
  typename Real_embeddable_traits<typename internal::Innermost_coefficient_type<NT>::Type>::Is_real_embeddable>
{};

CGAL_END_NAMESPACE
#endif // CGAL_POLYNOMIAL_REAL_EMBEDDABLE_TRAITS_H
