// Copyright (c) 2014
// INRIA Saclay-Ile de France (France)
//
// 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; either version 3 of the License,
// or (at your option) any later version.
//
// 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.
//
// $URL$
// $Id$
//
// Author(s)     : Marc Glisse

#ifndef CGAL_LA_EIGEN_CONSTRUCTORS_H
#define CGAL_LA_EIGEN_CONSTRUCTORS_H
#include <CGAL/config.h>
#ifndef CGAL_EIGEN3_ENABLED
#error Requires Eigen
#endif
#include <boost/type_traits/is_arithmetic.hpp>
#include <boost/utility/enable_if.hpp>
#include <CGAL/Dimension.h>
#include <Eigen/Dense>
#include <CGAL/iterator_from_indices.h>
#include <CGAL/NewKernel_d/utils.h>
#include <boost/preprocessor/repetition.hpp>
#include <boost/preprocessor/repetition/enum.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>

namespace CGAL {
  template <class Vector_> struct Construct_eigen {
    typedef Vector_ result_type;
    typedef typename Vector_::Scalar NT;

    private:
    static void check_dim(int CGAL_assertion_code(d)){
      CGAL_assertion_code(int m = result_type::MaxSizeAtCompileTime;)
      CGAL_assertion((m == Eigen::Dynamic) || (d <= m));
    }
    public:

    struct Dimension {
      // Initialize with NaN if possible?
      result_type operator()(int d) const {
	check_dim(d);
	return result_type(d);
      }
    };

    struct Iterator {
      template<typename Iter>
	result_type operator()(int d,Iter const& f,Iter const& e) const {
	  check_dim(d);
	  CGAL_assertion(d==std::distance(f,e));
	  result_type a(d);
	  // TODO: check the right way to do this
	  std::copy(f,e,&a[0]);
	  return a;
	}
    };

#if 0
    struct Iterator_add_one {
      template<typename Iter>
	result_type operator()(int d,Iter const& f,Iter const& e) const {
	  check_dim(d);
	  CGAL_assertion(d==std::distance(f,e)+1);
	  result_type a(d);
	  std::copy(f,e,&a[0]);
	  a[d-1]=1;
	  return a;
	}
    };
#endif

    struct Iterator_and_last {
      template<typename Iter,typename T>
	result_type operator()(int d,Iter const& f,Iter const& e,CGAL_FORWARDABLE(T) t) const {
	  check_dim(d);
	  CGAL_assertion(d==std::distance(f,e)+1);
	  result_type a(d);
	  std::copy(f,e,&a[0]);
	  a[d-1]=CGAL_FORWARD(T,t);
	  return a;
	}
    };

#ifdef CGAL_CXX11
    struct Initializer_list {
      // Fix T==NT?
      template<class T>
	result_type operator()(std::initializer_list<T> l) const {
	  return Iterator()(l.size(),l.begin(),l.end());
	}
    };
#endif

    struct Values {
#ifdef CGAL_CXX11
      // TODO avoid going through Initializer_list which may cause extra copies. Possibly use forward_as_tuple.
      template<class...U>
	result_type operator()(U&&...u) const {
	  check_dim(sizeof...(U)); // TODO: use static_assert
	  return Initializer_list()({forward_safe<NT,U>(u)...});
	}
#else

#define CGAL_CODE(Z,N,_) result_type operator()(BOOST_PP_ENUM_PARAMS(N,NT const& t)) const { \
  check_dim(N); \
  result_type a(N); \
  a << BOOST_PP_ENUM_PARAMS(N,t); \
  return a; \
}
BOOST_PP_REPEAT_FROM_TO(1, 11, CGAL_CODE, _ )
#undef CGAL_CODE

#endif
    };

    struct Values_divide {
#ifdef CGAL_CXX11
      template<class H,class...U>
	result_type operator()(H const&h,U&&...u) const {
	  check_dim(sizeof...(U)); // TODO: use static_assert
	  return Initializer_list()({Rational_traits<NT>().make_rational(std::forward<U>(u),h)...});
	}
#else

#define CGAL_VAR(Z,N,_) ( Rational_traits<NT>().make_rational( t##N ,h) )
#define CGAL_CODE(Z,N,_) template <class H> result_type \
  operator()(H const&h, BOOST_PP_ENUM_PARAMS(N,NT const& t)) const { \
    check_dim(N); \
    result_type a(N); \
    a << BOOST_PP_ENUM(N,CGAL_VAR,); \
    return a; \
  }
  BOOST_PP_REPEAT_FROM_TO(1, 11, CGAL_CODE, _ )
#undef CGAL_CODE
#undef CGAL_VAR

#endif
    };
  };
}
#endif
