/*=============================================================================
    Copyright (c) 2001-2011 Hartmut Kaiser
    Copyright (c) 2001-2014 Joel de Guzman
    Copyright (c) 2013 Agustin Berge

    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
==============================================================================*/
#ifndef BOOST_SPIRIT_X3_ATTR_JUL_23_2008_0956AM
#define BOOST_SPIRIT_X3_ATTR_JUL_23_2008_0956AM

#include <boost/spirit/home/x3/core/parser.hpp>
#include <boost/spirit/home/x3/support/unused.hpp>
#include <boost/spirit/home/x3/support/traits/container_traits.hpp>
#include <boost/spirit/home/x3/support/traits/move_to.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/type_traits/remove_reference.hpp>
#include <cstddef>
#include <string>
#include <utility>

namespace boost {
namespace spirit {
namespace x3 {

namespace detail {
template <typename Value, std::size_t N
          , typename = std::make_index_sequence<N>>
struct array_helper;

template <typename Value, std::size_t N, std::size_t... Is>
struct array_helper<Value, N, std::index_sequence<Is...>>
{
    constexpr
    array_helper(Value const (&value)[N])
        : value_{ value[Is]... } {}

    constexpr
    array_helper(Value (&&value)[N])
        : value_{ static_cast<Value&&>(value[Is])... } {}

    Value value_[N];
};
}

template <typename Value>
struct attr_parser : parser<attr_parser<Value>>
{
    typedef Value attribute_type;

    static bool const has_attribute =
        !is_same<unused_type, attribute_type>::value;
    static bool const handles_container =
        traits::is_container<attribute_type>::value;

    constexpr
    attr_parser(Value const& value)
        : value_(value) {}
    constexpr
    attr_parser(Value&& value)
        : value_(std::move(value)) {}

    template <typename Iterator, typename Context
              , typename RuleContext, typename Attribute>
    bool
    parse(Iterator& /* first */, Iterator const& /* last */
          , Context const& /* context */, RuleContext&, Attribute& attr_) const
    {
        // $$$ Change to copy_to once we have it $$$
        traits::move_to(value_, attr_);
        return true;
    }

    Value value_;
};

template <typename Value, std::size_t N>
struct attr_parser<Value[N]> : parser<attr_parser<Value[N]>>
    , detail::array_helper<Value, N>
{
    using detail::array_helper<Value, N>::array_helper;

    typedef Value attribute_type[N];

    static bool const has_attribute =
        !is_same<unused_type, attribute_type>::value;
    static bool const handles_container = true;

    template <typename Iterator, typename Context
    , typename RuleContext, typename Attribute>
    bool
    parse(Iterator& /* first */, Iterator const& /* last */
    , Context const& /* context */, RuleContext&, Attribute& attr_) const
    {
        // $$$ Change to copy_to once we have it $$$
        traits::move_to(this->value_ + 0, this->value_ + N, attr_);
        return true;
    }
};

template <typename Value>
struct get_info<attr_parser<Value>>
{
    typedef std::string result_type;
    std::string
    operator()(attr_parser<Value> const& /*p*/) const
    {
        return "attr";
    }
};

struct attr_gen
{
    template <typename Value>
    constexpr attr_parser<typename remove_cv<
    typename remove_reference<Value>::type>::type>
    operator()(Value&& value) const
    {
        return { std::forward<Value>(value) };
    }
};

constexpr auto attr = attr_gen{};
}
}
}

#endif
