//
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// 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 BEAST_HTTP_PARSER_HPP
#define BEAST_HTTP_PARSER_HPP

#include <beast/http/basic_parser.hpp>
#include <beast/http/error.hpp>
#include <beast/http/message.hpp>
#include <boost/optional.hpp>
#include <functional>
#include <type_traits>
#include <utility>

namespace beast {
namespace http {

/** A HTTP parser.

    The parser may only be used once.
*/
template<bool isRequest, class Body, class Headers>
class parser
    : public basic_parser<parser<isRequest, Body, Headers>>
{
    using message_type =
        message<isRequest, Body, Headers>;

    message_type m_;
    typename message_type::body_type::reader r_;
    bool started_ = false;

public:
    parser(parser&&) = default;

    parser()
        : http::basic_parser<parser>(isRequest)
        , r_(m_)
    {
    }

    /// Returns `true` if at least one byte has been processed
    bool
    started()
    {
        return started_;
    }

    message_type
    release()
    {
        return std::move(m_);
    }

private:
    friend class http::basic_parser<parser>;

    void
    on_start()
    {
        started_ = true;
    }

    void
    on_field(std::string const& field, std::string const& value)
    {
        m_.headers.insert(field, value);
    }

    void
    on_headers_complete(error_code&)
    {
        // vFALCO TODO Decode the Content-Length and
        // Transfer-Encoding, see if we can reserve the buffer.
        //
        // r_.reserve(content_length)
    }

    bool
    on_request(http::method_t method, std::string const& url,
        int major, int minor, bool keep_alive, bool upgrade,
            std::true_type)
    {
        m_.method = method;
        m_.url = url;
        m_.version = major * 10 + minor;
        return true;
    }

    bool
    on_request(http::method_t, std::string const&,
        int, int, bool, bool,
            std::false_type)
    {
        return true;
    }

    bool
    on_request(http::method_t method, std::string const& url,
        int major, int minor, bool keep_alive, bool upgrade)
    {
        return on_request(method, url,
            major, minor, keep_alive, upgrade,
                typename message_type::is_request{});
    }

    bool
    on_response(int status, std::string const& reason,
        int major, int minor, bool keep_alive, bool upgrade,
            std::true_type)
    {
        m_.status = status;
        m_.reason = reason;
        m_.version = major * 10 + minor;
        // VFALCO TODO return expect_body_
        return true;
    }
    
    bool
    on_response(int, std::string const&, int, int, bool, bool,
        std::false_type)
    {
        return true;
    }

    bool
    on_response(int status, std::string const& reason,
        int major, int minor, bool keep_alive, bool upgrade)
    {
        return on_response(
            status, reason, major, minor, keep_alive, upgrade,
                std::integral_constant<bool, ! message_type::is_request::value>{});
    }

    void
    on_body(void const* data,
        std::size_t size, error_code& ec)
    {
        r_.write(data, size, ec);
    }

    void
    on_complete()
    {
    }
};

} // http
} // beast

#endif