/*

Copyright (c) 2007-2016, Arvid Norberg
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

*/

#ifndef TORRENT_UDP_SOCKET_HPP_INCLUDED
#define TORRENT_UDP_SOCKET_HPP_INCLUDED

#include "libtorrent/socket.hpp"
#include "libtorrent/io_service.hpp"
#include "libtorrent/error_code.hpp"
#include "libtorrent/session_settings.hpp"
#include "libtorrent/buffer.hpp"
#include "libtorrent/deadline_timer.hpp"
#include "libtorrent/debug.hpp"
#include "libtorrent/span.hpp"
#include "libtorrent/aux_/allocating_handler.hpp"

namespace libtorrent
{
	struct socks5;

	class TORRENT_EXTRA_EXPORT udp_socket : single_threaded
	{
	public:
		udp_socket(io_service& ios);

		enum flags_t {
			peer_connection = 1
			, tracker_connection = 2
			, dont_queue = 4
			, dont_fragment = 8
		};

		bool is_open() const { return m_abort == false; }
		io_service& get_io_service() { return m_socket.get_io_service(); }

		template <typename Handler>
		void async_read(Handler h)
		{
			m_socket.async_receive(null_buffers(), h);
		}

		template <typename Handler>
		void async_write(Handler h)
		{
			m_socket.async_send(null_buffers(), h);
		}

		struct packet
		{
			span<char> data;
			udp::endpoint from;
			error_code error;
		};

		int read(span<packet> pkts, error_code& ec);

		// this is only valid when using a socks5 proxy
		void send_hostname(char const* hostname, int port, span<char const> p
			, error_code& ec, int flags = 0);

		void send(udp::endpoint const& ep, span<char const> p
			, error_code& ec, int flags = 0);
		void bind(udp::endpoint const& ep, error_code& ec);
		void close();
		int local_port() const { return m_bind_port; }

		void set_proxy_settings(aux::proxy_settings const& ps);
		aux::proxy_settings const& get_proxy_settings() { return m_proxy_settings; }
		void set_force_proxy(bool f) { m_force_proxy = f; }

		bool is_closed() const { return m_abort; }
		udp::endpoint local_endpoint(error_code& ec) const
		{ return m_socket.local_endpoint(ec); }

		typedef udp::socket::receive_buffer_size receive_buffer_size;
		typedef udp::socket::send_buffer_size send_buffer_size;

		template <class SocketOption>
		void get_option(SocketOption const& opt, error_code& ec)
		{
				m_socket.get_option(opt, ec);
		}

		template <class SocketOption>
		void set_option(SocketOption const& opt, error_code& ec)
		{
			m_socket.set_option(opt, ec);
		}

		template <class SocketOption>
		void get_option(SocketOption& opt, error_code& ec)
		{
			m_socket.get_option(opt, ec);
		}

	private:

		// non-copyable
		udp_socket(udp_socket const&);
		udp_socket& operator=(udp_socket const&);

		void wrap(udp::endpoint const& ep, span<char const> p, error_code& ec, int flags);
		void wrap(char const* hostname, int port, span<char const> p, error_code& ec, int flags);
		bool unwrap(udp::endpoint& from, span<char>& buf);

		udp::socket m_socket;

		using receive_buffer = std::array<char, 1500>;
		std::unique_ptr<receive_buffer> m_buf;

		std::uint16_t m_bind_port;

		aux::proxy_settings m_proxy_settings;

		std::shared_ptr<socks5> m_socks5_connection;

		// TODO: 3 add a unit test for force-proxy
		bool m_force_proxy:1;
		bool m_abort:1;

#if TORRENT_USE_ASSERTS
		bool m_started;
		int m_magic;
#endif
	};
}

#endif