/*

Copyright (c) 2007, 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_UPNP_HPP
#define TORRENT_UPNP_HPP

#include "libtorrent/socket.hpp"
#include "libtorrent/http_connection.hpp"
#include <boost/date_time/posix_time/ptime.hpp>
#include <boost/function.hpp>
#include <boost/noncopyable.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition.hpp>

#if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
#include <fstream>
#endif

namespace libtorrent
{

// int: external tcp port
// int: external udp port
// std::string: error message
typedef boost::function<void(int, int, std::string const&)> portmap_callback_t;

class upnp : boost::noncopyable
{
public:
	upnp(io_service& ios, address const& listen_interface
		, std::string const& user_agent, portmap_callback_t const& cb);
	~upnp();

	void rebind(address const& listen_interface);

	// maps the ports, if a port is set to 0
	// it will not be mapped
	void set_mappings(int tcp, int udp);

	void close();

private:

	enum { num_mappings = 2 };
	enum { default_lease_time = 3600 };
	
	void update_mapping(int i, int port);
	void resend_request(asio::error_code const& e);
	void on_reply(asio::error_code const& e
		, std::size_t bytes_transferred);
	void discover_device();

	struct rootdevice;
	
	void on_upnp_xml(asio::error_code const& e
		, libtorrent::http_parser const& p, rootdevice& d);
	void on_upnp_map_response(asio::error_code const& e
		, libtorrent::http_parser const& p, rootdevice& d
		, int mapping);
	void on_upnp_unmap_response(asio::error_code const& e
		, libtorrent::http_parser const& p, rootdevice& d
		, int mapping);
	void on_expire(asio::error_code const& e);

	void post(rootdevice& d, std::stringstream const& s
		, std::string const& soap_action);
	void map_port(rootdevice& d, int i);
	void unmap_port(rootdevice& d, int i);

	struct mapping_t
	{
		mapping_t()
			: need_update(false)
			, local_port(0)
			, external_port(0)
			, protocol(1)
		{}

		// the time the port mapping will expire
		boost::posix_time::ptime expires;
		
		bool need_update;

		// the local port for this mapping. If this is set
		// to 0, the mapping is not in use
		int local_port;

		// the external (on the NAT router) port
		// for the mapping. This is the port we
		// should announce to others
		int external_port;

		// 1 = udp, 0 = tcp
		int protocol;
	};

	struct rootdevice
	{
		rootdevice(): lease_duration(default_lease_time)
			, supports_specific_external(true)
		{
			mapping[0].protocol = 0;
			mapping[1].protocol = 1;
		}
		
		// the interface url, through which the list of
		// supported interfaces are fetched
		std::string url;
	
		// the url to the WANIP or WANPPP interface
		std::string control_url;
		// either the WANIP namespace or the WANPPP namespace
		std::string service_namespace;

		mapping_t mapping[num_mappings];
		
		std::string hostname;
		int port;
		std::string path;

		int lease_duration;
		// true if the device supports specifying a
		// specific external port, false if it doesn't
		bool supports_specific_external;

		boost::shared_ptr<http_connection> upnp_connection;

		void close() const { if (upnp_connection) upnp_connection->close(); }
		
		bool operator<(rootdevice const& rhs) const
		{ return url < rhs.url; }
	};
	
	int m_udp_local_port;
	int m_tcp_local_port;

	std::string const& m_user_agent;
	
	// the set of devices we've found
	std::set<rootdevice> m_devices;
	
	portmap_callback_t m_callback;

	// current retry count
	int m_retry_count;

	// used to receive responses in	
	char m_receive_buffer[1024];

	// the endpoint we received the message from
	udp::endpoint m_remote;

	// the local address we're listening on
	address_v4 m_local_ip;
	
	// the udp socket used to send and receive
	// multicast messages on the network
	datagram_socket m_socket;

	// used to resend udp packets in case
	// they time out
	deadline_timer m_broadcast_timer;

	// timer used to refresh mappings
	deadline_timer m_refresh_timer;
	
	// locks m_closing and m_devices
	boost::mutex m_mutex;
	boost::condition m_condvar;
	
	bool m_disabled;
	bool m_closing;

#if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
	std::ofstream m_log;
#endif
};

}


#endif