-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- 

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local tostring = tostring;

local type = type;

local xpcall = xpcall;

local s_format = string.format;

local traceback = debug.traceback;

local logger = require "logger";

local log = logger.init("xmppserver_listener");

local st = require "util.stanza";

local connlisteners_register = require "net.connlisteners".register;

local new_xmpp_stream = require "util.xmppstream".new;

local s2s_new_incoming = require "core.s2smanager".new_incoming;

local s2s_streamopened = require "core.s2smanager".streamopened;

local s2s_streamclosed = require "core.s2smanager".streamclosed;

local s2s_destroy_session = require "core.s2smanager".destroy_session;

local s2s_attempt_connect = require "core.s2smanager".attempt_connection;

local stream_callbacks = { default_ns = "jabber:server",

		streamopened = s2s_streamopened, streamclosed = s2s_streamclosed, handlestanza =  core_process_stanza };

local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";

function stream_callbacks.error(session, error, data)

	if error == "no-stream" then

		session:close("invalid-namespace");

	elseif error == "parse-error" then

		session.log("debug", "Server-to-server XML parse error: %s", tostring(error));

		session:close("not-well-formed");

	elseif error == "stream-error" then

		local condition, text = "undefined-condition";

		for child in data:children() do

			if child.attr.xmlns == xmlns_xmpp_streams then

				if child.name ~= "text" then

					condition = child.name;

				else

					text = child:get_text();

				end

				if condition ~= "undefined-condition" and text then

					break;

				end

			end

		end

		text = condition .. (text and (" ("..text..")") or "");

		session.log("info", "Session closed by remote with error: %s", text);

		session:close(nil, text);

	end

end

local function handleerr(err) log("error", "Traceback[s2s]: %s: %s", tostring(err), traceback()); end

function stream_callbacks.handlestanza(session, stanza)

	if stanza.attr.xmlns == "jabber:client" then --COMPAT: Prosody pre-0.6.2 may send jabber:client

		stanza.attr.xmlns = nil;

	end

	stanza = session.filter("stanzas/in", stanza);

	if stanza then

		return xpcall(function () return core_process_stanza(session, stanza) end, handleerr);

	end

end

local sessions = {};

local xmppserver = { default_port = 5269, default_mode = "*a" };

-- These are session methods --

local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};

local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };

local function session_close(session, reason, remote_reason)

	local log = session.log or log;

	if session.conn then

		if session.notopen then

			session.sends2s("<?xml version='1.0'?>");

			session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag());

		end

		if reason then

			if type(reason) == "string" then -- assume stream error

				log("info", "Disconnecting %s[%s], <stream:error> is: %s", session.host or "(unknown host)", session.type, reason);

				session.sends2s(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));

			elseif type(reason) == "table" then

				if reason.condition then

					local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();

					if reason.text then

						stanza:tag("text", stream_xmlns_attr):text(reason.text):up();

					end

					if reason.extra then

						stanza:add_child(reason.extra);

					end

					log("info", "Disconnecting %s[%s], <stream:error> is: %s", session.host or "(unknown host)", session.type, tostring(stanza));

					session.sends2s(stanza);

				elseif reason.name then -- a stanza

					log("info", "Disconnecting %s->%s[%s], <stream:error> is: %s", session.from_host or "(unknown host)", session.to_host or "(unknown host)", session.type, tostring(reason));

					session.sends2s(reason);

				end

			end

		end

		session.sends2s("</stream:stream>");

		if session.notopen or not session.conn:close() then

			session.conn:close(true); -- Force FIXME: timer?

		end

		session.conn:close();

		xmppserver.ondisconnect(session.conn, remote_reason or (reason and (reason.text or reason.condition)) or reason or "stream closed");

	end

end

-- End of session methods --

local function initialize_session(session)

	local stream = new_xmpp_stream(session, stream_callbacks);

	session.stream = stream;

	session.notopen = true;

	function session.reset_stream()

		session.notopen = true;

		session.stream:reset();

	end

	local filter = session.filter;

	function session.data(data)

		data = filter("bytes/in", data);

		if data then

			local ok, err = stream:feed(data);

			if ok then return; end

			(session.log or log)("warn", "Received invalid XML: %s", data);

			(session.log or log)("warn", "Problem was: %s", err);

			session:close("not-well-formed");

		end

	end

	session.close = session_close;

	local handlestanza = stream_callbacks.handlestanza;

	function session.dispatch_stanza(session, stanza)

		return handlestanza(session, stanza);

	end

end

function xmppserver.onconnect(conn)

	if not sessions[conn] then -- May be an existing outgoing session

		local session = s2s_new_incoming(conn);

		sessions[conn] = session;

		-- Logging functions --

		local conn_name = "s2sin"..tostring(conn):match("[a-f0-9]+$");

		session.log = logger.init(conn_name);

		session.log("info", "Incoming s2s connection");

		initialize_session(session);

	end

end

function xmppserver.onincoming(conn, data)

	local session = sessions[conn];

	if session then

		session.data(data);

	end

end

function xmppserver.onstatus(conn, status)

	if status == "ssl-handshake-complete" then

		local session = sessions[conn];

		if session and session.direction == "outgoing" then

			local to_host, from_host = session.to_host, session.from_host;

			session.log("debug", "Sending stream header...");

			session.sends2s(s_format([[<stream:stream xmlns='jabber:server' xmlns:db='jabber:server:dialback' xmlns:stream='http://etherx.jabber.org/streams' from='%s' to='%s' version='1.0'>]], from_host, to_host));

		end

	end

end

function xmppserver.ondisconnect(conn, err)

	local session = sessions[conn];

	if session then

		if err and err ~= "closed" and session.srv_hosts then

			(session.log or log)("debug", "s2s connection attempt failed: %s", err);

			if s2s_attempt_connect(session, err) then

				(session.log or log)("debug", "...so we're going to try another target");

				return; -- Session lives for now

			end

		end

		(session.log or log)("info", "s2s disconnected: %s->%s (%s)", tostring(session.from_host), tostring(session.to_host), tostring(err or "closed"));

		s2s_destroy_session(session, err);

		sessions[conn]  = nil;

		session = nil;

	end

end

function xmppserver.register_outgoing(conn, session)

	session.direction = "outgoing";

	sessions[conn] = session;

	initialize_session(session);

end

connlisteners_register("xmppserver", xmppserver);

-- We need to perform some initialisation when a connection is created

-- We also need to perform that same initialisation at other points (SASL, TLS, ...)

-- ...and we need to handle data

-- ...and record all sessions associated with connections