local hosts = hosts;

local sessions = sessions;

local socket = require "socket";

local format = string.format;

local tostring, pairs, ipairs, getmetatable, print, newproxy, error, tonumber

    = tostring, pairs, ipairs, getmetatable, print, newproxy, error, tonumber;

local connlisteners_get = require "net.connlisteners".get;

local wraptlsclient = require "net.server".wraptlsclient;

local modulemanager = require "core.modulemanager";

local uuid_gen = require "util.uuid".generate;

local logger_init = require "util.logger".init;

local log = logger_init("s2smanager");

local md5_hash = require "util.hashes".md5;

local dialback_secret = "This is very secret!!! Ha!";

module "s2smanager"

function connect_host(from_host, to_host)

end

function send_to_host(from_host, to_host, data)

	if hosts[to_host] then

		-- Write to connection

		hosts[to_host].send(data);

		log("debug", "stanza sent over s2s");

	else

		log("debug", "opening a new outgoing connection for this stanza");

		local host_session = new_outgoing(from_host, to_host);

		-- Store in buffer

		host_session.sendq = { data };

	end

end

function disconnect_host(host)

end

local open_sessions = 0;

function new_incoming(conn)

	local session = { conn = conn,  priority = 0, type = "s2sin_unauthed", direction = "incoming" };

	if true then

		session.trace = newproxy(true);

		getmetatable(session.trace).__gc = function () open_sessions = open_sessions - 1; print("s2s session got collected, now "..open_sessions.." s2s sessions are allocated") end;

	end

	open_sessions = open_sessions + 1;

	local w = conn.write;

	session.send = function (t) w(tostring(t)); end

	return session;

end

function new_outgoing(from_host, to_host)

		local host_session = { to_host = to_host, from_host = from_host, notopen = true, type = "s2sout_unauthed", direction = "outgoing" };

		hosts[to_host] = host_session;

		local cl = connlisteners_get("xmppserver");

		local conn, handler = socket.tcp()

		--FIXME: Below parameters (ports/ip) are incorrect (use SRV)

		conn:connect(to_host, 5269);

		conn = wraptlsclient(cl, conn, to_host, 5269, 0, 1, hosts[from_host].ssl_ctx );

		host_session.conn = conn;

		-- Register this outgoing connection so that xmppserver_listener knows about it

		-- otherwise it will assume it is a new incoming connection

		cl.register_outgoing(conn, host_session);

		do

			local conn_name = "s2sout"..tostring(conn):match("[a-f0-9]*$");

			host_session.log = logger_init(conn_name);

		end

		local w = conn.write;

		host_session.send = function (t) w(tostring(t)); end

		conn.write(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));

		return host_session;

end

function streamopened(session, attr)

	session.log("debug", "s2s stream opened");

	local send = session.send;

	session.version = tonumber(attr.version) or 0;

	if session.version >= 1.0 and not (attr.to and attr.from) then

		print("to: "..tostring(attr.to).." from: "..tostring(attr.from));

		--error(session.to_host.." failed to specify 'to' or 'from' hostname as per RFC");

		log("warn", (session.to_host or "(unknown)").." failed to specify 'to' or 'from' hostname as per RFC");

	end

	if session.direction == "incoming" then

		-- Send a reply stream header

		for k,v in pairs(attr) do print("", tostring(k), ":::", tostring(v)); end

		session.to_host = attr.to;

		session.from_host = attr.from;

		session.streamid = uuid_gen();

		print(session, session.from_host, "incoming s2s stream opened");

		send("<?xml version='1.0'?>");

		send(format("<stream:stream xmlns='jabber:server' xmlns:db='jabber:server:dialback' xmlns:stream='http://etherx.jabber.org/streams' id='%s' from='%s'>", session.streamid, session.to_host));

		if session.from_host then

			-- Need to perform dialback to check identity

			print("to: "..tostring(attr.to).." from: "..tostring(attr.from));

			print("Need to do dialback here you know!!");

		end

	elseif session.direction == "outgoing" then

		-- If we are just using the connection for verifying dialback keys, we won't try and auth it

		if not session.dialback_verifying then

			-- generate dialback key

			if not attr.id then error("stream response did not give us a streamid!!!"); end

			session.streamid = attr.id;

			session.dialback_key = generate_dialback(session.streamid, session.to_host, session.from_host);

			session.send(format("<db:result from='%s' to='%s'>%s</db:result>", session.from_host, session.to_host, session.dialback_key));

			session.log("info", "sent dialback key on outgoing s2s stream");

		else

			mark_connected(session);

		end

	end

	--[[

	local features = {};

	modulemanager.fire_event("stream-features-s2s", session, features);

	send("<stream:features>");

	for _, feature in ipairs(features) do

		send(tostring(feature));

	end

	send("</stream:features>");]]

	log("info", "s2s stream opened successfully");

	session.notopen = nil;

end

function generate_dialback(id, to, from)

	return md5_hash(id..to..from..dialback_secret); -- FIXME: See XEP-185 and XEP-220

end

function verify_dialback(id, to, from, key)

	return key == generate_dialback(id, to, from);

end

function make_authenticated(session)

	if session.type == "s2sout_unauthed" then

		session.type = "s2sout";

	elseif session.type == "s2sin_unauthed" then

		session.type = "s2sin";

	else

		return false;

	end

	session.log("info", "connection is now authenticated");

	mark_connected(session);

	return true;

end

function mark_connected(session)

	local sendq, send = session.sendq, session.send;

	if sendq then

		session.log("debug", "sending queued stanzas across new connection");

		for _, data in ipairs(sendq) do

			session.log("debug", "sending: %s", tostring(data));

			send(data);

		end

	end

end

return _M;