bosh.lua


local init_xmlhandlers = require "core.xmlhandlers";
local st = require "util.stanza";

local stream_mt = setmetatable({}, { __index = verse.stream_mt });
stream_mt.__index = stream_mt;

local xmlns_stream = "http://etherx.jabber.org/streams";
local xmlns_bosh = "http://jabber.org/protocol/httpbind";

function verse.new_bosh(logger, url)
	local stream = {
		bosh_conn_pool = {};
		bosh_waiting_requests = {};
		bosh_rid = math.random(1,999999);
		bosh_outgoing_buffer = {};
		bosh_url = url;
		conn = {};
	};
	function stream:reopen()
		self.bosh_need_restart = true;
		self:flush(true);
	end
	function stream.bosh_response_handler(response, code, request)
		return stream:_handle_response(response, code, request);
	end
	local conn = verse.new(logger, stream);
	conn:add_plugin("http");
	return setmetatable(conn, stream_mt);
end

function stream_mt:connect()
	self:_send_session_request();
end

function stream_mt:send(data)
	self:debug("Putting into BOSH send buffer: %s", tostring(data));
	self.bosh_outgoing_buffer[#self.bosh_outgoing_buffer+1] = st.clone(data);
	self:flush(); --TODO: Optimize by doing this on next tick (give a chance for data to buffer)
end

function stream_mt:flush(force)
	if self.connected
	and #self.bosh_waiting_requests < self.bosh_max_requests
	and (force or #self.bosh_outgoing_buffer > 0) then
		self:debug("Flushing...");
		local payload = self:_make_body();
		local buffer = self.bosh_outgoing_buffer;
		for i, stanza in ipairs(buffer) do
			payload:add_child(stanza);
			buffer[i] = nil;
		end
		local request = self.http.request(self.bosh_url, { body = tostring(payload) }, self.bosh_response_handler);
		table.insert(self.bosh_waiting_requests, request);
	else
		self:debug("Decided not to flush.");
	end
end

function stream_mt:_send_session_request()
	local body = self:_make_body();
	
	-- XEP-0124
	body.attr.hold = "1";
	body.attr.wait = "60";
	body.attr["xml:lang"] = "en";
	body.attr.ver = "1.6";

	-- XEP-0206
	body.attr.from = self.jid;
	body.attr.to = self.host;
	body.attr.secure = 'true';
	
	self.http.request(self.bosh_url, { body = tostring(body) }, function (response)
		-- Handle session creation response
		local payload = self:_parse_response(response)
		if not payload then
			self:warn("Invalid session creation response");
			self:event("disconnected");
			return;
		end
		self.bosh_sid = payload.attr.sid;
		self.bosh_wait = tonumber(payload.attr.wait);
		self.bosh_hold = tonumber(payload.attr.hold);
		self.bosh_max_requests = tonumber(payload.attr.requests) or self.bosh_hold;
		self.connected = true;
		self:event("connected");
		self:_handle_response_payload(payload);
	end);
end

function stream_mt:_handle_response(response, code, request)
	if self.bosh_waiting_requests[1] ~= request then
		self:warn("Server replied to request that wasn't the oldest");
	else
		table.remove(self.bosh_waiting_requests, 1);
	end
	local payload = self:_parse_response(response);
	if payload then
		self:_handle_response_payload(payload);
	end
	if #self.bosh_waiting_requests == 0 then
		self:debug("We have no requests open, so forcing flush...");
		self:flush(true);
	else
		self:debug("We have %d requests open, so no need to force a flush", #self.bosh_waiting_requests);
	end
end

function stream_mt:_handle_response_payload(payload)
	for stanza in payload:childtags() do
		if stanza.attr.xmlns == xmlns_stream then
			self:event("stream-"..stanza.name, stanza);
		elseif stanza.attr.xmlns then
			self:event("stream/"..stanza.attr.xmlns, stanza);
		else
			self:event("stanza", stanza);
		end
	end
end

local stream_callbacks = {
	stream_ns = "http://jabber.org/protocol/httpbind", stream_tag = "body",
	default_ns = "jabber:client",
	streamopened = function (session, attr) session.notopen = nil; session.payload = verse.stanza("body", attr); return true; end;
	handlestanza = function (session, stanza) session.payload:add_child(stanza); end;
};
function stream_mt:_parse_response(response)
	self:debug("Parsing response: %s", response);
	local session = { notopen = true, log = self.log };
	local parser = lxp.new(init_xmlhandlers(session, stream_callbacks), "\1");
	parser:parse(response);
	return session.payload;
end

function stream_mt:_make_body()
	self.bosh_rid = self.bosh_rid + 1;
	local body = verse.stanza("body", {
		xmlns = xmlns_bosh;
		content = "text/xml; charset=utf-8";
		sid = self.bosh_sid;
		rid = self.bosh_rid;
	});
	if self.bosh_need_restart then
		self.bosh_need_restart = nil;
		body.attr.restart = 'true';
	end
	return body;
end