local add_filter = require "util.filters".add_filter;

local remove_filter = require "util.filters".remove_filter;

local datetime = require "util.datetime";

local xmlns_delay = "urn:xmpp:delay";

-- Raise an error if the modules has been loaded as a component in prosody's config

if module:get_host_type() == "component" then

	error(module.name.." should NOT be loaded as a component, check out http://prosody.im/doc/components", 0);

end

local add_delay = function(stanza, session)

	if stanza and stanza.name == "message" and stanza:get_child("delay", xmlns_delay) == nil then

		-- only add delay tag to chat or groupchat messages (should we add a delay to anything else, too???)

		if stanza.attr.type == "chat" or stanza.attr.type == "groupchat" then

			-- session.log("debug", "adding delay to message %s", tostring(stanza));

			stanza = stanza:tag("delay", { xmlns = xmlns_delay, from = session.host, stamp = datetime.datetime()});

		end

	end

	return stanza;

end

module:hook("resource-bind", function(event)

	add_filter(event.session, "stanzas/in", add_delay, 1);

end);

module:hook("pre-resource-unbind", function (event)

	remove_filter(event.session, "stanzas/in", add_delay);

end);