-- mod_muc_notifications

--

-- Copyright (C) 2019 Marcos de Vera Piquero <marcos.devera@quobis.com>

--

-- This file is MIT/X11 licensed.

--

-- A module to notify non-present members of messages in a group chat

--

local id = require"util.id"

local st = require"util.stanza"

local use_invite = module:get_option_boolean("muc_notification_invite", false)

-- Given a stanza, compute if it qualifies as important (notifiable)

-- return true for message stanzas with non-empty body

-- Should probably use something similar to muc-message-is-historic event

local function is_important(stanza)

	local body = stanza:find("body#")

	return body and #body

end

local function handle_muc_message(event)

	-- event.room and event.stanza are available

	local room = event.room

	local stanza = event.stanza

	for jid, aff in pairs(room._affiliations) do

		if aff ~= "outcast" then

			local is_occupant = false

			for _, occupant in pairs(room._occupants) do

				if occupant.bare_jid == jid then

					is_occupant = true

					break

				end

			end

			if not is_occupant and is_important(stanza) then

				-- send notification to jid

				local attrs = {

					to = jid,

					id = id.short(),

					from = room.jid,

				}

				local not_attrs = {

					xmlns = "http://quobis.com/xmpp/muc#push",

					jid = room.jid,

				}

				local reason = "You have messages in group chat "..(room:get_name() or room.jid)

				local notification = st.message(attrs)

					:body(reason):up()

					:tag("notification", not_attrs):up()

					:tag("no-store", {xmlns = "urn:xmpp:hints"})

				local invite = st.message(attrs):tag("x", {xmlns = "http://jabber.org/protocol/muc#user"})

					:tag("invite", {from = stanza.attr.from})

					:tag("reason"):text(reason):up():up():up()

					:tag("notification", not_attrs):up()

					:tag("no-store", {xmlns = "urn:xmpp:hints"})

				module:log("debug", "notifying with %s", tostring(use_invite and invite or notification))

				module:send(use_invite and invite or notification)

				module:log("debug", "sent notification of MUC message %s", use_invite and invite or notification)

			end

		end

	end

end

module:hook("muc-broadcast-message", handle_muc_message)

module:log("debug", "Module loaded")