local st = require "util.stanza";

local jid = require "util.jid";

local nodeprep = require "util.encodings".stringprep.nodeprep;

local unprepped_access_lists = module:get_option("muc_access_lists", {});

local access_lists = {};

-- Make sure all input is prepped

for unprepped_room_name, unprepped_list in pairs(unprepped_access_lists) do

	local prepped_room_name = nodeprep(unprepped_room_name);

	if not prepped_room_name then

		module:log("error", "Invalid room name: %s", unprepped_room_name);

	else

		local prepped_list = {};

		for _, unprepped_jid in ipairs(unprepped_list) do

			local prepped_jid = jid.prep(unprepped_jid);

			if not prepped_jid then

				module:log("error", "Invalid JID: %s", unprepped_jid);

			else

				prepped_list[prepped_jid] = true;

			end

		end

		access_lists[prepped_room_name] = prepped_list;

	end

end

local function is_restricted(room, who)

	local allowed = access_lists[room];

	if allowed == nil or allowed[who] or allowed[select(2, jid.split(who))] then

		return nil;

	end

	return "forbidden";

end

module:hook("presence/full", function(event)

	local stanza = event.stanza;

	if stanza.name == "presence" and stanza.attr.type == "unavailable" then   -- Leaving events get discarded

		return;

	end

	-- Get the room

	local room = jid.split(stanza.attr.to);

        if not room then return; end

	-- Get who has tried to join it

	local who = jid.bare(stanza.attr.from)

	-- Checking whether room is restricted

	local check_restricted = is_restricted(room, who)

	if check_restricted ~= nil then

		event.allowed = false;

		event.stanza.attr.type = 'error';

		return event.origin.send(st.error_reply(event.stanza, "cancel", "forbidden", "You're not allowed to enter this room: " .. check_restricted));

	end

end, 10);