-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- Copyright (C) 2014 Daurnimator

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local st = require "util.stanza";

local muc_util = module:require "muc/util";

local valid_roles = muc_util.valid_roles;

local function create_subject_message(from, subject)

	return st.message({from = from; type = "groupchat"})

		:tag("subject"):text(subject):up();

end

local function get_changesubject(room)

	return room._data.changesubject;

end

local function set_changesubject(room, changesubject)

	changesubject = changesubject and true or nil;

	if get_changesubject(room) == changesubject then return false; end

	room._data.changesubject = changesubject;

	return true;

end

module:hook("muc-config-form", function(event)

	table.insert(event.form, {

		name = "muc#roomconfig_changesubject";

		type = "boolean";

		label = "Allow Occupants to Change Subject?";

		value = get_changesubject(event.room);

	});

end);

module:hook("muc-config-submitted/muc#roomconfig_changesubject", function(event)

	if set_changesubject(event.room, event.value) then

		event.status_codes["104"] = true;

	end

end);

local function get_subject(room)

	-- a <message/> stanza from the room JID (or from the occupant JID of the entity that set the subject)

	return room._data.subject_from or room.jid, room._data.subject;

end

local function send_subject(room, to)

	local msg = create_subject_message(get_subject(room));

	msg.attr.to = to;

	room:route_stanza(msg);

end

local function set_subject(room, from, subject)

	if subject == "" then subject = nil; end

	local old_from, old_subject = get_subject(room);

	if old_subject == subject and old_from == from then return false; end

	room._data.subject_from = from;

	room._data.subject = subject;

	local msg = create_subject_message(from, subject);

	room:broadcast_message(msg);

	return true;

end

-- Send subject to joining user

module:hook("muc-occupant-session-new", function(event)

	send_subject(event.room, event.stanza.attr.from);

end, 20);

-- Prosody has made the decision that messages with <subject/> are exclusively subject changes

-- e.g. body will be ignored; even if the subject change was not allowed

module:hook("muc-occupant-groupchat", function(event)

	local stanza = event.stanza;

	local subject = stanza:get_child("subject");

	if subject then

		local occupant = event.occupant;

		-- Role check for subject changes

		local role_rank = valid_roles[occupant and occupant.role or "none"];

		if role_rank >= valid_roles.moderator or

			( role_rank >= valid_roles.participant and get_changesubject(event.room) ) then -- and participant

			set_subject(event.room, occupant.nick, subject:get_text());

			return true;

		else

			event.origin.send(st.error_reply(stanza, "auth", "forbidden"));

			return true;

		end

	end

end, 20);

return {

	get_changesubject = get_changesubject;

	set_changesubject = set_changesubject;

	get = get_subject;

	set = set_subject;

	send = send_subject;

};