-- Prosody IM v0.4

-- Copyright (C) 2008-2009 Matthew Wild

-- Copyright (C) 2008-2009 Waqas Hussain

-- 

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

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

--

local datamanager = require "util.datamanager";

local datetime = require "util.datetime";

local register_component = require "core.componentmanager".register_component;

local deregister_component = require "core.componentmanager".deregister_component;

local jid_split = require "util.jid".split;

local jid_bare = require "util.jid".bare;

local st = require "util.stanza";

local log = require "util.logger".init("mod_muc");

local multitable_new = require "util.multitable".new;

local t_insert, t_remove = table.insert, table.remove;

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

	error("MUC should be loaded as a component, please see http://prosody.im/doc/components", 0);

end

local muc_domain = module:get_host();

local muc_name = "Chatrooms";

local history_length = 20;

-- room_name -> room

	-- occupant_room_nick -> data

		-- affiliation = ...

		-- role

		-- jid = occupant's real jid

local rooms = multitable_new();

local jid_nick = multitable_new(); -- real jid -> room's jid -> room nick

-- room_name -> info

	-- name - the room's friendly name

	-- subject - the room's subject

	-- non-anonymous = true|nil

	-- persistent = true|nil

	-- history = {preserialized stanzas}

local rooms_info = multitable_new();

local persist_list = datamanager.load(nil, muc_domain, 'room_list') or {};

for room in pairs(persist_list) do

	rooms_info:set(room, datamanager.store(room, muc_domain, 'rooms') or nil);

end

local component;

function filter_xmlns_from_array(array, filters)

	local count = 0;

	for i=#array,1,-1 do

		local attr = array[i].attr;

		if filters[attr and attr.xmlns] then

			t_remove(array, i);

			count = count + 1;

		end

	end

	return count;

end

function filter_xmlns_from_stanza(stanza, filters)

	if filters then

		if filter_xmlns_from_array(stanza.tags, filters) ~= 0 then

			return stanza, filter_xmlns_from_array(stanza, filters);

		end

	end

	return stanza, 0;

end

local presence_filters = {["http://jabber.org/protocol/muc"]=true;["http://jabber.org/protocol/muc#user"]=true};

function get_filtered_presence(stanza)

	return filter_xmlns_from_stanza(st.clone(stanza), presence_filters);

end

local kickable_error_conditions = {

	["gone"] = true;

	["internal-server-error"] = true;

	["item-not-found"] = true;

	["jid-malformed"] = true;

	["recipient-unavailable"] = true;

	["redirect"] = true;

	["remote-server-not-found"] = true;

	["remote-server-timeout"] = true;

	["service-unavailable"] = true;

};

function get_kickable_error(stanza)

	for _, tag in ipairs(stanza.tags) do

		if tag.name == "error" and tag.attr.xmlns == "jabber:client" then

			for _, cond in ipairs(tag.tags) do

				if cond.attr.xmlns == "urn:ietf:params:xml:ns:xmpp-stanzas" then

					return kickable_error_conditions[cond.name] and cond.name;

				end

			end

			return true; -- malformed error message

		end

	end

	return true; -- malformed error message

end

function getUsingPath(stanza, path, getText)

	local tag = stanza;

	for _, name in ipairs(path) do

		if type(tag) ~= 'table' then return; end

		tag = tag:child_with_name(name);

	end

	if tag and getText then tag = table.concat(tag); end

	return tag;

end

function getTag(stanza, path) return getUsingPath(stanza, path); end

function getText(stanza, path) return getUsingPath(stanza, path, true); end

function get_disco_info(stanza)

	return st.iq({type='result', id=stanza.attr.id, from=muc_domain, to=stanza.attr.from}):query("http://jabber.org/protocol/disco#info")

		:tag("identity", {category='conference', type='text', name=muc_name}):up()

		:tag("feature", {var="http://jabber.org/protocol/muc"}); -- TODO cache disco reply

end

function get_disco_items(stanza)

	local reply = st.iq({type='result', id=stanza.attr.id, from=muc_domain, to=stanza.attr.from}):query("http://jabber.org/protocol/disco#items");

	for room in pairs(rooms_info:get()) do

		reply:tag("item", {jid=room, name=rooms_info:get(room, "name")}):up();

	end

	return reply; -- TODO cache disco reply

end

function get_room_disco_info(stanza)

	return st.iq({type='result', id=stanza.attr.id, from=stanza.attr.to, to=stanza.attr.from}):query("http://jabber.org/protocol/disco#info")

		:tag("identity", {category='conference', type='text', name=rooms_info:get(stanza.attr.to, "name")}):up()

		:tag("feature", {var="http://jabber.org/protocol/muc"}); -- TODO cache disco reply

end

function get_room_disco_items(stanza)

	return st.iq({type='result', id=stanza.attr.id, from=stanza.attr.to, to=stanza.attr.from}):query("http://jabber.org/protocol/disco#items");

end -- TODO allow non-private rooms

function save_room(room)

	local persistent = rooms_info:get(room, 'persistent');

	if persistent then

		datamanager.store(room, muc_domain, 'rooms', rooms_info:get(room));

	end

	if persistent ~= persist_list[room] then

		if not persistent then

			datamanager.store(room, muc_domain, 'rooms', nil);

		end

		persist_list[room] = persistent;

		datamanager.store(nil, muc_domain, 'room_list', persist_list);

	end

end

function set_subject(current_nick, room, subject)

	-- TODO check nick's authority

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

	rooms_info:set(room, 'subject', subject);

	save_room();

	local msg = st.message({type='groupchat', from=current_nick})

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

	broadcast_message_stanza(room, msg, false);

	return true;

end

function broadcast_message_stanza(room, stanza, historic)

	local r = rooms:get(room);

	if r then

		for occupant, o_data in pairs(r) do

			for jid in pairs(o_data.sessions) do

				stanza.attr.to = jid;

				core_route_stanza(component, stanza);

			end

		end

		if historic then -- add to history

			local history = rooms_info:get(room, 'history');

			if not history then history = {}; rooms_info:set(room, 'history', history); end

			-- stanza = st.clone(stanza);

			stanza:tag("delay", {xmlns = "urn:xmpp:delay", from = muc_domain, stamp = datetime.datetime()}):up(); -- XEP-0203

			stanza:tag("x", {xmlns = "jabber:x:delay", from = muc_domain, stamp = datetime.legacy()}):up(); -- XEP-0091 (deprecated)

			t_insert(history, st.clone(st.preserialize(stanza)));

			while #history > history_length do t_remove(history, 1) end

		end

	end

end

function broadcast_presence_stanza(room, stanza, code, nick)

	stanza = get_filtered_presence(stanza);

	local data = rooms:get(room, stanza.attr.from);

	stanza:tag("x", {xmlns='http://jabber.org/protocol/muc#user'})

		:tag("item", {affiliation=data.affiliation, role=data.role, nick=nick}):up();

	if code then

		stanza:tag("status", {code=code}):up();

	end

	local me;

	local r = rooms:get(room);

	if r then

		for occupant, o_data in pairs(r) do

			if occupant ~= stanza.attr.from then

				for jid in pairs(o_data.sessions) do

					stanza.attr.to = jid;

					core_route_stanza(component, stanza);

				end

			else

				me = o_data;

			end

		end

	end

	if me then

		stanza:tag("status", {code='110'});

		for jid in pairs(me.sessions) do

			stanza.attr.to = jid;

			core_route_stanza(component, stanza);

		end

	end

end

function handle_to_occupant(origin, stanza) -- PM, vCards, etc

	local from, to = stanza.attr.from, stanza.attr.to;

	local room = jid_bare(to);

	local current_nick = jid_nick:get(from, room);

	local type = stanza.attr.type;

	log("debug", "room: %s, current_nick: %s, stanza: %s", room or "nil", current_nick or "nil", stanza:top_tag());

	if (select(2, jid_split(from)) == muc_domain) then error("Presence from the MUC itself!!!"); end

	if stanza.name == "presence" then

		local pr = get_filtered_presence(stanza);

		pr.attr.from = current_nick;

		if type == "error" then -- error, kick em out!

			if current_nick then

				log("debug", "kicking %s from %s", current_nick, room);

				handle_to_occupant(origin, st.presence({type='unavailable', from=from, to=to}):tag('status'):text('This participant is kicked from the room because he sent an error presence')); -- send unavailable

			end

		elseif type == "unavailable" then -- unavailable

			if current_nick then

				log("debug", "%s leaving %s", current_nick, room);

				local data = rooms:get(room, current_nick);

				data.role = 'none';

				broadcast_presence_stanza(room, pr);

				rooms:remove(room, current_nick);

				jid_nick:remove(from, room);

			end

		elseif not type then -- available

			if current_nick then

				if #pr == #stanza or current_nick ~= to then

					if current_nick == to then -- simple presence

						log("debug", "%s broadcasted presence", current_nick);

						rooms:get(room, current_nick).sessions[from] = pr;

						broadcast_presence_stanza(room, pr);

					else -- change nick

						if rooms:get(room, to) then

							log("debug", "%s couldn't change nick", current_nick);

							origin.send(st.error_reply(stanza, "cancel", "conflict"));

						else

							local data = rooms:get(room, current_nick);

							local to_nick = select(3, jid_split(to));

							if to_nick then

								log("debug", "%s (%s) changing nick to %s", current_nick, data.jid, to);

								local p = st.presence({type='unavailable', from=current_nick});

								broadcast_presence_stanza(room, p, '303', to_nick);

								rooms:remove(room, current_nick);

								rooms:set(room, to, data);

								jid_nick:set(from, room, to);

								pr.attr.from = to;

								rooms:get(room, to).sessions[from] = pr;

								broadcast_presence_stanza(room, pr);

							else

								--TODO malformed-jid

							end

						end

					end

				else -- possible rejoin

					log("debug", "%s had connection replaced", current_nick);

					handle_to_occupant(origin, st.presence({type='unavailable', from=from, to=to}):tag('status'):text('Replaced by new connection'):up()); -- send unavailable

					handle_to_occupant(origin, stanza); -- resend available

				end

			else -- enter room

				local new_nick = to;

				if rooms:get(room, to) then

					new_nick = nil;

				end

				if not new_nick then

					log("debug", "%s couldn't join due to nick conflict: %s", from, to);

					origin.send(st.error_reply(stanza, "cancel", "conflict"));

				else

					log("debug", "%s joining as %s", from, to);

					local data;

					if not rooms:get(room) and not rooms_info:get(room) then -- new room

						rooms_info:set(room, 'name', (jid_split(room)));

						data = {affiliation='owner', role='moderator', jid=from, sessions={[from]=get_filtered_presence(stanza)}};

					end

					if not data then -- new occupant

						data = {affiliation='none', role='participant', jid=from, sessions={[from]=get_filtered_presence(stanza)}};

					end

					rooms:set(room, to, data);

					jid_nick:set(from, room, to);

					local r = rooms:get(room);

					if r then

						for occupant, o_data in pairs(r) do

							if occupant ~= to then

								local pres = get_filtered_presence(o_data.sessions[o_data.jid]);

								pres.attr.to, pres.attr.from = from, occupant;

								pres:tag("x", {xmlns='http://jabber.org/protocol/muc#user'})

									:tag("item", {affiliation=o_data.affiliation, role=o_data.role}):up();

								core_route_stanza(component, pres);

							end

						end

					end

					pr.attr.from = to;

					broadcast_presence_stanza(room, pr);

					local history = rooms_info:get(room, 'history'); -- send discussion history

					if history then

						for _, msg in ipairs(history) do

							msg = st.deserialize(msg);

							msg.attr.to=from;

							core_route_stanza(component, msg);

						end

					end

					if rooms_info:get(room, 'subject') then

						core_route_stanza(component, st.message({type='groupchat', from=room, to=from}):tag("subject"):text(rooms_info:get(room, 'subject')));

					end

				end

			end

		elseif type ~= 'result' then -- bad type

			origin.send(st.error_reply(stanza, "modify", "bad-request")); -- FIXME correct error?

		end

	elseif not current_nick and type ~= "error" then -- not in room

		origin.send(st.error_reply(stanza, "cancel", "not-acceptable"));

	elseif stanza.name == "message" and type == "groupchat" then -- groupchat messages not allowed in PM

		origin.send(st.error_reply(stanza, "modify", "bad-request"));

	elseif stanza.name == "message" and type == "error" and get_kickable_error(stanza) then

		log("debug", "%s kicked from %s for sending an error message", current_nick, room);

		handle_to_occupant(origin, st.presence({type='unavailable', from=from, to=to}):tag('status'):text('This participant is kicked from the room because he sent an error message to another occupant')); -- send unavailable

	else -- private stanza

		local o_data = rooms:get(room, to);

		if o_data then

			log("debug", "%s sent private stanza to %s (%s)", from, to, o_data.jid);

			local jid = o_data.jid;

			if stanza.name=='iq' and type=='get' and stanza.tags[1].attr.xmlns == 'vcard-temp' then jid = jid_bare(jid); end

			stanza.attr.to, stanza.attr.from = jid, current_nick;

			core_route_stanza(component, stanza);

		elseif type ~= "error" and type ~= "result" then -- recipient not in room

			origin.send(st.error_reply(stanza, "cancel", "item-not-found", "Recipient not in room"));

		end

	end

end