-- Prosody IM

-- 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 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;

local muc_domain = nil; --module:get_host();

local history_length = 20;

------------

local 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

local 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};

local 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;

};

local 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

local 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

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

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

-----------

--[[function get_room_disco_info(room, 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=room._data["name"]):up()

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

end

function get_room_disco_items(room, 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]]

--

local function room_broadcast_presence(room, stanza, code, nick)

	stanza = get_filtered_presence(stanza);

	local data = room._participants[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;

	for occupant, o_data in pairs(room._participants) do

		if occupant ~= stanza.attr.from then

			for jid in pairs(o_data.sessions) do

				stanza.attr.to = jid;

				room:route_stanza(stanza);

			end

		else

			me = o_data;

		end

	end

	if me then

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

		for jid in pairs(me.sessions) do

			stanza.attr.to = jid;

			room:route_stanza(stanza);

		end

	end

end

local function room_broadcast_message(room, stanza, historic)

	for occupant, o_data in pairs(room._participants) do

		for jid in pairs(o_data.sessions) do

			stanza.attr.to = jid;

			room:route_stanza(stanza);

		end

	end

	if historic then -- add to history

		local history = room._data['history'];

		if not history then history = {}; room._data['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

local function room_send_occupant_list(room, to)

	local current_nick = room._jid_nick[to];

	for occupant, o_data in pairs(room._participants) do

		if occupant ~= current_nick then

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

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

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

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

			room:route_stanza(pres);

		end

	end

end

local function room_send_history(room, to)

	local history = room._data['history']; -- send discussion history

	if history then

		for _, msg in ipairs(history) do

			msg = st.deserialize(msg);

			msg.attr.to=to;

			room:route_stanza(msg);

		end

	end

	if room._data['subject'] then

		room:route_stanza(st.message({type='groupchat', from=room.jid, to=to}):tag("subject"):text(room._data['subject']));

	end

end

local function room_get_disco_info(self, stanza) end

local function room_get_disco_items(self, stanza) end

local function room_set_subject(room, current_nick, subject)

	-- TODO check nick's authority

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

	room._data['subject'] = subject;

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

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

	room_broadcast_message(room, msg, false);

	return true;

end

local function room_handle_to_occupant(self, origin, stanza) -- PM, vCards, etc

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

	local room = jid_bare(to);

	local current_nick = self._jid_nick[from];

	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);

				room_handle_to_occupant(self, 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 = self._participants[current_nick];

				data.role = 'none';

				room_broadcast_presence(self, pr);

				self._participants[current_nick] = nil;

				self._jid_nick[from] = nil;

			end

		elseif not type then -- available

			if current_nick then

				--if #pr == #stanza or current_nick ~= to then -- commented because google keeps resending directed presence

					if current_nick == to then -- simple presence

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

						self._participants[current_nick].sessions[from] = pr;

						room_broadcast_presence(self, pr);

					else -- change nick

						if self._participants[to] then

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

							origin.send(st.error_reply(stanza, "cancel", "conflict"):tag("x", {xmlns = "http://jabber.org/protocol/muc"}));

						else

							local data = self._participants[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});

								room_broadcast_presence(self, p, '303', to_nick);

								self._participants[current_nick] = nil;

								self._participants[to] = data;

								self._jid_nick[from] = to;

								pr.attr.from = to;

								self._participants[to].sessions[from] = pr;

								room_broadcast_presence(self, 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 self._participants[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"):tag("x", {xmlns = "http://jabber.org/protocol/muc"}));

				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

					self._participants[to] = data;

					self._jid_nick[from] = to;

					room_send_occupant_list(self, from);

					pr.attr.from = to;

					room_broadcast_presence(self, pr);

					room_send_history(self, from);

				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" and type ~= "result" 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);

		room_handle_to_occupant(self, 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 = self._participants[to];

		if o_data then

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

			local jid = o_data.jid;

			-- TODO 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;

			self:route_stanza(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

local function room_handle_to_room(self, origin, stanza) -- presence changes and groupchat messages, along with disco/etc

	local type = stanza.attr.type;

	if stanza.name == "iq" and type == "get" then -- disco requests

		local xmlns = stanza.tags[1].attr.xmlns;

		if xmlns == "http://jabber.org/protocol/disco#info" then

			origin.send(room_get_disco_info(self, stanza));

		elseif xmlns == "http://jabber.org/protocol/disco#items" then

			origin.send(room_get_disco_items(self, stanza));

		else

			origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));

		end

	elseif stanza.name == "message" and type == "groupchat" then

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

		local room = jid_bare(to);

		local current_nick = self._jid_nick[from];

		if not current_nick then -- not in room

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

		else

			local from = stanza.attr.from;

			stanza.attr.from = current_nick;

			local subject = getText(stanza, {"subject"});

			if subject then

				self:set_subject(current_nick, subject); -- TODO use broadcast_message_stanza

			else

				room_broadcast_message(self, stanza, true);

			end

		end

	elseif stanza.name == "presence" then -- hack - some buggy clients send presence updates to the room rather than their nick

		local to = stanza.attr.to;

		local current_nick = self._jid_nick[stanza.attr.from];

		if current_nick then

			stanza.attr.to = current_nick;

			room_handle_to_occupant(self, origin, stanza);

			stanza.attr.to = to;

		elseif type ~= "error" and type ~= "result" then

			origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));

		end

	elseif stanza.name == "message" and not stanza.attr.type and #stanza.tags == 1 and self._jid_nick[stanza.attr.from]

		and stanza.tags[1].name == "x" and stanza.tags[1].attr.xmlns == "http://jabber.org/protocol/muc#user" and #stanza.tags[1].tags == 1

		and stanza.tags[1].tags[1].name == "invite" and stanza.tags[1].tags[1].attr.to then

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

		local _invitee = stanza.tags[1].tags[1].attr.to;

		stanza.attr.from, stanza.attr.to = _to, _invitee;

		stanza.tags[1].tags[1].attr.from, stanza.tags[1].tags[1].attr.to = _from, nil;

		self:route_stanza(stanza);

		stanza.tags[1].tags[1].attr.from, stanza.tags[1].tags[1].attr.to = nil, _invitee;

		stanza.attr.from, stanza.attr.to = _from, _to;

	else

		if type == "error" or type == "result" then return; end

		origin.send(st.error_reply(stanza, "cancel", "service-unavailable"));

	end

end

local function room_handle_stanza(self, origin, stanza)

	local to_node, to_host, to_resource = jid_split(stanza.attr.to);

	if to_resource then

		room_handle_to_occupant(self, origin, stanza);

	else

		room_handle_to_room(self, origin, stanza);

	end

end

module "muc"

function new_room(jid)

	return {

		jid = jid;

		handle_stanza = room_handle_stanza;

		set_subject = room_set_subject;

		route_stanza = function(room, stanza) end; -- Replace with a routing function, e.g., function(room, stanza) core_route_stanza(origin, stanza); end

		_jid_nick = {};

		_participants = {};

		_data = {};