-- 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 jid_prep = require "util.jid".prep;

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 setmetatable = setmetatable;

local base64 = require "util.encodings".base64;

local md5 = require "util.hashes".md5;

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):reset(), 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;

	["malformed error"] = true;

};

local function get_error_condition(stanza)

	local _, condition = stanza:get_error();

	return condition or "malformed error";

end

local function is_kickable_error(stanza)

	local cond = get_error_condition(stanza);

	return kickable_error_conditions[cond] and cond;

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

-----------

local room_mt = {};

room_mt.__index = room_mt;

function room_mt:get_default_role(affiliation)

	if affiliation == "owner" or affiliation == "admin" then

		return "moderator";

	elseif affiliation == "member" or not affiliation then

		return "participant";

	end

end

function room_mt:broadcast_presence(stanza, sid, code, nick)

	stanza = get_filtered_presence(stanza);

	local occupant = self._occupants[stanza.attr.from];

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

		:tag("item", {affiliation=occupant.affiliation or "none", role=occupant.role or "none", nick=nick}):up();

	if code then

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

	end

	self:broadcast_except_nick(stanza, stanza.attr.from);

	local me = self._occupants[stanza.attr.from];

	if me then

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

		stanza.attr.to = sid;

		self:_route_stanza(stanza);

	end

end

function room_mt:broadcast_message(stanza, historic)

	local to = stanza.attr.to;

	for occupant, o_data in pairs(self._occupants) do

		for jid in pairs(o_data.sessions) do

			stanza.attr.to = jid;

			self:_route_stanza(stanza);

		end

	end

	stanza.attr.to = to;

	if historic then -- add to history

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

		if not history then history = {}; self._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.preserialize(stanza));

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

	end

end

function room_mt:broadcast_except_nick(stanza, nick)

	for rnick, occupant in pairs(self._occupants) do

		if rnick ~= nick then

			for jid in pairs(occupant.sessions) do

				stanza.attr.to = jid;

				self:_route_stanza(stanza);

			end

		end

	end

end

function room_mt:send_occupant_list(to)

	local current_nick = self._jid_nick[to];

	for occupant, o_data in pairs(self._occupants) 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 or "none", role=o_data.role or "none"}):up();

			self:_route_stanza(pres);

		end

	end

end

function room_mt:send_history(to)

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

	if history then

		for _, msg in ipairs(history) do

			msg = st.deserialize(msg);

			msg.attr.to=to;

			self:_route_stanza(msg);

		end

	end

	if self._data['subject'] then

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

	end

end

function room_mt:get_disco_info(stanza)

	return st.reply(stanza):query("http://jabber.org/protocol/disco#info")

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

		:tag("feature", {var="http://jabber.org/protocol/muc"});

end

function room_mt:get_disco_items(stanza)

	local reply = st.reply(stanza):query("http://jabber.org/protocol/disco#items");

	for room_jid in pairs(self._occupants) do

		reply:tag("item", {jid = room_jid, name = room_jid:match("/(.*)")}):up();

	end

	return reply;

end

function room_mt:set_subject(current_nick, subject)

	-- TODO check nick's authority

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

	self._data['subject'] = subject;

	if self.save then self:save(); end

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

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

	self:broadcast_message(msg, false);

	return true;

end

local function build_unavailable_presence_from_error(stanza)

	local type, condition, text = stanza:get_error();

	local error_message = "Kicked: "..condition:gsub("%-", " ");

	if text then

		error_message = error_message..": "..text;

	end

	return st.presence({type='unavailable', from=stanza.attr.from, to=stanza.attr.to})

		:tag('status'):text(error_message);

end

function room_mt: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 = 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);

				self:handle_to_occupant(origin, build_unavailable_presence_from_error(stanza));

			end

		elseif type == "unavailable" then -- unavailable

			if current_nick then

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

				local occupant = self._occupants[current_nick];

				local new_jid = next(occupant.sessions);

				if new_jid == from then new_jid = next(occupant.sessions, new_jid); end

				if new_jid then

					local jid = occupant.jid;

					occupant.jid = new_jid;

					occupant.sessions[from] = nil;

					pr.attr.to = from;

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

						:tag("item", {affiliation=occupant.affiliation or "none", role='none'}):up()

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

					self:_route_stanza(pr);

					if jid ~= new_jid then

						pr = st.clone(occupant.sessions[new_jid])

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

							:tag("item", {affiliation=occupant.affiliation or "none", role=occupant.role or "none"});

						pr.attr.from = current_nick;

						self:broadcast_except_nick(pr, current_nick);

					end

				else

					occupant.role = 'none';

					self:broadcast_presence(pr, from);

					self._occupants[current_nick] = nil;

				end

				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._occupants[current_nick].sessions[from] = pr;

						self:broadcast_presence(pr, from);

					else -- change nick

						local occupant = self._occupants[current_nick];

						local is_multisession = next(occupant.sessions, next(occupant.sessions));

						if self._occupants[to] or is_multisession then

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

							local reply = st.error_reply(stanza, "cancel", "conflict"):up();

							reply.tags[1].attr.code = "409";

							origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));

						else

							local data = self._occupants[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});

								self:broadcast_presence(p, from, '303', to_nick);

								self._occupants[current_nick] = nil;

								self._occupants[to] = data;

								self._jid_nick[from] = to;

								pr.attr.from = to;

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

								self:broadcast_presence(pr, from);

							else

								--TODO malformed-jid

							end

						end

					end

				--else -- possible rejoin

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

				--	self:handle_to_occupant(origin, st.presence({type='unavailable', from=from, to=to})

				--		:tag('status'):text('Replaced by new connection'):up()); -- send unavailable

				--	self:handle_to_occupant(origin, stanza); -- resend available

				--end

			else -- enter room

				local new_nick = to;

				local is_merge;

				if self._occupants[to] then

					if jid_bare(from) ~= jid_bare(self._occupants[to].jid) then

						new_nick = nil;

					end

					is_merge = true;

				end

				if not new_nick then

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

					local reply = st.error_reply(stanza, "cancel", "conflict"):up();

					reply.tags[1].attr.code = "409";

					origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));

				else

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

					if not next(self._affiliations) then -- new room, no owners

						self._affiliations[jid_bare(from)] = "owner";

					end

					local affiliation = self:get_affiliation(from);

					local role = self:get_default_role(affiliation)

					if role then -- new occupant

						if not is_merge then

							self._occupants[to] = {affiliation=affiliation, role=role, jid=from, sessions={[from]=get_filtered_presence(stanza)}};

						else

							self._occupants[to].sessions[from] = get_filtered_presence(stanza);

						end

						self._jid_nick[from] = to;

						self:send_occupant_list(from);

						pr.attr.from = to;

						if not is_merge then

							self:broadcast_presence(pr, from);

						else

							pr.attr.to = from;

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

								:tag("item", {affiliation=affiliation or "none", role=role or "none"}):up()

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

						end

						self:send_history(from);

					else -- banned

						local reply = st.error_reply(stanza, "auth", "forbidden"):up();

						reply.tags[1].attr.code = "403";

						origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));

					end

				end

			end

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

			if type ~= 'visible' and type ~= 'invisible' then -- COMPAT ejabberd can broadcast or forward XEP-0018 presences

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

			end

		end

	elseif not current_nick then -- not in room

		if type == "error" or type == "result" then

			local id = stanza.name == "iq" and stanza.attr.id and base64.decode(stanza.attr.id);

			local _nick, _id, _hash = (id or ""):match("^(.+)%z(.*)%z(.+)$");

			local occupant = self._occupants[stanza.attr.to];

			if occupant and _nick and self._jid_nick[_nick] and _id and _hash then

				local id, _to = stanza.attr.id;

				for jid in pairs(occupant.sessions) do

					if md5(jid) == _hash then

						_to = jid;