-- Prosody IM v0.1

-- Copyright (C) 2008 Matthew Wild

-- Copyright (C) 2008 Waqas Hussain

-- 

-- This program is free software; you can redistribute it and/or

-- modify it under the terms of the GNU General Public License

-- as published by the Free Software Foundation; either version 2

-- of the License, or (at your option) any later version.

-- 

-- This program is distributed in the hope that it will be useful,

-- but WITHOUT ANY WARRANTY; without even the implied warranty of

-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

-- GNU General Public License for more details.

-- 

-- You should have received a copy of the GNU General Public License

-- along with this program; if not, write to the Free Software

-- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

--

local log = require "util.logger".init("presencemanager")

local require = require;

local pairs, ipairs = pairs, ipairs;

local t_concat = table.concat;

local s_find = string.find;

local tonumber = tonumber;

local st = require "util.stanza";

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

local hosts = hosts;

local rostermanager = require "core.rostermanager";

local sessionmanager = require "core.sessionmanager";

local offlinemanager = require "core.offlinemanager";

module "presencemanager"

function handle_presence(origin, stanza, from_bare, to_bare, core_route_stanza, inbound)

	local type = stanza.attr.type;

	if type and type ~= "unavailable" then

		if inbound then

			handle_inbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare, core_route_stanza);

		else

			handle_outbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare, core_route_stanza);

		end

	elseif not inbound and not stanza.attr.to then

		handle_normal_presence(origin, stanza, core_route_stanza);

	else

		core_route_stanza(origin, stanza);

	end

end

function handle_normal_presence(origin, stanza, core_route_stanza)

	if origin.roster then

		for jid in pairs(origin.roster) do -- broadcast to all interested contacts

			local subscription = origin.roster[jid].subscription;

			if subscription == "both" or subscription == "from" then

				stanza.attr.to = jid;

				core_route_stanza(origin, stanza);

			end

		end

		local node, host = jid_split(stanza.attr.from);

		for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast to all resources

			if res ~= origin and res.full_jid then -- to resource. FIXME is res.full_jid the correct check? Maybe it should be res.presence

				stanza.attr.to = res.full_jid;

				core_route_stanza(origin, stanza);

			end

		end

		if stanza.attr.type == nil and not origin.presence then -- initial presence

			local probe = st.presence({from = origin.full_jid, type = "probe"});

			for jid in pairs(origin.roster) do -- probe all contacts we are subscribed to

				local subscription = origin.roster[jid].subscription;

				if subscription == "both" or subscription == "to" then

					probe.attr.to = jid;

					core_route_stanza(origin, probe);

				end

			end

			for _, res in pairs(hosts[host].sessions[node].sessions) do -- broadcast from all available resources

				if res ~= origin and res.presence then

					res.presence.attr.to = origin.full_jid;

					core_route_stanza(res, res.presence);

					res.presence.attr.to = nil;

				end

			end

			if origin.roster.pending then -- resend incoming subscription requests

				for jid in pairs(origin.roster.pending) do

					origin.send(st.presence({type="subscribe", from=jid})); -- TODO add to attribute? Use original?

				end

			end

			local request = st.presence({type="subscribe", from=origin.username.."@"..origin.host});

			for jid, item in pairs(origin.roster) do -- resend outgoing subscription requests

				if item.ask then

					request.attr.to = jid;

					core_route_stanza(origin, request);

				end

			end

			for _, msg in ipairs(offlinemanager.load(node, host) or {}) do

				origin.send(msg); -- FIXME do we need to modify to/from in any way?

			end

			offlinemanager.deleteAll(node, host);

		end

		origin.priority = 0;

		if stanza.attr.type == "unavailable" then

			origin.presence = nil;

		else

			origin.presence = stanza;

			local priority = stanza:child_with_name("priority");

			if priority and #priority > 0 then

				priority = t_concat(priority);

				if s_find(priority, "^[+-]?[0-9]+$") then

					priority = tonumber(priority);

					if priority < -128 then priority = -128 end

					if priority > 127 then priority = 127 end

					origin.priority = priority;

				end

			end

		end

		stanza.attr.to = nil; -- reset it

	else

		log("error", "presence recieved from client with no roster");

	end

end

function send_presence_of_available_resources(user, host, jid, recipient_session, core_route_stanza)

	local h = hosts[host];

	local count = 0;

	if h and h.type == "local" then

		local u = h.sessions[user];

		if u then

			for k, session in pairs(u.sessions) do

				local pres = session.presence;

				if pres then

					pres.attr.to = jid;

					pres.attr.from = session.full_jid;

					core_route_stanza(session, pres);

					pres.attr.to = nil;

					pres.attr.from = nil;

					count = count + 1;

				end

			end

		end

	end

	log("info", "broadcasted presence of "..count.." resources from "..user.."@"..host.." to "..jid);

	return count;

end

function handle_outbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare, core_route_stanza)

	local node, host = jid_split(from_bare);

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

	stanza.attr.from, stanza.attr.to = from_bare, to_bare;

	log("debug", "outbound presence "..stanza.attr.type.." from "..from_bare.." for "..to_bare);

	if stanza.attr.type == "subscribe" then

		-- 1. route stanza

		-- 2. roster push (subscription = none, ask = subscribe)

		if rostermanager.set_contact_pending_out(node, host, to_bare) then

			rostermanager.roster_push(node, host, to_bare);

		end -- else file error

		core_route_stanza(origin, stanza);

	elseif stanza.attr.type == "unsubscribe" then

		-- 1. route stanza

		-- 2. roster push (subscription = none or from)

		if rostermanager.unsubscribe(node, host, to_bare) then

			rostermanager.roster_push(node, host, to_bare); -- FIXME do roster push when roster has in fact not changed?

		end -- else file error

		core_route_stanza(origin, stanza);

	elseif stanza.attr.type == "subscribed" then

		-- 1. route stanza

		-- 2. roster_push ()

		-- 3. send_presence_of_available_resources

		if rostermanager.subscribed(node, host, to_bare) then

			rostermanager.roster_push(node, host, to_bare);

		end

		core_route_stanza(origin, stanza);

		send_presence_of_available_resources(node, host, to_bare, origin, core_route_stanza);

	elseif stanza.attr.type == "unsubscribed" then

		-- 1. route stanza

		-- 2. roster push (subscription = none or to)

		if rostermanager.unsubscribed(node, host, to_bare) then

			rostermanager.roster_push(node, host, to_bare);

		end

		core_route_stanza(origin, stanza);

	end

	stanza.attr.from, stanza.attr.to = st_from, st_to;

end

function handle_inbound_presence_subscriptions_and_probes(origin, stanza, from_bare, to_bare, core_route_stanza)

	local node, host = jid_split(to_bare);

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

	stanza.attr.from, stanza.attr.to = from_bare, to_bare;

	log("debug", "inbound presence "..stanza.attr.type.." from "..from_bare.." for "..to_bare);

	if stanza.attr.type == "probe" then

		if rostermanager.is_contact_subscribed(node, host, from_bare) then

			if 0 == send_presence_of_available_resources(node, host, from_bare, origin, core_route_stanza) then

				-- TODO send last recieved unavailable presence (or we MAY do nothing, which is fine too)

			end

		else

			core_route_stanza(origin, st.presence({from=to_bare, to=from_bare, type="unsubscribed"}));

		end

	elseif stanza.attr.type == "subscribe" then

		if rostermanager.is_contact_subscribed(node, host, from_bare) then

			core_route_stanza(origin, st.presence({from=to_bare, to=from_bare, type="subscribed"})); -- already subscribed

			-- Sending presence is not clearly stated in the RFC, but it seems appropriate

			if 0 == send_presence_of_available_resources(node, host, from_bare, origin, core_route_stanza) then

				-- TODO send last recieved unavailable presence (or we MAY do nothing, which is fine too)

			end

		else

			if not rostermanager.is_contact_pending_in(node, host, from_bare) then

				if rostermanager.set_contact_pending_in(node, host, from_bare) then

					sessionmanager.send_to_available_resources(node, host, stanza);

				end -- TODO else return error, unable to save

			end

		end

	elseif stanza.attr.type == "unsubscribe" then

		if rostermanager.process_inbound_unsubscribe(node, host, from_bare) then

			rostermanager.roster_push(node, host, from_bare);

		end

	elseif stanza.attr.type == "subscribed" then

		if rostermanager.process_inbound_subscription_approval(node, host, from_bare) then

			rostermanager.roster_push(node, host, from_bare);

		end

	elseif stanza.attr.type == "unsubscribed" then

		if rostermanager.process_inbound_subscription_cancellation(node, host, from_bare) then

			rostermanager.roster_push(node, host, from_bare);

		end

	end -- discard any other type

	stanza.attr.from, stanza.attr.to = st_from, st_to;

end

return _M;