-- Prosody IM v0.2

-- 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("stanzarouter")

local st = require "util.stanza";

local send_s2s = require "core.s2smanager".send_to_host;

local user_exists = require "core.usermanager".user_exists;

local rostermanager = require "core.rostermanager";

local sessionmanager = require "core.sessionmanager";

local offlinemanager = require "core.offlinemanager";

local s2s_verify_dialback = require "core.s2smanager".verify_dialback;

local s2s_make_authenticated = require "core.s2smanager".make_authenticated;

local modules_handle_stanza = require "core.modulemanager".handle_stanza;

local component_handle_stanza = require "core.componentmanager".handle_stanza;

local handle_outbound_presence_subscriptions_and_probes = require "core.presencemanager".handle_outbound_presence_subscriptions_and_probes;

local handle_inbound_presence_subscriptions_and_probes = require "core.presencemanager".handle_inbound_presence_subscriptions_and_probes;

local handle_normal_presence = require "core.presencemanager".handle_normal_presence;

local format = string.format;

local tostring = tostring;

local t_concat = table.concat;

local t_insert = table.insert;

local tonumber = tonumber;

local s_find = string.find;

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

local print = print;

function core_process_stanza(origin, stanza)

	(origin.log or log)("debug", "Received[%s]: %s", origin.type, stanza:pretty_print()) --top_tag())

	if not stanza.attr.xmlns then stanza.attr.xmlns = "jabber:client"; end -- FIXME Hack. This should be removed when we fix namespace handling.

	-- TODO verify validity of stanza (as well as JID validity)

	if stanza.name == "iq" and not(#stanza.tags == 1 and stanza.tags[1].attr.xmlns) then

		if stanza.attr.type == "set" or stanza.attr.type == "get" then

			error("Invalid IQ");

		elseif #stanza.tags > 1 and not(stanza.attr.type == "error" or stanza.attr.type == "result") then

			error("Invalid IQ");

		end

	end

	if origin.type == "c2s" and not origin.full_jid

		and not(stanza.name == "iq" and stanza.tags[1].name == "bind"

				and stanza.tags[1].attr.xmlns == "urn:ietf:params:xml:ns:xmpp-bind") then

		error("Client MUST bind resource after auth");

	end

	-- TODO also, stanzas should be returned to their original state before the function ends

	if origin.type == "c2s" then

		stanza.attr.from = origin.full_jid;

	end

	local node, host, resource = jid_split(to);

	local to_bare = node and (node.."@"..host) or host; -- bare JID

	local from = stanza.attr.from;

	local from_node, from_host, from_resource = jid_split(from);

	local from_bare = from_node and (from_node.."@"..from_host) or from_host; -- bare JID

	--[[if to and not(hosts[to]) and not(hosts[to_bare]) and (hosts[host] and hosts[host].type ~= "local") then -- not for us?

		log("warn", "stanza recieved for a non-local server");

		return; -- FIXME what should we do here?

	end]] -- FIXME

	-- FIXME do stanzas not of jabber:client get handled by components?

		if not to then

			core_handle_stanza(origin, stanza);

		elseif hosts[to] and hosts[to].type == "local" then -- directed at a local server

			core_handle_stanza(origin, stanza);

		elseif stanza.attr.xmlns and stanza.attr.xmlns ~= "jabber:client" and stanza.attr.xmlns ~= "jabber:server" then

			modules_handle_stanza(host or origin.host or origin.to_host, origin, stanza);

		elseif hosts[to_bare] and hosts[to_bare].type == "component" then -- hack to allow components to handle node@server

			component_handle_stanza(origin, stanza);

		elseif hosts[to] and hosts[to].type == "component" then -- hack to allow components to handle node@server/resource and server/resource

			component_handle_stanza(origin, stanza);

		elseif hosts[host] and hosts[host].type == "component" then -- directed at a component

			component_handle_stanza(origin, stanza);

		elseif origin.type == "c2s" and stanza.name == "presence" and stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then

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

		elseif origin.type ~= "c2s" and stanza.name == "iq" and not resource then -- directed at bare JID

			core_handle_stanza(origin, stanza);

		else

			core_route_stanza(origin, stanza);

		end

	else

		core_handle_stanza(origin, stanza);

	end

end

-- This function handles stanzas which are not routed any further,

-- that is, they are handled by this server

function core_handle_stanza(origin, stanza)

	-- Handlers

	if modules_handle_stanza(stanza.attr.to or origin.host, origin, stanza) then return; end

	if origin.type == "c2s" or origin.type == "s2sin" then

		if origin.type == "c2s" then

			if stanza.name == "presence" and origin.roster then

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

					handle_normal_presence(origin, stanza, core_route_stanza);

				else

					log("warn", "Unhandled c2s presence: %s", tostring(stanza));

					if (stanza.attr.xmlns == "jabber:client" or stanza.attr.xmlns == "jabber:server") and stanza.attr.type ~= "error" then

						origin.send(st.error_reply(stanza, "cancel", "service-unavailable")); -- FIXME correct error?

					end

				end

			else

				log("warn", "Unhandled c2s stanza: %s", tostring(stanza));

				if (stanza.attr.xmlns == "jabber:client" or stanza.attr.xmlns == "jabber:server") and stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

					origin.send(st.error_reply(stanza, "cancel", "service-unavailable")); -- FIXME correct error?

				end

			end

		else -- s2s stanzas

			log("warn", "Unhandled s2s stanza: %s", tostring(stanza));

			if (stanza.attr.xmlns == "jabber:client" or stanza.attr.xmlns == "jabber:server") and stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

				origin.send(st.error_reply(stanza, "cancel", "service-unavailable")); -- FIXME correct error?

			end

		end

	else

		log("warn", "Unhandled %s stanza: %s", origin.type, tostring(stanza));

	end

end

function core_route_stanza(origin, stanza)

	-- Hooks

	--- ...later

	-- Deliver

	local to = stanza.attr.to;

	local node, host, resource = jid_split(to);

	local to_bare = node and (node.."@"..host) or host; -- bare JID

	local from = stanza.attr.from;

	local from_node, from_host, from_resource = jid_split(from);

	local from_bare = from_node and (from_node.."@"..from_host) or from_host; -- bare JID

	-- Auto-detect origin if not specified

	origin = origin or hosts[from_host];

	if not origin then return false; end

	if stanza.name == "presence" and (stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable") then resource = nil; end

	local host_session = hosts[host]

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

		-- Local host

		local user = host_session.sessions[node];

		if user then

			local res = user.sessions[resource];

			if not res then

				-- if we get here, resource was not specified or was unavailable

				if stanza.name == "presence" then

					if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then

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

					else -- sender is available or unavailable

						for _, session in pairs(user.sessions) do -- presence broadcast to all user resources.

							if session.full_jid then -- FIXME should this be just for available resources? Do we need to check subscription?

								stanza.attr.to = session.full_jid; -- reset at the end of function

								session.send(stanza);

							end

						end

					end

				elseif stanza.name == "message" then -- select a resource to recieve message

					local priority = 0;

					local recipients = {};

					for _, session in pairs(user.sessions) do -- find resource with greatest priority

						local p = session.priority;

						if p > priority then

							priority = p;

							recipients = {session};

						elseif p == priority then

							t_insert(recipients, session);

						end

					end

					local count = 0;

					for _, session in pairs(recipients) do

						session.send(stanza);

						count = count + 1;

					end

					if count == 0 then

						offlinemanager.store(node, host, stanza);

						-- TODO deal with storage errors

					end

				else

					-- TODO send IQ error

				end

			else

				-- User + resource is online...

				stanza.attr.to = res.full_jid; -- reset at the end of function

				res.send(stanza); -- Yay \o/

			end

		else

			-- user not online

			if user_exists(node, host) then

				if stanza.name == "presence" then

					if stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" then

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

					else

						-- TODO send unavailable presence or unsubscribed

					end

				elseif stanza.name == "message" then

					if stanza.attr.type == "chat" or stanza.attr.type == "normal" or not stanza.attr.type then

						offlinemanager.store(node, host, stanza);

						-- FIXME don't store messages with only chat state notifications

					end

					-- TODO allow configuration of offline storage

					-- TODO send error if not storing offline

				elseif stanza.name == "iq" then

					-- TODO send IQ error

				end

			else -- user does not exist

				-- TODO we would get here for nodeless JIDs too. Do something fun maybe? Echo service? Let plugins use xmpp:server/resource addresses?

				if stanza.name == "presence" then

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

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

					end

					-- else ignore

				else

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

				end

			end

		end

	elseif origin.type == "c2s" then

		-- Remote host

		local xmlns = stanza.attr.xmlns;

		--stanza.attr.xmlns = "jabber:server";

		stanza.attr.xmlns = nil;

		log("debug", "sending s2s stanza: %s", tostring(stanza));

		send_s2s(origin.host, host, stanza); -- TODO handle remote routing errors

		stanza.attr.xmlns = xmlns; -- reset

	elseif origin.type == "component" or origin.type == "local" then

		-- Route via s2s for components and modules

		log("debug", "Routing outgoing stanza for %s to %s", origin.host, host);

		send_s2s(origin.host, host, stanza);

	else

		log("warn", "received stanza from unhandled connection type: %s", origin.type);

	end

	stanza.attr.to = to; -- reset

end