-- 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 log = require "util.logger".init("stanzarouter")

local hosts = _G.hosts;

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 = function()end;--require "core.presencemanager".handle_outbound_presence_subscriptions_and_probes;

local handle_inbound_presence_subscriptions_and_probes = function()end;--require "core.presencemanager".handle_inbound_presence_subscriptions_and_probes;

local handle_normal_presence = function()end;--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 pairs = pairs;

local ipairs = ipairs;

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

local jid_prepped_split = require "util.jid".prepped_split;

local print = print;

local select_best_resources;

function core_process_stanza(origin, stanza)

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

	-- Currently we guarantee every stanza to have an xmlns, should we keep this rule?

	if not stanza.attr.xmlns then stanza.attr.xmlns = "jabber:client"; end

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

	if stanza.attr.type == "error" and #stanza.tags == 0 then return; end -- TODO invalid stanza, log

	if stanza.name == "iq" then

		if (stanza.attr.type == "set" or stanza.attr.type == "get") and #stanza.tags ~= 1 then

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

			return;

		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 to, xmlns = stanza.attr.to, stanza.attr.xmlns;

	local from = stanza.attr.from;

	local node, host, resource;

	local from_node, from_host, from_resource;

	local to_bare, from_bare;

	if to then

		node, host, resource = jid_prepped_split(to);

		if not host then

			log("warn", "Received stanza with invalid destination JID: %s", to);

			origin.send(st.error_reply(stanza, "modify", "jid-malformed", "The destination address is invalid: "..to));

			return;

		end

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

		if resource then to = to_bare.."/"..resource; else to = to_bare; end

		stanza.attr.to = to;

	end

	if from then

		-- We only stamp the 'from' on c2s stanzas, so we still need to check validity

		from_node, from_host, from_resource = jid_prepped_split(from);

		if not from_host then

			log("warn", "Received stanza with invalid source JID: %s", from);

			origin.send(st.error_reply(stanza, "modify", "jid-malformed", "The source address is invalid: "..from));

			return;

		end

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

		if from_resource then from = from_bare.."/"..from_resource; else from = from_bare; end

		stanza.attr.from = from;

	end

	--[[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

	if (origin.type == "s2sin" or origin.type == "c2s" or origin.type == "component") and xmlns == "jabber:client" then

		if origin.type == "s2sin" and not origin.dummy then

			local host_status = origin.hosts[from_host];

			if not host_status or not host_status.authed then -- remote server trying to impersonate some other server?

				log("warn", "Received a stanza claiming to be from %s, over a stream authed for %s!", from_host, origin.from_host);

				return; -- FIXME what should we do here? does this work with subdomains?

			end

		end

		core_post_stanza(origin, stanza);

	else

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

	end

end

function core_post_stanza(origin, stanza)

	local to = stanza.attr.to;

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

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

	local to_type;

	if node then

		if resource then

			to_type = '/full';

		else

			to_type = '/bare';

		end

	else

		if host then

			to_type = '/host';

		else

			to_type = '/bare';

		end

	end

	local event_data = {origin=origin, stanza=stanza};

	if origin.full_jid then -- c2s connection

		if hosts[origin.host].events.fire_event('pre-'..stanza.name..to_type, event_data) then return; end -- do preprocessing

	end

	local h = hosts[to_bare] or hosts[host or origin.host];

	if h then

		if h.type == "component" then

			component_handle_stanza(origin, stanza);

			return;

		else

			if h.events.fire_event(stanza.name..to_type, event_data) then return; end -- do processing

		end

	else -- non-local recipient

		core_route_stanza(origin, stanza);

		return;

	end

	if host and fire_event(host.."/"..stanza.name, event_data) then

		-- event handled

	elseif stanza.name == "presence" and origin.host and fire_event(origin.host.."/"..stanza.name, event_data) then

		-- event handled

	elseif not to then

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

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

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

		component_handle_stanza(origin, stanza);

	elseif hosts[host] and hosts[host].type == "local" and stanza.name == "iq" and not resource then -- directed at bare JID

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

	else

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

		return component_handle_stanza(origin, stanza);

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

		return component_handle_stanza(origin, stanza);

	end

	if stanza.name == "presence" and (stanza.attr.type ~= nil and stanza.attr.type ~= "unavailable" and stanza.attr.type ~= "error") 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 res then -- resource is online...

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

			else

				-- 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" and stanza.attr.type ~= "error" then

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

					elseif not resource then -- sender is available or unavailable or error

						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

					stanza.attr.to = to_bare;

					if stanza.attr.type == 'headline' then

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

							if session.presence and session.priority >= 0 then

								session.send(stanza);

							end

						end

					elseif resource and stanza.attr.type == 'groupchat' then

						-- Groupchat message sent to offline resource

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

					else

						local count = 0;

						for _, session in ipairs(select_best_resources(user)) do

							session.send(stanza);

							count = count + 1;

						end

						if count == 0 and (stanza.attr.type == "chat" or stanza.attr.type == "normal" or not stanza.attr.type) then

							offlinemanager.store(node, host, stanza);

							-- TODO deal with storage errors

						end

					end

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

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

				end

			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" and stanza.attr.type ~= "error" 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 -- FIXME if full jid, then send out to resources with highest priority

					stanza.attr.to = to_bare; -- TODO not in RFC, but seems obvious. Should discuss on the mailing list.

					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

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

						local reply = st.error_reply(stanza, "cancel", "service-unavailable");

						reply.attr.from = to;

						origin.send(reply);

					end

					-- TODO allow configuration of offline storage

					-- TODO send error if not storing offline

				elseif stanza.name == "iq" and (stanza.attr.type == "get" or stanza.attr.type == "set") then

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

				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

					local t = stanza.attr.type;

					if t == "subscribe" or t == "probe" then

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

					end

					-- else ignore

				elseif stanza.attr.type ~= "error" and (stanza.name ~= "iq" or stanza.attr.type ~= "result") then

					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

function select_best_resources(user)

	local priority = 0;

	local recipients = {};

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

		if session.presence then

			local p = session.priority;

			if p > priority then

				priority = p;

				recipients = {session};

			elseif p == priority then

				t_insert(recipients, session);

			end

		end

	end

	return recipients;

end