-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 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.prosody.hosts;

local tostring = tostring;

local st = require "util.stanza";

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

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

local full_sessions = _G.prosody.full_sessions;

local bare_sessions = _G.prosody.bare_sessions;

local function handle_unhandled_stanza(host, origin, stanza)

	local name, xmlns, origin_type = stanza.name, stanza.attr.xmlns or "jabber:client", origin.type;

	if name == "iq" and xmlns == "jabber:client" then

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

			xmlns = stanza.tags[1].attr.xmlns or "jabber:client";

			log("debug", "Stanza of type %s from %s has xmlns: %s", name, origin_type, xmlns);

		else

			log("debug", "Discarding %s from %s of type: %s", name, origin_type, stanza.attr.type);

			return true;

		end

	end

		log("debug", "Unhandled %s stanza: %s; xmlns=%s", origin.type, stanza.name, xmlns); -- we didn't handle it

		if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

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

		end

	elseif not((name == "features" or name == "error") and xmlns == "http://etherx.jabber.org/streams") then -- FIXME remove check once we handle S2S features

		origin:close("unsupported-stanza-type");

	end

end

local iq_types = { set=true, get=true, result=true, error=true };

function core_process_stanza(origin, stanza)

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

	-- 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 not stanza.attr.id then stanza.attr.id = ""; end -- COMPAT Jabiru doesn't send the id attribute on roster requests

		if not iq_types[stanza.attr.type] or ((stanza.attr.type == "set" or stanza.attr.type == "get") and (#stanza.tags ~= 1)) then

			origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid IQ type or incorrect number of children"));

			return;

		end

	end

	if origin.type == "c2s" and not stanza.attr.xmlns then

		if not origin.full_jid

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

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

			-- authenticated client isn't bound and current stanza is not a bind request

			if stanza.attr.type ~= "result" and stanza.attr.type ~= "error" then

				origin.send(st.error_reply(stanza, "auth", "not-authorized")); -- FIXME maybe allow stanzas to account or server

			end

			return;

		end

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

		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

		if full_sessions[to] or bare_sessions[to] or hosts[to] then

			node, host = jid_split(to); -- TODO only the host is needed, optimize

		else

			node, host, resource = jid_prepped_split(to);

			if not host then

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

				if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

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

				end

				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

	end

	if from and not origin.full_jid 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);

			if stanza.attr.type ~= "error" and stanza.attr.type ~= "result" then

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

			end

			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 (origin.type == "s2sin" or origin.type == "c2s" or origin.type == "component") and xmlns == nil 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);

				origin:close("not-authorized");

				return;

			elseif not hosts[to_host] then

				log("warn", "Remote server %s sent us a stanza for %s, closing stream", origin.from_host, to_host);

				origin:close("host-unknown");

				return;

			end

		end

		core_post_stanza(origin, stanza, origin.full_jid);

	else

		local h = hosts[stanza.attr.to or origin.host or origin.to_host];

		if h then

			local event;

			if xmlns == nil then

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

					event = "stanza/iq/"..stanza.tags[1].attr.xmlns..":"..stanza.tags[1].name;

				else

					event = "stanza/"..stanza.name;

				end

			else

				event = "stanza/"..xmlns..":"..stanza.name;

			end

			if h.events.fire_event(event, {origin = origin, stanza = stanza}) then return; end

		end

		if host and not hosts[host] then host = nil; end -- COMPAT: workaround for a Pidgin bug which sets 'to' to the SRV result

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

	end

end

function core_post_stanza(origin, stanza, preevents)

	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, to_self;

	if node then

		if resource then

			to_type = '/full';

		else

			to_type = '/bare';

			if node == origin.username and host == origin.host then

				stanza.attr.to = nil;

				to_self = true;

			end

		end

	else

		if host then

			to_type = '/host';

		else

			to_type = '/bare';

			to_self = true;

		end

	end

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

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

		if to_self and h.events.fire_event(stanza.name..'/self', event_data) then return; end -- do processing

		handle_unhandled_stanza(h.host, origin, stanza);

	else

		core_route_stanza(origin, stanza);

	end

end

function core_route_stanza(origin, stanza)

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

	local from_node, from_host, from_resource = jid_split(stanza.attr.from);

	-- Auto-detect origin if not specified

	origin = origin or hosts[from_host];

	if not origin then return false; end

	if hosts[host] then

		-- old stanza routing code removed

		core_post_stanza(origin, stanza);

	else

		log("debug", "Routing to remote...");

		local host_session = hosts[from_host];

		if not host_session then

			log("error", "No hosts[from_host] (please report): %s", tostring(stanza));

		else

			local xmlns = stanza.attr.xmlns;

			stanza.attr.xmlns = nil;

			local routed = host_session.events.fire_event("route/remote", { origin = origin, stanza = stanza, from_host = from_host, to_host = host });

			stanza.attr.xmlns = xmlns; -- reset

			if not routed then

				core_route_stanza(host_session, st.error_reply(stanza, "cancel", "not-allowed", "Communication with remote domains is not enabled"));

			end

		end

	end

end