local jid = require "util.jid";

local jid_bare, jid_host = jid.bare, jid.host;

local set = require "util.set";

local st = require "util.stanza";

local stanza_types = set.new{"message", "presence", "iq"};

local jid_types = set.new{"bare", "full", "host"};

local except_domains = module:get_option_inherited_set("isolate_except_domains", {});

local except_users = module:get_option_inherited_set("isolate_except_users", {});

if not module.may then

	module:depends("compat_roles");

end

function check_stanza(event)

	local origin, stanza = event.origin, event.stanza;

	if origin.no_host_isolation then return; end

	local to_host = jid_host(event.stanza.attr.to);

	if to_host and to_host ~= origin.host and not except_domains:contains(to_host) then

		if to_host:match("^[^.]+%.(.+)$") == origin.host then -- Permit subdomains

			except_domains:add(to_host);

			return;

		end

		if origin.type == "local" then

			-- this is code-generated, which means that set_session_isolation_flag has never triggered.

			-- we need to check explicitly.

			if not is_jid_isolated(jid_bare(event.stanza.attr.from)) then

				module:log("debug", "server-generated stanza from %s is allowed, as the jid is not isolated", event.stanza.attr.from);

				return;

			end

		end

		module:log("warn", "Forbidding stanza from %s to %s", stanza.attr.from or origin.full_jid, stanza.attr.to);

		origin.send(st.error_reply(stanza, "auth", "forbidden", "Communication with "..to_host.." is not available"));

		return true;

	end

end

for stanza_type in stanza_types do

	for jid_type in jid_types do

		module:hook("pre-"..stanza_type.."/"..jid_type, check_stanza, 1);

	end

end

module:default_permission("prosody:admin", "xmpp:federate");

function is_jid_isolated(bare_jid)

	if except_users:contains(bare_jid) or module:may("xmpp:federate", bare_jid) then

		return false;

	else

		return true;

	end

end

function set_session_isolation_flag(event)

	local session = event.session;

	local bare_jid = jid_bare(session.full_jid);

	if not is_jid_isolated(bare_jid) then

		session.no_host_isolation = true;

	end

	module:log("debug", "%s is %sisolated", session.full_jid or "[?]", session.no_host_isolation and "not " or "");

end

module:hook("resource-bind", set_session_isolation_flag);