#!/bin/sh
# vim: set noexpandtab tabstop=4 shiftwidth=4 softtabstop=4 :

name=$0
basename="$(basename $0)"

log() {
	logger -p daemon.info -t "${basename}" "$@"
}

get_ip() {
	uci -q set openmptcprouter.vps.ipv4=$(wget -4 -qO- -T 3 http://ip.openmptcprouter.com)
	if [ "$(sysctl -n net.ipv6.conf.all.disable_ipv6 | tr -d '\n')" = "0" ]; then
		uci -q set openmptcprouter.vps.ipv6=$(wget -6 -qO- -T 3 http://ip.openmptcprouter.com)
	fi
}

timeout=${OMR_TRACKER_TIMEOUT:-5}
interval=${OMR_TRACKER_INTERVAL:-10}
retry=${OMR_TRACKER_TRIES:-4}
proxy=${OMR_TRACKER_PROXY:-127.0.0.1:1111}
hosts=${OMR_TRACKER_HOSTS:-1.1.1.1 1.0.0.1}

nodns=0

last=0
nocontact=""
uci -q set openmptcprouter.vps.shadowsocks="up"
get_ip

while true; do
	host="${hosts%% *}"
	[ "$host" = "$hosts" ] || {
		hosts="${hosts#* } $host"
	}
	if curl -s --socks5 "${proxy}" --max-time "${timeout}" "$host" &>/dev/null ; then
		nocontact=""
		[ "${last}" -ge "${retry}" ] && {
			log "Shadowsocks is up (can contact ${host})"
			uci -q set openmptcprouter.vps.shadowsocks="up"
		}
		if ! /etc/init.d/shadowsocks-libev rules_exist ; then
			/etc/init.d/shadowsocks-libev rules_up 2> /dev/null
			get_ip
		fi
		[ "$(uci -q get openmptcprouter.vps.ipv4)" = "" ] || ([ "$(sysctl -n net.ipv6.conf.all.disable_ipv6 | tr -d '\n')" = "0" ] && [ "$(uci -q get openmptcprouter.vps.ipv6)" = "" ]) && get_ip
		last=0
	else
		last=$((last + 1 ))
		[ -z "$nocontact" ] && nocontact="$host" || nocontact="$nocontact, $host"
		[ "${last}" -ge "${retry}" ] && {
			if /etc/init.d/shadowsocks-libev rules_exist ; then
				log "Shadowsocks is down (can't contact ${nocontact})"
				uci -q set openmptcprouter.vps.shadowsocks="down"
				/etc/init.d/shadowsocks-libev rules_down 2> /dev/null
				get_ip
			fi
		}
	fi
	sleep "${interval}"
done