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

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

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

_ping_server() {
	local host=$1
	ret=$(ping \
	    -w "$OMR_TRACKER_TIMEOUT" \
	    -c 1 \
	    -q \
	    "${host}"
	) && echo "$ret" | grep -sq " 0% packet loss" && {
		server_ping=true
	}
}

_check_server() {
	local host=$1
	local port=$2
	local k=0
	while [ "$server_ping" = false ] && [ "$k" -le "$retry" ]; do
		ret=$(curl -4 \
		    --max-time "$OMR_TRACKER_TIMEOUT" \
		    -s \
		    -k \
		    "https://${host}:${port}/"
		)
		[ -n "$ret" ] && server_ping=true
		k=$((k+1))
		sleep "${intervaltries}"
	done
}

_check_master() {
	local name=$1
	config_get master $1 master
	config_get ip $1 ip
	config_get port $1 port "65500"
	config_get disabled $1 disabled
	[ "$master" = "1" ] && [ -n "$ip" ] && [ "$disabled" != "1" ] && {
		#_ping_server $ip
		_check_server $ip $port
		[ "$server_ping" = true ] && [ "$(uci -q get shadowsocks-libev.sss0.server | tr -d '\n')" != "$ip" ] && {
			logger -t "OMR-Tracker-Server" "Master server up, set it back"
			logger -t "OMR-Tracker-Server" "$(uci -q get shadowsocks-libev.sss0.server | tr -d '\n') - $ip"
			uci -q batch <<-EOF >/dev/null
				set shadowsocks-libev.sss0.server=$ip
				commit shadowsocks-libev
				set v2ray.omrout.s_vmess_address=$ip
				set v2ray.omrout.s_vless_address=$ip
				commit v2ray
				set glorytun.vpn.host=$ip
				commit glorytun
				set dsvpn.vpn.host=$ip
				commit dsvpn
				set mlvpn.general.host=$ip
				commit mlvpn
				del openvpn.omr.remote
				add_list openvpn.omr.remote=$ip
				commit openvpn
			EOF
			/etc/init.d/openmptcprouter-vps get_openvpn_key $name >/dev/null 2>/dev/null
			/etc/init.d/shadowsocks-libev restart >/dev/null 2>/dev/null
			/etc/init.d/v2ray restart >/dev/null 2>/dev/null
			/etc/init.d/glorytun restart >/dev/null 2>/dev/null
			/etc/init.d/glorytun-udp restart >/dev/null 2>/dev/null
			/etc/init.d/mlvpn restart >/dev/null 2>/dev/null
			/etc/init.d/openvpn restart >/dev/null 2>/dev/null
			/etc/init.d/dsvpn restart >/dev/null 2>/dev/null
		}
		break
	}
}

_check_backup() {
	local name=$1
	config_get backup $1 backup
	config_get ip $1 ip
	config_get port $1 port
	config_get disabled $1 disabled
	[ "$backup" = "1" ] && [ -n "$ip" ] && [ "$disabled" != "1" ] && {
		#_ping_server $ip
		_check_server $ip $port
		[ "$server_ping" = true ] && [ "$(uci -q get shadowsocks-libev.sss0.server | tr -d '\n')" = "$ip" ] && break
		[ "$server_ping" = true ] && [ "$(uci -q get shadowsocks-libev.sss0.server | tr -d '\n')" != "$ip" ] && {
			logger -t "OMR-Tracker-Server" "Use backup server $1 ($ip)"
			uci -q batch <<-EOF >/dev/null
				set shadowsocks-libev.sss0.server=$ip
				commit shadowsocks-libev
				set v2ray.omrout.s_vmess_address=$ip
				set v2ray.omrout.s_vless_address=$ip
				commit v2ray
				set glorytun.vpn.host=$ip
				commit glorytun
				set dsvpn.vpn.host=$ip
				commit dsvpn
				set mlvpn.general.host=$ip
				commit mlvpn
				del openvpn.omr.remote
				add_list openvpn.omr.remote=$ip
				commit openvpn
			EOF
			/etc/init.d/openmptcprouter-vps get_openvpn_key $name >/dev/null 2>/dev/null
			/etc/init.d/shadowsocks-libev restart >/dev/null 2>/dev/null
			/etc/init.d/v2ray restart >/dev/null 2>/dev/null
			/etc/init.d/glorytun restart >/dev/null 2>/dev/null
			/etc/init.d/glorytun-udp restart >/dev/null 2>/dev/null
			/etc/init.d/mlvpn restart >/dev/null 2>/dev/null
			/etc/init.d/openvpn restart >/dev/null 2>/dev/null
			/etc/init.d/dsvpn restart >/dev/null 2>/dev/null
			sleep $waittest
			break
		}
	}
}

. /lib/functions.sh

timeout=${OMR_TRACKER_TIMEOUT:-5}
interval=${OMR_TRACKER_INTERVAL:-10}
intervaltries=${OMR_TRACKER_INTERVAL_TRIES:-2}
retry=${OMR_TRACKER_TRIES:-4}
waittest=${OMR_TRACKER_WAIT_TEST:-0}

while true; do
	server_ping=false
	config_load openmptcprouter
	config_foreach _check_master server
	[ "$server_ping" = false ] && {
		config_foreach _check_backup server
	}
	sleep "${interval}"
done