#!/bin/sh
. /lib/functions.sh
. "${OMR_LIB_DIR:-/usr/share/omr/lib}/omr-vps-curl.sh"

intf=$1

timeout=$(uci -q get openmptcprouter.settings.status_getip_timeout)
[ -z "$timeout" ] && timeout="1"

get_ip_from_server() {
	[ -n "$ip" ] && return
	serverport=$(uci -q get openmptcprouter.$1.port)
	get_ip() {
		[ -n "$ip" ] && return
		serverip=$1
		getip="$(omr_vps_curl -s -k -4 -m ${timeout} --interface $intf https://$serverip:$serverport/clienthost 2>/dev/null)"
		[ -n "$getip" ] && getip=$(echo $getip | jsonfilter -e '@.client_host' | sed 's/::ffff://')
		if expr "$getip" : '[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*$' >/dev/null; then
			ip=$getip
			return
		fi
	}
	config_list_foreach $1 ip get_ip
}

get_ip_from_website() {
	local host addresses address ipset_added="" nft_added="" getip
	check_ipv4_website="$(uci -q get openmptcprouter.settings.check_ipv4_website)"
	[ -z "$check_ipv4_website" ] && check_ipv4_website="http://ip.openmptcprouter.com"
	# Query the URL's host, keeping each DNS answer separate.
	host="${check_ipv4_website#*://}"
	host="${host%%[/?#]*}"
	case "$host" in
		\[*) host="${host#\[}"; host="${host%%\]*}" ;;
		*) host="${host%%:*}" ;;
	esac
	addresses=$(dig +nocmd +noall +answer A "$host" | awk '$4 == "A" {print $5}')
	for address in $addresses; do
		# A failed add must not give this probe ownership of an entry.
		if ! ipset test ss_rules_dst_bypass_all "$address" >/dev/null 2>&1 &&
			ipset add ss_rules_dst_bypass_all "$address" >/dev/null 2>&1; then
			ipset_added="$ipset_added $address"
		fi
		if ! nft get element inet fw4 omr_dst_bypass_all_4 "{ $address }" >/dev/null 2>&1 &&
			nft add element inet fw4 omr_dst_bypass_all_4 "{ $address }" >/dev/null 2>&1; then
			nft_added="$nft_added $address"
		fi
	done
	getip="$(curl -s -4 -m "$timeout" --interface "$intf" "$check_ipv4_website" 2>/dev/null)"
	# Preserve entries that belonged to bypass policy before the probe.
	for address in $ipset_added; do
		ipset del ss_rules_dst_bypass_all "$address" >/dev/null 2>&1
	done
	for address in $nft_added; do
		nft delete element inet fw4 omr_dst_bypass_all_4 "{ $address }" >/dev/null 2>&1
	done
	if expr "$getip" : '[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*$' >/dev/null; then
		ip=$getip
	fi
	for address in $addresses; do
		[ "$ip" = "$address" ] && ip=""
	done
}

[ -z "$intf" ] && return
if [ -n "$(ip -4 a show dev $intf)" ]; then
	ip=""
	config_load openmptcprouter
	config_foreach get_ip_from_server server
	[ -z "$ip" ] && get_ip_from_website
	echo $ip
fi