#!/bin/bash
# FILE:       	wg_peer_list
# DESCRIPTION:	Get peers in the same subnet as an ip
# USAGE:      	list ip json|tsv
# ERRORS:
# 	3: bad usage
# 	4: nslookup failed
# 	5: wg failed
# 	6: Config file not found
# 	7: wg not found
# 	8: wg found no peers

CONFIG_FILE='/etc/wgapi/config'
if ! [ -f "${CONFIG_FILE}" ]; then
	printf 'ERROR! %s Config file not found\n' "${0}" >>"${LOGFILE}"
	exit 6
fi & if ! [ ${#} -eq 2 ]; then
	printf 'ERROR! Bad usage: %s %s\n' "$0" "$*" >>"${LOGFILE}"
	exit 3
fi & if ! [ -x /usr/bin/wg ]; then
	printf 'ERROR! %s /usr/bin/wg not found\n' "${0}" >>"${LOGFILE}"
	exit 5
fi
source "${CONFIG_FILE}"

# Get peer IP list
if ! wg_output="$(sudo /usr/bin/wg show "${TLD}" allowed-ips)"; then
	printf 'ERROR! Wireguard failed!\n' >>"${LOGFILE}"
	exit 5
fi

# Filter out this user's
user_peers="$(grep "${1%[.:]*}" <<<"${wg_output}" 2>/dev/null)"
if [ "${user_peers}" == "" ]; then
	printf "ERROR! %s accessed the dashboard but isn't on the network!\n" "${1}" >>"${LOGFILE}"
	exit 8
fi

# Loop through each peer in parallel and do an rDNS lookup for the hostnames
do_lookup(){
	pubkey="$(<<<"${1}" cut -d '	' -f1)"
	ips="$(<<<"${1}" cut -d '	' -f2 | tr ' ' '\n')"
	ipv4="$(<<<"${ips}" grep '\.')"
	ipv6="$(<<<"${ips}" grep ':')"
	ipv4="${ipv4%%/*}"
	ipv6="${ipv6%%/*}"
	if ! domain="$("${LIB_DIR:?}/ns_lookup_rdns" "${ipv4:?}" | xargs)"
		then exit 4
	fi
	case "${2}" in
		'json') printf '{"domain":"%s","ipv4":"%s","ipv6":"%s","pubkey":"%s"},' \
				"${domain}" "${ipv4}" "${ipv6}" "${pubkey}";;
		'tsv') printf '%s\t%s\t%s\t%s\n' "${domain}" "${ipv4}" "${ipv6}" "${pubkey}";;
	esac
}; while IFS= read -r line
	do do_lookup "${line}" "${2}" &
	[ $( jobs | wc -l ) -ge $( nproc ) ] && wait
done <<<"${user_peers}" \
	| sed 's/\n//g' | sed 's/,$//' # Remove trailing comma and newline