#!/bin/bash
# FILE:       	peer_add
# DESCRIPTION:	Add a new peer
# USAGE:      	add remote_ip querystring
# ERRORS:
# 	 3: bad args/usage
# 	 4: vars file not found
# 	 5: Wireguard not installed
# 	 6: Hostname in use
# 	 7: Hostname too short
# 	 8: Invalid token
# 	 9: Token file not found
# 	10: Failed to get peer data from wg
# 	11: Failed to generate new IPs
# 	12: Servers file doesn't exist
# 	15: Failed to add user to local wireguard
# 	16: Failed to add user to federated server
# 	17: User not found

CONFIG_FILE='/etc/wgapi/config'
SERVERS_FILE='/etc/wgapi/servers'
if ! [ ${#} -eq 2 ]; then
	printf 'ERROR! Bad input: %s %s\n' "${0}" "${*}" >>"${LOGFILE}"
	exit 3
fi & if ! [ -x '/usr/bin/wg' ]; then
	printf 'ERROR! %s could not find /usr/bin/wg\n' "${0}" >>"${LOGFILE}"
	exit 5
fi & if ! [ -f "${CONFIG_FILE}" ]; then
	printf 'ERROR! %s could not find %s!\n' "${0}" "${CONFIG_FILE}" >>"${LOGFILE}"
	exit 4
fi
source "${CONFIG_FILE}"
if ! [ -f "${SERVERS_FILE}" ]; then
	printf 'ERROR! %s could not find %s!\n' "${0}" "${SERVERS_FILE}" >>"${LOGFILE}"
	exit 12
fi & if ! [ -f "${TOKENS_FILE}" ]; then
	printf 'ERROR! %s could not find %s!\n' "${0}" "${TOKENS_FILE}" >>"${LOGFILE}"
	exit 9
fi
ip="${1}"
qs="$(<<<"${2}" tr '&' '\n' | sed 's/?//')"

# Check hostname
hostname="$(<<<"${qs}" grep -oP 'name=(.*)' | sed 's/^name//' | xargs | tr -dc 'a-z0-9' | head -c10)"
printf '%s requested new peer with hostname %s\n' "${ip}" "${hostname}" >>"${LOGFILE}"
if ! [[ ${#hostname} -ge 3 ]]; then
	printf 'Rejecting hostname %s because it is too short.\n' "${hostname}" >>"${LOGFILE}"
	printf 'Hostname too short\n' | "${LIB_DIR}/http_res" 400
	exit 7
fi

# Check token
token_fail(){
	printf 'Rejecting %s request for new peer due to %s token\n' "${ip}" "${1}" >>"${LOGFILE}"
	printf 'Invalid token\n' | "${LIB_DIR}/http_res" 403
	exit 8
}
saved_token="$(grep "${ip}" "${TOKENS_FILE}" | cut -f2)"
[ "${saved_token}" == "" ] && token_fail 'missing' &
<<<"${qs}" grep -qx "t=${saved_token}" || token_fail 'mismatched'
printf '%s token was valid\n' "${ip}" >>"${LOGFILE}"

# Check user
username="$("${LIB_DIR}/ns_lookup_rdns" "${ip}" | cut -d'.' -f2)" || (
	printf 'User not found for %s\n' "${ip}" >>"${LOGFILE}"
	printf 'User not found' | "${LIB_DIR}/http_res" 403
	exit 17
)
printf '%s identified as %s\n' "${ip}" "${username}" >>"${LOGFILE}"
domain="${hostname}.${username}.${TLD}"

# Check if new peer already exists
if "${LIB_DIR}/ns_lookup_send" "${domain}" >/dev/null; then
	printf '%s.%s.%s already exists!\n' "${hostname}" "${username}" "${TLD}" >>"${LOGFILE}"
	printf 'Hostname %s already exists!\n' "${hostname}" | "${LIB_DIR}/http_res" 409
	exit 6
fi

# Create new domain
domain="${hostname:?}.${username:?}.${TLD:?}"
printf 'New domain will be %s\n' "${domain}" >>"${LOGFILE}"

# Create new IPs
if ! peers="$("${LIB_DIR}/wg_peer_list" "${ip}" tsv)"; then
	printf 'ERROR! Failed to retrieve peers for %s!\n' "${ip}" >>"${LOGFILE}"
	exit 10
fi
hostnames="$(<<<"${peers}" awk '{print $1}' | cut -d'.' -f1)"
ipv4s="$(<<<"${peers}" awk '{print $2}')"
ipv6s="$(<<<"${peers}" awk '{print $3}')"
usernumber="$(<<<"${ipv4s}" head -n1 | cut -d'.' -f3)"
# Increment hostnumber from 1 until an unused one is found
used_hostnumbers="$(<<<"${ipv4s}" cut -d'.' -f4 | sort | uniq)"
hostnumber=1; while <<<"${used_hostnumbers}" grep -q "${hostnumber}"
	do ((hostnumber++))
done
ipv4="${IPV4_NET%.*.*}.${usernumber}.${hostnumber}"
ipv6="${IPV6_NET%:*:*}:${usernumber}:${hostnumber}"
if ! printf 'IP addresses for %s created: %s %s\n' "${domain:?}" "${ipv4:?}" "${ipv6:?}" \
	>>"${LOGFILE}"; then
		printf 'ERROR! Failed to create IP addresses for %s!' "${domain}" >>"${LOGFILE}"
		exit 11
fi

# Create wg config
privkey="$(/usr/bin/wg genkey)"
pubkey="$(echo "${privkey}" | /usr/bin/wg pubkey)"
address="${ipv4}/${IPV4_NET##*/},${ipv6}/${IPV6_NET##*/}"

# Update nameserver
if "${LIB_DIR}/ns_update_add" "${domain:?}" "${ipv4:?}" "${ipv6:?}"
	then printf 'Successfully added %s to DNS server.\n' "${domain}" >>"${LOGFILE}"
	else printf 'ERROR! Failed to add %s %s %s to DNS server!\n' "${domain}" "${ipv4}" "${ipv6}" >>"${LOGFILE}"
fi &

# Create SSL cert
if "${LIB_DIR}/ssl_peer_add" "${hostname:?}" "${username:?}" "IP:${ipv4},IP:${ipv6}"
	then printf 'Successfully signed SSL certs for %s\n' "${domain}" >>"${LOGFILE}"
	else printf 'ERROR! Failed to create certs for %s with IPS: %s %s!\n' "${domain}" "${ipv4}" "${ipv6}" >>"${LOGFILE}"
fi

# Do the wireguard and tell the user
server_blocks=''
while IFS=$'\t' read -r server_hostname server_ipv4 server_ipv6 server_pubkey server_endpoint server_admin server_secret; do
	[[ ${server_hostname:0:1} = \# ]] && continue
	server_psk="$(/usr/bin/wg genpsk)"
	server_blocks="${server_blocks}\n[Peer] # ${server_hostname}.${TLD}\nPublicKey=${server_pubkey}\nPresharedKey=${server_psk}\nAllowedIPs=${server_ipv4}/32,${server_ipv6}/128\nEndpoint=${server_endpoint}\n"
	if [ "${server_hostname}" == "${LOCAL_SERVER}" ]; then
		# Add new user to local server
		if "${LIB_DIR}/wg_peer_add" "${pubkey}" "${server_psk}" "${ipv4}/32,${ipv6}/128"; then
			printf 'Added %s to local wireguard server.\n' "${domain}" >>"${LOGFILE}"
		else
			printf 'ERROR! Failed to add %s to local wireguard server!\n' "${domain}" >>"${LOGFILE}"
			# TODO: clear existing progress
			exit 15
		fi
	# TODO: Send new user config to federated server
	#else
	#	if "${LIB_DIR}/fed_peer_add" "${server_admin}" "${pubkey}" "${server_psk}" "${ipv4}/32,${ipv6}/128" "${server_secret}"; then
	#	printf 'Sent %s to remote wireguard server %s.\n' "${domain}" "${server_hostname}" >>"${LOGFILE}"
	#else
	#	printf 'ERROR! Failed to send %s to remote wireguard server %s!\n' "${domain}" "${server_hostname}" >>"${LOGFILE}"
	#	# TODO: clear existing progress
	# exit 16
	#fi
	fi
done <"${SERVERS_FILE}"
wg_config="[Interface] # ${hostname}.${username}.${TLD}\nPrivateKey=${privkey:?}\nAddress=${address:?}\n${WG_DNS}\n${server_blocks:?}"
<<<"${wg_config}" "${LIB_DIR}/http_res" 202