#!/bin/ash
# Sync time via network

. /etc/openslx

ntp_sync() {
	# Try to merge with servers from DHCP. Prefer DHCP, skip duplicates
	for SERVER in $SLX_NTP_SERVER; do
		if ! echo "$SLX_DHCP_NTP" | grep -wq "$SERVER"; then
			SLX_DHCP_NTP="$SLX_DHCP_NTP $SERVER"
		fi
	done
	local SUCCESS=
	for SERVER in $SLX_DHCP_NTP; do
		if timeout 3 ntpd -q -n -p "$SERVER"; then
			echo "Successfully queried $SERVER for time."
			if [ "x$SLX_BIOS_CLOCK" = "xlocal" ]; then
				usleep 100000
				hwclock -l -w || echo "... but could not set BIOS clock to localtime"
			elif [ "x$SLX_BIOS_CLOCK" = "xutc" ]; then
				usleep 100000
				hwclock -u -w || echo "... but could not set BIOS clock to UTC"
			fi
			SUCCESS=1
			break
		fi
		echo "Error querying $SERVER for current time."
	done
	if [ -z "$SUCCESS" ]; then
		echo "No NTP server reachable"
		# See if we have a timestamp in our server-config - should only be a few seconds off by now
		if [ -n "$SLX_NOW" ] && [ "$SLX_NOW" -gt 1234567890 ]; then
			TTS="$SLX_NOW"
			if [ -n "$CONFIG_DOWNLOAD_TIME" ]; then
				NOW_TIME=$(sed -r 's/^([0-9]+)\.([0-9]+).*$/\1\2/' /proc/uptime)
				if [ "$CONFIG_DOWNLOAD_TIME" -gt 0 ] && [ "$NOW_TIME" -gt 0 ]; then
					TTS=$(( TTS + ( NOW_TIME - CONFIG_DOWNLOAD_TIME ) / 100 ))
				fi
			fi
			echo "Setting time to SLX_NOW ($SLX_NOW, corrected $TTS)"
			date -s "@$TTS"
		else
			echo "No fallback option for timesync available, relying on correct RTC setup"
			if [ "x$SLX_BIOS_CLOCK" = "xlocal" ]; then
				# Linux defaults to RTC = UTC, so read again in this case
				hwclock -l -s
			fi
		fi
	fi
	echo "Timesync finished"
}

if command -v systemd-cat > /dev/null; then
	ntp_sync 2>&1 | systemd-cat
else
	ntp_sync
fi

true