#!/bin/bash

# Copyright 2016 Peter Palfrader
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


set -e
set -u

MAX=2

temp="$(mktemp)"
trap "rm -f '$temp'" EXIT

timedatectl > "$temp"
ut=$(sed '/Universal time:/ { s/^[^:]*: *//; p}; d' "$temp")
rtc=$(sed '/RTC time:/ { s/^[^:]*: *//; p}; d' "$temp")

uts=$(TZ=UTC date -d "$ut" +%s)
rtcs=$(TZ=UTC date -d "$rtc" +%s)

d=$((uts - rtcs))

if [ "$d" -lt "-$MAX" ] ||
   [ "$d" -gt "$MAX" ]; then
	echo "Warning: time desync $d: RTC vs. system time: $rtc vs. $ut"
	exit 1
fi


bool=$(sed '/\(NTP enabled\|Network time on\):/ { s/^[^:]*: *//; p}; d' "$temp")
if [ "$bool" != "yes" ]; then
	echo "Warning: NTP not enabled!"
	exit 1
fi

bool=$(sed '/NTP synchronized:/ { s/^[^:]*: *//; p}; d' "$temp")
if [ "$bool" != "yes" ]; then
	echo "Warning: not synced with NTP (but clock is OK for now)."
	exit 1
fi

echo "OK: synced at $ut."