#! /bin/sh

# Copyright © 2022 Adam Spragg
# SPDX-License-Identifier: LGPL-3.0-or-later
#
# This file is part of apt-desktop-upgrades
#
# apt-desktop-upgrades is free software: you can redistribute it and/or modify
# under the terms of the GNU Lesser General Public License as published by the
# Free Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# apt-desktop-upgrades is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
# for more details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with apt-desktop-upgrades.  If not, see <https://www.gnu.org/licenses/>.

set -e

SBINDIR=/usr/local/sbin

UPDATE_SYMLINK="/system-update"
UPDATE_TARGET="${SBINDIR}/adu-upgrade"

if [ x"$(realpath -- "${UPDATE_SYMLINK}")" != x"${UPDATE_TARGET}" ]; then
	exit 0
fi

# man:systemd.offline-updates(7):
#    "Make sure to remove the /system-update symlink as early as possible in
#    the update script to avoid reboot loops in case the update fails."
rm -f -- "${UPDATE_SYMLINK}"

# Do the update
apt-get upgrade -y --no-download --ignore-missing

# man:systemd.offline-updates(7):
#    "The update service should now do its job. [...] After completion
#    (regardless whether the update succeeded or failed) the machine must be
#    rebooted, for example by calling `systemctl reboot`."
systemctl reboot