#!/bin/bash
# I, Ian Kelling, follow the GNU license recommendations at
# https://www.gnu.org/licenses/license-recommendations.en.html. They
# recommend that small programs, < 300 lines, be licensed under the
# Apache License 2.0. This file contains or is part of one or more small
# programs. If a small program grows beyond 300 lines, I plan to switch
# its license to GPL.

# Copyright 2024 Ian Kelling

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


# We setup kd as a server which runs profanity, because profanity
# contains important state which it does not save to disk: the most
# recent read message in each chat room and for private messages.
# To do this, uses data directories in /d/p.

# However, if we need to take kd down for maintenance, we can run
# profanity on HOST2 with data directory in /p. To do this, stop
# profanity, run prof-backup, and then systemctl start profanity from
# HOST2, and then run prof. To connect from other machines, run prof
# HOST2_SSH_NAME. To have the profanity service stopped and started with
# switch-mail-host, do touch /p/profanity-here. To do the reverse,
#
# systemctl stop profanity
# rsync /p/profanity{,-config} kdwg.b8.nz:/d/p
# ssh root@kdwg.b8.nz systemctl --now enable profanity

if [ -z "$BASH_VERSION" ]; then echo "error: shell is not bash" >&2; exit 1; fi
source /a/bin/bash-bear-trap/bash-bear

source /a/bin/bash_unpublished/source-state
if [[ ! $HOSTNAME ]]; then
  HOSTNAME=$(cat /etc/hostname)
fi
if [[ $HOSTNAME != "$HOST2" ]]; then
  exit 0
fi

case $HOSTNAME in
  kd)
    if systemctl --quiet is-active profanity; then
      rsync /d/p/profanity{,-config} /p
    fi
    ;;
  *)
    if ssh iank@b8.nz systemctl --user --quiet is-active profanity; then
      rsync -a b8.nz:/d/p/profanity{,-config} /p
    fi
    ;;
esac