#!/bin/bash
# Adapted from https://borgbackup.readthedocs.io/en/stable/quickstart.html#automating-backups

export SSH_SERVER="<%= @user %>@<%= @host %>"
export SSH_PORT="<%= @port %>"

export HOSTNAME=`cat /etc/hostname`

# Setting this, so the repo does not need to be given on the commandline:
export BORG_REPO=ssh://$SSH_SERVER:$SSH_PORT//var/backups/remote/$HOSTNAME/borg

# Setting this, so you won't be asked for your repository passphrase:
export BORG_PASSPHRASE='<%= @password %>'
# or this to ask an external program to supply the passphrase:
#export BORG_PASSCOMMAND='pass show backup'

# Custom keyfile support
if [ "<%= @encryption %>" == "keyfile" ] && [ ! -z "<%= @keyfile %>" ]; then
  if [ ! -e "<%= @keyfile %>" ]; then
    fatal "Keyfile not found: <%= @keyfile %>. Please create it manually."
  fi

  export BORG_KEY_FILE="<%= @keyfile %>"
fi

# some helpers and error handling:
#info() { printf "\n%s %s\n\n" "$( date )" "$*" >&2; }
trap 'info $( date ) Backup interrupted >&2; exit 2' INT TERM

# Check
if [ "$1" == "--check" ]; then
  borg list
  exit $?
fi

# Initialize
if ! ssh $SSH_SERVER -p $SSH_PORT test -f /var/backups/remote/$HOSTNAME/borg/config; then
  info "Initializing borg repository at ssh://$SSH_SERVER:$SSH_PORT//var/backups/remote/$HOSTNAME/borg..."
  borg init --encryption=<%= @encryption %> ssh://$SSH_SERVER:$SSH_PORT//var/backups/remote/$HOSTNAME/borg

  init_exit=$?

  if [ "$init_exit" != "0" ]; then
    fatal "Error initializing repository"
  fi
fi

# Backup the most important directories into an archive named after
# the machine this script is currently running on:

info "Starting backup..."

borg create                          \
  --verbose                          \
  --filter AME                       \
  --list                             \
  --stats                            \
  --show-rc                          \
  --compression lz4                  \
  --exclude-caches                   \
  --exclude '/home/*/.cache/*'       \
  --exclude '/var/cache/*'           \
  --exclude '/var/tmp/*'             \
<% @exclude_unencrypted.each do |del| -%>
  --exclude <%= del %>               \
<% end -%>
  ::'{hostname}-{now}'               \
<% @include_unencrypted.each do |add| -%>
  <%= add %>                         \
<% end -%>

  backup_exit=$?

#if [ "$backup_exit" != "0" ]; then
#  fatal "Error creating snapshot"
#fi

info "Pruning repository..."

# Use the `prune` subcommand to maintain 7 daily, 4 weekly and 6 monthly
# archives of THIS machine. The '{hostname}-' prefix is very important to
# limit prune's operation to this machine's archives and not apply to
# other machines' archives also:

borg prune                            \
  --list                              \
  --prefix '{hostname}-'              \
  --show-rc                           \
  --keep-daily    <%= @keepdaily %>   \
  --keep-weekly   <%= @keepweekly %>  \
  --keep-monthly  <%= @keepmonthly %> \

  prune_exit=$?

#if [ "$prune_exit" != "0" ]; then
#  fatal "Error pruning repository"
#fi

# Use highest exit code as global exit code
global_exit=$(( backup_exit > prune_exit ? backup_exit : prune_exit ))

if [ ${global_exit} -eq 1 ]; then
  info "Backup and/or Prune finished with a warning"
fi

if [ ${global_exit} -gt 1 ]; then
  info "Backup and/or Prune finished with an error"
fi

if [ "${global_exit}" != "0" ]; then
  fatal "Error completing borg action: exit code ${global_exit}"
fi