#!/bin/bash
#
# restic-cron - Runs a Restic backup on the homedir
#
# by Paul van Tilburg <paul@luon.net>

# Nofication function
notify() {
  test -z "$RESTIC_QUIET" && echo "I: $1"
  notify-send -t 10000 -i drive-harddisk "Restic Backup" "$1"
}

# Check if a --verbose argument is passed, otherwise use quiet
RESTIC_QUIET="--quiet"
if [ "$1" = "--verbose" ]; then
  RESTIC_QUIET=""
fi

# Restic settings
RESTIC_BACKUP_OPTIONS="--exclude-file=$HOME/.config/restic/exclude --cleanup-cache"
RESTIC_FORGET_OPTIONS="--keep-weekly=4 --keep-monthly=12 --keep-yearly=60"
RESTIC_DIR="$HOME"
export RESTIC_REPOSITORY="sftp://void//media/Backup/paul/restic-laptops"

# Start the backup by asking for the passphrase
notify "Starting backup…"
export RESTIC_PASSWORD=$(zenity --title="Restic backup passphrase" --password)

if [ -z "$RESTIC_PASSWORD" ]; then
  notify "Backup aborted due to empty passphrase or cancellation!"
  exit 1
fi

# Create a new backup
test -z "$RESTIC_QUIET" && echo "I: Backup step…"
restic $RESTIC_QUIET backup $RESTIC_DIR $RESTIC_BACKUP_OPTIONS
status=$?
if [ $status -ne 0 ]; then
  notify "Unable to finish the backup!"
  exit 2
fi

# Forget old snapshots and prune the repository
test -z "$RESTIC_QUIET" && echo "I: Forget step…"
restic $RESTIC_QUIET forget --prune $RESTIC_FORGET_OPTIONS
status=$?
if [ $status -ne 0 ]; then
  echo "E: Exit code was $status"
  notify "Was not able to forget old snapshots and/or prune the repository!"
  exit 3
fi

# Verify the backup every 4 weeks
if [ $(($(date +%-W) % 4)) = 0 ]; then
  test -z "$RESTIC_QUIET" && echo "I: Check step…"
  restic $RESTIC_QUIET check
  status=$?
  if [ $status -ne 0 ]; then
    echo "E: Exit code was $status"
    notify "Repository check of the backup failed!"
    exit 5
  fi
else
  echo "I: Skipping check step this time!"
fi

notify "Backup finished!"