#!/bin/bash

# This script is based on the script at:
# https://borgbackup.readthedocs.io/en/stable/quickstart.html#automating-backups

# The repo path is relative to the directory the server `cd`s to before calling `borg serve`, i.e. `repos/<hostname>/`
# https://borgbackup.readthedocs.io/en/stable/usage/general.html#repository-urls
export BORG_REPO=ssh://borg@borg.caspervk.net:22222/./auto

# Use stdout of the following command to answer the passphrase question for encrypted repositories
export BORG_PASSCOMMAND='cat /usr/local/etc/borg/passphrase.key'

# When running Borg using an automated script, ssh might still ask for a password, even if there is an SSH key for
# the target server. Use this to make scripts more robust:
export BORG_RSH='ssh -oBatchMode=yes'

# Initialize remote repository (doesn't matter if it already has been)
borg init --encryption=repokey-blake2

# Backup directories into an archive named after the machine and current utc time.
# Patterns:
#  A backup root (starting point) path starts with the prefix R, followed by a path.
#  An include rule starts with the prefix +.
#  An exclude rule starts with the prefix -.
#  An exclude-norecurse rule starts with !.
borg create                                                                           \
    --show-rc                                                                         \
    --progress                                                                        \
    --stats                                                                           \
    --compression zstd                                                                \
    --exclude-caches                                                                  \
                                                                                      \
    --pattern '! /dev'                                                                \
    --pattern '! /proc'                                                               \
    --pattern '! /sys'                                                                \
    --pattern '! /var/run'                                                            \
    --pattern '! /var/tmp'                                                            \
    --pattern '! /run'                                                                \
    --pattern '! /tmp'                                                                \
    --pattern '! /lost+found'                                                         \
    --pattern '! /var/cache'                                                          \
    --pattern '! /**/found.000/*'                                                     \
    --pattern '! /mnt'                                                                \
                                                                                      \
    --pattern '! /var/lib/apport/coredump'                                            \
    --pattern '! /var/lib/docker'                                                     \
    --pattern '! /var/lib/libvirt/images'                                             \
    --pattern '! /var/lib/snapd/snaps'                                                \
    --pattern '! /var/local/borg/repos'                                               \
    --pattern '! /**/.cache'                                                          \
    --pattern '! /**/Cache'                                                           \
    --pattern '! /**/cache'                                                           \
    --pattern '! /**/.terraform'                                                      \
    --pattern '- *.tmp'                                                               \
                                                                                      \
    --pattern '! /home/*/.steam'                                                      \
    --pattern '! /home/*/Android/Sdk'                                                 \
    --pattern '! /home/*/GOG Games'                                                   \
    --pattern '! /home/*/Downloads'                                                   \
    --pattern '! /home/*/go'                                                          \
    --pattern '! /home/*/.local/share/JetBrains/Toolbox/apps'                         \
    --pattern '! /home/*/.local/share/Trash'                                          \
                                                                                      \
    --pattern '+ /media/caspervk/C/Users/Casper/Desktop'                              \
    --pattern '+ /media/caspervk/C/Users/Casper/Documents'                            \
    --pattern '+ /media/caspervk/C/Program Files (x86)/World of Warcraft/_classic_'   \
    --pattern '+ /media/caspervk/Backup/borg'                                         \
    --pattern '- /media'                                                              \
                                                                                      \
    ::'{hostname}-{utcnow}'                                                           \
    /
backup_exit=$?

# Prunes repository by deleting all archives not matching any of the specified retention options. Repository disk space
# is NOT freed until `borg compact` is run.
# See https://borgbackup.readthedocs.io/en/stable/usage/prune.html for an explanation of the 'keep' options.
borg prune            \
    --show-rc         \
    --list            \
    --keep-daily   14 \
    --keep-weekly  6  \
    --keep-monthly 12
prune_exit=$?

# _Actually_ free repository disk space by compacting segments
borg compact
compact_exit=$?


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