#!/bin/bash

################################################################################
# Backup Borg
# ---------------------------
#
# TODO
#
# Author: Robin Meier - robin@meier.si
################################################################################

# Import logging functionality
script_dir=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
logfile=${script_dir}/log/backup.log
log_identifier="BORG"
source ${script_dir}/functions/logging.sh

# Input parameters
BORG_NAME=$1
TIMESTAMP=$2
BORG_DIRS=$3
BORG_OPTS=$4
if [[ -z "$BORG_NAME" || -z "$TIMESTAMP" || -z "$BORG_DIRS" ]]; then
  log_echo "[ERROR] Positional parameter missing! (name, timestamp, directories (, borg options))"
  exit 40
fi

# Check if required env vars are set
if [[ -z "$BORG_REPO" || -z "$BORG_PASSPHRASE" ]]; then
  log_echo "[ERROR] Repo location or passphrase env var missing!"
  exit 42
fi

# Automated negative response to these questions
export BORG_RELOCATED_REPO_ACCESS_IS_OK=no
export BORG_UNKNOWN_UNENCRYPTED_REPO_ACCESS_IS_OK=no

# Error handling
# trap 'log "Backup interrupted"; exit 2' INT TERM # untested
trap 'echo $( date ) Backup interrupted >&2; exit 2' INT TERM

# Output current version
log_echo "Backup borg version: $(borg --version)"

# Create backup
log_echo "Creating backup..."

borg create $BORG_BACKUP_OPTS $BORG_OPTS \
  --stats                                \
  --verbose                       \
  --filter AME                    \
  --list                          \
  --show-rc                       \
  --compression lz4               \
  --exclude-caches                \
  ::"{hostname}-${BORG_NAME}-${TIMESTAMP}"  \
  $BORG_DIRS

backup_exit=$?

log_echo "Finished creating backup ($backup_exit)"


# Prune no longer needed backups
log "Pruning backups from repository"

borg prune                                       \
    --list                                       \
    --glob-archives "{hostname}-${BORG_NAME}-*"  \
    --show-rc                                    \
    --keep-daily    7                            \
    --keep-weekly   4                            \
    --keep-monthly  6

prune_exit=$?

log "Finished pruning backups from repository ($prune_exit)"


# Compact repository
log "Compacting repository"

# TODO: Maybe first check if compacting is supported by the client? (Older versions)
borg compact

compact_exit=$?

log "Finished compacting repository ($compact_exit)"


# Calculate global exit code
global_exit=$(( backup_exit > prune_exit ? backup_exit : prune_exit ))
global_exit=$(( compact_exit > global_exit ? compact_exit : global_exit ))

if [ ${global_exit} -eq 0 ]; then
  log "Backup, Prune, and Compact finished successfully"
elif [ ${global_exit} -eq 1 ]; then
  log_echo "Backup, Prune, and/or Compact finished with warnings"
else
  log_echo "Backup, Prune, and/or Compact finished with errors"
fi


log "Backup Finished ($global_exit)"

exit ${global_exit}