#!/usr/bin/env bash

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
set -o allexport
eval $(cat ${DIR}'/.env' | sed -e '/^#/d;/^\s*$/d' -e 's/\(\w*\)[ \t]*=[ \t]*\(.*\)/\1=\2/' -e "s/=['\"]\(.*\)['\"]/=\1/g" -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
set +o allexport

info() { printf "\n%s %s\n\n" "$( date )" "$*" >&2; }
trap 'echo $( date ) Backup interrupted >&2; exit 2' INT TERM

if [ -z ${BORG_REPO+x} ]; then info "BORG_REPO must be set, check your .env"; exit 1; fi
if [ -z ${BORG_PASSPHRASE+x} ]; then info "BORG_PASSPHRASE must be set, check your .env"; exit 1; fi
node_metrics_enabled=${NODE_METRICS_ENABLED:-1}
node_metrics_path=${NODE_METRICS_PATH:-/usr/local/lib/prom}

start=$(date +%s)

exec {lock_fd}>/var/lock/borg-backup.lock || exit 1
flock -n "$lock_fd" || { echo "ERROR: flock() failed." >&2; exit 1; }

patternfile=$(mktemp)
cat patterns.* > $patternfile

if [ ${DOCKER_VOLUMES_ENABLED} -eq 1 ]; then
	info "Collecting docker volumes..."
	: ${DOCKER_COMMAND:=/usr/bin/docker}
	volumes=$(${DOCKER_COMMAND} volume ls -f label=org.zknt.backup -f driver=local --format "{{.Name}}")
	dockerpatterns=$(mktemp)
	for volume in ${volumes}; do
		mountpoint=$(${DOCKER_COMMAND} volume inspect ${volume} --format "{{.Mountpoint}}")
		echo "R $(dirname ${mountpoint})" >> $dockerpatterns
	done
	cat $dockerpatterns >> $patternfile
	rm $dockerpatterns
fi

info "Starting borg..."
borg create \
    --warning \
    --filter AME \
    --list \
    --stats \
    --show-rc \
    --compression lz4 \
    --exclude-caches \
    --exclude '/home/*/.cache/*' \
    --exclude '/var/tmp/*' \
    ::'{hostname}-{now}' \
    --patterns-from $patternfile

backup_exit=$?

rm $patternfile

borg prune \
    --list \
    --prefix '{hostname}-' \
    --show-rc \
    --keep-daily ${BORG_PRUNE_KEEP_DAILY:-14} \
    --keep-weekly ${BORG_PRUNE_KEEP_WEEKLY:-4} \
    --keep-monthly ${BORG_PRUNE_KEEP_MONTHLY:-6}

prune_exit=$?

global_exit=$(( backup_exit > prune_exit ? backup_exit : prune_exit ))

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

end=$(date +%s)

if [ ${node_metrics_enabled} -eq 1 ]; then
	echo "borg_last_run ${end}" > ${node_metrics_path}/borg_backup.prom.$$
	echo "borg_last_duration $(($end - $start))" >> ${node_metrics_path}/borg_backup.prom.$$
	mv ${node_metrics_path}/borg_backup.prom{.$$,}
fi

flock -u "$lock_fd"