#!/bin/sh
set -eu

backup_keep=1m

main() {
    # remove stale locks
    resticw unlock || :

    # run backup
    resticw backup \
        --skip-if-unchanged \
        --files-from "/usr/share/resticbackup/includes" \
        --files-from "/etc/resticbackup/includes" \
        --exclude-file "/usr/share/resticbackup/excludes" \
        --exclude-file "/etc/resticbackup/excludes" \
        --tag resticbackup

    # prune backups older than $backup_keep duration
    resticw forget \
        --keep-within "${backup_keep}" \
        --prune \
        --group-by "paths,tags" \
        --tag resticbackup

    resticw check

    # TODO: dump stats to file in metrics format to /run/prom/restic
}

exit_hook() {
    # shellcheck disable=3043
    local rc=$?

    resticw unlock || :

    if [ "$rc" = 0 ]; then
        logger --id=$$ --msgid=BACKUPEND --priority=notice "backup finished"
    else
        logger --id=$$ --msgid=BACKUPEND --priority=error "backup failed"
    fi
}
trap exit_hook INT EXIT

logger --id=$$ --msgid=BACKUPSTART --priority=notice "backup starting..."

main >>"/var/log/resticbackup.log" 2>&1