#!/bin/bash

### Usage message
if [[ -z $1 ]]; then
    cat <<- EOT
Usage: $0 <PATH_TO_DIR_WITH_BACKUPS> [RETENTION]

PATH_TO_DIR_WITH_BACKUPS - self explainatory, eg. /opt/backups

RETENTION - number of last backups to leave (based on modification time)

EOT
    exit 1
fi


# will leave last N files untouched
RETENTION=${2:-5}

BASEDIR=$(dirname $0)
BACKUP_DIR=$1
FILES_LIST=( $(ls -1trh ${BACKUP_DIR}/*.sql.bz2) )
ARR_SIZE=${#FILES_LIST[@]}

if [[ ${ARR_SIZE} -gt ${RETENTION} ]]; then
    LEAVE_END_IDX=$((ARR_SIZE - RETENTION))
    LEAVE=${FILES_LIST[@]:0:${LEAVE_END_IDX}}

    rm ${LEAVE[@]}
fi