#!/usr/bin/env bash
#
# SPDX-License-Identifier: MIT

if [ $# -ne 2 ]; then
  echo "2 Parameters required: SRCDIR and LOGBASE."
  echo " Example: $0 /opt/work WORKfacldump"
  exit 1
fi

# starting tree of the filesystem to dump ACLs
SRCDIR=$1
# base filename to prepend in /var/log/facldump
LOGBASE=$2

if [ ! -d "${SRCDIR}" ]; then
  echo "${SRCDIR} does not exist! Exiting."
  exit 1
fi

# some changes here could affect code, take care
LOGDIR=/var/log/facldump
DURATION_KEEP=28
DSPEC="+%Y%m%d_%H%M"
CEXT=gz

# avoid aliases, bad PATH, etc.
DT=/bin/date
GF=/usr/bin/getfacl
GZ=/bin/gzip
RM=/bin/rm
MK=/usr/bin/mkdir

# get our date/timestamp cutoff for cleanup
DATE_KEEP=$($DT --date "now - $DURATION_KEEP days" +"%Y%m%d")
# get our date/timespec to name new files
DATE_SAVE=$($DT $DSPEC)
# get the length of the above + . + extension (20130209_1106.gz = 16 e.g.)
TLEN=$((${#DATE_SAVE}+${#CEXT}+1))

# cleanup older than DURATION_KEEP by comparing the YYYMMDD in the filename
#  to the YYYYMMDD of the DATE_KEEP generated above
cleanup_older (){
  for logfile in "${LOGDIR}/${LOGBASE}."*; do
    TLEN=${#logfile}
    DTS=${logfile:(-$TLEN):8}
    # shellcheck disable=SC2086
    if [ $DTS -lt $DATE_KEEP ]; then
      ${RM} -f "${logfile}"
    fi
  done
}

create_dump (){
  ${GF} -R -p "${SRCDIR}" | ${GZ} --fast > "${LOGDIR}/${LOGBASE}.$(date $DSPEC).${CEXT}"
}

if [ ! -d "${LOGDIR}" ]; then
  ${MK} -p "${LOGDIR}"
fi

create_dump
cleanup_older

exit 0