#!/bin/sh
#
# create snapshots of hammer2 directories

if [ -r /etc/defaults/periodic.conf ]
then
    . /etc/defaults/periodic.conf
    source_periodic_confs
fi

case "${PERIODIC}" in
	weekly)
	snap_dirs=${weekly_snapshot_hammer2_dirs:-"auto"}
	snap_capacity=${weekly_snapshot_hammer2_capacity:-"90"}
	snap_keep=${weekly_snapshot_hammer2_keep:-"auto"}
	snap_keep_auto=6
	snap_tag=${weekly_snapshot_hammer2_tag:-"weekly"}
	snap_enable="${weekly_snapshot_hammer2_enable}"
	;;
	monthly)
	snap_dirs=${monthly_snapshot_hammer2_dirs:-"auto"}
	snap_capacity=${monthly_snapshot_hammer2_capacity:-"90"}
	snap_keep=${monthly_snapshot_hammer2_keep:-"auto"}
	snap_keep_auto=12
	snap_tag=${monthly_snapshot_hammer2_tag:-"monthly"}
	snap_enable="${monthly_snapshot_hammer2_enable}"
	;;
	*)
	snap_dirs=${daily_snapshot_hammer2_dirs:-"auto"}
	snap_capacity=${daily_snapshot_hammer2_capacity:-"90"}
	snap_keep=${daily_snapshot_hammer2_keep:-"auto"}
	snap_keep_auto=15
	snap_tag=${daily_snapshot_hammer2_tag:-"daily"}
	snap_enable="${daily_snapshot_hammer2_enable}"
	;;
esac

rc=0

case "${snap_enable}" in
	[Yy][Ee][Ss])
	echo ""
	echo "HAMMER2 snapshots:"

	if [ "${snap_dirs}" = "auto" ]; then
		snap_dirs="$(mount -v -t hammer2 | awk '{ print $3; }')"
	fi

	for dir in ${snap_dirs}; do
		echo -n "${dir}: "
		if [ ! -d "${dir}" ]; then
			echo "omitted, not a directory"
			continue
		fi
		_df=$(df ${dir} | grep -oE "[0-9]+%")
		_pcnt=${_df%%%}
		if [ ${_pcnt} -gt ${snap_capacity} ]; then
			echo "omitted, not enough free space"
			continue
		fi
		hammer2 snapshot ${dir} ${dir}.${snap_tag}.$(date +%Y%m%d.%H:%M) \
			|| rc=1
		_keep=${snap_keep}
		if [ "${_keep}" = "auto" ]; then
			# adjust number of snapshots dynamically, according to free space
			_keep=$(echo "scale=2;inc=((${snap_capacity}-${_pcnt})/50* \
				${snap_keep_auto});scale=0;${snap_keep_auto}+inc/1" | bc)
		fi
		_keep=$((_keep+1))
		for _stale in $(hammer2 -s ${dir} pfs-list | grep -v "^Type" | \
				grep -oE "${dir}\.${snap_tag}\..*$" | \
				sort -r | tail -n+${_keep}); do
			hammer2 -s ${dir} pfs-delete ${_stale} || rc=1
		done
		echo "${dir}: $(hammer2 -s ${dir} pfs-list | grep -v "^Type" | \
				grep -coE "${dir}\.${snap_tag}\..*$") snapshot(s)"
	done
	;;
esac

exit $rc