#!/sbin/openrc-run

# shellcheck shell=bash

## bees variables
rundir="/run/bees"
logdir="/var/log/bees"
mnt="$rundir/mnt/${fsuuid}"
device="/dev/disk/by-uuid/${fsuuid}"
beeshome="${mnt}/.beeshome"
hashfile="${beeshome}/beeshash.dat"
export BEESSTATUS="${statusfile:-${rundir}/${fsuuid}.status}"

# optional variables can be set in conf.d
: "${logfile:="${logdir}/${RC_SVCNAME}.log"}"
: "${loglevel:=5}"
: "${bees_args:="-m 3"}"
: "${scheduler:="idle"}"
: "${SSD_IONICELEVEL:=3}"
: "${SSD_NICELEVEL:=19}"


## OpenRC
name="${RC_SVCNAME}"
description="Best-Effort Extent-Same, a btrfs dedupe agent"
command="/usr/libexec/bees"
command_args="-v ${loglevel} ${bees_args} \"${mnt}\" "
command_background="true"
extra_started_commands="suspend resume"
description_suspend="Suspends bees without unloading it."
description_resume="Resumes normal operation."

start_stop_daemon_args="--scheduler ${scheduler} --stdout ${logfile} --stderr ${logfile}"
pidfile="/run/${RC_SVCNAME}.pid"
retry=${GRACEFUL_TIMEOUT:-120}

depend() {
	use lvm device-mapper localmount
}

checkconfig() {
	if [ -z $hashfile ]; then
		eerror "hashsize not set!"
		return 1
	fi
	if [ ! -b "${device}" ]; then
		eerror "${device} not found!"
		return 1
	fi
	if [ ! "$(blkid -s TYPE -o value "${device}")" == "btrfs" ]; then
		eerror "${device} is not a btrfs filesystem"
		return 1
	fi;
	if [ ! -z "${logfile}" ]; then
		checkpath -f -m 0600 -o root:root "${logfile}"
	fi
}

start_pre() {
	ebegin "Config check"
	checkconfig || return 1

	if  findmnt "${mnt}" >/dev/null ; then
		eerror "${mnt} is already mounted. Aborting."
		return 1
	fi
	checkpath -d -m 0700 -o root:root "${logdir}"
	checkpath -d -m 0700 -o root:root "${rundir}"
	checkpath -d -m 0700 -o root:root "${rundir}/mnt"
	checkpath -d -m 0700 -o root:root "${mnt}"

	ebegin "Preparing ${fsuuid} mountpoint"
	mount -osubvolid=5 "${device}" "${mnt}" || return 1

 	if [ ! -d "${beeshome}" ]; then
		btrfs subvolume create "${beeshome}" || return 1
		checkpath -d -m 0700 -o root:root "${beeshome}"
	else
		# btrfs subvolume show "${beeshome}" > /dev/null || return 1
		checkpath -d -m 0700 -o root:root "${beeshome}"
	fi

	checkpath -f -m 0600 -o root:root "${hashfile}"
	old_hashsize="$(du -b "${hashfile}" | cut -f1)"
	if [ "${old_hashsize}" == "0" ] ; then
		truncate -s "${hashsize}" "${hashfile}"
	fi
	if [ "${hashsize}" != "${old_hashsize}" ] ; then
		eerror "Hash table size mismatch! Expected ${hashsize}b but found ${old_hashsize}b"
		return 1
	fi
	pushd "${mnt}" >/dev/null
	eend $?
}
stop_pre() {
	# make sure bees is not suspended before stopping.
	start-stop-daemon --signal SIGCONT --pidfile "${pidfile}"
	return $?
}

stop_post() {
	ebegin "Unmounting ${fsuuid}"
	umount "${mnt}"
	eend $?
}

suspend() {
	# Suspending bees is useful to avoid a 'btrfs send' bug
	# that exists with some kernels.
	# See https://zygo.github.io/bees/btrfs-kernel.md
	ebegin "Suspending ${RC_SVCNAME}"
	start-stop-daemon --signal SIGSTOP --pidfile "${pidfile}"
	eend $?
}

resume() {
	ebegin "Resuming ${RC_SVCNAME}"
	start-stop-daemon --signal SIGCONT --pidfile "${pidfile}"
	eend $?
}