#!/bin/sh

DAEMON=ndas
. /etc/init.d/modlibrc

NDAS_CONF="/mod/etc/ndas.conf"
NDAS_NAME="ndas-01"

# display a failure message (passed in $1) and exit with return code 1
die() {
	echo "failed:$1"
	exit 1
}

call_rc_script() {
	local service="$1"; shift
	[ -x "/mod/etc/init.d/rc.$service" ] && /mod/etc/init.d/rc.$service "$@"
}

# return cell value of a tabular organized file
# $1 - row specifier (usually NDAS name), the 1st cell of the row must exactly match given specifier
# $2 - column index
# $3 - input file e.g. /proc/ndas/devs or /proc/modules
cellValue() {
	awk '$1 == "'"$1"'" { print $'"$2"' }' $3 2>/dev/null
}

# override modlib_check_running from modlibrc (this makes it possible to reuse some functions from it, e.g. modlib_status, modlib_start)
modlib_check_running() {
	local admin_active=$(cellValue ndas_sal 3 /proc/modules) # obtain number of dependencies of the module ndas_sal
	[ -z "$admin_active" ] && admin_active=0

	# if number of dependencies is greater than 2 then NDAS is already running, TODO: find a more reliable way to determine it?
	[ "$admin_active" -gt 2 ] && return 0 # running
	return 3 # stopped
}

config() {
	[ ! -c /dev/ndas ] && mknod -m 644 /dev/ndas c 60 0  # create necessary character/block device nodes
	[ ! -b /dev/nda  ] && mknod -m 644 /dev/nda  b 60 0  # if these don't exist yet

	# create a block device node for each partition on the network disk
	partition=1
	while [ $partition -le "$NDAS_NUMBEROFPARTITIONS" ]; do
		[ ! -b /dev/nda${partition} ] && mknod -m 644 /dev/nda${partition} b 60 $partition
		let partition++
	done
}

start() {
	[ -z "$NDAS_ID" ] && die "NDAS Device-ID is missing"

	config

	# load required modules
	modprobe ndas_sal                                                || die "ndas module ndas_sal could not be loaded"
	modprobe ndas_core ${NDAS_INTERFACE:+ndas_dev=${NDAS_INTERFACE}} || die "ndas module ndas_core could not be loaded"
	modprobe ndas_block                                              || die "ndas module ndas_block could not be loaded"

	# start admin if not yet running
	modlib_check_running || /usr/bin/ndasadmin start

	if [ ! -e "$NDAS_CONF" ]; then
		# no config file exists => NDAS is not registered yet => register it
		/usr/bin/ndasadmin register "${NDAS_ID}$([ "$NDAS_ACCESSMODE" == 'w' ] && echo "-${NDAS_WRITEKEY}")" --name "$NDAS_NAME" | sed -n -r -e '/^.+$/ { p; q }'
		[ -e "$NDAS_CONF" ] || die "NDAS could not be registered"
	fi

	# give the system some time to found NDAS
	local count=0
	while [ "$count" -lt 5 -a "$(tail -1 /proc/ndas/devs 2>/dev/null | awk '{ print $6 }')" == "N/A" ]; do
		sleep 1
		let count++
	done

	local slot_number="$(cellValue "$NDAS_NAME" 7 /proc/ndas/devs)"
	[ -n "$slot_number" ] || die "NDAS slot number could not be determined"

	# enable the registered netdisk using the slot number
	/usr/bin/ndasadmin enable -s "$slot_number" -o "$NDAS_ACCESSMODE" 2>&1 | head -n 1

	# TODO: very unreliable code, do it better
	#       instead of specifying the mound cmd, user should specify the mount point and if necessary the filesystem type
	#       mount device could and should be determined automatically (/dev/nda$partition)
	#       any attempts to parse mount parameters should be eliminated
	local partition=1
	while [ $partition -le "$NDAS_NUMBEROFPARTITIONS" ]; do  # for each partition determine the device and the mount point from the mount cmd
		eval ndas_mountcmd=\$NDAS_MOUNTCMD$partition
		if [ -n "$ndas_mountcmd" ]; then
			for m in $ndas_mountcmd; do
				if [ "${m:0:5}" == "/dev/" ]; then
					local mountdevice=$m
				fi
			done
			local mountpoint=$m
			[ ! -d $mountpoint ] && mkdir -p $mountpoint

			# TODO: is it a right thing to do? should not we fail instead if the partition is already mounted
			if ! grep -q "$mountdevice" /proc/mounts; then
				# TODO: what if the user specified wrong mount cmd?
				$ndas_mountcmd
			fi
		fi
		let partition++
	done

	[ "$NDAS_RESTART_SMB" == 'yes' ] && call_rc_script samba restart
	[ "$NDAS_RESTART_NFS" == 'yes' ] && call_rc_script nfsd restart
}

stop() {
	[ "$NDAS_RESTART_SMB" == 'yes' ] && call_rc_script samba stop
	[ "$NDAS_RESTART_NFS" == 'yes' ] && call_rc_script nfsd stop

	# TODO: rewrite me, s. comment above
	local partition=1
	while [ $partition -le "$NDAS_NUMBEROFPARTITIONS" ]; do # for each partition determint the device and unmount the device
		eval ndas_mountcmd=\$NDAS_MOUNTCMD$partition
		if [ -n "$ndas_mountcmd" ]; then
			for i in $ndas_mountcmd; do
				if [ "${i:0:5}" == "/dev/" ]; then
					local mountdevice=$i
				fi
			done
			if grep -q "$mountdevice" /proc/mounts; then
				# if mounted, unmount the device
				umount $mountdevice
			fi
		fi
		let partition++
	done

	[ "$NDAS_RESTART_SMB" == 'yes' ] && call_rc_script samba start
	[ "$NDAS_RESTART_NFS" == 'yes' ] && call_rc_script nfsd start

	if [ "$(cat /proc/ndas/devs 2>/dev/null | wc -l)" -ge "2" ]; then
		local slot_number=$(cellValue "$NDAS_NAME" 7 /proc/ndas/devs)
		if [ -n "$slot_number" ]; then
			local diskstatus=$(cellValue "$NDAS_NAME" 6 /proc/ndas/devs)
			if echo "${diskstatus}" | grep -qiE "^(online|offline|error)$"; then
				/usr/bin/ndasadmin disable -s "$slot_number"
			fi
		fi
	fi

	#TODO: are the following three lines really necessary?
	[ -c /dev/ndas ] && /usr/bin/ndasadmin stop                 # if character device exists stop NDAS
	#TODO: what about other modules?
	modprobe -r ndas_block                                      # remove ndas_block kernel module
	[ -e "$NDAS_CONF" -a ! -s "$NDAS_CONF" ] && rm "$NDAS_CONF" # delete the NDAS config file if it has a zero size
}

case $1 in
	""|load)
		modreg cgi 'ndas' 'ndas'
		modreg daemon ndas
		modlib_start $NDAS_ENABLED
		;;
	unload)
		modunreg daemon ndas
		modunreg cgi 'ndas'
		stop
		;;
	start)
		start
		;;
	stop)
		stop
		;;
	restart)
		stop
		start
		;;
	status)
		modlib_status
		;;
	*)
		echo "Usage: $0 [load|unload|start|stop|restart|status]" 1>&2
		exit 1
		;;
esac

exit 0