#!/bin/sh

# Copyright 2016 Dell EMC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Notes:
#  - Please install "jq" package before using this driver.
#  - Please install and configure REX-Ray before using this driver

# detect which binary is available: rexray-client or rexray
if which -s rexray-client; then
	REXRAY_BIN=$(which rexray-client)
elif which -s rexray; then
	REXRAY_BIN=$(which rexray)
else
	echo "error: rexray-client/rexray not detected"
	exit 1
fi

err() {
	printf "%b" "$*" 1>&2
}

log() {
	printf "%b" "$*" >&1
}

success() {
	log '{"status": "Success"}'
	exit 0
}

usage() {
	err "error: invalid usage\n"
	err "\t$0 init\n"
	err "\t$0 attach <json params>\n"
	err "\t$0 detach <mount device>\n"
	err "\t$0 mount <mount dir> <mount device> <json params>\n"
	err "\t$0 unmount <mount dir>\n"
	exit 1
}

ismounted() {
	MOUNT=$(findmnt -n "${MNTPATH}" 2>/dev/null | cut -d' ' -f1)
	if [ "${MOUNT}" = "${MNTPATH}" ]; then
		echo "1"
	else
		echo "0"
	fi
}

attach() {
	VOLUMEID=$(echo "$1" | jq -r '.volumeID')
	FORCE_ATTACH=$(echo "$1" | jq -r '.forceAttach')
	FORCE_ATTACH_DELAY=$(echo "$1" | jq -r '.forceAttachDelay')

	if [ -z "$VOLUMEID" ]; then
		err '{"status": "Failure", "message": "Unable to extract volumeID"}'
		exit 1
	fi

	if [ "$FORCE_ATTACH" = "true" ]; then
		if echo "$FORCE_ATTACH_DELAY" | grep '^-\{0,1\}[[:digit:]]\{1,\}$' > /dev/null; then
			STATUS_CHECKS=$(( FORCE_ATTACH_DELAY / 5 ))
			COUNTER=0
			COUNTER_LOGGED=1
			while [ "$COUNTER" -lt "$STATUS_CHECKS" ]; do
				VOLUME_STATUS=$(${REXRAY_BIN} volume ls "${VOLUMEID}" --format json 2>/dev/null | jq '.[0].attachmentState')
				if [ "$FLEXREX_DEBUG" -eq "1" ]; then
					echo "checked volume status. volume status is ${VOLUME_STATUS}" >> /var/log/flexrex_force.log
				fi
				if [ "$VOLUME_STATUS" -eq "3" ] || [ "$VOLUME_STATUS" -eq "2" ]; then
					if [ "$FLEXREX_DEBUG" -eq "1" ]; then
						echo "volume is available, breaking loop" >> /var/log/flexrex_force.log
					fi
					break;
				fi
				if [ "$FLEXREX_DEBUG" -eq "1" ]; then
					echo "sleeping for 5 seconds after status check #${COUNTER_LOGGED}" >> /var/log/flexrex_force.log
				fi
				sleep 5
				[ "$(( COUNTER=COUNTER+1 ))" -ne 0 ]
				[ "$(( COUNTER_LOGGED=COUNTER_LOGGED+1 ))" -ne 0 ]
			done
		fi
		OUTPUT=$(${REXRAY_BIN} volume attach "${VOLUMEID}" -i --force --format json 2>/dev/null)
		ATTACH_EXIT_CODE=$?
	else
		OUTPUT=$(${REXRAY_BIN} volume attach "${VOLUMEID}" -i --format json 2>/dev/null)
		ATTACH_EXIT_CODE=$?
	fi

	if [ "$ATTACH_EXIT_CODE" -ne "0" ]; then
		err "{\"status\": \"Failure\", \"message\": \"REX-Ray returned error during attach\"}"
		exit 1
	fi

	# Make second call to get device info
	OUTPUT=$(${REXRAY_BIN} volume ls "${VOLUMEID}" --path --format json 2>/dev/null)
	DEV=$(echo "${OUTPUT}" | jq -r '.[0].attachments[0].deviceName')
	if [ -z "$DEV" ]; then
		err '{"status": "Failure", "message": "REX-Ray did not return attached device name"}'
		exit 1
	fi
	if [ ! -b "${DEV}" ]; then
		err "{\"status\": \"Failure\", \"message\": \"Volume ${VOLUMEID} not present at ${DEV}\"}"
		exit 1
	fi
	log "{\"status\": \"Success\", \"device\":\"${DEV}\"}"
	exit 0
}

detach() {
	DEV=$1
	if [ ! -b "${DEV}" ]; then
		err "{\"status\": \"Failure\", \"message\": \"Device ${DEV} does not exist\"}"
		exit 1
	fi

	VOLUMES=$(${REXRAY_BIN} volume ls --path --format json 2>/dev/null)
	VOLUMEID=$(echo "${VOLUMES}" | jq -r "[.[] | {id: .id, device:.attachments[0].deviceName}] | .[] | select(.device == '${DEV}') | .id")

	if [ -z "$VOLUMEID" ]; then
		err "{\"status\": \"Failure\", \"message\": \"Could not find source volume for device ${DEV}\"}"
		exit 1
	fi

	${REXRAY_BIN} volume detach -i "${VOLUMEID}" >/dev/null 2>&1
	DETACH_EXIT_CODE=$?
	if [ "$DETACH_EXIT_CODE" -ne "0" ]; then
		err "{\"status\": \"Failure\", \"message\": \"REX-Ray returned error during detach\"}"
		exit 1
	fi

	log "{\"status\": \"Success\"}"
	exit 0
}

domount() {
	MNTPATH=$1
	DEV=$2
	FSTYPE=$(echo "$3" | jq -r '.["kubernetes.io/fsType"]')

	if [ ! -b "${DEV}" ]; then
		err "{\"status\": \"Failure\", \"message\": \"${DEV} does not exist\"}"
		exit 1
	fi

	if [ "$(ismounted)" -eq "1" ] ; then
		success
	fi

	VOLFSTYPE=$(blkid -o udev "${DEV}" 2>/dev/null | grep "ID_FS_TYPE"| cut -d"=" -f2)
	if [ "${VOLFSTYPE}" = "" ]; then
		CMD="mkfs -t ${FSTYPE}"
		if [ "$FSTYPE" = "ext4" ]; then
			CMD="${CMD} -F"
		elif [ "$FSTYPE" = "xfs" ]; then
			CMD="${CMD} -f"
		fi
		if ! ${CMD} "${DEV}" > /dev/null 2>&1; then
			err "{ \"status\": \"Failure\", \"message\": \"Failed to create fs ${FSTYPE} on device ${DEV}\"}"
			exit 1
		fi
	fi

	mkdir -p "${MNTPATH}" > /dev/null 2>&1
	if ! mount "${DEV}" "${MNTPATH}" > /dev/null 2>&1; then
		err "{ \"status\": \"Failure\", \"message\": \"Failed to mount device ${DEV} at ${MNTPATH}\"}"
		exit 1
	fi
	success
}

unmount() {
	MNTPATH=$1
	if [ "$(ismounted)" -eq "0" ] ; then success; fi


	if ! umount "${MNTPATH}" > /dev/null 2>&1; then
		err "{ \"status\": \"Failed\", \"message\": \"Failed to unmount volume at ${MNTPATH}\"}"
		exit 1
	fi
	rmdir "${MNTPATH}" > /dev/null 2>&1

	success
}

op=$1

if [ "$op" = "init" ]; then success; fi
if [ "$#" -lt "2" ]; then usage; fi

shift

case "$op" in
	attach)
		if [ "$FLEXREX_DEBUG" -eq "1" ]; then
			printf "%s\t%b\n" "$(date)" "$*" >> /var/log/flexrex_attach.log
		fi
		attach "$@"
		;;
	detach)
		detach "$@"
		;;
	mount)
		if [ "$FLEXREX_DEBUG" -eq "1" ]; then
			printf "%s\t%b\n" "$(date)" "$*" >> /var/log/flexrex_mount.log
		fi
		domount "$@"
		;;
	unmount)
		unmount "$@"
		;;
	*)
		usage
esac

exit 1