#!/bin/bash

# Notes:
#  - Please install "jq" package before using this driver.

DIR=$(dirname "$(readlink -f "$0")")
JQ="/usr/bin/jq"
MOUNT_CIFS="$DIR/cifs"
LOG="/var/log/cifs-driver.log"
VER="1.0.0"

usage() {
	err "Invalid usage. Usage: "
	err "\t$0 init"
	err "\t$0 mount <mount dir> <mount device> <json params>"
	err "\t$0 unmount <mount dir>"
	exit 1
}

err() {
	echo $* 1>&2
}

log() {
	echo $* >&1
}

ismounted() {
	MOUNT=`findmnt -n ${MNTPATH} 2>/dev/null | cut -d' ' -f1`
	[ "${MOUNT}" = "${MNTPATH}" ]
}

mount() {
	MNTPATH="$1"
	VOLUME_SRC=$(echo "$2"|"$JQ" -r '.source')
	READ_MODE=$(echo "$2"|"$JQ" -r '.["kubernetes.io/readwrite"]')
	MOUNT_OPTIONS=$(echo "$2"|"$JQ" -r '.mountOptions // empty')
	USERNAME=$(echo "$2"|"$JQ" -r '.["kubernetes.io/secret/username"] // empty'|base64 -d)
	PASSWORD=$(echo "$2"|"$JQ" -r '.["kubernetes.io/secret/password"] // empty'|base64 -d)

	ALL_OPTIONS="username=${USERNAME},password=${PASSWORD},${READ_MODE}"
	if [ -n "$MOUNT_OPTIONS" ]; then
		ALL_OPTIONS="${ALL_OPTIONS},${MOUNT_OPTIONS}"
	fi
	
	if ismounted ; then
		log '{"status": "Success"}'
		exit 0
	fi

	echo "`date` EXEC: mkdir -p ${MNTPATH}" >> $LOG
	mkdir -p ${MNTPATH} >>$LOG 2>&1

	#mounting
	echo "`date` EXEC: /bin/mount -t cifs ${VOLUME_SRC} ${MNTPATH}" >>$LOG
	
	/bin/mount -t cifs "${VOLUME_SRC}" "${MNTPATH}" -o "${ALL_OPTIONS}" >>$LOG 2>&1
	if [ $? -ne 0 ]; then
		errorLog=`tail -n 1 "${LOG}"`
		err "{ \"status\": \"Failure\", \"message\": \"Failed to mount device ${DMDEV} at ${MNTPATH}, user:${USERNAME}, ${VOLUME_SRC}, error log:${errorLog}\" }"
		exit 1
	fi
	log '{"status": "Success"}'
	exit 0
}

unmount() {
	MNTPATH="$1"
	if ! ismounted ; then
		log '{"status": "Success"}'
		exit 0
	fi

	echo "`date` EXEC: umount $MNTPATH" >>$LOG
	umount "${MNTPATH}" >>$LOG 2>&1
	if [ $? -ne 0 ]; then
		errorLog=`tail -n 1 "${LOG}"`
		err "{ \"status\": \"Failed\", \"message\": \"Failed to unmount volume at ${MNTPATH}, error log:${errorLog}\" }"
		exit 1
	fi
	echo "`date` EXEC: rmdir ${MNTPATH}" >> $LOG
	rmdir "${MNTPATH}" >> $LOG 2>&1

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

op=$1

if [ "$op" = "init" ]; then
	log '{"status": "Success", "capabilities": {"attach": false}}'
	exit 0
fi

if [ $# -lt 2 ]; then
	usage
fi

shift

case "$op" in
	mount)
		mount $*
		;;			
	unmount)
		unmount $*
		;;
	*)
	usage
esac

exit 1