#!/usr/bin/env bash

set -e

rootdir=$(readlink -f $(dirname $0))/..

function usage() {
	echo "Usage: [-j] $0 -n BDEV_NAME -d BASE_BDEV [-u UUID] [-c CACHE]"
	echo "UUID is required when restoring device state"
	echo
	echo "BDEV_NAME - name of the bdev"
	echo "BASE_BDEV - name of the bdev to be used as underlying device"
	echo "UUID - bdev's uuid (used when in restore mode)"
	echo "CACHE - name of the bdev to be used as write buffer cache"
}

function create_json_config() {
	echo "{"
	echo '"subsystem": "bdev",'
	echo '"config": ['
	echo '{'
	echo '"method": "bdev_ftl_create",'
	echo '"params": {'
	echo "\"name\": \"$1\","
	echo "\"base_bdev\": \"$2\","
	if [ -n "$4" ]; then
		echo "\"uuid\": \"$3\","
		echo "\"cache\": \"$4\""
	else
		echo "\"uuid\": \"$3\""
	fi
	echo '}'
	echo '}'
	echo ']'
	echo '}'
}

uuid=00000000-0000-0000-0000-000000000000

while getopts ":c:d:hn:u:" arg; do
	case "$arg" in
		n) name=$OPTARG ;;
		d) base_bdev=$OPTARG ;;
		u) uuid=$OPTARG ;;
		c) cache=$OPTARG ;;
		h)
			usage
			exit 0
			;;
		*)
			usage
			exit 1
			;;
	esac
done

if [[ -z "$name" || -z "$base_bdev" ]]; then
	usage
	exit 1
fi

create_json_config $name $base_bdev $uuid $cache