parse_arguments()
{
	FORCE=0
	HELP=0
	SCRIPT_OUTPUT=/proc/self/fd/1
	PROGRAM_OUTPUT=/dev/null

	# Parse options
	while getopts ":fhvq" o; do
		case $o in
		f) FORCE=1;;
		h) HELP=1;;
		v) PROGRAM_OUTPUT=/proc/self/fd/1;;
		q) SCRIPT_OUTPUT=/dev/null;;
		\?) usage && exit;;
		esac
	done
	shift $(( $OPTIND - 1 ))

	if [ $HELP -eq 1 ]; then
		help
		exit
	fi

	# The 1st argument is the device. If no other argument is passed, the default mode is used.
	# If other 4 arguments are passed, the manual mode is used (the arguments are the sizes of the partitions)
	# Otherwise, the script exits
	if [ $# -eq 1 ]; then
		MODE=default
	elif [ $# -eq 5 ] && [ $FORCE -ne 1 ]; then
		MODE=manual
	else
		usage && exit
	fi
	DEVICE="$1"
	check_device
	DEVICE_SIZE=$(blockdev --getsz "${DEVICE}")
	RAM_SIZE=$(to_sectors $(grep MemTotal: /proc/meminfo | awk '{print $2}')K)
	$MODE $@
}

default()
{
	MIN_SIZE=$(( $(to_sectors 100G) + $RAM_SIZE + $(to_sectors 2G) ))
	BEST_SIZE=$(( $(to_sectors 200G) + 2 * $RAM_SIZE ))

	if [ $DEVICE_SIZE -lt $MIN_SIZE ]; then
		fatal ${MINSIZE_E} "to use default mode, the disk must have at least $(sectors_to_gibibytes ${MIN_SIZE})GB".
	elif [ $DEVICE_SIZE -lt $BEST_SIZE ] && [ $FORCE -ne 1 ]; then
		fatal ${BESTSIZE_E} "to use default mode, it is reccomended that the disk have at least $(sectors_to_gibibytes ${BEST_SIZE})GB. If you know what you are doing, you can force default mode with -f".
	fi
	VM_SIZE=$(to_sectors 100G)
	SWAP_SIZE=$(( $RAM_SIZE + $(to_sectors 1G) ))
	FREE_SIZE=$(( ( $DEVICE_SIZE - $VM_SIZE - $SWAP_SIZE ) / 10 ))
	CONDOR_SIZE=$(( ( $DEVICE_SIZE - $FREE_SIZE ) / 10 * 4 ))
	TEMP_SIZE=$(( ( $DEVICE_SIZE - $FREE_SIZE ) / 10 * 6 ))
}

manual()
{
	TEMP_SIZE=$(to_sectors $2)
	CONDOR_SIZE=$(to_sectors $3)
	SWAP_SIZE=$(to_sectors $4)
	VM_SIZE=$(to_sectors $5)
	if [ $(( $TEMP_SIZE + $CONDOR_SIZE + $SWAP_SIZE + $VM_SIZE )) -gt $DEVICE_SIZE ]; then
		fatal ${MANUALSIZE_E} "can't use this sizes: ${DEVICE} has only $(sectors_to_gibibytes ${DEVICE_SIZE})G"
	fi
}

usage()
{
	echo "Usage:"
	echo "${PROGRAM_NAME} [-qvf] device"
	echo "${PROGRAM_NAME} [-qv] device temp_size condor_size swap_size vm_size"
	echo "${PROGRAM_NAME} -h[v]"
	exit $USAGE_E
}

help()
{
	cat <<-help-end
		newdisk automator
		This program can be used in two mode: automatic and manual.
		For help, use -h. For info about error codes, use both help and verbose flags.
		WARNING! This program does not mount the new partitions, nor update the fstab: these operations have to be performed afterwards.

		Automatic:
		newdisk-automator [-qvf] device
		device is partitioned according to the following scheme:
			- calcolo: 100GB
			- swap: ram size + 1GB
			- free space: 10% of the total
			- condor: 40% of remaining space
			- tempdir: 60% of remaining space
		If the size of the disk is less than 102GB + ram size, this mode cannot be used.
		If the size of the disk is greater than the minimum size, but still less than (100GB + ram size) * 2, to use this mode the -f option must be passed.
		Be careful: in the automatic mode, calcolo and swap size are fixed, and forcing it with -f could result in having very small tempdir and condor partitions. 

		Manual:
		newdisk-automator [-qv] device temp_size condor_size swap_size vm_size
		The partitions are assigned the size passed on the command line. S, b, K, M, G can be appended to the sizes for 512-byte-sectors, bytes, kibibytes, mebibytes and gibibytes. The default is bytes.
		If the total passed with the command line is greater than the size of the disk, the program stops.
	help-end
	if [ "$PROGRAM_OUTPUT" = "/proc/self/fd/1" ]; then
		cat <<-error-end

			Error codes:
			10 Usage error
			11 Size units error
			
			20 Device file does not exist
			21 Device is not a block file
			22 Device is mounted
			23 Device is used as swap
			24 Device is part of a used lvm volume
			25 Device is part of a lvm volume group shared with other physical volumes
			26 Device is not a regular disk (it may be a partition or another type of block file)
			
			30 Device is too small to use default mode
			31 Device does not have the reccomended size. Force with -f to use default mode
			32 Device is smaller than the manually specified size
			
			40 One of the programs called from the script returned a non 0 value. Check the stderr to get the code
			41 The effective user id of the calling user is not 0. Only root can run this tool
		error-end
	fi
}