#!/bin/sh

# This script set a specific grub entry (winLOOSE…) for the next boot.
# Then reboot the host

# Vars {{{
readonly PROGNAME=$(basename "${0}")
readonly PROGDIR=$(readlink -m $(dirname "${0}"))
readonly ARGS="${*}"
readonly NBARGS="${#}"

readonly GRUB_DEFAULT_PATH='/etc/default/grub'
readonly GRUB_DEFAULT_DIR='/etc/default/grub.d'
readonly WIN_GRUB="2"
# }}}

main() {                                                        # {{{

	# First check in Grub default dir if saved mode is set
	if grep -q -E -R -- "^GRUB_DEFAULT=saved" "${GRUB_DEFAULT_DIR}"
	then
		printf '%b' "Reboot to windaube partition\\n"
		sudo grub-reboot "${WIN_GRUB}"
		sudo systemctl reboot
	fi

	# Otherwise check the default grub file
	if grep -q -E -- "^GRUB_DEFAULT=saved" "${GRUB_DEFAULT_PATH}"
	then
		printf '%b' "Reboot to windaube partition\\n"
		sudo grub-reboot "${WIN_GRUB}"
		sudo systemctl reboot
	else

		printf '%b' "GRUB_DEFAULT is not set in 'saved' mode\\n"
		sudo sed -i 's/\(^GRUB_DEFAULT.*\)/#\1\nGRUB_DEFAULT=saved/' "${GRUB_DEFAULT_PATH}"
		GRUB_DEFAULT_ENTRY=$(grep -E -- "#GRUB_DEFAULT=" "${GRUB_DEFAULT_PATH}" | cut -d"=" -f2)
		sudo grub-set-default "${GRUB_DEFAULT_ENTRY}"
		sudo update-grub
		printf '%b' "Please launch this script (${PROGDIR}/${PROGNAME} ${ARGS}) once again.\\n"
	fi
}
# }}}

main

exit 0