#!/bin/sh

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

# 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 once again.\\n"
fi

exit 0