#!/usr/bin/env bash
log() {
	local CODE=$?
	echo >&2 "$*"
	return $CODE
}
print-help() {
	log "\
usage: ${0##*/} [-h] [--] (install|uninstall)
Install initramfs scripts for Ubuntu.

# Options
-h	display this help & exit

# Subcommands
install	install initramfs scripts
uninstall	remove initramfs scripts"
}
usage-error() {
	print-help
	exit 2
}
action-install() {
	local SCRIPT_DIR="$(cd -P -- "$(dirname -- "$BASH_SOURCE")" && pwd)"
	install {"$SCRIPT_DIR",/etc/initramfs-tools}/hooks/grub-btrfs-overlay
	install {"$SCRIPT_DIR",/etc/initramfs-tools}/scripts/local-bottom/grub-btrfs-overlay
}
action-uninstall() {
	rm -f /etc/initramfs-tools/{hooks,scripts/local-bottom}/grub-btrfs-overlay
}
set -e
while getopts h OPT
do case "$OPT" in
	h)
		print-help
		exit
	;;
	*)
		usage-error
esac done
shift $(( OPTIND - 1 ))
OPTIND=1
ACTION=
case "$#" in
	0)
		log event: a subcommand is required
		usage-error
		;;
	1)
		case "$1" in
			install|uninstall)
				ACTION="action-$1"
				;;
			*)
				log "\
event: unknown subcommand
subcommand: $1"
				usage-error
		esac
		;;
	*)
		log "\
event: too many arguments
arguments: $*"
		usage-error
esac
"$ACTION" || log "\
event: execution failure
suggestion: rerun with sudo"
exec update-initramfs -u