#!/bin/bash -eu
#
# Tag a release
#

function usage()
{
	cat <<EOF
Usage: $(basename "${0}") [-f] [-h]

Tag a release commit.

Optional arguments:
  -f, --force  Overwrite an already existing tag.
  -h, --help   Show this help text and exit.
EOF
}

force=0

while [ ${#} -gt 0 ] ; do
	case "${1}" in
		-f|--force)
			force=1
			;;
		-h|--help)
			usage
			exit
			;;
		*)
			echo "Invalid argument: ${1}" >&2
			exit 2
			;;
	esac
	shift
done

version=$(git log --format='%s' -1 | sed -n 's/^UBUNTU: Ubuntu-//p')
if [ -z "${version}" ] ; then
	echo "Current HEAD is not an Ubuntu release commit" >&2
	exit 1
fi

tag=Ubuntu-${version}

if [ ${force} -eq 0 ] && git rev-parse "${tag}" >/dev/null 2>&1 ; then
	echo "Tag exists already: ${tag}" >&2
	exit 1
fi

git tag -f -s -m  "UBUNTU: ${tag}" "${tag}"