#!/bin/sh
set -eu

while getopts 'n:' flag; do
	case "$flag" in
		n)
			PROJECT="$OPTARG"
			;;
		*)
			exit 2
			;;
	esac
done
shift $((OPTIND -1))

assert_arg() {
	if [ -z "$1" ]; then
		echo "Missing $2" >&2
		exit 2
	fi
}

assert_arg "${PROJECT:-}" '-n PROJECT'


SIGNATURES="$(git notes --ref=refs/notes/signatures/tar.gz list | cut -d\  -f2)"
for tag in $(git tag); do
	COMMIT="$(git rev-list -n1 "$tag")"
	if echo "$SIGNATURES" | grep -qF "$COMMIT"; then
		continue
	fi
	echo "Adding missing signature to $tag" >&2
	git notes --ref=refs/notes/signatures/tar.gz add -C "$(
		git archive --format tar.gz --prefix "$PROJECT-$tag/" "$tag" |
		gpg --output - --armor --detach-sign |
		git hash-object -w --stdin
	)" "$tag"
done