#!/bin/sh -eu

# gpg signs all *.tar.* files under the release directory.
# Invoke from that dir, or let the script try to figure it out for you.

# Key used is from env var EXIM_KEY; if git config finds user.signingkey, then
# that is the default.  You can set this per-repo with:
#    git config --local user.signingkey SOME_IDENTIFIER
#
# If not set in git config then you _MUST_ set the env var.

# woe betide the poor sod who does not use a gpg agent, so has
# to enter their password for every file...

prog="$(basename "$0")"
warn() { printf >&2 "%s: %s\n" "$prog" "$*" ; }

: "${GPG_COMMAND:=gpg}"
umask 022

# We've always expected an explicit key for signing, instead of just using the
# gnupg config.  It make sense to honor the git config value.  It makes sense
# to honor env.  But git doesn't allow specifying multiple subkeys, it only
# passes one -u option.
# UID specs explicitly allow whitespace in several formats.
# We have one scalar value, we're sh, we're not going to try using an array.
#
# So if you want to sign with multiple subkeys, then set it up with multiple
# local-user directives in ~/.gnupg/gpg.conf & set EXIM_KEY=default in environ.

if repo_signing_key="$(git config user.signingkey)"; then
	: "${EXIM_KEY:=$repo_signing_key}"
else
	if [ ".${EXIM_KEY:-}" = "." ]; then
		warn "no EXIM_KEY found, trusting local gpg config"
	fi
fi

case "${EXIM_KEY:-default}" in
default|DEFAULT)
	gpg_sign() { ${GPG_COMMAND} --detach-sig --armor "${1:?}" ; }
	;;
*) 
	gpg_sign() { ${GPG_COMMAND} --local-user "${EXIM_KEY}" --detach-sig --armor "${1:?}" ; }
	;;
esac

cd_to() { echo "Working in: $1"; cd "$1"; }

okay=false
if [ -d ../../release-process ] && [ "${PWD##*/}" = "pkgs" ]; then
	okay=true # we are in right dir
elif [ -d release-process ]; then
	b="$(find . -maxdepth 1 -name 'exim-packaging-*' | sort | tail -n 1)"
	if [ ".$b" != "." ]; then
		cd_to "$b/pkgs"
		okay=true
	fi
fi
if ! $okay; then
	if [ -d "${1:?need a directory to look in}" ]; then
		cd_to "$1"
		shift
	else
		printf "%s: %s\n" >&2 "$(basename "$0")" "where should I be looking"
		exit 1
	fi
fi

# Assumes no whitespace (strictly, $IFS) in filenames, which we're okay with
set $(find . -name '*.asc' -prune -o -type f -print | cut -c 3- | sort)

for FILE
do
	echo "Signing: $FILE"
	gpg_sign "$FILE"
done