#!/bin/sh


PROMPT='Password:'

usage() {
	printf '%s: key [description]\n' "${0##*/}"
}


escape() {
	printf '%s' "${1}" | tr ' ' '+'
}


key="${1}"
description="${2}"

if [ -z "${key}" ]; then
	usage >&2
	exit 2
elif [ "${key}" = '-h' ] || [ "${key}" = '--help' ]; then
	usage
	exit 0
fi
if [ -z "${description}" ]; then
	description=$(printf 'Enter the password for %s' "${key}")
fi


sleep .125
umask 0077

agentpipe=$(mktemp -u)
mkfifo ${agentpipe}
trap 'rm ${agentpipe}' EXIT

printf 'GET_PASSPHRASE --data cachedpass:%s X %s %s' \
	"$(escape "${key}")" \
	"${PROMPT}" \
	"$(escape "${description}")" \
	| gpg-connect-agent > ${agentpipe} &
while read msg args; do
	case "${msg}" in
	ERR)
		printf '%s\n' "${args#* }" >&2
		exit 1
		;;
	OK)
		;;
	D)
		printf '%s' "${args}" | xclip -i -l 1 -sel clip
		;;
	*)
		printf 'Unexpected response from gpg-agent: %s %s' \
			"${msg}" "${args}" >&2
		exit 1
	esac
done < ${agentpipe}