#!/usr/bin/env bash

# Edit a single attribute of a sops json file
# Helps working with multiline strings in json

set -euo pipefail

print_help() {
	cat << EOF
clerie-sops-edit <secrets_file> <action> <key>

  This script allows editing single secrets in a secrets file by key.

  <secrets_file> is a sops secrets file
  <action> is one of "edit", "read", "set" and "append"
  <key> is the key of the secret in the secrets file to modify
EOF
}

if [[ $# != 3 ]]; then
	print_help
	exit 1
fi

SECRETS_FILE="$1"

if [[ ! -f "${SECRETS_FILE}" ]]; then
	echo "File \"${SECRETS_FILE}\" does not exist"
	echo
	print_help
	exit 1
fi

ACTION="$2"

if ! echo "edit read set append" | grep -wq "${ACTION}"; then
	echo "Action \"${ACTION}\" not supported"
	echo
	print_help
	exit 1
fi

KEY="$3"
KEY_SELECTOR="$(jq -Rsc '[.]' <(echo -n "${KEY}"))"

if [[ -n $EDITOR ]]; then
	EDITOR=vim
fi

TMP_FILE="$(mktemp)"
DECRYPT_ERROR_FILE="$(mktemp)"

if ! clerie-sops --decrypt --extract "${KEY_SELECTOR}" "${SECRETS_FILE}" > "${TMP_FILE}" 2> "${DECRYPT_ERROR_FILE}"; then
	# Ignore that the key does not exist, but fail for all other errors
	if ! grep -q "component .* not found" "${DECRYPT_ERROR_FILE}"; then
		cat "${DECRYPT_ERROR_FILE}"
		exit 1
	fi
fi

TMP_FILE_HASH_BEFORE="$(sha256sum "${TMP_FILE}")"

case "${ACTION}" in
	edit)
		"${EDITOR}" "${TMP_FILE}"
		;;
	read)
		cat "${TMP_FILE}"
		;;
	set)
		cat > "${TMP_FILE}"
		;;
	append)
		cat >> "${TMP_FILE}"
		;;
	*)
		echo "Unsupported action"
		exit 1
		;;
esac

TMP_FILE_HASH_AFTER="$(sha256sum "${TMP_FILE}")"

# Don't write value back when it hasn't changed
if [[ "${TMP_FILE_HASH_BEFORE}" == "${TMP_FILE_HASH_AFTER}" ]]; then
	exit 0
fi

JSON_QUOTED_SECRET="$(jq -Rsc '.' "${TMP_FILE}")"

rm "${TMP_FILE}"

clerie-sops --set "${KEY_SELECTOR} ${JSON_QUOTED_SECRET}" "${SECRETS_FILE}"