#!/usr/bin/env bash
set -Eeuo pipefail

conf='/etc/exim4/update-exim4.conf.conf'

args=()
while [ "$#" -gt 0 ]; do
	key="$1"
	value="$2"
	shift 2

	if ! grep -qE "^#?${key}=" "$conf"; then
		echo >&2 "error: '$key' not found in '$conf'"
		exit 1
	fi

	sed_escaped_value="$(sed -e 's/[\/&]/\\&/g' <<<"$value")"
	args+=( -e "s/^#?(${key})=.*/\1='${sed_escaped_value}'/" )
done

if [ "${#args[@]}" -eq 0 ]; then
	echo >&2 "error: nothing to do?"
	exit 1
fi

set -x
sed -ri "${args[@]}" "$conf"
update-exim4.conf -v