#!/bin/sh -e
#
# 2020 Dennis Camera (dennis.camera@ssrq-sds-fds.ch)
#
# This file is part of cdist.
#
# cdist is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# cdist is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with cdist. If not, see <http://www.gnu.org/licenses/>.
#

quote() { printf "'%s'" "$(printf '%s' "$*" | sed -e "s/'/'\\\\''/g")"; }
drop_awk_comments() { quote "$(sed '/^[[:blank:]]*#.*$/d;/^$/d' "$@")"; }

aliases_file=$(cat "${__object:?}/explorer/aliases_file")

test -n "${aliases_file}" || {
	echo 'Could not determine aliases file path.' >&2
	exit 1
}


state_should=$(cat "${__object:?}/parameter/state")

case ${state_should}
in
	(present)
		if cmp -s "${__object:?}/explorer/aliases" "${__object:?}/parameter/alias"
		then
			# all good!
			exit 0
		fi

		test -s "${__object:?}/parameter/alias" || {
			printf 'The --alias parameter is required if --state present.\n' >&2
			printf 'Use --state absent to remove all aliases.\n' >&2
			exit 1
		}

		if test -s "${__object:?}/explorer/aliases"
		then
			echo "update aliases" >>"${__messages_out:?}"
		else
			echo "add aliases" >>"${__messages_out:?}"
		fi
		;;
	(absent)
		# nothing to do if no aliases found.
		test -s "${__object:?}/explorer/aliases" || exit 0

		echo "delete aliases" >>"${__messages_out:?}"
		;;
	(*)
		printf 'Invalid --state: %s.\n' "${state_should}" >&2
		printf 'Acceptable values are: present, absent.\n' >&2
		exit 1
esac

cat <<EOF
test -f $(quote "${aliases_file}") || touch $(quote "${aliases_file}")

awk $(drop_awk_comments "${__type:?}/files/update_aliases.awk") <$(quote "${aliases_file}") >$(quote "${aliases_file}.tmp") \
|| {
	rm -f $(quote "${aliases_file}.tmp")
	echo 'Generating new aliases file failed!' >&2
	exit 1
}

if ! cmp -s $(quote "${aliases_file}") $(quote "${aliases_file}.tmp")
then
	# aliases file was modified, replace:
	cat $(quote "${aliases_file}.tmp") >$(quote "${aliases_file}")

	# then, run newaliases if present ("missing" on Alpine Linux because of typo)
	command -v newaliases >/dev/null 2>&1 && newaliases || true
fi
rm -f $(quote "${aliases_file}.tmp")
EOF