#!/bin/sh -e
#
# 2020 Dennis Camera (dennis.camera at 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/>.
#

CONFIG_FILE_PATH='/etc/systemd/network'

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

test -n "${networkctl_bin}" || {
	printf 'This system is not supported by this type (%s).' "${__type##*/}" >&2
	printf ' The networkctl tool could not be found.\n' >&2
	exit 1
}

{
	# shellcheck disable=SC2034
	read -r state_is
	read -r config_is || true
} <"${__object:?}/explorer/state"

if test -f "${__object:?}/parameter/name"
then
	name=$(cat "${__object:?}/parameter/name")
else
	name=${__object_id:?}
fi

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

config_file=$(printf '%s/%02u-%s.network' "${CONFIG_FILE_PATH}" "${priority}" "${__object_id:?}")

if test -f "${__object:?}/parameter/auto-reload"
then
	reload_cmd="${networkctl_bin} reload"
else
	reload_cmd=
fi

gen_conf() {
	echo '[Match]'

	if test -s "${__object:?}/parameter/match"
	then
		cat "${__object:?}/parameter/match"
	else
		# By default match against the interface name
		printf 'Name=%s\n' "${name}"
	fi

	{
		grep -e '^Network\.' "${__object:?}/parameter/option"

		grep -v -e '^\(Match\|Network\)\.' "${__object:?}/parameter/option" \
		| sort -t . -k 1
	} | while read -r _option
	    do
		    _section=${_option%%.*}

		    if test "${_cur_section}" != "${_section}"
		    then
			    # new section
			    printf '\n[%s]\n' "${_section}"
			    _cur_section=$_section
		    fi

		    echo "${_option#*.}"
	    done
}


if test -n "${config_is}" -a "${config_is}" != "${config_file}"
then
	# Check if only the priority has changed!
	# We cannot in all cases delete the old config file as it might be a default
	# config.
	if test "$(dirname "${config_file}")" = "$(dirname "${config_is}")" \
			&& test "$(basename "${config_is}" | sed -e 's/^[0-9]*//')" \
			      = "$(basename "${config_file}" | sed -e 's/^[0-9]*//')"
	then
		# Remove old config, but do not reload, yet.
		# reload will be done after new config file has been written…
		require="__file${config_file}" __file "${config_is}" --state absent
	fi
fi


case $state_should
in
	(present)
		__directory "${CONFIG_FILE_PATH}" --state pre-exists
		export require=__directory"${CONFIG_FILE_PATH}"

		gen_conf | __file "${config_file}" --state "${state_should}" \
			--owner 0 --mode 0644 --source - \
			--onchange "${reload_cmd}"
		;;
	(absent)
		__file "${config_file}" --state absent \
			--onchange "${reload_cmd}"
		;;
	(*)
		printf 'Invalid --state: %s\n' "${state_should}"
		;;
esac