#!/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/>.
#

grep_line() { echo "$2" | grep -qxF "$1"; }
unquote_lines() {
	sed -e '/^".*"$/{s/^"//;s/"$//}' \
	    -e '/'"^'.*'"'$/{s/'"^'"'//;s/'"'$"'//}'
}

append_values() {
	while read -r _value
	do
		set -- "$@" --value "${_value}"
	done
	unset _value
	"$@" </dev/null
}

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

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

case $state_should
in
	(present)
		test -f "${__object:?}/parameter/type" || {
			echo 'Parameter --type is required.' >&2
			exit 1
		}
		type_is=$(cat "${__object:?}/explorer/type")
		type_should=$(cat "${__object:?}/parameter/type")

		if test -f "${__object:?}/parameter/option"
		then
			optnames_should=$(
				sed -e 's/=.*$//' "${__object:?}/parameter/option" | sort -u)
		fi

		if test -n "${type_is}"
		then
			if test "${type_is}" != "${type_should##*.}"
			then
				# Check if section type matches (section exists and --type provided)
				printf 'Section type "%s" does not match --type "%s".\n' \
					"${type_is}" "${type_should}" >&2
				exit 1
			fi
			sect_type=${type_is}
		else
			sect_type=${type_should##*.}
		fi

		if test -z "${section}"
		then
			# No section exists and --match was used.
			# So we generate a new section identifier from $__object_id.
			case ${__object_id:?}
			in
				(*.*) section=${__object_id:?} ;;
				(*) section="${type_should%%.*}.${__object_id:?}" ;;
			esac
		fi

		# Make sure the section itself is present
		__uci "${section}" --state present --transaction "${transaction_name}" \
			--value "${sect_type}"
		export require=__uci/"${section}"

		# Delete options not in "should"
		sed -e 's/=.*$//;s/^.*\.//' "${__object:?}/explorer/options" \
		| while read -r optname
		  do
			  if ! grep_line "${optname}" "${optnames_should}"
			  then
				  __uci "${section}.${optname}" --state absent \
					  --transaction "${transaction_name}" </dev/null
			  fi
		  done

		# Set "should" options
		echo "${optnames_should}" \
		| while read -r optname
		  do
			  test -n "${optname}" || continue  # ignore empty lines

			  grep "^${optname}=" <"${__object:?}/parameter/option" \
			  | sed -e 's/^.*=//' \
			  | unquote_lines \
			  | append_values \
				    __uci "${section}.${optname}" --state present \
					    --transaction "${transaction_name}"
		  done
		;;
	(absent)
		# if explorer found no section there is nothing to delete
		test -n "${section}" || exit 0

		__uci "${section}" --state absent --transaction "${transaction_name}"
		;;
	(*)
		printf 'Invalid --state: %s\n' "${state_should}" >&2
		exit 1
		;;
esac