#!/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/>.
#

in_list() {
	printf '%s\n' "$@" | { grep -qxF "$(read -r ndl; echo "${ndl}")"; }
}

quote() {
	for _arg
	do
		shift
		if test -n "$(printf %s "${_arg}" | tr -d -c '\t\n \042-\047\050-\052\073-\077\133\\`|~' | tr -c '' '.')"
		then
			# needs quoting
			set -- "$@" "$(printf "'%s'" "$(printf %s "${_arg}" | sed -e "s/'/'\\\\''/g")")"
		else
			set -- "$@" "${_arg}"
		fi
	done
	unset _arg

	# NOTE: Use printf because POSIX echo interprets escape sequences
	printf '%s' "$*"
}

uci_cmd() {
	# Usage: uci_cmd [UCI ARGUMENTS]...
	# Will output a shell command to be executed locally to add the given
	# command to $tmpfile.
	printf "printf '%%s\\\\n' %s" "$(quote "$(quote "$@")")"
	printf ' >>%s\n' "$(quote "${tmpfile}")"
}

uci_validate_name() {
	# like util.c uci_validate_name()
	test -n "$*" && test -z "$(echo "$*" | tr -d '[:alnum:]_')"
}

uci_validate_tuple() (
	tok=${1:?}
	case $tok
	in
		(*.*.*)
			# check option
			option=${tok##*.}
			uci_validate_name "${option}" || {
				printf 'Invalid option: %s\n' "${option}" >&2
				return 1
			}
			tok=${tok%.*}
			;;
		(*.*)
			# no option (section definition)
			;;
		(*)
			printf 'Invalid tuple: %s\n' "$1" >&2
			return 1
			;;
	esac

	case ${tok#*.}
	in
		(@*) section=$(expr "${tok#*.}" : '@\(.*\)\[-*[0-9]*\]$') ;;
		(*)  section=${tok#*.} ;;
	esac
	uci_validate_name "${section}" || {
		printf 'Invalid section: %s\n' "${1#*.}" >&2
		return 1
	}

	config=${tok%%.*}
	uci_validate_name "${config}" || {
		printf 'Invalid config: %s\n' "${config}" >&2
		return 1
	}
)


config=${__object_id:?}
uci_validate_tuple "${config}"

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

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

tmpdir="${__global:?}/tmp/__uci"
# HACK
mkdir -p "${tmpdir}"

tmpfile="${tmpdir}/${transaction_name}.txt"


case ${state_should}
in
	(present)
		if in_list "${state_is}" 'present' 'rearranged'
		then
			# NOTE: order is ignored so rearranged is also fine.
			exit 0
		fi

		# Determine type
		type=$(cat "${__object:?}/parameter/type" 2>/dev/null || true)
		case ${type}
		in
			(option|list) ;;
			('')
				# Guess type by the number of values
				test "$(wc -l "${__object:?}/parameter/value")" -gt 1 \
					 && type=list \
					 || type=option
				;;
			(*)
				printf 'Invalid --type: %s\n' "${type}" >&2
				exit 1
				;;
		esac

		case ${type}
		in
			(list)
				printf 'set_list %s\n' "${config}" >>"${__messages_out:?}"

				if test "${state_is}" != 'absent'
				then
					uci_cmd delete "${config}"
				fi

				while read -r value
				do
					uci_cmd add_list "${config}"="${value}"
				done <"${__object:?}/parameter/value"
				;;
			(option)
				printf 'set %s\n' "${config}" >>"${__messages_out:?}"

				value=$(cat "${__object:?}/parameter/value")
				uci_cmd set "${config}"="${value}"
				;;
		esac
		;;
	(absent)
		if in_list "${state_is}" 'absent'
		then
			exit 0
		fi

		printf 'delete %s\n' "${config}" >>"${__messages_out:?}"
		uci_cmd delete "${config}"
		;;
	(*)
		printf 'Invalid --state: %s\n' "${state_should}" >&2
		exit 1
		;;
esac