#!/bin/bash

# -*- mode: shell-script; indent-tabs-mode: true; tab-width: 4; -*-

# This script turns sysuser.d files into scriptlets mandated by Fedora

# packaging guidelines. The general idea is to define users using the

# declarative syntax but to turn this into traditional scriptlets.

user() {

	user="$1"

	uid="$2"

	desc="$3"

	group="$4"

	home="$5"

	shell="$6"

	[ "$desc" = '-' ] && desc=

	{ [ "$home" = '-' ] || [ "$home" = '' ]; } && home=/

	{ [ "$shell" = '-' ] || [ "$shell" = '' ]; } && shell=/usr/sbin/nologin

	if [ "$uid" = '-' ] || [ "$uid" = '' ]; then

		cat <<-EOF

		getent passwd '$user' >/dev/null || \\

			useradd -r -g '$group' -d '$home' -s '$shell' -c '$desc' '$user' || :

		EOF

	else

		cat <<-EOF

		if ! getent passwd '$user' >/dev/null; then

			if ! getent passwd '$uid' >/dev/null; then

			useradd -r -u '$uid' -g '$group' -d '$home' -s '$shell' -c '$desc' '$user' || :

			else

			useradd -r -g '$group' -d '$home' -s '$shell' -c '$desc' '$user' || :

			fi

		fi

		EOF

	fi

}

group() {

	group="$1"

	gid="$2"

	if [ "$gid" = '-' ]; then

		cat <<-EOF

		getent group '$group' >/dev/null || groupadd -r '$group' || :

		EOF

	else

		cat <<-EOF

		getent group '$group' >/dev/null || groupadd -f -g '$gid' -r '$group' || :

		EOF

	fi

}

usermod() {

	user="$1"

	group="$2"

	cat <<-EOF

	if getent group '$group' >/dev/null; then

		usermod -a -G '$group' '$user' || :

	fi

	EOF

}

parse() {

	while read -r line || [ -n "$line" ] ; do

		{ [ "${line:0:1}" = '#' ] || [ "${line:0:1}" = ';' ]; } && continue

		line="${line## *}"

		[ -z "$line" ] && continue

		eval "arr=( $line )"

		case "${arr[0]}" in

			('u')

				if [[ "${arr[2]}" == *":"* ]]; then

					user "${arr[1]}" "${arr[2]%:*}" "${arr[3]}" "${arr[2]#*:}" "${arr[4]}" "${arr[5]}"

				else

					group "${arr[1]}" "${arr[2]}"

					user "${arr[1]}" "${arr[2]}" "${arr[3]}" "${arr[1]}" "${arr[4]}" "${arr[5]}"

				fi

				;;

			('g')

				group "${arr[1]}" "${arr[2]}"

				;;

			('m')

				group "${arr[2]}" "-"

				user "${arr[1]}" "-" "" "${arr[1]}" "" ""

				usermod "${arr[1]}" "${arr[2]}"

				;;

		esac

	done

}

for fn in "$@"; do

	[ -e "$fn" ] || continue

	echo "# generated from $(basename "$fn")"

	parse <"$fn"

done