#!/bin/sh

set -e

pathfind() {
	OLDIFS="$IFS"
	IFS=:
	for p in $PATH; do
		if [ -x "$p/$*" ]; then
			IFS="$OLDIFS"
			return 0
		fi
	done
	IFS="$OLDIFS"
	return 1
}

remove_gns() {
	# abort if /etc/nsswitch.conf does not exist
	if ! [ -e /etc/nsswitch.conf ]; then
		return
	fi
	perl -i -pe '
		my @remove=(
			"gns [NOTFOUND=return]",
		);
		sub remove {
			my $s=shift;
			foreach my $bit (@remove) {
				$s=~s/\s+\Q$bit\E//g;
			}
			return $s;
		}
		s/^(hosts:)(.*)/$1.remove($2)/e;
	' /etc/nsswitch.conf
}


case "${1}" in
	purge)
		if [ -e /usr/share/debconf/confmodule ]
		then
			. /usr/share/debconf/confmodule
			db_version 2.0

			db_get gnunet-systempeer/username
			_USERNAME="${RET:-gnunet}"

			db_get gnunet-systempeer/groupname
			_GROUPNAME="${RET:-gnunet}"

			db_get gnunet-dns/libnsswitch
			_LIBNSSWITCH="${RET}"
		else
			_USERNAME="gnunet"
			_GROUPNAME="gnunet"
		fi

		GNUNETDNS_GROUP="gnunetdns"

		if $_LIBNSSWITCH
		then
			rm -rf /usr/lib/x86_64-linux-gnu/usr/libnss_gns.so.2
			rm -rf /usr/lib/x86_64-linux-gnu/usr/libnss_gns4.so.2
			rm -rf /usr/lib/x86_64-linux-gnu/usr/libnss_gns6.so.2
			remove_gns
		fi

		if pathfind deluser
		then
			deluser --quiet --system ${_USERNAME} || true
		fi

		if pathfind delgroup
		then
			delgroup --quiet --system --only-if-empty ${_GROUPNAME} || true
			delgroup --quiet --system --only-if-empty ${GNUNETDNS_GROUP} || true
		fi

		rm -rf /var/log/gnunet.log /var/lib/gnunet /etc/default/gnunet
		;;

	remove|upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)

		if $_LIBNSSWITCH
		then
			rm -rf /usr/lib/x86_64-linux-gnu/usr/libnss_gns.so.2
			rm -rf /usr/lib/x86_64-linux-gnu/usr/libnss_gns4.so.2
			rm -rf /usr/lib/x86_64-linux-gnu/usr/libnss_gns6.so.2
			remove_gns
		fi

		;;

	*)
		echo "postrm called with unknown argument \`${1}'" >&2
		exit 1
		;;
esac

#DEBHELPER#

exit 0