#!/bin/sh
set -e

remove_nss_entry() {
    local file=$1
    local pkg=$2
    local module=$3
    refcount=$(dpkg-query -f '${db:Status-Abbrev} ${binary:Package}\n' \
        -W $pkg | grep '^i' | wc -l)
    if [ "$refcount" -gt 0 ] ; then
        # package is installed for other architectures still, do nothing
        return
    fi
    echo "Checking NSS setup..."
    # abort if file does not exist
    if ! [ -e $file ]; then
        echo "Could not find ${file}."
        return
    fi
    # we must remove possible [foo=bar] options as well
    sed -i -r "/(passwd|group):/ s/[[:space:]]+$module\b([[:space:]]*\[[^]]*\])*//" $file
}

if [ "$1" = remove ]; then
    remove_nss_entry /etc/nsswitch.conf libnss-systemd systemd
fi