#!/bin/bash

# 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=/sbin/nologin

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

        cat <

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

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

EOF

    else

        cat <

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

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

        useradd -r -u '$uid' -g '$group' -d '$home' -s /sbin/nologin -c '$desc' '$user'

    else

        useradd -r -g '$group' -d '$home' -s /sbin/nologin -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

}

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')

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

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

                # TODO: user:group support

                ;;

            ('g')

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

                ;;

            ('m')

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

                user "${arr[1]}" "-" "" "${arr[2]}"

                ;;

        esac

    done

}

for fn in "$@"; do

    [ -e "$fn" ] || continue

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

    parse <"$fn"

done