#!/usr/bin/env bash
# -*- coding: utf-8 -*-
# region imports
source "/usr/lib/rebash/core.sh"
core.import exceptions
exceptions.activate
# endregion

in_device="$1"
nbd_device="$2" # TODO detect first free nbd device

systemd-preserve-process-marker qemu-nbd --connect="$nbd_device" \
    "$in_device" --read-only --persistent --nocache

# TODO better way to wait for the device to be made?
i=0
while [ ! -b "$nbd_device" ]; do
    [ $i -ge 20 ] && exit 1
    if [ $UDEVVERSION -ge 143 ]; then
        udevadm settle --exit-if-exists="$nbd_device"
    else
        sleep 0.1
    fi
    i=$(($i + 1))
done

# NBD doesn't emit uevents when it gets connected, so kick it
# TODO get path from $nbd_device
echo change > /sys/block/nbd0/uevent
udevadm settle

# region vim modline
# vim: set tabstop=4 shiftwidth=4 expandtab:
# vim: foldmethod=marker foldmarker=region,endregion:
# endregion