#!/usr/env/bin bash

set -e

DISKFILE="/tmp/disk.img"
BINFILE="/tmp/file.bin"
LOOPNUM=$((RANDOM % 156 + 100))
LOOPDEV="/dev/loop${LOOPNUM}"

echo "Using device: ${LOOPDEV}"

cleanup() {
    echo "Cleaning up..."
    set +e
    sudo losetup -d ${LOOPDEV}
    sudo rm ${LOOPDEV}
    sudo rm ${BINFILE} ${DISKFILE}
}

trap cleanup EXIT INT TERM

if losetup ${LOOPDEV} >/dev/null 2>&1; then
    echo "${LOOPDEV} already in use" >&2
    cleanup
    exit 1
fi

if [ ! -f ${DISKFILE} ]; then
    dd if=/dev/zero of=${DISKFILE} bs=1M count=256
fi

if [ ! -f ${BINFILE} ]; then
    dd if=/dev/urandom of=${BINFILE} bs=1M count=64
fi

if [ ! -e ${LOOPDEV} ]; then
    sudo losetup ${LOOPDEV} ${DISKFILE}
fi

sudo ./writeimg -nd ${LOOPDEV} ${BINFILE}
sudo ./writeimg -vnd ${LOOPDEV} ${BINFILE}

echo "Looks good!"