#!/bin/bash
# title           :iso2usb.sh
# description     :Script for writing an ISO image to a USB device
# author          :Alexander Zhirov
# date            :20240122
# version         :0.1.0
# usage           :bash iso2usb.sh
#===============================================================================

set -e
# set -x

PARTED=$(which parted)

if [ ! -x ${PARTED} ]
then
    echo "The parted utility is missing" && exit 1
fi

TMP_USB_PATH="/tmp/usb_$(date +"%Y%m%d-%H%M%S")"
TMP_ISO_PATH="/tmp/iso_$(date +"%Y%m%d-%H%M%S")"

format_usb_device() {
    local USB_DEVICE="${1}"

    parted -s ${USB_DEVICE} mklabel msdos
    parted -s ${USB_DEVICE} mkpart primary fat32 0% 100%
    parted -s ${USB_DEVICE} set 1 boot on
    mkfs -Vt fat ${USB_DEVICE}1
}

mount_usb_device() {
    local USB_DEVICE="${1}1"
    mkdir -v ${TMP_USB_PATH}
    mount -v ${USB_DEVICE} ${TMP_USB_PATH}
}

umount_usb_device() {
    local USB_DEVICE="${1}1"
    umount -v ${USB_DEVICE}
    rm -rv ${TMP_USB_PATH}
}

mount_iso_image() {
    local ISO_IMAGE="${1}"
    mkdir -v ${TMP_ISO_PATH}
    mount -o loop,ro ${ISO_IMAGE} ${TMP_ISO_PATH}
}

umount_iso_image() {
    umount -v ${TMP_ISO_PATH}
    rm -rv ${TMP_ISO_PATH}
}

copy_iso_to_usb() {
    cp -rpv ${TMP_ISO_PATH}/* ${TMP_USB_PATH}
}

main () {
    local USB_DEVICE="${1}"
    local ISO_IMAGE="${2}"

    [ -z "${USB_DEVICE}" ] && echo "USB device is not specified" && exit 1
    [ -z "${ISO_IMAGE}" ] && echo "ISO image is not specified" && exit 1

    local PARTEDS=$(ls ${USB_DEVICE}* | grep -o "${USB_DEVICE}[0-9]")

    for PARTED in ${PARTEDS[@]}
    do
        if [ ! -z "$(mount | grep "${PARTED}" )" ]
        then
            umount "${PARTED}"
        fi
    done

    format_usb_device ${USB_DEVICE}
    
    mount_usb_device ${USB_DEVICE}
    mount_iso_image ${ISO_IMAGE}

    copy_iso_to_usb

    umount_iso_image
    umount_usb_device ${USB_DEVICE}
}

main "${@}"