#!/bin/bash

# set -x

if [[ $(id -u) -ne 0 ]]; then
    echo "You must be root to execute this script."
    exit 1
fi

if [[ $# -lt 2 ]]; then
    echo "Usage: $0 /path/to/windows.iso /dev/destination/pendrive"
    exit 1
fi

ISOFILE=$1
ISODIR=/tmp/iso.$$
DSTDEVICE=$2
DSTDIR=/tmp/mounted.$$


function check_dirs() {
    if [[ ! -d "$ISODIR" ]]; then
        mkdir -p $ISODIR
    fi
    if [[ ! -d "$DSTDIR" ]]; then
        mkdir -p $DSTDIR
    fi
}


function gogogo() {
    # $1 - isofile
    # $2 - /dst/device
    echo "Checking for dependencies... "
    apt-get install gparted grub-pc-bin p7zip-full ntfs-3g -y -q > /dev/null \
    && check_dirs \
    && echo "Preparing device $2"; create_partition $2 \
    && mount $1 ${ISODIR} > /dev/null \
    && mount ${2}1 ${DSTDIR} > /dev/null \
    && echo "rsync $ISODIR -> $DSTDIR"; rsync --progress -a $ISODIR/ $DSTDIR/ \
    ls -l $DSTDIR
    echo
    UUID=$(blkid | grep ${DSTDEVICE}1 | cut -d '"' -f 2)
    echo "UUID: $UUID"
    install_grub $UUID
    echo "Syncing...."; sync
}


function install_grub() {
    # $1 - device UUID
    sudo grub-install --target=i386-pc --boot-directory="$DSTDIR/boot" ${DSTDEVICE}
    cat <<- _EOF_ > $DSTDIR/boot/grub/grub.cfg
echo "If you see this, you have successfully booted from USB :)"
insmod ntfs
insmod search_fs_uuid
search --no-floppy --fs-uuid $1 --set root
ntldr /bootmgr
boot
_EOF_
}


function create_partition() {
    #
    # create new partition table on device with bootable NTFS partition
    #
    echo "WARNING! Non turning back point ahead."
    echo "If you continue, you will lose all data on $1 device."
    echo "Press ENTER to proceed."
    read
    (
        echo o
        echo n
        echo
        echo
        echo
        echo
        echo a
        echo w
    ) | fdisk $1 > /dev/null \
    && mkfs.ntfs -f ${1}1 > /dev/null 
}


function cleanup() {
    umount $ISODIR
    umount $DSTDIR
    rm -rf $ISODIR $DSTDIR
}

echo "WARNING! WARNING! WARNING! WARNING! WARNING!"
echo "All data on $2 will be lost."
echo -n "Are you sure, you want to continue? [y/n]: "
read choice
case "$choice" in
    y|Y)
        gogogo $ISOFILE $DSTDEVICE
        ;;
    *)
        echo "Bye"
        exit 0
esac
cleanup