#!/usr/bin/env bash

set -x

if [[ "$(id -u)" -ne 0 ]]; then
    >&2 echo "$0: please run this script as root"
    exit 1
fi

KICKSTART_BASE="Rocky"
TODAY="$(TZ='UTC' date +%Y.%m.%d)"
KICKSTART_FILE="${KICKSTART_BASE}.ks"
APPLIANCE_NAME="${KICKSTART_BASE}-$(source <(grep VERSION_ID /etc/os-release) && awk -F '.' '{print $1}' <<< $VERSION_ID)-$(uname -m)-minimal-${TODAY}"
IMAGE_NAME="${APPLIANCE_NAME}.raw"
COMMANDS_TO_CHECK=('appliance-creator' 'hdparm' 'shasum' 'zstd')

for COMMAND in "${COMMANDS_TO_CHECK[@]}"; do
    if ! command -v "${COMMAND}" > /dev/null; then
        >&2 echo "$0: ERROR: unable to find command '${COMMAND}' in PATH"
        exit 1
    fi
done

if [[ -n "$1" ]]; then
    GUSER="^$1"
    if ! grep $GUSER /etc/shadow > /dev/null; then
        >&2 echo "$0: ERROR: unable to find user '$1'"
        exit 1
    fi
fi

function create_new_image {
    UBOOT_MAX_SIZE='64'
    IMAGE_SIZE=$(( $(stat -c '%s' "${IMAGE_NAME}") / 1024 / 1024 ))
    NEW_IMAGE_NAME="${IMAGE_NAME}.new"
    truncate -s "$(( IMAGE_SIZE + UBOOT_MAX_SIZE ))"MiB "${NEW_IMAGE_NAME}"

    LOOPBACK_01=$(losetup -f -P --show "${IMAGE_NAME}")
    LOOPBACK_02=$(losetup -f -P --show "${NEW_IMAGE_NAME}")
    # 1 MiB = 2048 * (1 block/sector (512 bytes))
    UEFI_SECTORS="$(( $(fdisk -l "${LOOPBACK_01}" | grep "${LOOPBACK_01}p1" | awk '{print $4}') + 2048 ))"
    BOOT_SECTORS="$(( $(fdisk -l "${LOOPBACK_01}" | grep "${LOOPBACK_01}p2" | awk '{print $4}') + 4096 ))"

    cat << EOF | fdisk "${LOOPBACK_02}"
    g
    n
    1
    65536
    +${UEFI_SECTORS}
    n
    2

    +${BOOT_SECTORS}
    n
    3


    w
EOF
    sync; sync; sync; sync;
    sleep 10
    hdparm -z "${LOOPBACK_02}"

    dd bs=4M conv=sync status=progress if="${LOOPBACK_01}p3" of="${LOOPBACK_02}p3"
    dd bs=4M conv=sync status=progress if="${LOOPBACK_01}p2" of="${LOOPBACK_02}p2"
    dd bs=4M conv=sync status=progress if="${LOOPBACK_01}p1" of="${LOOPBACK_02}p1"
    sync; sync; sync; sync;
    sleep 10

    losetup -d "${LOOPBACK_02}"
    losetup -d "${LOOPBACK_01}"
    mv "${NEW_IMAGE_NAME}" "${IMAGE_NAME}"
    sync; sync; sync; sync;
    sleep 10
}

script -q -c "appliance-creator \
    --config ${KICKSTART_FILE} \
    --name ${APPLIANCE_NAME} \
    --format raw \
    --outdir ${PWD} \
    --no-compress \
    --debug \
    --cache /root/cache \
    --verbose" | tee "${APPLIANCE_NAME}.log" || exit 1
# the script command creates a file called typescript
rm -vf typescript

if [[ -d "${APPLIANCE_NAME}" ]]; then
    pushd "${APPLIANCE_NAME}" || exit 1
    mv "../${APPLIANCE_NAME}.log" .
    mv "${APPLIANCE_NAME}-sda.raw" "${IMAGE_NAME}"
    create_new_image
    zstd --compress -9 "${IMAGE_NAME}"
    sha512sum -- *.raw* > SHA512SUMS
    sha256sum -- *.raw* > SHA256SUMS
    popd || exit 0
else
    >&2 echo "$0: ERROR: unable to find the appliance output directory"
    >&2 echo "$0: ${APPLIANCE_NAME}"
    exit 1
fi

if [[ -n "$1" ]]; then
    chown "$1":"$1" -vR "${APPLIANCE_NAME}"
fi