#!/bin/sh
set -eu

MNT=/mnt
USB_DEV=/dev/sda
EMMC_DEV=/dev/mmcblk0
DEFAULT_GLOB="${MNT}/$${BUILD_TAG}_RELEASE_IMAGE"

mkdir -p "$MNT"

echo "[*] Mounting USB..."
mount "$USB_DEV" "$MNT"

# Find a default image (first match)
DEFAULT_IMG="$(ls $DEFAULT_GLOB 2>/dev/null | head -n1 || true)"

echo
if [ -n "$DEFAULT_IMG" ]; then
    echo "Default image found:"
    echo "  $DEFAULT_IMG"
else
    echo "No default image found under $DEFAULT_GLOB"
fi
echo

# Prompt user
printf "Image Location (%s): " "${DEFAULT_IMG:-/mnt/...}"
read -r IMG

# Use default if empty
if [ -z "$IMG" ]; then
    IMG="$DEFAULT_IMG"
fi

# Validate
if [ -z "$IMG" ] || [ ! -f "$IMG" ]; then
    echo "Invalid image: $IMG"
    umount "$MNT" || true
    exit 1
fi

echo
echo "About to write:"
echo "  Image: $IMG"
echo "  Target: $EMMC_DEV"
echo

printf "Type 'YES' to continue: "
read -r CONFIRM

if [ "$CONFIRM" != "YES" ]; then
    echo "Aborted."
    umount "$MNT" || true
    exit 1
fi

echo "[*] Flashing..."
gunzip -c "$IMG" > "$EMMC_DEV"

echo "[*] Syncing..."
sync

echo "[*] Done."
umount "$MNT" || true

echo "[*] Rebooting..."
reboot -f