#!/usr/bin/env bash
set -euo pipefail

DEBIAN_RELEASE=${VERSION:-"buster"}
ROOTFS_DIR="debian-${DEBIAN_RELEASE}"

echo "[INFO] Bootstrapping Debian $DEBIAN_RELEASE rootfs..."
apt-get update
apt-get install -y --no-install-recommends debootstrap bzip2

debootstrap --verbose --variant=minbase --components=main,contrib,non-free \
  --include=apt,ca-certificates --arch=amd64 "$DEBIAN_RELEASE" "$ROOTFS_DIR" \
  http://deb.debian.org/debian/

for dir in dev dev/pts proc sys; do
  mount --bind "/$dir" "$ROOTFS_DIR/$dir"
done

echo "[CHROOT] Configuring Debian system..."
chroot "$ROOTFS_DIR" /bin/bash <<'EOF'
echo 'APT::Get::Assume-Yes "true";' > /etc/apt/apt.conf.d/10-assume_yes
apt-get update
apt-get upgrade
apt-get install --no-install-recommends software-properties-common bash wget curl nano locales
echo 'en_US.UTF-8 UTF-8' >> /etc/locale.gen
locale-gen
update-locale LANG=en_US.UTF-8
apt-get remove --purge --allow-remove-essential pinentry-curses whiptail kmod iptables iproute2 dmidecode || true
apt-get clean
apt-get install -f
find /var/lib/apt/lists/ -type f -delete
EOF

echo "[INFO] Unmounting system directories (ignore errors)..."
for dir in sys proc dev/pts dev; do
  umount -lf "$ROOTFS_DIR/$dir" 2>/dev/null || true
done

echo "[INFO] Creating compressed base image..."
mkdir -p "/output/$DEBIAN_RELEASE"
TARBALL="/output/$DEBIAN_RELEASE/debian-${DEBIAN_RELEASE}.tar.bz2"
tar -cjf "$TARBALL" -C "$ROOTFS_DIR" .
echo "[INFO] Tarball ready: $TARBALL"