#!/bin/bash
set -euo pipefail

DEFAULT_SUITE="bookworm"
BASE="/var/lib/machines"

if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root" 1>&2
   exit 1
fi

function show_help {
    cat <<-EOF
Usage: $0 -h | -n NAME [-s SUITE] [-t [SNAPSHOT_NAME] -r] [-d]

Create a nspanw container called NAME

-h      help
-n      container name
-s      debian suite (default: ${DEFAULT_SUITE})
-t      snapshot container
-r      rollback to snapshot
-d      delete container
EOF
}

while getopts 'hn:s:t:rd' flag; do
  case "${flag}" in
    h) show_help; exit 0;;
    n) name="${OPTARG}" ;;
    s) suite="${OPTARG}" ;;
    t) snapshot="${OPTARG}" ;;
    r) rollback=1 ;;
    d) delete=1 ;;
    *) echo "Unexpected option ${flag}" ;;
  esac
done

SUITE=${suite:-$DEFAULT_SUITE}

if [[ -z ${name:-} ]]; then
    echo "Container name is unset"
    echo
    show_help
    exit;
else
    echo "Container name is $name and suite is ${SUITE}"
fi

if [[ -n ${snapshot:-} ]]; then
    dest_snapshot_name="${BASE}/.${name}_${snapshot}"
    if [[ -n ${rollback:-} ]]; then
        if [[ -d ${dest_snapshot_name} ]]; then
            btrfs subvolume delete "${BASE}/${name}"
            btrfs subvolume snapshot "${dest_snapshot_name}" "${BASE}/${name}"
            exit 0
        else
            echo "Can't rollback as '${snapshot}' does not exist"
            exit 1
        fi
    else
        btrfs subvolume snapshot -r "${BASE}/${name}" "${dest_snapshot_name}"
        exit 0
    fi
fi

if [[ -n ${delete:-} ]]; then
    btrfs subvolume delete "${BASE}/${name}" "${BASE}/.${name}_"*
    exit 0
fi

btrfs subvolume create "${BASE}/${name}"

APT_CACHE_DIR="/var/cache/apt/archives"

if [[ -d ${APT_CACHE_DIR} ]]; then
    CACHE_ARGS="--cache-dir=${APT_CACHE_DIR}"
else
    CACHE_ARGS=""
fi

debootstrap ${CACHE_ARGS} "${SUITE}" "${BASE}/${name}"

mkdir -p "$BASE/$name/root/.ssh"
chmod 700 "$BASE/$name/root/.ssh"
if [ -f "/root/.ssh/authorized_keys" ]; then
	cp -v /root/.ssh/authorized_keys "$BASE/$name/root/.ssh/authorized_keys"
	chmod 600 "$BASE/$name/root/.ssh/authorized_keys"
	echo "added ssh keys to root"
fi

if [[ -e "$BASE/$name/etc/resolv.conf" ]]; then
    rm "$BASE/$name/etc/resolv.conf"
fi

if [[ -e "$BASE/$name/etc/hostname" ]]; then
    rm "$BASE/$name/etc/hostname"
fi

systemd-nspawn --console=pipe -D "$BASE/$name" /bin/bash <<'EOF'
echo "Now running inside nspawn $(pwd)"

source /etc/os-release

if [[ "$ID" == "ubuntu" ]]; then
    sed -i '1 s/$/ restricted universe multiverse/' /etc/apt/sources.list
elif [[ "$ID" == "debian" ]]; then
    if [[ $VERSION_ID -le 11 ]]; then
        sed -i '1 s/$/ contrib non-free/' /etc/apt/sources.list
    else
        sed -i '1 s/$/ contrib non-free non-free-firmware/' /etc/apt/sources.list
    fi
fi

apt-get update
apt-get install --yes --no-install-recommends locales dbus ssh python3 libnss-resolve

echo "locales locales/default_environment_locale select en_US.UTF-8" | debconf-set-selections
echo "locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8, et_EE.UTF-8 UTF-8" | debconf-set-selections
rm /etc/locale.gen
dpkg-reconfigure --frontend noninteractive locales
ln -fs /usr/share/zoneinfo/Europe/Tallinn /etc/localtime
dpkg-reconfigure -f noninteractive tzdata

apt install --yes --no-install-recommends neovim
update-alternatives --set editor /usr/bin/nvim
ln -sf /usr/share/nvim/runtime/macros/less.sh /usr/local/bin/vless


systemctl enable systemd-networkd
# Needed by libnss-resolve config in /etc/nsswitch.conf
systemctl enable systemd-resolved
EOF