#!/bin/bash

DEBIAN_MIRROR="https://deb.debian.org/debian"
DEBIAN_RELEASE="buster"

SCRIPT_DIR=$(dirname $(realpath ${BASH_SOURCE}))
DBS_BASE=$(realpath ${SCRIPT_DIR}/../build/debootstrap)
DBS_ROOT=${DBS_BASE}/rootfs
CACHE_DIR=${DBS_BASE}/var-cache-apt-archives


run_debootstrap() {
    [[ -d ${DBS_ROOT} ]] && rm -rf ${DBS_ROOT}

    [[ -f ${CACHE_DIR}/lock ]] && rm -f ${CACHE_DIR}/lock
    mkdir -p ${CACHE_DIR} ${DBS_ROOT}/var/cache/apt/archives 
    mount --bind ${CACHE_DIR} ${DBS_ROOT}/var/cache/apt/archives

    debootstrap --verbose --merged-usr --variant=minbase \
        --include=systemd-sysv,locales \
        --exclude=sysv-rc,initscripts,startpar,lsb-base,insserv \
        ${DEBIAN_RELEASE} ${DBS_ROOT} ${DEBIAN_MIRROR}
}

run_chroot_stage() {
    mount chproc ${DBS_ROOT}/proc -t proc
    mount chsys ${DBS_ROOT}/sys -t sysfs

    cp --preserve=mode ${SCRIPT_DIR}/build-user-rootfs-stage-two ${DBS_ROOT}/root/install.sh

    DEBIAN_FRONTEND=noninteractive DEBCONF_NONINTERACTIVE_SEEN=true LC_ALL=C LANGUAGE=C LANG=C chroot ${DBS_ROOT} /root/install.sh ${DEBIAN_RELEASE} ${DEBIAN_MIRROR}
    rm -f ${DBS_ROOT}/root/install.sh
}


cleanup_chroot() {
    umount ${DBS_ROOT}/proc
    umount ${DBS_ROOT}/sys
    umount ${DBS_ROOT}/var/cache/apt/archives
    rm -f ${DBS_ROOT}/var/cache/apt/pkgcache.bin
    rm -f ${DBS_ROOT}/var/cache/apt/srcpkgcache.bin
}

generate_tarball() {
    printf "\n\n----- Generating rootfs tarball -----\n\n"
    tar -C ${DBS_ROOT} -c --xattrs --xattrs-include=* -f ${DBS_BASE}/user-rootfs.tar .
    xz --force --threads=0 ${DBS_BASE}/user-rootfs.tar
    ls -al ${DBS_BASE}/user-rootfs.tar
    printf "\n\n"
}


run_debootstrap
run_chroot_stage
cleanup_chroot
generate_tarball