FROM scratch as base
ENV VERSION=1.36.1
ENV SRC_HASH=b8cc24c9574d809e7279c3be349795c5d5ceb6fdf19ca709f80cde50e47de314
ENV SRC_FILE=busybox-${VERSION}.tar.bz2
ENV SRC_SITE=https://busybox.net/downloads/${SRC_FILE}

FROM base as fetch
ADD --checksum=sha256:${SRC_HASH} ${SRC_SITE} .

FROM fetch as build
COPY --from=stagex/stage3 . /
RUN tar -xjf ${SRC_FILE}
WORKDIR busybox-${VERSION}
ENV KCONFIG_NOTIMESTAMP=1
RUN --network=none <<-EOF
    set -eux
    setConfs='
        CONFIG_LAST_SUPPORTED_WCHAR=0
        CONFIG_STATIC=y
    '
    unsetConfs='
        CONFIG_FEATURE_SYNC_FANCY
        CONFIG_FEATURE_HAVE_RPC
        CONFIG_FEATURE_INETD_RPC
        CONFIG_FEATURE_UTMP
        CONFIG_FEATURE_WTMP
    '
    make defconfig
    for conf in $unsetConfs; do
        sed -i \
            -e "s!^$conf=.*\$!# $conf is not set!" \
            .config
    done
    for confV in $setConfs; do
        conf="${confV%=*}"
        sed -i \
            -e "s!^$conf=.*\$!$confV!" \
            -e "s!^# $conf is not set\$!$confV!" \
            .config
        if ! grep -q "^$confV\$" .config; then
            echo "$confV" >> .config
        fi
    done
    make oldconfig
    for conf in $unsetConfs; do
        ! grep -q "^$conf=" .config
    done
    for confV in $setConfs; do
        grep -q "^$confV\$" .config
    done
    make
EOF

FROM build as install
RUN --network=none <<-EOF
    set -eux
    mkdir -p /rootfs/bin
    cp busybox /rootfs/bin
    cp busybox /bin
    cd /rootfs
    mkdir -p home/user var/tmp etc tmp lib bin
    /bin/busybox --install -s bin
    echo "user:x:1000:" > etc/group
    echo "user:x:1000:1000::/home/user:/bin/sh" > etc/passwd
    ln -sT /lib lib64
    chown -R 1000:1000 /rootfs/home/user /rootfs/tmp /rootfs/var/tmp
EOF
RUN find /rootfs -exec touch -hcd "@0" "{}" +

FROM scratch as package
COPY --from=install /rootfs /
WORKDIR /home/user
USER 1000:1000
ENTRYPOINT ["/bin/sh"]
ENV TZ=UTC
ENV LANG=C.UTF-8
ENV SOURCE_DATE_EPOCH=1
ENV KCONFIG_NOTIMESTAMP=1
ENV PS1="stage4 $ "