#!/bin/sh
umask 022
set -e

if [ "$(id -u)" != "0" ]; then
    echo "Please run this script as root" 1>&2
    exit 1
fi

if [ ! "$rocket" ]; then
    echo 'Please set the $rocket variable' 1>&2
    exit 1
fi

rocket="$(realpath "$rocket")"

checkmount() {
    local point="$(eval echo \${$#})"
    if cut -d' ' -f2 /proc/mounts | grep "$point" > /dev/null; then
        true
    else
        mount $@
    fi
}

mkdir -p "$rocket/dev" "$rocket/proc" "$rocket/sys" "$rocket/run"
checkmount --bind /dev "$rocket/dev"
checkmount -t devpts devpts "$rocket/dev/pts"
checkmount -t proc proc "$rocket/proc"
checkmount -t tmpfs tmpfs "$rocket/run"
if [ -h "$rocket/dev/shm" ]; then
    mkdir -p "$rocket/$(readlink "$rocket/dev/shm")"
fi

mkdir -p "$rocket/etc"
cp /etc/resolv.conf "$rocket/etc/resolv.conf"

chroot "$rocket" /tools/bin/env -i \
    HOME=/root \
    TERM="$TERM" \
    PS1="(buildenv) \u:\w \$ " \
    PATH=/bin:/sbin:/usr/bin:/usr/sbin:/tools/bin \
    MAKEFLAGS="$MAKEFLAGS" \
    /tools/bin/ash -l

umount "$rocket/dev/pts"
umount "$rocket/dev"
umount "$rocket/proc"
umount "$rocket/run"