#!/bin/sh -eux
echo "$release" >/dev/null # fail on -u if release unset
arch=${1:-amd64}
case $arch in
	amd64)
		iface=ens3
		qarch=x86_64
		kpkg=linux-image-amd64
		;;
	arm64)
		iface=enp0s1
		qarch=aarch64
		kpkg=linux-image-arm64
		;;
	ppc64el)
		iface=enp0s0
		qarch=ppc64le
		kpkg=linux-image-powerpc64le
		;;
	*)
		echo "unsupported architecture $arch"
		exit 1
		;;
esac

cleanup() {
	# The order here is important if you don't want to hose your mounts
	cat /mnt/debootstrap/debootstrap.log || true
	umount /mnt/dev/pts 2>/dev/null || true
	umount /mnt/dev/shm 2>/dev/null || true
	umount /mnt/dev 2>/dev/null || true
	umount /mnt/proc 2>/dev/null || true
	umount /mnt/run 2>/dev/null || true
	umount /mnt/sys 2>/dev/null || true
	umount /mnt/boot 2>/dev/null || true 
	umount /mnt 2>/dev/null || true 
	qemu-nbd --disconnect /dev/nbd0 || true
}

mkdir -p "$arch"

qemu-img create -f qcow2 $arch/root.img.qcow2 24G
modprobe nbd max_part=16
qemu-nbd --connect=/dev/nbd0 $arch/root.img.qcow2
trap cleanup EXIT

if [ "$arch" = "amd64" ]
then
	dd if=/usr/lib/syslinux/mbr/mbr.bin of=/dev/nbd0 bs=1 count=440
fi

sfdisk --no-reread /dev/nbd0 <<EOF
1M,100M,L,*
,2048M,S
,,L
EOF

mkfs.ext4 /dev/nbd0p1
mkswap /dev/nbd0p2
mkfs.ext4 /dev/nbd0p3

mount /dev/nbd0p3 /mnt
mkdir /mnt/boot
mount /dev/nbd0p1 /mnt/boot

if [ "$arch" = "amd64" ]
then
	debootstrap --include=gnupg2 --arch=$arch $release /mnt
else
	../qemu-debootstrap --include=gnupg2 --arch=$arch $release /mnt
fi

mount --bind /dev /mnt/dev
mount --bind /dev/pts /mnt/dev/pts
mount --bind /dev/shm /mnt/dev/shm
mount --bind /proc /mnt/proc
mount --bind /run /mnt/run
mount --bind /sys /mnt/sys

if [ "$arch" != "amd64" ]
then
	cp /usr/bin/qemu-$qarch-static /mnt/usr/bin
fi

run_root() {
	chroot /mnt /usr/bin/env \
		PATH=/sbin:/usr/sbin:/bin:/usr/bin \
		sh -c "$*"
}

echo 'nameserver 8.8.8.8' >/mnt/etc/resolv.conf
echo 'nameserver 8.8.4.4' >>/mnt/etc/resolv.conf
cat > /mnt/etc/network/interfaces <<EOF
auto lo
iface lo inet loopback

auto $iface
iface $iface inet static
	hostname build
	address 10.0.2.15
	netmask 255.255.255.0
	gateway 10.0.2.2
EOF
echo build > /mnt/etc/hostname
cat > /mnt/etc/hosts <<EOF 
127.0.0.1 localhost
127.0.0.1 build
EOF

echo 'APT::Install-Recommends "False";' > /mnt/etc/apt/apt.conf.d/60recommends

run_root apt-key update
run_root apt-get update
run_root apt-get -y install locales
run_root apt-get -y install $kpkg
run_root apt-get -y install build-essential git mercurial ssh sudo \
	gnupg dirmngr ca-certificates apt-transport-https curl dbus \
	systemd-timesyncd

run_root ln -sf /usr/share/zoneinfo/UTC /etc/localtime
run_root systemctl enable systemd-timesyncd.service

run_root useradd -mG sudo build
run_root passwd -d build
echo '%sudo ALL=(ALL) NOPASSWD: ALL' >> /mnt/etc/sudoers

echo "PermitEmptyPasswords yes" >> /mnt/etc/ssh/sshd_config
echo ssh >> /mnt/etc/securetty
run_root systemctl enable ssh

# Prevent docker from mucking up networking
mkdir -p /mnt/etc/docker
cat >/mnt/etc/docker/daemon.json <<EOF
{
	"bip": "172.18.0.1/16"
}
EOF

run_root update-initramfs -u

linuxver=$(ls /mnt/boot | grep vmlinuz | cut -d- -f2-)

cat >>/mnt/etc/fstab <<EOF
/dev/vda1 /boot ext4 rw,relatime,data=ordered 0 0
/dev/vda2 swap swap defaults 0 0
/dev/vda3 / ext4 rw,relatime,data=ordered 0 0
EOF

cat >/mnt/home/build/.gitconfig <<EOF
[user]
  name = builds.sr.ht
  email = builds@sr.ht
EOF
chown build:build /mnt/home/build/.gitconfig

# Boot setup
case "$arch" in 
	amd64)
		run_root apt-get -y install extlinux
		extlinux -i /mnt/boot

		cat >/mnt/boot/extlinux.conf <<-EOF
		default debian
		label debian
			linux vmlinuz-$linuxver
			initrd initrd.img-$linuxver
			append root=/dev/vda3 rw quiet
		EOF
		;;
	arm64)
		cp /mnt/boot/vmlinuz-* $arch/vmlinuz
		cp /mnt/boot/initrd.img-* $arch/initrd.img
		;;
	ppc64el)
		cp /mnt/boot/vmlinux-* $arch/vmlinux
		cp /mnt/boot/initrd.img-* $arch/initrd.img
		;;
esac

sync