#!/bin/sh

. ../lib/common.sh

cleanup()
{
    zpool export "$pool" || :
    qemu-nbd -d /dev/nbd0 || :
    rm -rf "$tmpdir"
}

command -v zfs > /dev/null && grep -q zfs /proc/modules || exit 222

set -ef
trap cleanup EXIT INT

devmgr=${DEVMGR:-proc}
arch=${ARCH:-$(uname -m)}
kernel=${KERNEL:-$(uname -r)}
vmlinuz=${VMLINUZ:-"/boot/vmlinuz-${kernel}"}

mkdir -p "${tmpdir:=${TMPDIR:-/tmp}/${0##*/}.$$}"

pool="pool$$"
root="${tmpdir}/root"
config="${tmpdir}/config"
image="${tmpdir}/root.qcow2"
initrd="${tmpdir}/initramfs-$(uname -r)"

qemu-img create -f qcow2 "$image" 1G
qemu-nbd -c /dev/nbd0 "$image"

# o: Create MBR table.
# n: Add new partition to table.
# p: Primary partition.
# 1: Partition number.
# newline: Use default value for first sector.
# newline: Use default value for last sector.
# w: Write changes and re-read partition table.
fdisk /dev/nbd0 << EOF
o
n
p
1


w
EOF

dd bs=512 count=1 if=/dev/urandom of="${tmpdir}/key"

zpool create -m none "$pool" /dev/nbd0p1
zfs create \
    -o mountpoint=legacy \
    -o canmount=noauto \
    -o encryption=on \
    -o keyformat=passphrase \
    -o keylocation="file://${tmpdir}/key" \
    "${pool}/root"

cat > "$config" << EOF
hooks=$devmgr,zfs
root=${pool}/root
root_type=zfs
# required if mountpoint != legacy
#root_opts=zfsutil
zfs_key=${tmpdir}/key
# toybox/busybox blkid doesn't support zfs. fallback to /dev/* (unstable)
zfs_root=/dev/vda1
EOF

mkdir -p "$root"
mount -t zfs "${pool}/root" "$root"

(
    tmpdir=$root; cd "$tmpdir"

    mkdir -p \
        dev sys tmp run proc \
        root usr/lib usr/bin

    ln -s usr/lib lib
    ln -s usr/bin bin
    ln -s usr/bin sbin
    ln -s bin     usr/sbin

    copy_exec sh
    copy_exec zfs

    cat > sbin/init << EOF
#!/bin/sh
exec zfs set success:=true "${pool}/root"
EOF

    chmod +x sbin/init
)

zpool export "$pool"
qemu-nbd -d /dev/nbd0

(cd .. && ./tinyramfs -lk "$kernel" -c "$config" "$initrd")

set -- \
    -no-reboot \
    -initrd "$initrd" \
    -kernel "$vmlinuz" \
    -device virtio-scsi \
    -drive  file="$image",if=virtio

if [ -c /dev/kvm ]; then
    set -- -enable-kvm -cpu host "$@"
fi

if [ "$DEBUG" ]; then
    set -- -append 'panic=-1 rdpanic debug rddebug console=ttyS0' -nographic "$@"
else
    set -- -append 'panic=-1 rdpanic' -display none "$@"
fi

"qemu-system-${arch}" "$@"

qemu-nbd -c /dev/nbd0 "$image"

# Re-read partition table.
fdisk /dev/nbd0 << EOF
w
EOF

zpool import -Nd /dev/nbd0p1 "$pool"

[ "$(zfs get -Ho value success: "${pool}/root")" = true ]