#!/bin/sh
# shellcheck disable=SC2016,SC1004

grep -wq debug /proc/cmdline && debug=1
[ -n "$debug" ] && echo "zfs-generator: starting" >> /dev/kmsg

GENERATOR_DIR="$1"
[ -n "$GENERATOR_DIR" ] || {
    echo "zfs-generator: no generator directory specified, exiting" >> /dev/kmsg
    exit 1
}

[ -f /lib/dracut-lib.sh ] && dracutlib=/lib/dracut-lib.sh
[ -f /usr/lib/dracut/modules.d/99base/dracut-lib.sh ] && dracutlib=/usr/lib/dracut/modules.d/99base/dracut-lib.sh
command -v getarg >/dev/null 2>&1 || {
    [ -n "$debug" ] && echo "zfs-generator: loading Dracut library from $dracutlib" >> /dev/kmsg
    . "$dracutlib"
}

. /lib/dracut-zfs-lib.sh

[ -z "$root" ]       && root=$(getarg root=)
[ -z "$rootfstype" ] && rootfstype=$(getarg rootfstype=)
[ -z "$rootflags" ]  && rootflags=$(getarg rootflags=)

# If root is not ZFS= or zfs: or rootfstype is not zfs
# then we are not supposed to handle it.
[ "${root##zfs:}" = "${root}" ] &&
	[ "${root##ZFS=}" = "${root}" ] &&
	[ "$rootfstype" != "zfs" ] &&
	exit 0

case ",${rootflags}," in
	*,zfsutil,*) ;;
	,,)	rootflags=zfsutil ;;
	*)	rootflags="zfsutil,${rootflags}" ;;
esac

if [ "${root}" != "zfs:AUTO" ]; then
  root="${root##zfs:}"
  root="${root##ZFS=}"
fi

[ -n "$debug" ] && echo "zfs-generator: writing extension for sysroot.mount to $GENERATOR_DIR/sysroot.mount.d/zfs-enhancement.conf" >> /dev/kmsg


mkdir -p "$GENERATOR_DIR"/sysroot.mount.d "$GENERATOR_DIR"/initrd-root-fs.target.requires "$GENERATOR_DIR"/dracut-pre-mount.service.d
{
    echo "[Unit]"
    echo "Before=initrd-root-fs.target"
    echo "After=zfs-import.target"
    echo
    echo "[Mount]"
    if [ "${root}" = "zfs:AUTO" ]; then
      echo "PassEnvironment=BOOTFS"
      echo 'What=${BOOTFS}'
    else
      echo "What=${root}"
    fi
    echo "Type=zfs"
    echo "Options=${rootflags}"
} > "$GENERATOR_DIR"/sysroot.mount.d/zfs-enhancement.conf
ln -fs ../sysroot.mount "$GENERATOR_DIR"/initrd-root-fs.target.requires/sysroot.mount


if [ "${root}" = "zfs:AUTO" ]; then
  {
      echo "[Unit]"
      echo "Before=initrd-root-fs.target"
      echo "After=sysroot.mount"
      echo "DefaultDependencies=no"
      echo
      echo "[Service]"
      echo "Type=oneshot"
      echo "PassEnvironment=BOOTFS"
      echo "ExecStart=/bin/sh -c '" '                                        \
        . /lib/dracut-zfs-lib.sh;                                            \
        _zfs_nonroot_necessities_cb() {                                      \
            zfs mount | grep -m1 -q "^$1 " && return 0;                      \
            echo "Mounting $1 on /sysroot$2";                                \
            mount -o zfsutil -t zfs "$1" "/sysroot$2";                       \
        };                                                                   \
        for_relevant_root_children "${BOOTFS}" _zfs_nonroot_necessities_cb;' \
      "'"
  } > "$GENERATOR_DIR"/zfs-nonroot-necessities.service
  ln -fs ../zfs-nonroot-necessities.service "$GENERATOR_DIR"/initrd-root-fs.target.requires/zfs-nonroot-necessities.service
else
  # We can solve this statically at generation time, so do!
  _zfs_generator_cb() {
      dset="${1}"
      mpnt="${2}"
      unit="sysroot$(echo "$mpnt" | tr '/' '-').mount"

      {
          echo "[Unit]"
          echo "Before=initrd-root-fs.target"
          echo "After=sysroot.mount"
          echo
          echo "[Mount]"
          echo "Where=/sysroot${mpnt}"
          echo "What=${dset}"
          echo "Type=zfs"
          echo "Options=zfsutil"
      } > "$GENERATOR_DIR/${unit}"
      ln -fs ../"${unit}" "$GENERATOR_DIR"/initrd-root-fs.target.requires/"${unit}"
  }

  for_relevant_root_children "${root}" _zfs_generator_cb
fi


{
    echo "[Unit]"
    echo "After=zfs-import.target"
} > "$GENERATOR_DIR"/dracut-pre-mount.service.d/zfs-enhancement.conf

[ -n "$debug" ] && echo "zfs-generator: finished" >> /dev/kmsg

exit 0