# args: source, newroot, mountpoint
_mnt_dmsnapshot() {
  local img="${1}"
  local newroot="${2}"
  local mnt="${3}"
  local img_fullname="${img##*/}";
  local img_name="${img_fullname%%.*}"
  local dm_snap_name="${dm_snap_prefix}_${img_name}"
  local ro_dev ro_dev_size rw_dev

  ro_dev=$(losetup --find --show --read-only "${img}")
  echo ${ro_dev} >> /run/archiso/used_block_devices
  ro_dev_size=$(blockdev --getsz ${ro_dev})

  if [[ "${cow_persistent}" == "P" ]]; then
    if [[ -f "/run/archiso/cowspace/${cow_directory}/${img_name}.cow" ]]; then
      msg ":: Found '/run/archiso/cowspace/${cow_directory}/${img_name}.cow', using as persistent."
    else
      msg ":: Creating '/run/archiso/cowspace/${cow_directory}/${img_name}.cow' as persistent."
      truncate -s "${cow_spacesize}" "/run/archiso/cowspace/${cow_directory}/${img_name}.cow"
    fi
  else
    if [[ -f "/run/archiso/cowspace/${cow_directory}/${img_name}.cow" ]]; then
      msg ":: Found '/run/archiso/cowspace/${cow_directory}/${img_name}.cow' but non-persistent requested, removing."
      rm -f "/run/archiso/cowspace/${cow_directory}/${img_name}.cow"
    fi
    msg ":: Creating '/run/archiso/cowspace/${cow_directory}/${img_name}.cow' as non-persistent."
    truncate -s "${cow_spacesize}" "/run/archiso/cowspace/${cow_directory}/${img_name}.cow"
  fi

  rw_dev=$(losetup --find --show "/run/archiso/cowspace/${cow_directory}/${img_name}.cow")
  echo ${rw_dev} >> /run/archiso/used_block_devices

  dmsetup create ${dm_snap_name} --table "0 ${ro_dev_size} snapshot ${ro_dev} ${rw_dev} ${cow_persistent} ${cow_chunksize}"

  _mnt_dev "/dev/mapper/${dm_snap_name}" "${newroot}${mnt}" "-w" "defaults"
  echo $(readlink -f /dev/mapper/${dm_snap_name}) >> /run/archiso/used_block_devices
}

# args: source, newroot, mountpoint
_mnt_overlayfs() {
  local src="${1}"
  local newroot="${2}"
  local mnt="${3}"
  mkdir -p /run/archiso/cowspace/${cow_directory}/upperdir /run/archiso/cowspace/${cow_directory}/workdir
  mount -t overlay -o lowerdir=${src},upperdir=/run/archiso/cowspace/${cow_directory}/upperdir,workdir=/run/archiso/cowspace/${cow_directory}/workdir airootfs "${newroot}${mnt}"

}


# args: /path/to/image_file, mountpoint
_mnt_sfs() {
  local img="${1}"
  local mnt="${2}"
  local img_fullname="${img##*/}"
  local sfs_dev

  if [[ "${copytoram}" == "y" ]]; then
    msg -n ":: Copying squashfs image to RAM..."
    if ! cp "${img}" "/run/archiso/copytoram/${img_fullname}" ; then
      echo "ERROR: while copy '${img}' to '/run/archiso/copytoram/${img_fullname}'"
      launch_interactive_shell
    fi
    img="/run/archiso/copytoram/${img_fullname}"
    msg "done."
  fi
  sfs_dev=$(losetup --find --show --read-only "${img}")
  echo ${sfs_dev} >> /run/archiso/used_block_devices
  _mnt_dev "${sfs_dev}" "${mnt}" "-r" "defaults"
}

# args: device, mountpoint, flags, opts
_mnt_dev() {
  local dev="${1}"
  local mnt="${2}"
  local flg="${3}"
  local opts="${4}"

  mkdir -p "${mnt}"

  msg ":: Mounting '${dev}' to '${mnt}'"

  while ! poll_device "${dev}" 30; do
    echo "ERROR: '${dev}' device did not show up after 30 seconds..."
    echo "   Falling back to interactive prompt"
    echo "   You can try to fix the problem manually, log out when you are finished"
    launch_interactive_shell
  done

  if mount -o "${opts}" "${flg}" "${dev}" "${mnt}"; then
    msg ":: Device '${dev}' mounted successfully."
  else
    echo "ERROR; Failed to mount '${dev}'"
    echo "   Falling back to interactive prompt"
    echo "   You can try to fix the problem manually, log out when you are finished"
    launch_interactive_shell
  fi
}

_verify_checksum() {
  local _status
  cd "/run/archiso/bootmnt/${archisobasedir}/${arch}"
  sha512sum -c airootfs.sha512 > /tmp/checksum.log 2>&1
  _status=$?
  cd "${OLDPWD}"
  return ${_status}
}

_verify_signature() {
  local _status
  cd "/run/archiso/bootmnt/${archisobasedir}/${arch}"
  gpg --homedir /gpg --status-fd 1 --verify airootfs.sfs.sig 2>/dev/null | grep -qE '^\[GNUPG:\] GOODSIG'
  _status=$?
  cd "${OLDPWD}"
  return ${_status}
}

run_hook() {
  [[ -z "${arch}" ]] && arch="$(uname -m)"
  [[ -z "${copytoram_size}" ]] && copytoram_size="75%"
  [[ -z "${archisobasedir}" ]] && archisobasedir="arch"
  [[ -z "${dm_snap_prefix}" ]] && dm_snap_prefix="arch"
  [[ -z "${archisodevice}" ]] && archisodevice="/dev/disk/by-label/${archisolabel}"
  [[ -z "${cow_spacesize}" ]] && cow_spacesize="256M"

  if [[ -n "${cow_label}" ]]; then
    cow_device="/dev/disk/by-label/${cow_label}"
    [[ -z "${cow_persistent}" ]] && cow_persistent="P"
  elif [[ -n "${cow_device}" ]]; then
    [[ -z "${cow_persistent}" ]] && cow_persistent="P"
  else
    cow_persistent="N"
  fi

  [[ -z "${cow_flags}" ]] && cow_flags="defaults"
  [[ -z "${cow_directory}" ]] && cow_directory="persistent_${archisolabel}/${arch}"
  [[ -z "${cow_chunksize}" ]] && cow_chunksize="8"

  # set mount handler for archiso
  mount_handler="archiso_mount_handler"
}

# This function is called normally from init script, but it can be called
# as chain from other mount handlers.
# args: /path/to/newroot
archiso_mount_handler() {
  local newroot="${1}"

  if ! mountpoint -q "/run/archiso/bootmnt"; then
    _mnt_dev "${archisodevice}" "/run/archiso/bootmnt" "-r" "defaults"
    if [[ "${copytoram}" != "y" ]]; then
      echo $(readlink -f ${archisodevice}) >> /run/archiso/used_block_devices
    fi
  fi

  if [[ "${checksum}" == "y" ]]; then
    if [[ -f "/run/archiso/bootmnt/${archisobasedir}/${arch}/airootfs.sha512" ]]; then
      msg -n ":: Self-test requested, please wait..."
      if _verify_checksum; then
        msg "done. Checksum is OK, continue booting."
      else
        echo "ERROR: one or more files are corrupted"
        echo "see /tmp/checksum.log for details"
        launch_interactive_shell
      fi
    else
      echo "ERROR: checksum=y option specified but ${archisobasedir}/${arch}/airootfs.sha512 not found"
      launch_interactive_shell
    fi
  fi

  if [[ "${verify}" == "y" ]]; then
    if [[ -f "/run/archiso/bootmnt/${archisobasedir}/${arch}/airootfs.sfs.sig" ]]; then
      msg -n ":: Signature verification requested, please wait..."
      if _verify_signature; then
        msg "done. Signature is OK, continue booting."
      else
        echo "ERROR: one or more files are corrupted"
        launch_interactive_shell
      fi
    else
      echo "ERROR: verify=y option specified but ${archisobasedir}/${arch}/airootfs.sfs.sig not found"
      launch_interactive_shell
    fi
  fi

  mkdir -p /run/archiso/copytoram
  if [[ "${copytoram}" == "y" ]]; then
    msg ":: Mounting /run/archiso/copytoram (tmpfs) filesystem, size=${copytoram_size}"

    mount -t tmpfs -o "size=${copytoram_size}",mode=0755 copytoram /run/archiso/copytoram
  fi

  mkdir -p /run/archiso/cowspace
  if [[ -n "${cow_device}" ]]; then
    _mnt_dev "${cow_device}" "/run/archiso/cowspace" "-r" "${cow_flags}"
    echo $(readlink -f ${cow_device}) >> /run/archiso/used_block_devices
    mount -o remount,rw "/run/archiso/cowspace"
  else
    msg ":: Mounting /run/archiso/cowspace (tmpfs) filesystem, size=${cow_spacesize}..."
    mount -t tmpfs -o "size=${cow_spacesize}",mode=0755 cowspace /run/archiso/cowspace
  fi
  mkdir -p -m 0700 "/run/archiso/cowspace/${cow_directory}"

  _mnt_sfs "/run/archiso/bootmnt/${archisobasedir}/${arch}/airootfs.sfs" "/run/archiso/sfs/airootfs"
  if [[ -f "/run/archiso/sfs/airootfs/airootfs.img" ]]; then
    _mnt_dmsnapshot "/run/archiso/sfs/airootfs/airootfs.img" "${newroot}" "/"
  else
    _mnt_overlayfs "/run/archiso/sfs/airootfs" "${newroot}" "/"
  fi

  if [[ "${copytoram}" == "y" ]]; then
    umount -d /run/archiso/bootmnt
  fi

  mkdir -p -m 755 "/run/archiso/cowspace/${cow_directory}/upperdir/usr/bin"
  if [[ -n "${run}" ]]; then
    echo ":: running ${run}"
    echo ${run} > /run/archiso/cowspace/${cow_directory}/upperdir/usr/bin/run
  else
    if [ -f "/run/archiso/cowspace/${cow_directory}/upperdir/usr/bin/run" ]
    then
      rm /run/archiso/cowspace/${cow_directory}/upperdir/usr/bin/run
    fi
  fi
}

if [[ "${shell}" == "y" ]]; then
  echo "starting interactive_shell"
  launch_interactive_shell
fi

# vim:ft=sh:ts=4:sw=4:et:
