# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

. "${SRC_ROOT}/platform/dev/toolchain_utils.sh" || exit 1

cleanup_mounts() {
  local prev_ret=$?

  # Disable die on error.
  set +e

  # See if we ran out of space.  Only show if we errored out via a trap.
  if [[ ${prev_ret} -ne 0 ]]; then
    local df=$(df -B 1M "${root_fs_dir}")
    if [[ ${df} == *100%* ]]; then
      error "Here are the biggest files (by disk usage):"
      # Send final output to stderr to match `error` behavior.
      sudo find "${root_fs_dir}" -xdev -type f -printf '%b %P\n' | \
        awk '$1 > 16 { $1 = $1 * 512; print }' | sort -n | tail -100 1>&2
      error "Target image has run out of space:"
      error "${df}"
    fi
  fi

  echo "Cleaning up mounts"
  safe_umount_tree "${root_fs_dir}"
  safe_umount_tree "${stateful_fs_dir}"
  safe_umount_tree "${esp_fs_dir}"
  safe_umount_tree "${oem_fs_dir}"

   # Turn die on error back on.
  set -e
}

zero_free_space() {
  local fs_mount_point=$1
  info "Zeroing freespace in ${fs_mount_point}"
  # dd is a silly thing and will produce a "No space left on device" message
  # that cannot be turned off and is confusing to unsuspecting victims.
  info "${fs_mount_point}/filler"
  ( sudo dd if=/dev/zero of="${fs_mount_point}/filler" bs=4096 conv=fdatasync \
      status=noxfer || true ) 2>&1 | grep -v "No space left on device"
  sudo rm "${fs_mount_point}/filler"
}

# Usage: mk_fs <image_type> <partition_num> <image_file> <fs_uuid> <mount_dir>
# Args:
#   image_type: The layout name used to look up partition info in disk layout.
#   partition_num: The partition to look up in the disk layout.
#   image_file: The file to write the fs image to.
#   fs_uuid: 'clear' will set the UUID to all zeros.  'random' will initialize
#            the UUID with a new random value.
#   mount_dir: (optional) Where to mount the image after creating it
#
# Note: After we mount the fs, we will attempt to reset the root dir ownership
#       to 0:0 to workaround a bug in mke2fs (fixed in upstream git now).
mk_fs() {
  local image_type=$1
  local part_num=$2
  local fs_img=$3
  local fs_uuid=$4
  local mount_dir=$5

  # These are often not in non-root $PATH, but they contain tools that
  # we can run just fine w/non-root users when we work on plain files.
  local p
  for p in /sbin /usr/sbin; do
    if [[ ":${PATH}:" != *:${p}:* ]]; then
      PATH+=":${p}"
    fi
  done

  # Keep `local` decl split from assignment so return code is checked.
  local fs_bytes fs_label fs_format fs_block_size

  fs_bytes=$(get_filesystem_size ${image_type} ${part_num})
  fs_label=$(get_label ${image_type} ${part_num})
  fs_format=$(get_filesystem_format ${image_type} ${part_num})
  fs_block_size=$(get_fs_block_size)

  if [[ ${fs_bytes} -eq 0 ]]; then
    info "Skipping ${fs_img} (size == 0 bytes)"
    return 0
  fi

  info "Building ${fs_img}"
  truncate -s ${fs_bytes} "${fs_img}"
  case ${fs_format} in
  ext[234])
    mkfs.${fs_format} -F -q -U 00000000-0000-0000-0000-000000000000 \
      -b ${fs_block_size} "${fs_img}" "$((fs_bytes / fs_block_size))"
    tune2fs -L "${fs_label}" \
            -U "${fs_uuid}" \
            -c 0 \
            -i 0 \
            -T 20091119110000 \
            -m 0 \
            -r 0 \
            -e remount-ro \
            "${fs_img}"
    ;;
  fat12|fat16|fat32)
    mkfs.vfat -F ${fs_format#fat} -n "${fs_label}" "${fs_img}"
    ;;
  fat|vfat)
    mkfs.vfat -n "${fs_label}" "${fs_img}"
    ;;
  *)
    die "Unknown fs format '${fs_format}' for part ${part_num}";;
  esac

  if [[ -n ${mount_dir} ]]; then
    mkdir -p "${mount_dir}"
    local cmds=(
      "mount -o loop '${fs_img}' '${mount_dir}'"
      # mke2fs is funky and sets the root dir owner to current uid:gid.
      "chown 0:0 '${mount_dir}' 2>/dev/null || :"
    )
    sudo_multi "${cmds[@]}"
  fi
}

create_base_image() {
  local image_name=$1
  local rootfs_verification_enabled=$2
  local bootcache_enabled=$3
  local image_type="usb"

  if [[ "${FLAGS_disk_layout}" != "default" ]]; then
    image_type="${FLAGS_disk_layout}"
  else
    if should_build_image ${CHROMEOS_FACTORY_INSTALL_SHIM_NAME}; then
      image_type="factory_install"
    fi
  fi

  check_valid_layout "base"
  check_valid_layout ${image_type}

  info "Using image type ${image_type}"
  get_disk_layout_path
  info "Using disk layout ${DISK_LAYOUT_PATH}"

  root_fs_dir="${BUILD_DIR}/rootfs"
  stateful_fs_dir="${BUILD_DIR}/stateful"
  esp_fs_dir="${BUILD_DIR}/esp"
  oem_fs_dir="${BUILD_DIR}/oem"

  trap "cleanup_mounts && delete_prompt" EXIT
  cleanup_mounts &> /dev/null

  local root_fs_img="${BUILD_DIR}/rootfs.image"
  local stateful_fs_img="${BUILD_DIR}/stateful.image"
  local esp_fs_img="${BUILD_DIR}/esp.image"
  local oem_fs_img="${BUILD_DIR}/oem.image"

  # Build the various FS images.
  mk_fs "${image_type}" 3 "${root_fs_img}" clear "${root_fs_dir}"
  df -h "${root_fs_dir}"
  mk_fs "${image_type}" 1 "${stateful_fs_img}" random "${stateful_fs_dir}"
  mk_fs "${image_type}" 12 "${esp_fs_img}" clear
  mk_fs "${image_type}" 8 "${oem_fs_img}" random "${oem_fs_dir}"

  # Prepare stateful partition with some pre-created directories.
  sudo mkdir "${stateful_fs_dir}/dev_image" "${stateful_fs_dir}/var_overlay"

  # Create symlinks so that /usr/local/usr based directories are symlinked to
  # /usr/local/ directories e.g. /usr/local/usr/bin -> /usr/local/bin, etc.
  setup_symlinks_on_root "${stateful_fs_dir}/dev_image" \
    "${stateful_fs_dir}/var_overlay" "${stateful_fs_dir}"

  # Perform binding rather than symlinking because directories must exist
  # on rootfs so that we can bind at run-time since rootfs is read-only.
  info "Binding directories from stateful partition onto the rootfs"
  sudo mkdir -p "${root_fs_dir}/mnt/stateful_partition"
  sudo mount --bind "${stateful_fs_dir}" "${root_fs_dir}/mnt/stateful_partition"
  sudo mkdir -p "${root_fs_dir}/usr/local"
  sudo mount --bind "${stateful_fs_dir}/dev_image" "${root_fs_dir}/usr/local"
  sudo mkdir -p "${root_fs_dir}/var"
  sudo mount --bind "${stateful_fs_dir}/var_overlay" "${root_fs_dir}/var"
  sudo mkdir -p "${root_fs_dir}/dev"

  local oem_fs_bytes=$(get_filesystem_size ${image_type} 8)
  if [[ ${oem_fs_bytes} -gt 0 ]]; then
    info "Binding directories from OEM partition onto the rootfs"
    sudo mkdir -p "${root_fs_dir}/usr/share/oem"
    sudo mount --bind "${oem_fs_dir}" "${root_fs_dir}/usr/share/oem"
  fi

  # We need to install libc manually from the cross toolchain.
  # TODO: Improve this? It would be ideal to use emerge to do this.
  PKGDIR="/var/lib/portage/pkgs"
  LIBC_TAR="glibc-${LIBC_VERSION}.tbz2"
  LIBC_PATH="${PKGDIR}/cross-${CHOST}/${LIBC_TAR}"

  if ! [[ -e ${LIBC_PATH} ]]; then
  die_notrace \
    "${LIBC_PATH} does not exist. Try running ./setup_board" \
    "--board=${BOARD} to update the version of libc installed on that board."
  fi

  # Strip out files we don't need in the final image at runtime.
  local libc_excludes=(
    # Compile-time headers.
    'usr/include' 'sys-include'
    # Link-time objects.
    '*.[ao]'
  )
  pbzip2 -dc --ignore-trailing-garbage=1 "${LIBC_PATH}" | \
    sudo tar xpf - -C "${root_fs_dir}" ./usr/${CHOST} \
      --strip-components=3 "${libc_excludes[@]/#/--exclude=}"

  if should_build_image ${CHROMEOS_FACTORY_INSTALL_SHIM_NAME}; then
    # Install our custom factory install kernel with the appropriate use flags
    # to the image.
    emerge_custom_kernel "${root_fs_dir}"
  fi

  # We "emerge --root=${root_fs_dir} --root-deps=rdeps --usepkgonly" all of the
  # runtime packages for chrome os. This builds up a chrome os image from
  # binary packages with runtime dependencies only.  We use INSTALL_MASK to
  # trim the image size as much as possible.
  emerge_to_image --root="${root_fs_dir}" ${BASE_PACKAGE}

  # Set /etc/lsb-release on the image.
  "${OVERLAY_CHROMEOS_DIR}/scripts/cros_set_lsb_release" \
  --root="${root_fs_dir}" \
  --board="${BOARD}"

  # Create the boot.desc file which stores the build-time configuration
  # information needed for making the image bootable after creation with
  # cros_make_image_bootable.
  create_boot_desc "${image_type}"

  # Write out the GPT creation script.
  # This MUST be done before writing bootloader templates else we'll break
  # the hash on the root FS.
  write_partition_script "${image_type}" \
    "${root_fs_dir}/${PARTITION_SCRIPT_PATH}"

  # Populates the root filesystem with legacy bootloader templates
  # appropriate for the platform.  The autoupdater and installer will
  # use those templates to update the legacy boot partition (12/ESP)
  # on update.
  # (This script does not populate vmlinuz.A and .B needed by syslinux.)
  # Factory install shims may be booted from USB by legacy EFI BIOS, which does
  # not support verified boot yet (see create_legacy_bootloader_templates.sh)
  # so rootfs verification is disabled if we are building with --factory_install
  local enable_rootfs_verification=
  if [[ ${rootfs_verification_enabled} -eq ${FLAGS_TRUE} ]]; then
    enable_rootfs_verification="--enable_rootfs_verification"
  fi
  local enable_bootcache=
  if [[ ${bootcache_enabled} -eq ${FLAGS_TRUE} ]]; then
    enable_bootcache="--enable_bootcache"
  fi

  ${BUILD_LIBRARY_DIR}/create_legacy_bootloader_templates.sh \
    --arch=${ARCH} \
    --to="${root_fs_dir}"/boot \
    --boot_args="${FLAGS_boot_args}" \
      ${enable_rootfs_verification} \
      ${enable_bootcache}

  # Don't test the factory install shim
  if ! should_build_image ${CHROMEOS_FACTORY_INSTALL_SHIM_NAME}; then
    if [[ ${skip_test_image_content} -ne 1 ]]; then
      # Check that the image has been correctly created.
      test_image_content "$root_fs_dir"
    fi
  fi

  # Clean up symlinks so they work on a running target rooted at "/".
  # Here development packages are rooted at /usr/local.  However, do not
  # create /usr/local or /var on host (already exist on target).
  setup_symlinks_on_root "/usr/local" "/var" "${stateful_fs_dir}"

  # Our masking of files will implicitly leave behind a bunch of empty
  # dirs.  We can't differentiate between empty dirs we want and empty
  # dirs we don't care about, so just prune ones we know are OK.
  sudo find "${root_fs_dir}/usr/include" -depth -type d -exec rmdir {} + \
    2>/dev/null || :

  # Zero rootfs free space to make it more compressible so auto-update
  # payloads become smaller
  zero_free_space "${root_fs_dir}"

  cleanup_mounts

  # Create the GPT-formatted image.
  build_gpt "${BUILD_DIR}/${image_name}" \
          "${root_fs_img}" \
          "${stateful_fs_img}" \
          "${esp_fs_img}" \
          "${oem_fs_img}"

  # Clean up temporary files.
  rm -f "${root_fs_img}" "${stateful_fs_img}" "${esp_fs_img}" "{oem_fs_img}"

  # Emit helpful scripts for testers, etc.
  emit_gpt_scripts "${BUILD_DIR}/${image_name}" "${BUILD_DIR}"

  USE_DEV_KEYS=
  if should_build_image ${CHROMEOS_FACTORY_INSTALL_SHIM_NAME}; then
    USE_DEV_KEYS="--use_dev_keys"
  fi

  if [[ ${skip_kernelblock_install} -ne 1 ]]; then
    # Place flags before positional args.
    ${SCRIPTS_DIR}/bin/cros_make_image_bootable "${BUILD_DIR}" \
      ${image_name} ${USE_DEV_KEYS} --adjust_part="${FLAGS_adjust_part}"
  fi
}