# -*- coding: utf-8 -*- #
# Copyright 2022 Google LLC. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Command to list Cloud Storage resources."""

from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals

from googlecloudsdk.api_lib.storage import cloud_api
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.storage import encryption_util
from googlecloudsdk.command_lib.storage import errors
from googlecloudsdk.command_lib.storage import flags
from googlecloudsdk.command_lib.storage import list_util
from googlecloudsdk.command_lib.storage import ls_command_util
from googlecloudsdk.command_lib.storage import stdin_iterator
from googlecloudsdk.command_lib.storage import storage_url
from googlecloudsdk.core import log


_COMMAND_DESCRIPTION = """
List your Cloud Storage buckets in a project and objects in a bucket.
This command treats forward slashes in object names as directories. See
below for examples of how to use wildcards to get the listing behavior
you want.
"""
_GA_EXAMPLES = """
The following command lists the buckets in the default project:

  $ {command}

The following command lists the buckets in the specified project:

  $ {command} --project=my-project

The following command lists the contents of a bucket:

  $ {command} gs://my-bucket

You can use [wildcards](https://cloud.google.com/storage/docs/wildcards)
to match multiple paths (including multiple buckets). Bucket wildcards are
expanded to match only buckets contained in your current project. The
following command matches ``.txt'' objects that begin with ``log'' and
that are stored in buckets in your project that begin with ``my-b'':

  $ {command} gs://my-b*/log*.txt

You can use double-star wildcards to match zero or more directory levels
in a path. The following command matches all ``.txt'' objects in a bucket.

  $ {command} gs://my-bucket/**/*.txt

The wildcard `**` retrieves a flat list of objects in a single API call
and does not match prefixes. The following command would not match
`gs://my-bucket/dir/log.txt`:

  $ {command} gs://my-bucket/**/dir

Double-star expansion also can not be combined with other expressions in a
given path segment and operates as a single star in that context. For
example, the command `gs://my-bucket/dir**/log.txt` is treated as
`gs://my-bucket/dir*/log.txt`. To get the recursive behavior, the command
should instead be written the following way:

  gs://my-bucket/dir*/**/log.txt

The following command lists all items recursively with formatting by
using `--recursive`:

  $ {command} --recursive gs://bucket

Recursive listings are similar to `**` except recursive listings include
line breaks and header formatting for each subdirectory.
"""
_ALPHA_EXAMPLES = """
"""


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.GA)
class Ls(base.Command):
  """List Cloud Storage buckets and objects."""

  # pylint:disable=g-backslash-continuation
  detailed_help = {
      'DESCRIPTION': _COMMAND_DESCRIPTION,
      'EXAMPLES': _GA_EXAMPLES,
  }
  # pylint:enable=g-backslash-continuation

  @classmethod
  def Args(cls, parser):
    """Edit argparse.ArgumentParser for the command."""
    parser.add_argument(
        'path',
        nargs='*',
        help=(
            'The path of objects and directories to list. The path must begin'
            ' with gs:// and is allowed to contain wildcard characters.'
        ),
    )
    parser.add_argument(
        '-a',
        '--all-versions',
        action='store_true',
        help=(
            'Include noncurrent object versions in the listing. This flag is'
            ' typically only useful for buckets with [object'
            ' versioning](https://cloud.google.com/storage/docs/object-versioning)'
            ' enabled. If combined with the `--long` option, the metageneration'
            ' for each listed object is also included.'
        ),
    )
    parser.add_argument(
        '-b',
        '--buckets',
        action='store_true',
        help=(
            'When given a bucket URL, only return buckets. Useful for avoiding'
            ' the rule that prints the top-level objects of buckets matching a'
            ' query. Typically used in combination with `--full` to get the'
            ' full metadata of buckets.'
        ),
    )
    parser.add_argument(
        '-e',
        '--etag',
        action='store_true',
        help='Include ETag metadata in listings that use the `--long` flag.',
    )
    parser.add_argument(
        '--format',
        help=(
            'Use "gsutil" to get the style of the older gsutil CLI. (e.g.'
            ' "--format=gsutil"). Other format values (e.g. "json") do not'
            ' work. See different ls flags and commands for alternative'
            ' formatting.'
        ),
    )
    parser.add_argument(
        '--readable-sizes',
        action='store_true',
        help=(
            'When used with `--long`, print object sizes in human'
            ' readable format, such as 1 KiB, 234 MiB, or 2 GiB.'
        ),
    )
    parser.add_argument(
        '-R',
        '-r',
        '--recursive',
        action='store_true',
        help=(
            'Recursively list the contents of any directories that match the'
            ' path expression.'
        ),
    )

    output_styles = parser.add_group(mutex='True')
    output_styles.add_argument(
        '-l',
        '--long',
        action='store_true',
        help='For objects only. List size in bytes, creation time, and URL.',
    )
    output_styles.add_argument(
        '-L',
        '--full',
        action='store_true',
        help='List all available metadata about items in rows.',
    )
    output_styles.add_argument(
        '-j',
        '--json',
        action='store_true',
        help='List all available metadata about items as a JSON dump.',
    )

    flags.add_additional_headers_flag(parser)
    flags.add_encryption_flags(parser, command_only_reads_data=True)
    flags.add_fetch_encrypted_object_hashes_flag(parser, is_list=True)
    flags.add_read_paths_from_stdin_flag(parser)
    flags.add_soft_delete_flags(parser)

    if cls.ReleaseTrack() == base.ReleaseTrack.ALPHA:
      flags.add_metadata_filter_flag(parser)

  @classmethod
  def _get_args(cls, args):
    """Get the args for the command."""
    soft_deleted = getattr(args, 'soft_deleted', False)
    all_versions = getattr(args, 'all_versions', False)
    buckets = getattr(args, 'buckets', False)
    return soft_deleted, all_versions, buckets

  def Run(self, args):
    """Command execution logic."""

    encryption_util.initialize_key_store(args)

    # We cannot do a backward incompatible change, and thus we are throwing a
    # warning here so that users in the long term can avoid using the flags
    # incorrectly.
    soft_deleted, all_versions, buckets = self._get_args(args)
    # We do not support operations for soft deleted resources combined with
    # --all-versions flag.
    if soft_deleted and all_versions:
      log.warning(
          'The --all-versions flag has no effect when used with the'
          ' --soft-deleted flag. When --soft-deleted is used, all'
          ' soft-deleted versions of the resource are returned.'
      )
    # When listing buckets, only --soft-deleted flag is allowed.
    if buckets and all_versions:
      log.warning('The --all-versions flag has no effect when listing buckets.')

    use_gsutil_style = flags.check_if_use_gsutil_style(args)

    found_non_default_provider = False
    if args.path or args.read_paths_from_stdin:
      paths = stdin_iterator.get_urls_iterable(
          args.path, args.read_paths_from_stdin, allow_empty=True
      )
    else:
      paths = [cloud_api.DEFAULT_PROVIDER.value + '://']

    metadata_filter = getattr(args, 'metadata_filter', None)
    storage_urls = [storage_url.storage_url_from_string(path) for path in paths]
    for url in storage_urls:
      if not isinstance(url, storage_url.CloudUrl):
        raise errors.InvalidUrlError(
            'Ls only works for cloud URLs. Error for: {}'.format(url.url_string)
        )
      if (
          metadata_filter is not None
          and url.scheme != cloud_api.DEFAULT_PROVIDER
      ):
        raise errors.Error('Metadata filter is only supported for GCS URLs.')
      if url.scheme is not cloud_api.DEFAULT_PROVIDER:
        found_non_default_provider = True

    if args.full:
      display_detail = list_util.DisplayDetail.FULL
    elif args.json:
      display_detail = list_util.DisplayDetail.JSON
    elif args.long:
      display_detail = list_util.DisplayDetail.LONG
    else:
      display_detail = list_util.DisplayDetail.SHORT

    ls_command_util.LsExecutor(
        storage_urls,
        buckets_flag=buckets,
        display_detail=display_detail,
        fetch_encrypted_object_hashes=args.fetch_encrypted_object_hashes,
        halt_on_empty_response=not getattr(args, 'exhaustive', False),
        include_etag=args.etag,
        include_managed_folders=True,
        next_page_token=getattr(args, 'next_page_token', None),
        object_state=flags.get_object_state_from_flags(args),
        readable_sizes=args.readable_sizes,
        recursion_flag=args.recursive,
        use_gsutil_style=use_gsutil_style,
        soft_deleted_buckets=buckets and soft_deleted,
        list_filter=metadata_filter,
    ).list_urls()

    if found_non_default_provider and args.full:
      # We do guarantee full-style formatting for all metadata fields of
      # non-GCS providers. In this case, data is hidden.
      log.warning('For additional metadata information, please run ls --json.')


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.ALPHA)
class LsAlpha(Ls):
  """List Cloud Storage buckets and objects."""

  detailed_help = {
      'DESCRIPTION': _COMMAND_DESCRIPTION,
      'EXAMPLES': _GA_EXAMPLES + _ALPHA_EXAMPLES,
  }