# -*- coding: utf-8 -*- #
# Copyright 2021 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.
"""Implementation of Unix-like du command for cloud storage providers."""


import fnmatch
import sys

from googlecloudsdk.api_lib.storage import cloud_api
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.storage import du_command_util
from googlecloudsdk.command_lib.storage import errors
from googlecloudsdk.command_lib.storage import flags
from googlecloudsdk.command_lib.storage import regex_util
from googlecloudsdk.command_lib.storage import storage_url
from googlecloudsdk.core.util import files

_COMMAND_DESCRIPTION = """
Displays the amount of space in bytes used by the objects in a bucket,
subdirectory, or project. This command calculates the current space usage
by making a series of object listing requests, which can take a long time
for large buckets. If your bucket contains hundreds of thousands of
objects, or if you want to monitor your bucket size over time, use
Monitoring instead, as described in [Get bucket size](https://cloud.google.com/storage/docs/getting-bucket-size)
"""
_GA_EXAMPLES = """
To list the size of each object in a bucket:

  $ {command} gs://bucketname

To list the size of each object in the prefix subdirectory:

  $ {command} gs://bucketname/prefix/*

To print the total number of bytes in a bucket in human-readable form:

  $ {command} -c gs://bucketname

To see a summary of the total number of bytes in two given buckets:

  $ {command} -s gs://bucket1 gs://bucket2

To list the size of each object in a bucket with Object Versioning
enabled, including noncurrent objects:

  $ {command} -a gs://bucketname

To list the size of each object in a bucket, except objects that end in
".bak", with each object printed ending in a null byte:

  $ {command} -e "*.bak" -0 gs://bucketname

To list the size of each bucket in a project and the total size of the
project:

  $ {command} --summarize --readable-sizes --total
"""
_ALPHA_EXAMPLES = """
The following command summarizes the size of objects that match the specified
filter.

  $ {command} gs://my-bucket --metadata-filter='contexts."foo"="bar"' --summarize

"""


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.GA)
class Du(base.Command):
  """Displays the amount of space in bytes used by storage resources."""

  hints = base.CommandHint(read_only=True)

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

  @classmethod
  def Args(cls, parser):
    parser.add_argument('url', nargs='*', help='The url of objects to list.')
    parser.add_argument(
        '-0',
        '--zero-terminator',
        action='store_true',
        help=(
            'Ends each output line with a 0 byte rather than a newline. You'
            ' can use this to make the output machine-readable.'
        ),
    )
    parser.add_argument(
        '-a',
        '--all-versions',
        action='store_true',
        help='Includes noncurrent object versions for a bucket with Object'
        ' Versioning enabled. Also prints the generation and metageneration'
        ' number for each listed object.')
    parser.add_argument(
        '-c',
        '--total',
        action='store_true',
        help='Includes a total size of all input sources.',
    )
    parser.add_argument(
        '-e',
        '--exclude-name-pattern',
        action='append',
        default=[],
        help=(
            'Exclude a pattern from the report. Example: `-e "*.o"` excludes'
            ' any object that ends in ".o". Can be specified multiple times.'
        ),
    )
    parser.add_argument(
        '-r',
        '--readable-sizes',
        action='store_true',
        help=(
            'Prints object sizes in human-readable format. For example, 1 KiB,'
            ' 234 MiB, or 2GiB.'
        ),
    )
    parser.add_argument(
        '-s',
        '--summarize',
        action='store_true',
        help='Displays only the summary for each argument.',
    )
    parser.add_argument(
        '-X',
        '--exclude-name-pattern-file',
        help=(
            'Similar to -e, but excludes patterns from the given file.'
            ' The patterns to exclude should be listed one per line.'
        ),
    )

    flags.add_additional_headers_flag(parser)
    flags.add_metadata_filter_flag(parser)

  def Run(self, args):

    use_gsutil_style = flags.check_if_use_gsutil_style(args)
    metadata_filter = getattr(args, 'metadata_filter', None)

    if args.url:
      storage_urls = []
      for url_string in args.url:
        url_object = storage_url.storage_url_from_string(url_string)
        if not isinstance(url_object, storage_url.CloudUrl):
          raise errors.InvalidUrlError(
              'Du only works for valid cloud URLs.'
              ' {} is an invalid cloud URL.'.format(url_object.url_string)
          )
        if (
            metadata_filter is not None
            and url_object.scheme != cloud_api.DEFAULT_PROVIDER
        ):
          raise errors.Error('Metadata filter is only supported for GCS URLs.')
        storage_urls.append(url_object)
    else:
      storage_urls = [storage_url.CloudUrl(cloud_api.DEFAULT_PROVIDER)]

    exclude_fnmatch_strings = args.exclude_name_pattern
    if args.exclude_name_pattern_file:
      if args.exclude_name_pattern_file == '-':
        exclude_fnmatch_strings.extend([line.strip() for line in sys.stdin])
      else:
        with files.FileReader(args.exclude_name_pattern_file) as file:
          exclude_fnmatch_strings.extend([line.strip() for line in file])
    exclude_regex_strings = [
        fnmatch.translate(pattern) for pattern in exclude_fnmatch_strings
    ]

    du_command_util.DuExecutor(
        cloud_urls=storage_urls,
        exclude_patterns=regex_util.Patterns(exclude_regex_strings),
        object_state=flags.get_object_state_from_flags(args),
        readable_sizes=args.readable_sizes,
        summarize=args.summarize,
        total=args.total,
        use_gsutil_style=use_gsutil_style,
        zero_terminator=args.zero_terminator,
        list_filter=metadata_filter,
    ).list_urls()


@base.UniverseCompatible
@base.ReleaseTracks(base.ReleaseTrack.ALPHA)
class DuAlpha(Du):
  """Displays the amount of space in bytes used by storage resources."""

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