# -*- coding: utf-8 -*-
# Copyright 2018 Google Inc. 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.
"""This module provides the command to gsutil."""

from __future__ import absolute_import
from __future__ import print_function

import getopt
import textwrap

from gslib import metrics
from gslib.command import Command
from gslib.command_argument import CommandArgument
from gslib.cs_api_map import ApiSelector
from gslib.exception import CommandException
from gslib.exception import NO_URLS_MATCHED_TARGET
from gslib.help_provider import CreateHelpText
from gslib.third_party.storage_apitools import storage_v1_messages as apitools_messages
from gslib.utils.constants import NO_MAX
from gslib.utils.text_util import InsistOnOrOff

_SET_SYNOPSIS = """
  gsutil bucketpolicyonly set <on|off> bucket_url...
"""

_GET_SYNOPSIS = """
  gsutil bucketpolicyonly get bucket_url...
"""

_SYNOPSIS = _SET_SYNOPSIS + _GET_SYNOPSIS.lstrip('\n')

_SET_DESCRIPTION = """
<B>SET</B>
  The ``bucketpolicyonly set`` command enables or disables the Bucket Policy
  Only feature on Google Cloud Storage bucket(s).

<B>SET EXAMPLES</B>
  Configure your buckets to use Bucket Policy Only:

    gsutil bucketpolicyonly set on gs://redbucket gs://bluebucket

  Configure your buckets to NOT use Bucket Policy Only:

    gsutil bucketpolicyonly set off gs://redbucket gs://bluebucket
"""

_GET_DESCRIPTION = """
<B>GET</B>
  The ``bucketpolicyonly get`` command shows whether Bucket Policy Only is
  enabled for the specified Cloud Storage bucket(s).

<B>GET EXAMPLES</B>
  Check if your buckets are using Bucket Policy Only:

    gsutil bucketpolicyonly get gs://redbucket gs://bluebucket
"""

_DESCRIPTION = """
  The ``bucketpolicyonly`` command is used to retrieve or configure the Bucket
  Policy Only setting of Cloud Storage bucket(s). This command has two
  sub-commands, ``get`` and ``set``.
""" + _GET_DESCRIPTION + _SET_DESCRIPTION

_DETAILED_HELP_TEXT = CreateHelpText(_SYNOPSIS, _DESCRIPTION)
_set_help_text = CreateHelpText(_SET_SYNOPSIS, _SET_DESCRIPTION)
_get_help_text = CreateHelpText(_GET_SYNOPSIS, _GET_DESCRIPTION)

# Aliases to make these more likely to fit on one line.
IamConfigurationValue = apitools_messages.Bucket.IamConfigurationValue
BucketPolicyOnlyValue = IamConfigurationValue.BucketPolicyOnlyValue


class BucketPolicyOnlyCommand(Command):
  """Implements the gsutil bucketpolicyonly command."""

  command_spec = Command.CreateCommandSpec(
      'bucketpolicyonly',
      usage_synopsis=_SYNOPSIS,
      min_args=2,
      max_args=NO_MAX,
      supported_sub_args='',
      file_url_ok=False,
      provider_url_ok=False,
      urls_start_arg=2,
      gs_api_support=[ApiSelector.JSON],
      gs_default_api=ApiSelector.JSON,
      argparse_arguments={
          'get': [
              CommandArgument.MakeNCloudURLsArgument(1),
          ],
          'set': [
              CommandArgument('mode', choices=['on', 'off']),
              CommandArgument.MakeZeroOrMoreCloudBucketURLsArgument()
          ],
      })
  # Help specification. See help_provider.py for documentation.
  help_spec = Command.HelpSpec(
      help_name='bucketpolicyonly',
      help_name_aliases=[],
      help_type='command_help',
      help_one_line_summary='Configure Bucket Policy Only',
      help_text=_DETAILED_HELP_TEXT,
      subcommand_help_text={
          'get': _get_help_text,
          'set': _set_help_text,
      },
  )

  def _ValidateBucketListingRefAndReturnBucketName(self, blr):
    if blr.storage_url.scheme != 'gs':
      raise CommandException(
          'The %s command can only be used with gs:// bucket URLs.' %
          self.command_name)

  def _GetBucketPolicyOnly(self, blr):
    """Gets the Bucket Policy Only setting for a bucket."""
    self._ValidateBucketListingRefAndReturnBucketName(blr)
    bucket_url = blr.storage_url

    bucket_metadata = self.gsutil_api.GetBucket(
        bucket_url.bucket_name,
        fields=['iamConfiguration'],
        provider=bucket_url.scheme)
    iam_config = bucket_metadata.iamConfiguration
    bucket_policy_only = iam_config.bucketPolicyOnly

    fields = {'bucket': str(bucket_url).rstrip('/'),
              'enabled': bucket_policy_only.enabled}

    locked_time_line = ''
    if bucket_policy_only.lockedTime:
      fields['locked_time'] = bucket_policy_only.lockedTime
      locked_time_line = '  LockedTime: {locked_time}\n'

    if bucket_policy_only:
      print(('Bucket Policy Only setting for {bucket}:\n'
             '  Enabled: {enabled}\n' +
             locked_time_line).format(**fields))

  def _SetBucketPolicyOnly(self, blr, setting_arg):
    """Sets the Bucket Policy Only setting for a bucket on or off."""
    self._ValidateBucketListingRefAndReturnBucketName(blr)
    bucket_url = blr.storage_url

    iam_config = IamConfigurationValue()
    iam_config.bucketPolicyOnly = BucketPolicyOnlyValue()
    iam_config.bucketPolicyOnly.enabled = (setting_arg == 'on')

    bucket_metadata = apitools_messages.Bucket(
        iamConfiguration=iam_config)

    setting_verb = 'Enabling' if setting_arg == 'on' else 'Disabling'
    print('%s Bucket Policy Only for %s...'
          % (setting_verb, str(bucket_url).rstrip('/')))

    self.gsutil_api.PatchBucket(
        bucket_url.bucket_name,
        bucket_metadata,
        fields=['iamConfiguration'],
        provider=bucket_url.scheme)
    return 0

  def _BucketPolicyOnly(self):
    """Handles bucketpolicyonly command on a Cloud Storage bucket."""
    subcommand = self.args.pop(0)

    if subcommand not in ('get', 'set'):
      raise CommandException('bucketpolicyonly only supports get|set')

    subcommand_func = None
    subcommand_args = []
    setting_arg = None

    if subcommand == 'get':
      subcommand_func = self._GetBucketPolicyOnly
    elif subcommand == 'set':
      subcommand_func = self._SetBucketPolicyOnly
      setting_arg = self.args.pop(0)
      InsistOnOrOff(setting_arg,
                    'Only on and off values allowed for set option')
      subcommand_args.append(setting_arg)

    # Iterate over bucket args, performing the specified subsubcommand.
    some_matched = False
    url_args = self.args
    if not url_args:
      self.RaiseWrongNumberOfArgumentsException()
    for url_str in url_args:
      # Throws a CommandException if the argument is not a bucket.
      bucket_iter = self.GetBucketUrlIterFromArg(url_str)
      for bucket_listing_ref in bucket_iter:
        some_matched = True
        subcommand_func(bucket_listing_ref, *subcommand_args)

    if not some_matched:
      raise CommandException(NO_URLS_MATCHED_TARGET % list(url_args))
    return 0

  def RunCommand(self):
    """Command entry point for the bucketpolicyonly command."""
    if self.gsutil_api.GetApiSelector(provider='gs') != ApiSelector.JSON:
      raise CommandException('\n'.join(textwrap.wrap(
          'The "%s" command can only be used with the Cloud Storage JSON API.'
          % self.command_name)))

    action_subcommand = self.args[0]
    self.ParseSubOpts(check_args=True)

    if action_subcommand == 'get' or action_subcommand == 'set':
      metrics.LogCommandParams(sub_opts=self.sub_opts)
      metrics.LogCommandParams(subcommands=[action_subcommand])
      self._BucketPolicyOnly()
    else:
      raise CommandException('Invalid subcommand "%s", use get|set instead.' %
                             action_subcommand)
