# -*- coding: utf-8 -*-
# Copyright 2011 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.
"""Implementation of logging configuration command for buckets."""

from __future__ import absolute_import

import sys

from apitools.base.py import encoding

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.storage_url import StorageUrlFromString
from gslib.third_party.storage_apitools import storage_v1_messages as apitools_messages
from gslib.util import NO_MAX
from gslib.util import UrlsAreForSingleProvider

_SET_SYNOPSIS = """
  gsutil logging set on -b logging_bucket [-o log_object_prefix] url...
  gsutil logging set off url...
"""

_GET_SYNOPSIS = """
  gsutil logging get url
"""

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

_SET_DESCRIPTION = """
<B>SET</B>
  The set sub-command has two sub-commands:

<B>ON</B>
  The "gsutil logging set on" command will enable access logging of the
  buckets named by the specified URLs, outputting log files in the specified
  logging_bucket. logging_bucket must already exist, and all URLs must name
  buckets (e.g., gs://bucket). The required bucket parameter specifies the
  bucket to which the logs are written, and the optional log_object_prefix
  parameter specifies the prefix for log object names. The default prefix
  is the bucket name. For example, the command:

    gsutil logging set on -b gs://my_logging_bucket -o AccessLog \\
        gs://my_bucket1 gs://my_bucket2

  will cause all read and write activity to objects in gs://mybucket1 and
  gs://mybucket2 to be logged to objects prefixed with the name "AccessLog",
  with those log objects written to the bucket gs://my_logging_bucket.

  In addition to enabling logging on your bucket(s), you will also need to grant
  cloud-storage-analytics@google.com write access to the log bucket, using this
  command:

    gsutil acl ch -g cloud-storage-analytics@google.com:W gs://my_logging_bucket

  Note that log data may contain sensitive information, so you should make
  sure to set an appropriate default bucket ACL to protect that data. (See
  "gsutil help defacl".)

<B>OFF</B>
  This command will disable access logging of the buckets named by the
  specified URLs. All URLs must name buckets (e.g., gs://bucket).

  No logging data is removed from the log buckets when you disable logging,
  but Google Cloud Storage will stop delivering new logs once you have
  run this command.

"""

_GET_DESCRIPTION = """
<B>GET</B>
  If logging is enabled for the specified bucket url, the server responds
  with a JSON document that looks something like this:

    {
      "logObjectPrefix": "AccessLog",
      "logBucket": "my_logging_bucket"
    }

  You can download log data from your log bucket using the gsutil cp command.

"""

_DESCRIPTION = """
  Google Cloud Storage offers access logs and storage data in the form of
  CSV files that you can download and view. Access logs provide information
  for all of the requests made on a specified bucket in the last 24 hours,
  while the storage logs provide information about the storage consumption of
  that bucket for the last 24 hour period. The logs and storage data files
  are automatically created as new objects in a bucket that you specify, in
  24 hour intervals.

  The logging command has two sub-commands:
""" + _SET_DESCRIPTION + _GET_DESCRIPTION + """

<B>ACCESS LOG AND STORAGE DATA FIELDS</B>
  For a complete list of access log fields and storage data fields, see:
  https://cloud.google.com/storage/docs/access-logs#format
"""

_DETAILED_HELP_TEXT = CreateHelpText(_SYNOPSIS, _DESCRIPTION)

_get_help_text = CreateHelpText(_GET_SYNOPSIS, _GET_DESCRIPTION)
_set_help_text = CreateHelpText(_SET_SYNOPSIS, _SET_DESCRIPTION)


class LoggingCommand(Command):
  """Implementation of gsutil logging command."""

  # Command specification. See base class for documentation.
  command_spec = Command.CreateCommandSpec(
      'logging',
      command_name_aliases=['disablelogging', 'enablelogging', 'getlogging'],
      usage_synopsis=_SYNOPSIS,
      min_args=2,
      max_args=NO_MAX,
      supported_sub_args='b:o:',
      file_url_ok=False,
      provider_url_ok=False,
      urls_start_arg=0,
      gs_api_support=[ApiSelector.XML, ApiSelector.JSON],
      gs_default_api=ApiSelector.JSON,
      argparse_arguments=[
          CommandArgument('mode', choices=['on', 'off']),
          CommandArgument.MakeZeroOrMoreCloudBucketURLsArgument()
      ]
  )
  # Help specification. See help_provider.py for documentation.
  help_spec = Command.HelpSpec(
      help_name='logging',
      help_name_aliases=['loggingconfig', 'logs', 'log', 'getlogging',
                         'enablelogging', 'disablelogging'],
      help_type='command_help',
      help_one_line_summary='Configure or retrieve logging on buckets',
      help_text=_DETAILED_HELP_TEXT,
      subcommand_help_text={'get': _get_help_text, 'set': _set_help_text},
  )

  def _Get(self):
    """Gets logging configuration for a bucket."""
    bucket_url, bucket_metadata = self.GetSingleBucketUrlFromArg(
        self.args[0], bucket_fields=['logging'])

    if bucket_url.scheme == 's3':
      sys.stdout.write(self.gsutil_api.XmlPassThroughGetLogging(
          bucket_url, provider=bucket_url.scheme))
    else:
      if (bucket_metadata.logging and bucket_metadata.logging.logBucket and
          bucket_metadata.logging.logObjectPrefix):
        sys.stdout.write(str(encoding.MessageToJson(
            bucket_metadata.logging)) + '\n')
      else:
        sys.stdout.write('%s has no logging configuration.\n' % bucket_url)
    return 0

  def _Enable(self):
    """Enables logging configuration for a bucket."""
    # Disallow multi-provider 'logging set on' calls, because the schemas
    # differ.
    if not UrlsAreForSingleProvider(self.args):
      raise CommandException('"logging set on" command spanning providers not '
                             'allowed.')
    target_bucket_url = None
    target_prefix = None
    for opt, opt_arg in self.sub_opts:
      if opt == '-b':
        target_bucket_url = StorageUrlFromString(opt_arg)
      if opt == '-o':
        target_prefix = opt_arg

    if not target_bucket_url:
      raise CommandException('"logging set on" requires \'-b <log_bucket>\' '
                             'option')
    if not target_bucket_url.IsBucket():
      raise CommandException('-b option must specify a bucket URL.')

    # Iterate over URLs, expanding wildcards and setting logging on each.
    some_matched = False
    for url_str in self.args:
      bucket_iter = self.GetBucketUrlIterFromArg(url_str, bucket_fields=['id'])
      for blr in bucket_iter:
        url = blr.storage_url
        some_matched = True
        self.logger.info('Enabling logging on %s...', blr)
        logging = apitools_messages.Bucket.LoggingValue(
            logBucket=target_bucket_url.bucket_name,
            logObjectPrefix=target_prefix or url.bucket_name)

        bucket_metadata = apitools_messages.Bucket(logging=logging)
        self.gsutil_api.PatchBucket(url.bucket_name, bucket_metadata,
                                    provider=url.scheme, fields=['id'])
    if not some_matched:
      raise CommandException(NO_URLS_MATCHED_TARGET % list(self.args))
    return 0

  def _Disable(self):
    """Disables logging configuration for a bucket."""
    # Iterate over URLs, expanding wildcards, and disabling logging on each.
    some_matched = False
    for url_str in self.args:
      bucket_iter = self.GetBucketUrlIterFromArg(url_str, bucket_fields=['id'])
      for blr in bucket_iter:
        url = blr.storage_url
        some_matched = True
        self.logger.info('Disabling logging on %s...', blr)
        logging = apitools_messages.Bucket.LoggingValue()

        bucket_metadata = apitools_messages.Bucket(logging=logging)
        self.gsutil_api.PatchBucket(url.bucket_name, bucket_metadata,
                                    provider=url.scheme, fields=['id'])
    if not some_matched:
      raise CommandException(NO_URLS_MATCHED_TARGET % list(self.args))
    return 0

  def RunCommand(self):
    """Command entry point for the logging command."""
    # Parse the subcommand and alias for the new logging command.
    action_subcommand = self.args.pop(0)
    if action_subcommand == 'get':
      func = self._Get
    elif action_subcommand == 'set':
      state_subcommand = self.args.pop(0)
      if not self.args:
        self.RaiseWrongNumberOfArgumentsException()
      if state_subcommand == 'on':
        func = self._Enable
      elif state_subcommand == 'off':
        func = self._Disable
      else:
        raise CommandException((
            'Invalid subcommand "%s" for the "%s %s" command.\n'
            'See "gsutil help logging".') % (
                state_subcommand, self.command_name, action_subcommand))
    else:
      raise CommandException(('Invalid subcommand "%s" for the %s command.\n'
                              'See "gsutil help logging".') %
                             (action_subcommand, self.command_name))
    self.ParseSubOpts(check_args=True)
    func()
    return 0