# -*- 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 config command for creating a gsutil configuration file."""

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

import datetime
import json
import multiprocessing
import os
import signal
import socket
import stat
import sys
import textwrap
import time
import webbrowser

from six.moves import input
from six.moves.http_client import ResponseNotReady
import boto
from boto.provider import Provider
import gslib
from gslib.command import Command
from gslib.command import DEFAULT_TASK_ESTIMATION_THRESHOLD
from gslib.commands.compose import MAX_COMPOSE_ARITY
from gslib.cred_types import CredTypes
from gslib.exception import AbortException
from gslib.exception import CommandException
from gslib.metrics import CheckAndMaybePromptForAnalyticsEnabling
from gslib.sig_handling import RegisterSignalHandler
from gslib.utils import constants
from gslib.utils import system_util
from gslib.utils.hashing_helper import CHECK_HASH_ALWAYS
from gslib.utils.hashing_helper import CHECK_HASH_IF_FAST_ELSE_FAIL
from gslib.utils.hashing_helper import CHECK_HASH_IF_FAST_ELSE_SKIP
from gslib.utils.hashing_helper import CHECK_HASH_NEVER
from gslib.utils.parallelism_framework_util import ShouldProhibitMultiprocessing
from httplib2 import ServerNotFoundError
from oauth2client.client import HAS_CRYPTO

_SYNOPSIS = """
  gsutil [-D] config [-a] [-b] [-e] [-f] [-n] [-o <file>] [-r] [-s <scope>] [-w]
"""

_DETAILED_HELP_TEXT = ("""
<B>SYNOPSIS</B>
""" + _SYNOPSIS + """


<B>DESCRIPTION</B>
  The ``gsutil config`` command applies to users who have installed gsutil as a
  standalone tool. If you installed gsutil via the Cloud SDK, ``gsutil config``
  fails unless you are specifically using the ``-a`` flag or have configured
  gcloud to not pass its managed credentials to gsutil (via the command ``gcloud
  config set pass_credentials_to_gsutil false``). For all other use cases, Cloud
  SDK users should use the ``gcloud auth`` group of commands instead, which
  configures OAuth2 credentials that gcloud implicitly passes to gsutil at
  runtime. To check if you are using gsutil from the Cloud SDK or as a
  stand-alone, use ``gsutil version -l`` and in the output look for "using cloud
  sdk".

  The ``gsutil config`` command obtains access credentials for Google Cloud
  Storage and writes a `boto/gsutil configuration file
  <https://cloud.google.com/storage/docs/boto-gsutil>`_ containing the obtained
  credentials along with a number of other configuration-controllable values.

  Unless specified otherwise (see OPTIONS), the configuration file is written
  to ~/.boto (i.e., the file .boto under the user's home directory). If the
  default file already exists, an attempt is made to rename the existing file
  to ~/.boto.bak; if that attempt fails the command exits. A different
  destination file can be specified with the ``-o`` option (see OPTIONS).

  Because the boto configuration file contains your credentials you should
  keep its file permissions set so no one but you has read access. (The file
  is created read-only when you run ``gsutil config``.)


<B>CREDENTIALS</B>
  By default ``gsutil config`` obtains OAuth2 credentials and writes them to the
  [Credentials] section of the configuration file. Unless otherwise specified,
  it requests a token allowing full control of resources in several services,
  e.g. Cloud Storage, Cloud KMS (used for the 'kms' command), and Cloud Pub/Sub
  (used for the 'notification' command). To request a token with more limited
  scopes, you can specify additional options (see the OPTIONS section below for
  the full list). Some examples include:

  Create a token with read-only access for storage resources:

    gsutil config -r

  Create a token with read-write access for storage resources:

    gsutil config -w

  Create a token with full-control access for storage resources:

    gsutil config -f

  In addition, ``-s <scope>`` can be specified multiple times to request
  additional scopes, where ``<scope>`` is specified using the full URL of the
  desired scope as listed on
  https://developers.google.com/identity/protocols/googlescopes.

  If you want to use credentials based on access key and secret (the older
  authentication method before OAuth2 was supported) instead of OAuth2,
  see help about the ``-a`` option in the OPTIONS section.

  If you wish to use gsutil with other providers (or to copy data back and
  forth between multiple providers) you can edit their credentials into the
  [Credentials] section after creating the initial boto configuration file.


<B>CONFIGURING SERVICE ACCOUNT CREDENTIALS</B>
  Service accounts are useful for authenticating on behalf of a service or
  application (as opposed to a user). If you use gsutil as a standalone tool,
  you configure credentials for service accounts using the ``-e`` option:

    gsutil config -e

  Note that if you use gsutil through the Cloud SDK, you instead activate your
  service account via the `gcloud auth activate-service-account
  <https://cloud.google.com/sdk/gcloud/reference/auth/activate-service-account>`_
  command.

  When you run ``gsutil config -e``, you are prompted for the path to your
  private key file and, if not using a JSON key file, your service account
  email address and key file password. To get this data, follow the instructions
  on `Service Accounts <https://cloud.google.com/storage/docs/authentication#generating-a-private-key>`_.
  Using this information, gsutil populates the "gs_service_key_file" attribute
  in the boto configuration file. If not using a JSON key file, gsutil also
  populates the "gs_service_client_id" and "gs_service_key_file_password"
  attributes.

  Note that your service account is NOT considered an Owner for the purposes of
  API access (see "gsutil help creds" for more information about this). See
  https://developers.google.com/identity/protocols/OAuth2ServiceAccount for
  further information on service account authentication.


<B>OPTIONS</B>
  -a          Prompt for Google Cloud Storage access key and secret (the older
              authentication method before OAuth2 was supported) instead of
              obtaining an OAuth2 token.

  -b          Causes ``gsutil config`` to launch a browser to obtain OAuth2
              approval and the project ID instead of showing the URL for each
              and asking the user to open the browser. This will probably not
              work as expected if you are running gsutil from an ssh window, or
              using gsutil on Windows.

  -e          Prompt for service account credentials. This option requires that
              ``-a`` is not set.

  -f          Request token with full control (devstorage.full_control scope).
              Note that this does not provide non-storage scopes, such as those
              needed to edit Pub/Sub and KMS resources (used with the
              'notification' and 'kms' commands).

  -n          Write the configuration file without authentication configured.
              This flag is mutually exclusive with all flags other than ``-o``.

  -o <file>   Write the configuration to <file> instead of ~/.boto.
              Use ``-`` for stdout.

  -r          Request token with read-only access (devstorage.read_only scope).

  --reauth    Request token with reauth access (accounts.reauth scope).

  -s <scope>  Request a specific OAuth2 <scope> instead of the default(s). This
              option may be repeated to request multiple scopes, and may be used
              in conjunction with other flags that request a specific scope.

  -w          Request token with read-write access
              (devstorage.read_write scope).
""")

try:
  from gcs_oauth2_boto_plugin import oauth2_helper  # pylint: disable=g-import-not-at-top
except ImportError:
  pass

GOOG_CLOUD_CONSOLE_URI = 'https://cloud.google.com/console#/project'

CONFIG_PRELUDE_CONTENT = """
# This file contains credentials and other configuration information needed
# by the boto library, used by gsutil. You can edit this file (e.g., to add
# credentials) but be careful not to mis-edit any of the variable names (like
# "gs_access_key_id") or remove important markers (like the "[Credentials]" and
# "[Boto]" section delimiters).
#
"""

# Default number of OS processes and Python threads for parallel operations.
# On Linux systems we automatically scale the number of processes to match
# the underlying CPU/core count. Given we'll be running multiple concurrent
# processes on a typical multi-core Linux computer, to avoid being too
# aggressive with resources, the default number of threads is reduced from
# the previous value of 24 to 5.
#
# We also cap the maximum number of default processes at 32. Since each level
# of recursion depth gets its own process pool, this means a maximum of
# 64 processes with the current maximum recursion depth of 2.  We limit this
# number because testing with more than 200 processes showed fatal locking
# exceptions in Python's multiprocessing.Manager. More processes are
# probably not needed to saturate most networks.
#
# On Windows and Alpine Linux, Python multi-processing presents various
# challenges so we retain compatibility with the established parallel mode
# operation, i.e. one process and 24 threads.
should_prohibit_multiprocessing, unused_os = ShouldProhibitMultiprocessing()
if should_prohibit_multiprocessing:
  DEFAULT_PARALLEL_PROCESS_COUNT = 1
  DEFAULT_PARALLEL_THREAD_COUNT = 24
else:
  DEFAULT_PARALLEL_PROCESS_COUNT = min(multiprocessing.cpu_count(), 32)
  DEFAULT_PARALLEL_THREAD_COUNT = 5

# TODO: Once compiled crcmod is being distributed by major Linux distributions
# revert DEFAULT_PARALLEL_COMPOSITE_UPLOAD_THRESHOLD value to '150M'.
DEFAULT_PARALLEL_COMPOSITE_UPLOAD_THRESHOLD = '0'
DEFAULT_PARALLEL_COMPOSITE_UPLOAD_COMPONENT_SIZE = '50M'
DEFAULT_SLICED_OBJECT_DOWNLOAD_THRESHOLD = '150M'
DEFAULT_SLICED_OBJECT_DOWNLOAD_COMPONENT_SIZE = '200M'
DEFAULT_SLICED_OBJECT_DOWNLOAD_MAX_COMPONENTS = 4

# Compressed transport encoded uploads buffer chunks of compressed data. When
# running many uploads in parallel, compression may consume more memory than
# available. This restricts the number of compressed transport encoded uploads
# running in parallel such that they don't consume more memory than set here.
DEFAULT_MAX_UPLOAD_COMPRESSION_BUFFER_SIZE = '2G'

# gzip compression level. This is simply making the python stdlib default explicit.
DEFAULT_GZIP_COMPRESSION_LEVEL = 9

CONFIG_BOTO_SECTION_CONTENT = """
[Boto]

# http_socket_timeout specifies the timeout (in seconds) used to tell httplib
# how long to wait for socket timeouts. The default is 70 seconds. Note that
# this timeout only applies to httplib, not to httplib2 (which is used for
# OAuth2 refresh/access token exchanges).
#http_socket_timeout = 70

# The following two options control the use of a secure transport for requests
# to S3 and Google Cloud Storage. It is highly recommended to set both options
# to True in production environments, especially when using OAuth2 bearer token
# authentication with Google Cloud Storage.

# Set 'https_validate_certificates' to False to disable server certificate
# checking. The default for this option in the boto library is currently
# 'False' (to avoid breaking apps that depend on invalid certificates); it is
# therefore strongly recommended to always set this option explicitly to True
# in configuration files, to protect against "man-in-the-middle" attacks.
https_validate_certificates = True

# 'debug' controls the level of debug messages printed for the XML API only:
# 0 for none, 1 for basic boto debug, 2 for all boto debug plus HTTP
# requests/responses.
#debug = <0, 1, or 2>

# 'num_retries' controls the number of retry attempts made when errors occur
# during data transfers. The default is 6.
# Note 1: You can cause gsutil to retry failures effectively infinitely by
# setting this value to a large number (like 10000). Doing that could be useful
# in cases where your network connection occasionally fails and is down for an
# extended period of time, because when it comes back up gsutil will continue
# retrying.  However, in general we recommend not setting the value above 10,
# because otherwise gsutil could appear to "hang" due to excessive retries
# (since unless you run gsutil -D you won't see any logged evidence that gsutil
# is retrying).
# Note 2: Don't set this value to 0, as it will cause boto to fail when reusing
# HTTP connections.
#num_retries = <integer value>

# 'max_retry_delay' controls the max delay (in seconds) between retries. The
# default value is 60, so the backoff sequence will be 1 seconds, 2 seconds, 4,
# 8, 16, 32, and then 60 for all subsequent retries for a given HTTP request.
# Note: At present this value only impacts the XML API and the JSON API uses a
# fixed value of 60.
#max_retry_delay = <integer value>
"""

CONFIG_GOOGLECOMPUTE_SECTION_CONTENT = """
[GoogleCompute]

# 'service_account' specifies the a Google Compute Engine service account to
# use for credentials. This value is intended for use only on Google Compute
# Engine virtual machines and usually lives in /etc/boto.cfg. Most users
# shouldn't need to edit this part of the config.
#service_account = default
"""

CONFIG_INPUTLESS_GSUTIL_SECTION_CONTENT = """
[GSUtil]

# 'resumable_threshold' specifies the smallest file size [bytes] for which
# resumable Google Cloud Storage uploads are attempted. The default is 8388608
# (8 MiB).
#resumable_threshold = %(resumable_threshold)d

# 'rsync_buffer_lines' specifies the number of lines of bucket or directory
# listings saved in each temp file during sorting. (The complete set is
# split across temp files and separately sorted/merged, to avoid needing to
# fit everything in memory at once.) If you are trying to synchronize very
# large directories/buckets (e.g., containing millions or more objects),
# having too small a value here can cause gsutil to run out of open file
# handles. If that happens, you can try to increase the number of open file
# handles your system allows (e.g., see 'man ulimit' on Linux; see also
# http://docs.python.org/2/library/resource.html). If you can't do that (or
# if you're already at the upper limit), increasing rsync_buffer_lines will
# cause gsutil to use fewer file handles, but at the cost of more memory. With
# rsync_buffer_lines set to 32000 and assuming a typical URL is 100 bytes
# long, gsutil will require approximately 10 MiB of memory while building
# the synchronization state, and will require approximately 60 open file
# descriptors to build the synchronization state over all 1M source and 1M
# destination URLs. Memory and file descriptors are only consumed while
# building the state; once the state is built, it resides in two temp files that
# are read and processed incrementally during the actual copy/delete
# operations.
#rsync_buffer_lines = 32000

# 'state_dir' specifies the base location where files that
# need a static location are stored, such as pointers to credentials,
# resumable transfer tracker files, and the last software update check.
# By default these files are stored in ~/.gsutil
#state_dir = <file_path>
# gsutil periodically checks whether a new version of the gsutil software is
# available. 'software_update_check_period' specifies the number of days
# between such checks. The default is 30. Setting the value to 0 disables
# periodic software update checks.
#software_update_check_period = 30

# 'tab_completion_timeout' controls the timeout (in seconds) for tab
# completions that involve remote requests (such as bucket or object names).
# If tab completion does not succeed within this timeout, no tab completion
# suggestions will be returned.
# A value of 0 will disable completions that involve remote requests.
#tab_completion_timeout = 5

# 'parallel_process_count' and 'parallel_thread_count' specify the number
# of OS processes and Python threads, respectively, to use when executing
# operations in parallel. The default settings should work well as configured,
# however, to enhance performance for transfers involving large numbers of
# files, you may experiment with hand tuning these values to optimize
# performance for your particular system configuration.
#parallel_process_count = %(parallel_process_count)d
#parallel_thread_count = %(parallel_thread_count)d

# 'parallel_composite_upload_threshold' specifies the maximum size of a file to
# upload in a single stream. Files larger than this threshold will be
# partitioned into component parts and uploaded in parallel and then composed
# into a single object.
# The number of components will be the smaller of
# ceil(file_size / parallel_composite_upload_component_size) and
# MAX_COMPOSE_ARITY. The current value of MAX_COMPOSE_ARITY is
# %(max_compose_arity)d.
# If 'parallel_composite_upload_threshold' is set to 0, then automatic parallel
# uploads will never occur.
# Setting an extremely low threshold is unadvisable. The vast majority of
# environments will see degraded performance for thresholds below 80M, and it
# is almost never advantageous to have a threshold below 20M.
# 'parallel_composite_upload_component_size' specifies the ideal size of a
# component in bytes, which will act as an upper bound to the size of the
# components if ceil(file_size / parallel_composite_upload_component_size) is
# less than MAX_COMPOSE_ARITY.
# Values can be provided either in bytes or as human-readable values
# (e.g., "150M" to represent 150 mebibytes)
#
# Note: At present parallel composite uploads are disabled by default, because
# using composite objects requires a compiled crcmod (see "gsutil help crcmod"),
# and for operating systems that don't already have this package installed this
# makes gsutil harder to use. Google is actively working with a number of the
# Linux distributions to get crcmod included with the stock distribution. Once
# that is done we will re-enable parallel composite uploads by default in
# gsutil.
#
# Note: Parallel composite uploads should not be used with NEARLINE, COLDLINE,
# or ARCHIVE storage class buckets, as doing this incurs an early deletion
# charge for each component object.
#
# Note: Parallel composite uploads are not enabled with Cloud KMS encrypted
# objects as a source or destination, as composition with KMS objects is not yet
# supported.

#parallel_composite_upload_threshold = %(parallel_composite_upload_threshold)s
#parallel_composite_upload_component_size = %(parallel_composite_upload_component_size)s

# 'sliced_object_download_threshold' and
# 'sliced_object_download_component_size' have analogous functionality to
# their respective parallel_composite_upload config values.
# 'sliced_object_download_max_components' specifies the maximum number of
# slices to be used when performing a sliced object download.
#sliced_object_download_threshold = %(sliced_object_download_threshold)s
#sliced_object_download_component_size = %(sliced_object_download_component_size)s
#sliced_object_download_max_components = %(sliced_object_download_max_components)s

# Compressed transport encoded uploads buffer chunks of compressed data. When
# running a composite upload and/or many uploads in parallel, compression may
# consume more memory than available. This setting restricts the number of
# compressed transport encoded uploads running in parallel such that they
# don't consume more memory than set here. This is 2GiB by default.
# Values can be provided either in bytes or as human-readable values
# (e.g., "2G" to represent 2 gibibytes)
#max_upload_compression_buffer_size = %(max_upload_compression_buffer_size)s

# GZIP compression level, if using compression. Reducing this can have
# a dramatic impact on compression speed with minor size increases.
# This is a value from 0-9, with 9 being max compression.
# A good level to try is 6, which is the default used by the gzip tool.
#gzip_compression_level = %(gzip_compression_level)s

# 'task_estimation_threshold' controls how many files or objects gsutil
# processes before it attempts to estimate the total work that will be
# performed by the command. Estimation makes extra directory listing or API
# list calls and is performed only if multiple processes and/or threads are
# used. Estimation can slightly increase cost due to extra
# listing calls; to disable it entirely, set this value to 0.
#task_estimation_threshold=%(task_estimation_threshold)s

# 'use_magicfile' specifies if the 'file --mime <filename>' command should be
# used to guess content types instead of the default filename extension-based
# mechanism. Available on UNIX and macOS (and possibly on Windows, if you're
# running Cygwin or some other package that provides implementations of
# UNIX-like commands). When available and enabled use_magicfile should be more
# robust because it analyzes file contents in addition to extensions.
#use_magicfile = False

# Service account emails for testing the hmac command. If these fields are not
# populated with distinct service accounts the tests for the hmac command will
# not be run.  Primarily useful for tool developers.
#test_hmac_service_account =
#test_hmac_alt_service_account =
#test_hmac_list_service_account =

# Service account emails for testing impersonation credentials. If this field is
# not populated with a service account the tests for service account
# impersonation will not run.  Primarily useful for tool developers.
#test_impersonate_service_account =

# 'content_language' specifies the ISO 639-1 language code of the content, to be
# passed in the Content-Language header. By default no Content-Language is sent.
# See the ISO 639-1 column of
# http://www.loc.gov/standards/iso639-2/php/code_list.php for a list of
# language codes.
content_language = en

# 'check_hashes' specifies how strictly to require integrity checking for
# downloaded data. Legal values are:
#   '%(hash_fast_else_fail)s' - (default) Only integrity check if the digest
#       will run efficiently (using compiled code), else fail the download.
#   '%(hash_fast_else_skip)s' - Only integrity check if the server supplies a
#       hash and the local digest computation will run quickly, else skip the
#       check.
#   '%(hash_always)s' - Always check download integrity regardless of possible
#       performance costs.
#   '%(hash_never)s' - Don't perform download integrity checks. This setting is
#       not recommended except for special cases such as measuring download
#       performance excluding time for integrity checking.
# This option exists to assist users who wish to download a GCS composite object
# and are unable to install crcmod with the C-extension. CRC32c is the only
# available integrity check for composite objects, and without the C-extension,
# download performance can be significantly degraded by the digest computation.
# This option is ignored for daisy-chain copies, which don't compute hashes but
# instead (inexpensively) compare the cloud source and destination hashes.
#check_hashes = if_fast_else_fail

# 'encryption_key' specifies a single customer-supplied encryption key that
# will be used for all data written to Google Cloud Storage. See
# "gsutil help encryption" for more information
# Encryption key: RFC 4648 section 4 base64-encoded AES256 string
# Warning: If decrypt_key is specified without an encrypt_key, objects will be
# decrypted when copied in the cloud.
#encryption_key=

# Each 'decryption_key' entry specifies a customer-supplied decryption key that
# will be used to access and Google Cloud Storage objects encrypted with
# the corresponding key.
# Decryption keys: Up to 100 RFC 4648 section 4 base64-encoded AES256 strings
# in ascending numerical order, starting with 1.
#decryption_key1=
#decryption_key2=
#decryption_key3=

# The ability to specify an alternative JSON API version is primarily for cloud
# storage service developers.
#json_api_version = v1

# Specifies the API to use when interacting with cloud storage providers. If the
# gsutil command supports this API for the provider, it will be used instead of
# the default API. Commands typically default to XML for S3 and JSON for GCS.
# Note that if any encryption configuration options are set (see above), the
# JSON API will be used for interacting with Google Cloud Storage buckets even
# if XML is preferred, as gsutil does not currently support this functionality
# when using the XML API.
#prefer_api = json
#prefer_api = xml

# Disables the prompt asking for opt-in to data collection for analytics.
#disable_analytics_prompt = True

# The "test" command runs tests against regional buckets (unless you supply the
# `-b` option). By default, the region used is us-central1, but you can change
# the default region using this option.
#test_cmd_regional_bucket_location = us-central1

# Tests for the "notification watchbucket" command require a notification URL.
# If this option is not supplied, those tests will be skipped.
#test_notification_url = https://yourdomain.url/notification-endpoint

""" % {
    'hash_fast_else_fail': CHECK_HASH_IF_FAST_ELSE_FAIL,
    'hash_fast_else_skip': CHECK_HASH_IF_FAST_ELSE_SKIP,
    'hash_always': CHECK_HASH_ALWAYS,
    'hash_never': CHECK_HASH_NEVER,
    'resumable_threshold': constants.RESUMABLE_THRESHOLD_B,
    'parallel_process_count': DEFAULT_PARALLEL_PROCESS_COUNT,
    'parallel_thread_count': DEFAULT_PARALLEL_THREAD_COUNT,
    'parallel_composite_upload_threshold':
        (DEFAULT_PARALLEL_COMPOSITE_UPLOAD_THRESHOLD),
    'parallel_composite_upload_component_size':
        (DEFAULT_PARALLEL_COMPOSITE_UPLOAD_COMPONENT_SIZE),
    'sliced_object_download_threshold':
        (DEFAULT_PARALLEL_COMPOSITE_UPLOAD_THRESHOLD),
    'sliced_object_download_component_size':
        (DEFAULT_PARALLEL_COMPOSITE_UPLOAD_COMPONENT_SIZE),
    'sliced_object_download_max_components':
        (DEFAULT_SLICED_OBJECT_DOWNLOAD_MAX_COMPONENTS),
    'max_compose_arity': MAX_COMPOSE_ARITY,
    'task_estimation_threshold': DEFAULT_TASK_ESTIMATION_THRESHOLD,
    'max_upload_compression_buffer_size':
        (DEFAULT_MAX_UPLOAD_COMPRESSION_BUFFER_SIZE),
    'gzip_compression_level': DEFAULT_GZIP_COMPRESSION_LEVEL,
}

CONFIG_OAUTH2_CONFIG_CONTENT = """
[OAuth2]
# This section specifies options used with OAuth2 authentication.

# 'token_cache' specifies how the OAuth2 client should cache access tokens.
# Valid values are:
#  'in_memory': an in-memory cache is used. This is only useful if the boto
#      client instance (and with it the OAuth2 plugin instance) persists
#      across multiple requests.
#  'file_system' : access tokens will be cached in the file system, in files
#      whose names include a key derived from the refresh token the access token
#      based on.
# The default is 'file_system'.
#token_cache = file_system
#token_cache = in_memory

# 'token_cache_path_pattern' specifies a path pattern for token cache files.
# This option is only relevant if token_cache = file_system.
# The value of this option should be a path, with place-holders '%(key)s' (which
# will be replaced with a key derived from the refresh token the cached access
# token was based on), and (optionally), %(uid)s (which will be replaced with
# the UID of the current user, if available via os.getuid()).
# Note that the config parser itself interpolates '%' placeholders, and hence
# the above placeholders need to be escaped as '%%(key)s'.
# The default value of this option is
#  token_cache_path_pattern = <tmpdir>/oauth2client-tokencache.%%(uid)s.%%(key)s
# where <tmpdir> is the system-dependent default temp directory.

# The following options specify the label and endpoint URIs for the OAUth2
# authorization provider being used. Primarily useful for tool developers.
#provider_label = Google
#provider_authorization_uri = https://accounts.google.com/o/oauth2/auth
#provider_token_uri = https://oauth2.googleapis.com/token

# 'oauth2_refresh_retries' controls the number of retry attempts made when
# rate limiting errors occur for OAuth2 requests to retrieve an access token.
# The default value is 6.
#oauth2_refresh_retries = <integer value>

# The following options specify the OAuth2 client identity and secret that is
# used when requesting and using OAuth2 tokens. If not specified, a default
# OAuth2 client for the gsutil tool is used; for uses of the boto library (with
# OAuth2 authentication plugin) in other client software, it is recommended to
# use a tool/client-specific OAuth2 client. For more information on OAuth2, see
# http://code.google.com/apis/accounts/docs/OAuth2.html
"""


class ConfigCommand(Command):
  """Implementation of gsutil config command."""

  # Command specification. See base class for documentation.
  command_spec = Command.CreateCommandSpec(
      'config',
      command_name_aliases=['cfg', 'conf', 'configure'],
      usage_synopsis=_SYNOPSIS,
      min_args=0,
      max_args=0,
      supported_sub_args='abefhno:rs:w',
      supported_private_args=['reauth'],
      file_url_ok=False,
      provider_url_ok=False,
      urls_start_arg=0,
  )
  # Help specification. See help_provider.py for documentation.
  help_spec = Command.HelpSpec(
      help_name='config',
      help_name_aliases=['cfg', 'conf', 'configure', 'aws', 's3'],
      help_type='command_help',
      help_one_line_summary=(
          'Obtain credentials and create configuration file'),
      help_text=_DETAILED_HELP_TEXT,
      subcommand_help_text={},
  )

  def _OpenConfigFile(self, file_path):
    """Creates and opens a configuration file for writing.

    The file is created with mode 0600, and attempts to open existing files will
    fail (the latter is important to prevent symlink attacks).

    It is the caller's responsibility to close the file.

    Args:
      file_path: Path of the file to be created.

    Returns:
      A writable file object for the opened file.

    Raises:
      CommandException: if an error occurred when opening the file (including
          when the file already exists).
    """
    flags = os.O_RDWR | os.O_CREAT | os.O_EXCL
    # Accommodate Windows; copied from python2.6/tempfile.py.
    if hasattr(os, 'O_NOINHERIT'):
      flags |= os.O_NOINHERIT
    try:
      fd = os.open(file_path, flags, 0o600)
    except (OSError, IOError) as e:
      raise CommandException('Failed to open %s for writing: %s' %
                             (file_path, e))
    return os.fdopen(fd, 'w')

  def _CheckPrivateKeyFilePermissions(self, file_path):
    """Checks that the file has reasonable permissions for a private key.

    In particular, check that the filename provided by the user is not
    world- or group-readable. If either of these are true, we issue a warning
    and offer to fix the permissions.

    Args:
      file_path: The name of the private key file.
    """
    if system_util.IS_WINDOWS:
      # For Windows, this check doesn't work (it actually just checks whether
      # the file is read-only). Since Windows files have a complicated ACL
      # system, this check doesn't make much sense on Windows anyway, so we
      # just don't do it.
      return

    st = os.stat(file_path)
    if bool((stat.S_IRGRP | stat.S_IROTH) & st.st_mode):
      self.logger.warn(
          '\nYour private key file is readable by people other than yourself.\n'
          'This is a security risk, since anyone with this information can use '
          'your service account.\n')
      fix_it = input('Would you like gsutil to change the file '
                     'permissions for you? (y/N) ')
      if fix_it in ('y', 'Y'):
        try:
          os.chmod(file_path, 0o400)
          self.logger.info(
              '\nThe permissions on your file have been successfully '
              'modified.'
              '\nThe only access allowed is readability by the user '
              '(permissions 0400 in chmod).')
        except Exception as _:  # pylint: disable=broad-except
          self.logger.warn(
              '\nWe were unable to modify the permissions on your file.\n'
              'If you would like to fix this yourself, consider running:\n'
              '"sudo chmod 400 </path/to/key>" for improved security.')
      else:
        self.logger.info(
            '\nYou have chosen to allow this file to be readable by others.\n'
            'If you would like to fix this yourself, consider running:\n'
            '"sudo chmod 400 </path/to/key>" for improved security.')

  def _PromptForProxyConfigVarAndMaybeSaveToBotoConfig(self,
                                                       varname,
                                                       prompt,
                                                       convert_to_bool=False):
    """Prompts for one proxy config line, saves to boto.config if not empty.

    Args:
      varname: The config variable name.
      prompt: The prompt to output to the user.
      convert_to_bool: Whether to convert "y/n" to True/False.
    """
    value = input(prompt)
    if value:
      if convert_to_bool:
        if value == 'y' or value == 'Y':
          value = 'True'
        else:
          value = 'False'
      boto.config.set('Boto', varname, value)

  def _PromptForProxyConfig(self):
    """Prompts for proxy config data, loads non-empty values into boto.config.
    """
    self._PromptForProxyConfigVarAndMaybeSaveToBotoConfig(
        'proxy', 'What is your proxy host? ')
    self._PromptForProxyConfigVarAndMaybeSaveToBotoConfig(
        'proxy_type', 'What is your proxy type (socks4, socks5, http)? ')
    self._PromptForProxyConfigVarAndMaybeSaveToBotoConfig(
        'proxy_port', 'What is your proxy port? ')
    self._PromptForProxyConfigVarAndMaybeSaveToBotoConfig(
        'proxy_user', 'What is your proxy user (leave blank if not used)? ')
    self._PromptForProxyConfigVarAndMaybeSaveToBotoConfig(
        'proxy_pass', 'What is your proxy pass (leave blank if not used)? ')
    self._PromptForProxyConfigVarAndMaybeSaveToBotoConfig(
        'proxy_rdns',
        'Should DNS lookups be resolved by your proxy? (Y if your site '
        'disallows client DNS lookups; NOT supported for socks)? ',
        convert_to_bool=True)

  def _WriteConfigLineMaybeCommented(self, config_file, name, value, desc):
    """Writes proxy name/value pair or comment line to config file.

    Writes proxy name/value pair if value is not None.  Otherwise writes
    comment line.

    Args:
      config_file: File object to which the resulting config file will be
          written.
      name: The config variable name.
      value: The value, or None.
      desc: Human readable description (for comment).
    """
    if not value:
      name = '#%s' % name
      value = '<%s>' % desc
    config_file.write('%s = %s\n' % (name, value))

  def _WriteProxyConfigFileSection(self, config_file):
    """Writes proxy section of configuration file.

    Args:
      config_file: File object to which the resulting config file will be
          written.
    """
    config = boto.config
    config_file.write(
        '# To use a proxy, edit and uncomment the proxy and proxy_port lines.\n'
        '# If you need a user/password with this proxy, edit and uncomment\n'
        '# those lines as well. If your organization also disallows DNS\n'
        '# lookups by client machines, set proxy_rdns to True (the default).\n'
        '# If you have installed gsutil through the Cloud SDK and have \n'
        '# configured proxy settings in gcloud, those proxy settings will \n'
        '# override any other options (including those set here, along with \n'
        '# any settings in proxy-related environment variables). Otherwise, \n'
        '# if proxy_host and proxy_port are not specified in this file and\n'
        '# one of the OS environment variables http_proxy, https_proxy, or\n'
        '# HTTPS_PROXY is defined, gsutil will use the proxy server specified\n'
        '# in these environment variables, in order of precedence according\n'
        '# to how they are listed above.\n')
    self._WriteConfigLineMaybeCommented(config_file, 'proxy',
                                        config.get_value('Boto', 'proxy', None),
                                        'proxy host')
    self._WriteConfigLineMaybeCommented(
        config_file, 'proxy_type', config.get_value('Boto', 'proxy_type', None),
        'proxy type (socks4, socks5, http) | Defaults to http')
    self._WriteConfigLineMaybeCommented(
        config_file, 'proxy_port', config.get_value('Boto', 'proxy_port', None),
        'proxy port')
    self._WriteConfigLineMaybeCommented(
        config_file, 'proxy_user', config.get_value('Boto', 'proxy_user', None),
        'proxy user')
    self._WriteConfigLineMaybeCommented(
        config_file, 'proxy_pass', config.get_value('Boto', 'proxy_pass', None),
        'proxy password')
    self._WriteConfigLineMaybeCommented(
        config_file, 'proxy_rdns', config.get_value('Boto', 'proxy_rdns',
                                                    False),
        'let proxy server perform DNS lookups (True,False); socks proxy not supported'
    )

  # pylint: disable=dangerous-default-value,too-many-statements
  def _WriteBotoConfigFile(self,
                           config_file,
                           launch_browser=True,
                           oauth2_scopes=[constants.Scopes.CLOUD_PLATFORM],
                           cred_type=CredTypes.OAUTH2_USER_ACCOUNT,
                           configure_auth=True):
    """Creates a boto config file interactively.

    Needed credentials are obtained interactively, either by asking the user for
    access key and secret, or by walking the user through the OAuth2 approval
    flow.

    Args:
      config_file: File object to which the resulting config file will be
          written.
      launch_browser: In the OAuth2 approval flow, attempt to open a browser
          window and navigate to the approval URL.
      oauth2_scopes: A list of OAuth2 scopes to request authorization for, when
          using OAuth2.
      cred_type: There are three options:
        - for HMAC, ask the user for access key and secret
        - for OAUTH2_USER_ACCOUNT, walk the user through OAuth2 approval flow
          and produce a config with an oauth2_refresh_token credential.
        - for OAUTH2_SERVICE_ACCOUNT, prompt the user for OAuth2 for service
          account email address and private key file (and if the file is a .p12
          file, the password for that file).
      configure_auth: Boolean, whether or not to configure authentication in
          the generated file.
    """
    # Collect credentials
    provider_map = {'aws': 'aws', 'google': 'gs'}
    uri_map = {'aws': 's3', 'google': 'gs'}
    key_ids = {}
    sec_keys = {}
    service_account_key_is_json = False
    if configure_auth:
      if cred_type == CredTypes.OAUTH2_SERVICE_ACCOUNT:
        gs_service_key_file = input('What is the full path to your private '
                                    'key file? ')
        # JSON files have the email address built-in and don't require a
        # password.
        try:
          with open(gs_service_key_file, 'rb') as key_file_fp:
            json.loads(key_file_fp.read())
          service_account_key_is_json = True
        except ValueError:
          if not HAS_CRYPTO:
            raise CommandException(
                'Service account authentication via a .p12 file requires '
                'either\nPyOpenSSL or PyCrypto 2.6 or later. Please install '
                'either of these\nto proceed, use a JSON-format key file, or '
                'configure a different type of credentials.')

        if not service_account_key_is_json:
          gs_service_client_id = input('What is your service account email '
                                       'address? ')
          gs_service_key_file_password = input('\n'.join(
              textwrap.wrap(
                  'What is the password for your service key file [if you '
                  'haven\'t set one explicitly, leave this line blank]?')) +
                                               ' ')
        self._CheckPrivateKeyFilePermissions(gs_service_key_file)
      elif cred_type == CredTypes.OAUTH2_USER_ACCOUNT:
        oauth2_client = oauth2_helper.OAuth2ClientFromBotoConfig(
            boto.config, cred_type)
        try:
          oauth2_refresh_token = oauth2_helper.OAuth2ApprovalFlow(
              oauth2_client, oauth2_scopes, launch_browser)
        except (ResponseNotReady, ServerNotFoundError, socket.error):
          # TODO: Determine condition to check for in the ResponseNotReady
          # exception so we only run proxy config flow if failure was caused by
          # request being blocked because it wasn't sent through proxy. (This
          # error could also happen if gsutil or the oauth2 client had a bug
          # that attempted to incorrectly reuse an HTTP connection, for
          # example.)
          sys.stdout.write('\n'.join(
              textwrap.wrap(
                  "Unable to connect to accounts.google.com during OAuth2 flow. "
                  "This can happen if your site uses a proxy. If you are using "
                  "gsutil through a proxy, please enter the proxy's information; "
                  "otherwise leave the following fields blank.")) + '\n')
          self._PromptForProxyConfig()
          oauth2_client = oauth2_helper.OAuth2ClientFromBotoConfig(
              boto.config, cred_type)
          oauth2_refresh_token = oauth2_helper.OAuth2ApprovalFlow(
              oauth2_client, oauth2_scopes, launch_browser)
      elif cred_type == CredTypes.HMAC:
        got_creds = False
        for provider in provider_map:
          if provider == 'google':
            key_ids[provider] = input('What is your %s access key ID? ' %
                                      provider)
            sec_keys[provider] = input('What is your %s secret access '
                                       'key? ' % provider)
            got_creds = True
            if not key_ids[provider] or not sec_keys[provider]:
              raise CommandException(
                  'Incomplete credentials provided. Please try again.')
        if not got_creds:
          raise CommandException('No credentials provided. Please try again.')

    # Write the config file prelude.
    config_file.write(CONFIG_PRELUDE_CONTENT.lstrip())
    config_file.write(
        '# This file was created by gsutil version %s at %s.\n' %
        (gslib.VERSION, datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')))
    config_file.write(
        '#\n# You can create additional configuration files by '
        'running\n# gsutil config [options] [-o <config-file>]\n\n\n')

    # Write the config file Credentials section.
    config_file.write('[Credentials]\n\n')
    if configure_auth:
      if cred_type == CredTypes.OAUTH2_SERVICE_ACCOUNT:
        config_file.write('# Google OAuth2 service account credentials '
                          '(for "gs://" URIs):\n')
        config_file.write('gs_service_key_file = %s\n' % gs_service_key_file)
        if not service_account_key_is_json:
          config_file.write('gs_service_client_id = %s\n' %
                            gs_service_client_id)

          if not gs_service_key_file_password:
            config_file.write(
                '# If you would like to set your password, you can do so\n'
                '# using the following commands (replaced with your\n'
                '# information):\n'
                '# "openssl pkcs12 -in cert1.p12 -out temp_cert.pem"\n'
                '# "openssl pkcs12 -export -in temp_cert.pem -out cert2.p12"\n'
                '# "rm -f temp_cert.pem"\n'
                '# Your initial password is "notasecret" - for more\n'
                '# information, please see \n'
                '# http://www.openssl.org/docs/apps/pkcs12.html.\n')
            config_file.write('#gs_service_key_file_password =\n\n')
          else:
            config_file.write('gs_service_key_file_password = %s\n\n' %
                              gs_service_key_file_password)
      elif cred_type == CredTypes.OAUTH2_USER_ACCOUNT:
        config_file.write(
            '# Google OAuth2 credentials (for "gs://" URIs):\n'
            '# The following OAuth2 account is authorized for scope(s):\n')
        for scope in oauth2_scopes:
          config_file.write('#     %s\n' % scope)
        config_file.write('gs_oauth2_refresh_token = %s\n\n' %
                          oauth2_refresh_token)
      else:
        config_file.write(
            '# To add Google OAuth2 credentials ("gs://" URIs), '
            'edit and uncomment the\n# following line:\n'
            '#gs_oauth2_refresh_token = <your OAuth2 refresh token>\n\n')
    else:
      if system_util.InvokedViaCloudSdk():
        config_file.write(
            '# Google OAuth2 credentials are managed by the Cloud SDK and\n'
            '# do not need to be present in this file.\n')

    for provider in provider_map:
      key_prefix = provider_map[provider]
      uri_scheme = uri_map[provider]
      if provider in key_ids and provider in sec_keys:
        config_file.write('# %s credentials ("%s://" URIs):\n' %
                          (provider, uri_scheme))
        config_file.write('%s_access_key_id = %s\n' %
                          (key_prefix, key_ids[provider]))
        config_file.write('%s_secret_access_key = %s\n' %
                          (key_prefix, sec_keys[provider]))
      else:
        config_file.write(
            '# To add HMAC %s credentials for "%s://" URIs, edit and '
            'uncomment the\n# following two lines:\n'
            '#%s_access_key_id = <your %s access key ID>\n'
            '#%s_secret_access_key = <your %s secret access key>\n' %
            (provider, uri_scheme, key_prefix, provider, key_prefix, provider))
      host_key = Provider.HostKeyMap[provider]
      config_file.write(
          '# The ability to specify an alternate storage host and port\n'
          '# is primarily for cloud storage service developers.\n'
          '# Setting a non-default gs_host only works if prefer_api=xml.\n'
          '#%s_host = <alternate storage host address>\n'
          '#%s_port = <alternate storage host port>\n'
          '# In some cases, (e.g. VPC requests) the "host" HTTP header should\n'
          '# be different than the host used in the request URL.\n'
          '#%s_host_header = <alternate storage host header>\n' %
          (host_key, host_key, host_key))
      if host_key == 'gs':
        config_file.write(
            '#%s_json_host = <alternate JSON API storage host address>\n'
            '#%s_json_port = <alternate JSON API storage host port>\n'
            '#%s_json_host_header = <alternate JSON API storage host header>\n\n'
            % (host_key, host_key, host_key))
        config_file.write(
            '# To impersonate a service account for "%s://" URIs over\n'
            '# JSON API, edit and uncomment the following line:\n'
            '#%s_impersonate_service_account = <service account email>\n\n')
      config_file.write('\n')

    # Write the config file Boto section.
    config_file.write('%s\n' % CONFIG_BOTO_SECTION_CONTENT)
    self._WriteProxyConfigFileSection(config_file)

    # Write the Google Compute Engine section.
    config_file.write(CONFIG_GOOGLECOMPUTE_SECTION_CONTENT)

    # Write the config file GSUtil section that doesn't depend on user input.
    config_file.write(CONFIG_INPUTLESS_GSUTIL_SECTION_CONTENT)

    # Write the default API version.
    config_file.write("""
# 'default_api_version' specifies the default Google Cloud Storage XML API
# version to use. If not set below gsutil defaults to API version 1.
""")
    api_version = 2
    if cred_type == CredTypes.HMAC:
      api_version = 1

    config_file.write('default_api_version = %d\n' % api_version)

    # Write the config file GSUtil section that includes the default
    # project ID input from the user.
    if not system_util.InvokedViaCloudSdk():
      if launch_browser:
        sys.stdout.write(
            'Attempting to launch a browser to open the Google Cloud Console '
            'at URL: %s\n\n'
            '[Note: due to a Python bug, you may see a spurious error message '
            '"object is not\ncallable [...] in [...] Popen.__del__" which can '
            'be ignored.]\n\n' % GOOG_CLOUD_CONSOLE_URI)
        sys.stdout.write(
            'In your browser you should see the Cloud Console. Find the '
            'project you will\nuse, and then copy the Project ID string from '
            'the second '
            'column. Older projects do\nnot have Project ID strings. For such '
            'projects, click the project and then copy the\nProject Number '
            'listed under that project.\n\n')
        if not webbrowser.open(GOOG_CLOUD_CONSOLE_URI, new=1, autoraise=True):
          sys.stdout.write(
              'Launching browser appears to have failed; please navigate a '
              'browser to the following URL:\n%s\n' % GOOG_CLOUD_CONSOLE_URI)
        # Short delay; webbrowser.open on linux insists on printing out a
        # message which we don't want to run into the prompt for the auth code.
        time.sleep(2)
      else:
        sys.stdout.write(
            '\nPlease navigate your browser to %s,\nthen find the project '
            'you will use, and copy the Project ID string from the\nsecond '
            'column. Older projects do not have Project ID strings. For such '
            'projects,\n click the project and then copy the Project Number '
            'listed under that project.\n\n' % GOOG_CLOUD_CONSOLE_URI)

      default_project_id = input('What is your project-id? ').strip()
      project_id_section_prelude = """
# 'default_project_id' specifies the default Google Cloud Storage project ID to
# use with the 'mb' and 'ls' commands. This default can be overridden by
# specifying the -p option to the 'mb' and 'ls' commands.
"""
      if not default_project_id:
        raise CommandException(
            'No default project ID entered. The default project ID is needed '
            'by the\nls and mb commands; please try again.')
      config_file.write('%sdefault_project_id = %s\n\n\n' %
                        (project_id_section_prelude, default_project_id))

      CheckAndMaybePromptForAnalyticsEnabling()

    # Write the config file OAuth2 section that doesn't depend on user input.
    config_file.write(CONFIG_OAUTH2_CONFIG_CONTENT)

    # If the user ran gsutil config with a custom client ID, write that to the
    # config file.
    if (cred_type == CredTypes.OAUTH2_USER_ACCOUNT and configure_auth and
        oauth2_client.client_id != oauth2_helper.CLIENT_ID and
        oauth2_client.client_secret != oauth2_helper.CLIENT_SECRET):
      config_file.write('client_id = %s\nclient_secret = %s\n' %
                        (oauth2_client.client_id, oauth2_client.client_secret))
    else:
      config_file.write('#client_id = <OAuth2 client id>\n'
                        '#client_secret = <OAuth2 client secret>\n')

  def RunCommand(self):
    """Command entry point for the config command."""
    scopes = []
    cred_type = CredTypes.OAUTH2_USER_ACCOUNT
    launch_browser = False
    output_file_name = None
    has_a = False
    has_e = False
    configure_auth = True
    for opt, opt_arg in self.sub_opts:
      if opt == '-a':
        cred_type = CredTypes.HMAC
        has_a = True
      elif opt == '-b':
        launch_browser = True
      elif opt == '-e':
        cred_type = CredTypes.OAUTH2_SERVICE_ACCOUNT
        has_e = True
      elif opt == '-f':
        scopes.append(constants.Scopes.FULL_CONTROL)
      elif opt == '-n':
        configure_auth = False
      elif opt == '-o':
        output_file_name = opt_arg
      elif opt == '-r':
        scopes.append(constants.Scopes.READ_ONLY)
      elif opt == '--reauth':
        scopes.append(constants.Scopes.REAUTH)
      elif opt == '-s':
        scopes.append(opt_arg)
      elif opt == '-w':
        scopes.append(constants.Scopes.READ_WRITE)
      else:
        self.RaiseInvalidArgumentException()

    if has_e and has_a:
      raise CommandException('Both -a and -e cannot be specified. Please see '
                             '"gsutil help config" for more information.')

    if not configure_auth and (has_a or has_e or scopes or launch_browser):
      raise CommandException(
          'The -a, -b, -e, -f, -r, --reauth, -s, and -w flags cannot be '
          'specified with the -n flag. Please see "gsutil help config" for '
          'more information.')

    # Don't allow users to configure Oauth2 (any option other than -a and -n)
    # when running in the Cloud SDK, unless they have the Cloud SDK configured
    # not to pass credentials to gsutil.
    if (system_util.InvokedViaCloudSdk() and
        system_util.CloudSdkCredPassingEnabled() and not has_a and
        configure_auth):
      raise CommandException('\n'.join([
          'OAuth2 is the preferred authentication mechanism with the Cloud '
          'SDK.',
          'Run "gcloud auth login" to configure authentication, unless:',
          '\n'.join(
              textwrap.wrap(
                  'You don\'t want gsutil to use OAuth2 credentials from the Cloud '
                  'SDK, but instead want to manage credentials with .boto files '
                  'generated by running "gsutil config"; in which case run '
                  '"gcloud config set pass_credentials_to_gsutil false".',
                  initial_indent='- ',
                  subsequent_indent='  ')),
          '\n'.join(
              textwrap.wrap(
                  'You want to authenticate with an HMAC access key and secret, in '
                  'which case run "gsutil config -a".',
                  initial_indent='- ',
                  subsequent_indent='  ')),
      ]))

    if system_util.InvokedViaCloudSdk() and has_a:
      sys.stderr.write('\n'.join(
          textwrap.wrap(
              'This command will configure HMAC credentials, but gsutil will use '
              'OAuth2 credentials from the Cloud SDK by default. To make sure '
              'the HMAC credentials are used, run: "gcloud config set '
              'pass_credentials_to_gsutil false".')) + '\n\n')

    if not scopes:
      scopes.append(constants.Scopes.CLOUD_PLATFORM)
      scopes.append(constants.Scopes.REAUTH)

    default_config_path_bak = None
    if not output_file_name:
      # Check to see if a default config file name is requested via
      # environment variable. If so, use it, otherwise use the hard-coded
      # default file. Then use the default config file name, if it doesn't
      # exist or can be moved out of the way without clobbering an existing
      # backup file.
      boto_config_from_env = os.environ.get('BOTO_CONFIG', None)
      if boto_config_from_env:
        default_config_path = boto_config_from_env
      else:
        default_config_path = os.path.expanduser(os.path.join('~', '.boto'))
      if not os.path.exists(default_config_path):
        output_file_name = default_config_path
      else:
        default_config_path_bak = default_config_path + '.bak'
        if os.path.exists(default_config_path_bak):
          raise CommandException('Cannot back up existing config '
                                 'file "%s": backup file exists ("%s").' %
                                 (default_config_path, default_config_path_bak))
        else:
          try:
            sys.stderr.write(
                'Backing up existing config file "%s" to "%s"...\n' %
                (default_config_path, default_config_path_bak))
            os.rename(default_config_path, default_config_path_bak)
          except Exception as e:
            raise CommandException(
                'Failed to back up existing config '
                'file ("%s" -> "%s"): %s.' %
                (default_config_path, default_config_path_bak, e))
          output_file_name = default_config_path

    if output_file_name == '-':
      output_file = sys.stdout
    else:
      output_file = self._OpenConfigFile(output_file_name)
      sys.stderr.write('\n'.join(
          textwrap.wrap(
              'This command will create a boto config file at %s containing your '
              'credentials, based on your responses to the following questions.'
              % output_file_name)) + '\n')

    # Catch ^C so we can restore the backup.
    RegisterSignalHandler(signal.SIGINT, _CleanupHandler)
    try:
      self._WriteBotoConfigFile(output_file,
                                launch_browser=launch_browser,
                                oauth2_scopes=scopes,
                                cred_type=cred_type,
                                configure_auth=configure_auth)
    except Exception as e:
      user_aborted = isinstance(e, AbortException)
      if user_aborted:
        sys.stderr.write('\nCaught ^C; cleaning up\n')
      # If an error occurred during config file creation, remove the invalid
      # config file and restore the backup file.
      if output_file_name != '-':
        output_file.close()
        os.unlink(output_file_name)
        try:
          if default_config_path_bak:
            sys.stderr.write('Restoring previous backed up file (%s)\n' %
                             default_config_path_bak)
            os.rename(default_config_path_bak, output_file_name)
        except Exception as e:
          # Raise the original exception so that we can see what actually went
          # wrong, rather than just finding out that we died before assigning
          # a value to default_config_path_bak.
          raise e
      raise

    if output_file_name != '-':
      output_file.close()
      if not boto.config.has_option('Boto', 'proxy'):
        sys.stderr.write('\n' + '\n'.join(
            textwrap.wrap(
                'Boto config file "%s" created.\nIf you need to use a proxy to '
                'access the Internet please see the instructions in that file.'
                % output_file_name)) + '\n')

    return 0


def _CleanupHandler(unused_signalnum, unused_handler):
  raise AbortException('User interrupted config command')
