# -*- coding: utf-8 -*- #
# Copyright 2015 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.
"""Commands for updating backend buckets."""

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

from apitools.base.py import encoding
from googlecloudsdk.api_lib.compute import base_classes
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.compute import cdn_flags_utils as cdn_flags
from googlecloudsdk.command_lib.compute import exceptions
from googlecloudsdk.command_lib.compute import flags as compute_flags
from googlecloudsdk.command_lib.compute import scope as compute_scope
from googlecloudsdk.command_lib.compute import signed_url_flags
from googlecloudsdk.command_lib.compute.backend_buckets import backend_buckets_utils
from googlecloudsdk.command_lib.compute.backend_buckets import flags as backend_buckets_flags
from googlecloudsdk.command_lib.compute.security_policies import (
    flags as security_policy_flags)
from googlecloudsdk.core import log


@base.ReleaseTracks(base.ReleaseTrack.GA)
@base.UniverseCompatible
class Update(base.UpdateCommand):
  """Update a backend bucket.

  *{command}* is used to update backend buckets.
  """

  BACKEND_BUCKET_ARG = None
  EDGE_SECURITY_POLICY_ARG = None

  support_regional_global_flags = False

  @classmethod
  def Args(cls, parser):
    """Set up arguments for this command."""
    backend_buckets_flags.AddUpdatableArgs(
        cls, parser, 'update', cls.support_regional_global_flags
    )
    backend_buckets_flags.GCS_BUCKET_ARG.AddArgument(parser)
    signed_url_flags.AddSignedUrlCacheMaxAge(
        parser, required=False, unspecified_help='')

    cdn_flags.AddCdnPolicyArgs(parser, 'backend bucket', update_command=True)

    cls.EDGE_SECURITY_POLICY_ARG = (
        security_policy_flags.EdgeSecurityPolicyArgumentForTargetResource(
            resource='backend bucket'))
    cls.EDGE_SECURITY_POLICY_ARG.AddArgument(parser)

    backend_buckets_flags.AddCacheKeyExtendedCachingArgs(parser)

    backend_buckets_flags.AddCompressionMode(parser)

  def AnyArgsSpecified(self, args):
    """Returns true if any args for updating backend bucket were specified."""
    return (args.IsSpecified('description') or
            args.IsSpecified('gcs_bucket_name') or
            args.IsSpecified('enable_cdn') or
            args.IsSpecified('edge_security_policy') or
            args.IsSpecified('cache_key_include_http_header') or
            args.IsSpecified('cache_key_query_string_whitelist') or
            args.IsSpecified('compression_mode'))

  def AnyFlexibleCacheArgsSpecified(self, args):
    """Returns true if any Flexible Cache args for updating backend bucket were specified."""
    return any(
        (args.IsSpecified('cache_mode'), args.IsSpecified('client_ttl'),
         args.IsSpecified('no_client_ttl'), args.IsSpecified('default_ttl'),
         args.IsSpecified('no_default_ttl'), args.IsSpecified('max_ttl'),
         args.IsSpecified('no_max_ttl'),
         args.IsSpecified('custom_response_header'),
         args.IsSpecified('no_custom_response_headers'),
         args.IsSpecified('negative_caching'),
         args.IsSpecified('negative_caching_policy'),
         args.IsSpecified('no_negative_caching_policies'),
         args.IsSpecified('serve_while_stale'),
         args.IsSpecified('no_serve_while_stale'),
         args.IsSpecified('bypass_cache_on_request_headers'),
         args.IsSpecified('no_bypass_cache_on_request_headers')))

  def GetGetRequest(self, client, backend_bucket_ref):
    """Returns a request to retrieve the backend bucket."""
    if backend_bucket_ref.Collection() == 'compute.regionBackendBuckets':
      return (
          client.apitools_client.regionBackendBuckets,
          'Get',
          client.messages.ComputeRegionBackendBucketsGetRequest(
              project=backend_bucket_ref.project,
              region=backend_bucket_ref.region,
              backendBucket=backend_bucket_ref.Name(),
          ),
      )
    return (client.apitools_client.backendBuckets, 'Get',
            client.messages.ComputeBackendBucketsGetRequest(
                project=backend_bucket_ref.project,
                backendBucket=backend_bucket_ref.Name()))

  def GetSetRequest(self, client, backend_bucket_ref, replacement):
    """Returns a request to update the backend bucket."""
    if backend_bucket_ref.Collection() == 'compute.regionBackendBuckets':
      return (
          client.apitools_client.regionBackendBuckets,
          'Patch',
          client.messages.ComputeRegionBackendBucketsPatchRequest(
              project=backend_bucket_ref.project,
              region=backend_bucket_ref.region,
              backendBucket=backend_bucket_ref.Name(),
              backendBucketResource=replacement,
          ),
      )
    return (client.apitools_client.backendBuckets, 'Patch',
            client.messages.ComputeBackendBucketsPatchRequest(
                project=backend_bucket_ref.project,
                backendBucket=backend_bucket_ref.Name(),
                backendBucketResource=replacement))

  def GetSetEdgeSecurityPolicyRequest(self, client, backend_bucket_ref,
                                      security_policy_ref):
    """Returns a request to set the edge policy for the backend bucket."""
    if backend_bucket_ref.Collection() == 'compute.regionBackendBuckets':
      raise exceptions.ArgumentError(
          'Regional backend buckets do not support edge security policies.')
    return (client.apitools_client.backendBuckets, 'SetEdgeSecurityPolicy',
            client.messages.ComputeBackendBucketsSetEdgeSecurityPolicyRequest(
                project=backend_bucket_ref.project,
                backendBucket=backend_bucket_ref.Name(),
                securityPolicyReference=client.messages.SecurityPolicyReference(
                    securityPolicy=security_policy_ref)))

  def Modify(self, args, existing):
    """Modifies and returns the updated backend bucket."""
    holder = base_classes.ComputeApiHolder(self.ReleaseTrack())
    client = holder.client
    replacement = encoding.CopyProtoMessage(existing)
    cleared_fields = []

    if args.IsSpecified('description'):
      replacement.description = args.description

    if args.gcs_bucket_name:
      replacement.bucketName = args.gcs_bucket_name

    if args.enable_cdn is not None:
      replacement.enableCdn = args.enable_cdn

    backend_buckets_utils.ApplyCdnPolicyArgs(
        client,
        args,
        replacement,
        is_update=True,
        cleared_fields=cleared_fields)

    if args.custom_response_header is not None:
      replacement.customResponseHeaders = args.custom_response_header
    if args.no_custom_response_headers:
      replacement.customResponseHeaders = []
    if not replacement.customResponseHeaders:
      cleared_fields.append('customResponseHeaders')
    if (replacement.cdnPolicy is not None and
        replacement.cdnPolicy.cacheMode and args.enable_cdn is not False):  # pylint: disable=g-bool-id-comparison
      replacement.enableCdn = True

    if args.compression_mode is not None:
      replacement.compressionMode = (
          client.messages.BackendBucket.CompressionModeValueValuesEnum(
              args.compression_mode))

    if not replacement.description:
      cleared_fields.append('description')
    return replacement, cleared_fields

  def MakeRequests(self, args):
    """Makes the requests for updating the backend bucket."""
    holder = base_classes.ComputeApiHolder(self.ReleaseTrack())
    client = holder.client

    if self.support_regional_global_flags:
      backend_bucket_ref = backend_buckets_flags.GLOBAL_REGIONAL_BACKEND_BUCKET_ARG.ResolveAsResource(
          args,
          holder.resources,
          scope_lister=compute_flags.GetDefaultScopeLister(client),
          default_scope=compute_scope.ScopeEnum.GLOBAL,
      )
    else:
      backend_bucket_ref = self.BACKEND_BUCKET_ARG.ResolveAsResource(
          args, holder.resources
      )
    get_request = self.GetGetRequest(client, backend_bucket_ref)

    objects = client.MakeRequests([get_request])

    new_object, cleared_fields = self.Modify(args, objects[0])

    # If existing object is equal to the proposed object or if
    # Modify() returns None, then there is no work to be done, so we
    # print the resource and return.
    if objects[0] == new_object:
      # Only skip update if edge_security_policy is not set.
      if getattr(args, 'edge_security_policy', None) is None:
        log.status.Print(
            'No change requested; skipping update for [{0}].'.format(
                objects[0].name))
        return objects
      backend_bucket_result = []
    else:
      with client.apitools_client.IncludeFields(cleared_fields):
        backend_bucket_result = client.MakeRequests(
            [self.GetSetRequest(client, backend_bucket_ref, new_object)])

    # Empty string is a valid value.
    if getattr(args, 'edge_security_policy', None) is not None:
      if backend_bucket_ref.Collection() == 'compute.regionBackendBuckets':
        raise exceptions.ArgumentError(
            'argument --edge-security-policy: Regional backend buckets do not'
            ' support edge security policies.'
        )
      if getattr(args, 'edge_security_policy', None):
        security_policy_ref = self.EDGE_SECURITY_POLICY_ARG.ResolveAsResource(
            args, holder.resources).SelfLink()
      # If security policy is an empty string we should clear the current policy
      else:
        security_policy_ref = None
      edge_security_policy_request = self.GetSetEdgeSecurityPolicyRequest(
          client, backend_bucket_ref, security_policy_ref)
      edge_security_policy_result = client.MakeRequests(
          [edge_security_policy_request])
    else:
      edge_security_policy_result = []

    return backend_bucket_result + edge_security_policy_result

  def Run(self, args):
    """Issues the request necessary for updating a backend bucket."""
    if (not self.AnyArgsSpecified(args) and
        not args.IsSpecified('signed_url_cache_max_age') and
        not args.IsSpecified('request_coalescing') and
        not self.AnyFlexibleCacheArgsSpecified(args)):
      raise exceptions.UpdatePropertyError(
          'At least one property must be modified.')
    return self.MakeRequests(args)


@base.ReleaseTracks(base.ReleaseTrack.BETA)
@base.UniverseCompatible
class UpdateBeta(Update):
  """Update a backend bucket.

  *{command}* is used to update backend buckets.

    To delete a global backend bucket, run either of the following:

      $ {command} my-backend-bucket
        --no-enable-cdn
        --global

      $ {command} my-backend-bucket
        --no-enable-cdn

  To delete a regional backend bucket, run the following:

      $ {command} my-backend-bucket --region=us-central1
        --no-enable-cdn
  """

  support_regional_global_flags = True


@base.ReleaseTracks(base.ReleaseTrack.ALPHA)
@base.UniverseCompatible
class UpdateAlpha(UpdateBeta):
  """Update a backend bucket.

  *{command}* is used to update backend buckets.

      To delete a global backend bucket, run either of the following:

      $ {command} my-backend-bucket
        --no-enable-cdn
        --global

      $ {command} my-backend-bucket
        --no-enable-cdn

  To delete a regional backend bucket, run the following:

      $ {command} my-backend-bucket --region=us-central1
        --no-enable-cdn
  """

  support_regional_global_flags = True