# Copyright 2015 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.

"""Command for listing grantable roles for a given resource."""

from __future__ import absolute_import
from __future__ import unicode_literals

import textwrap

from apitools.base.py import list_pager

from googlecloudsdk.api_lib.iam import exceptions
from googlecloudsdk.api_lib.iam import util
from googlecloudsdk.calliope import base
from googlecloudsdk.command_lib.iam import flags
from googlecloudsdk.command_lib.iam import iam_util
from googlecloudsdk.core import resources


class ListGrantableRoles(base.Command):
  """List IAM grantable roles for a resource.

  This command displays the list of grantable roles for a resource.
  The resource can be referenced either via the full resource name or via a URI.
  User can then add IAM policy bindings to grant the roles.
  """

  detailed_help = {
      'EXAMPLES': textwrap.dedent("""\
          List grantable roles for a project:

            $ {command} //cloudresourcemanager.googleapis.com/projects/PROJECT_ID

          List grantable roles for a resource identified via full resource name:

            $ {command} //compute.googleapis.com/projects/example-project/zones/us-central1-f/instances/example-instance

          List grantable roles for a resource identified via URI:

            $ {command} https://www.googleapis.com/compute/v1/projects/example-project/zones/us-central1-f/instances/example-instance
      """),
  }

  @staticmethod
  def Args(parser):
    flags.GetResourceNameFlag('get the list of roles for').AddToParser(parser)
    base.FILTER_FLAG.AddToParser(parser)
    base.PAGE_SIZE_FLAG.AddToParser(parser)
    base.PAGE_SIZE_FLAG.SetDefault(parser, 100)

  def Run(self, args):
    resource = None
    if args.resource.startswith('//'):
      # The atomic resource path inputted, just use this
      resource = args.resource
    if args.resource.startswith('http'):
      # This is a full resource URL that needs to be converted to an atomic path
      resource_ref = resources.REGISTRY.Parse(args.resource)
      resource = iam_util.GetResourceName(resource_ref)

    if not resource:
      raise exceptions.InvalidResourceException(
          'The given resource is not a valid full resource name or URL.')

    client, messages = util.GetClientAndMessages()
    return list_pager.YieldFromList(
        client.roles,
        messages.QueryGrantableRolesRequest(fullResourceName=resource),
        field='roles',
        method='QueryGrantableRoles',
        batch_size=args.page_size,
        batch_size_attribute='pageSize')
