# -*- coding: utf-8 -*- #
# Copyright 2021 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.
"""Deletes temporary components and tracker files from a composite upload."""

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

import glob
import os

from googlecloudsdk.api_lib.storage import errors as api_errors
from googlecloudsdk.command_lib.storage import errors as command_errors
from googlecloudsdk.command_lib.storage import tracker_file_util
from googlecloudsdk.command_lib.storage.tasks import task
from googlecloudsdk.command_lib.storage.tasks.cp import copy_component_util
from googlecloudsdk.command_lib.storage.tasks.rm import delete_task
from googlecloudsdk.core import log


def _try_delete_and_return_permissions_error(component_url):
  """Attempts deleting component and returns any permissions errors."""
  try:
    delete_task.DeleteObjectTask(component_url, verbose=False).execute()
  except api_errors.CloudApiError as e:
    status = getattr(e, 'status_code', None)
    if status == 403:
      return e
    raise


class DeleteTemporaryComponentsTask(task.Task):
  """Deletes temporary components and tracker files after a composite upload."""

  def __init__(self, source_resource, destination_resource, random_prefix):
    """Initializes a task instance.

    Args:
      source_resource (resource_reference.FileObjectResource): The local,
          uploaded file.
      destination_resource (resource_reference.UnknownResource): The final
          composite object's metadata.
      random_prefix (str): ID added to temporary component names.
    """
    super(DeleteTemporaryComponentsTask, self).__init__()
    self._source_resource = source_resource
    self._destination_resource = destination_resource
    self._random_prefix = random_prefix

  def execute(self, task_status_queue=None):
    """Deletes temporary components and associated tracker files.

    Args:
      task_status_queue: See base class.

    Returns:
      A task.Output with tasks for deleting temporary components.
    """
    del task_status_queue

    component_tracker_path_prefix = tracker_file_util.get_tracker_file_path(
        copy_component_util.get_temporary_component_resource(
            self._source_resource, self._destination_resource,
            self._random_prefix, component_id='').storage_url,
        tracker_file_util.TrackerFileType.UPLOAD,
        # TODO(b/190093425): Setting component_number will not be necessary
        # after using the final destination to generate component tracker paths.
        component_number='')
    # Matches all paths, regardless of component number:
    component_tracker_paths = glob.iglob(component_tracker_path_prefix + '*')

    component_urls = []
    found_permissions_error = permissions_error = None
    for component_tracker_path in component_tracker_paths:
      tracker_data = tracker_file_util.read_resumable_upload_tracker_file(
          component_tracker_path)
      if tracker_data.complete:
        _, _, component_number = component_tracker_path.rpartition('_')
        component_url = (
            copy_component_util.get_temporary_component_resource(
                self._source_resource,
                self._destination_resource,
                self._random_prefix,
                component_id=component_number).storage_url)

        if found_permissions_error is None:
          permissions_error = _try_delete_and_return_permissions_error(
              component_url)
          found_permissions_error = permissions_error is not None
          if found_permissions_error:
            # Save URL for error message.
            component_urls.append(component_url)
        else:
          # Save URL to delete with task later.
          component_urls.append(component_url)

      os.remove(component_tracker_path)

    if permissions_error:
      log.error(
          'Parallel composite upload failed: Permissions error detected while'
          ' attempting to delete object component.'
          '\n\nTo disable parallel composite uploads, run:'
          '\ngcloud config set storage/parallel_composite_upload_enabled False'
          '\n\nTo delete the temporary objects left over by this command,'
          ' switch to an account with appropriate permissions and run:'
          '\ngcloud storage rm {}'.format(' '.join(
              [url.url_string for url in component_urls])))
      raise command_errors.FatalError(permissions_error)

    if component_urls:
      additional_task_iterators = [
          [
              delete_task.DeleteObjectTask(url, verbose=False)
              for url in component_urls
          ]
      ]
      return task.Output(
          additional_task_iterators=additional_task_iterators, messages=None)

  def __eq__(self, other):
    if not isinstance(other, type(self)):
      return NotImplemented
    return (
        self._source_resource == other._source_resource
        and self._destination_resource == other._destination_resource
        and self._random_prefix == other._random_prefix
    )