# Copyright 2020 Google LLC
#
# 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
#
#     https://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.

# DO NOT EDIT: Unless you're fixing a P0/P1 and/or a security issue. This class
# is frozen to all new features from `google-cloud-spanner/v2.11.0` onwards.


require "delegate"

module Google
  module Cloud
    module Spanner
      class Backup
        class Job
          ##
          # # List
          #
          # List is a special case Array with additional values for backup
          # operations.
          #
          # @deprecated Use the result of
          # {Google::Cloud::Spanner::Admin::Database#database_admin Client#list_backup_operations}
          # instead.
          #
          class List < DelegateClass(::Array)
            # @private
            # The gRPC Service object.
            attr_accessor :service

            # @private
            # The gRPC page enumerable object.
            attr_accessor :grpc

            ##
            # @private Create a new Backup::Job::List with an array of
            # Google::Lognrunning::Operation instances.
            def initialize arr = []
              super arr
            end

            ##
            # Whether there is a next page of backup jobs.
            #
            # @return [Boolean]
            #
            # @example
            #   require "google/cloud/spanner"
            #
            #   spanner = Google::Cloud::Spanner.new
            #
            #   instance = spanner.instance "my-instance"
            #
            #   jobs = instance.backup_operations
            #   if jobs.next?
            #     next_jobs = jobs.next
            #   end
            #
            def next?
              grpc.next_page?
            end

            ##
            # Retrieve the next page of backup jobs.
            #
            # @return [Backup::Job::List]
            #
            # @example
            #   require "google/cloud/spanner"
            #
            #   spanner = Google::Cloud::Spanner.new
            #
            #   instance = spanner.instance "my-instance"
            #
            #   jobs = instance.backup_operations
            #   if jobs.next?
            #     next_jobs = jobs.next
            #   end
            #
            def next
              ensure_service!

              return nil unless next?
              grpc.next_page
              self.class.from_grpc grpc, service
            end

            ##
            # Retrieves remaining results by repeatedly invoking {#next} until
            # {#next?} returns `false`. Calls the given block once for each
            # result, which is passed as the argument to the block.
            #
            # An Enumerator is returned if no block is given.
            #
            # This method will make repeated API calls until all remaining
            # results are retrieved. (Unlike `#each`, for example, which merely
            # iterates over the results returned by a single API call.) Use with
            # caution.
            #
            # @yield [job] The block for accessing each backup job.
            # @yieldparam [Google::Cloud::Spanner::Backup::Job] job The backup
            #   job object.
            #
            # @return [Enumerator]
            #
            # @example Iterating each backup job by passing a block:
            #   require "google/cloud/spanner"
            #
            #   spanner = Google::Cloud::Spanner.new
            #
            #   instance = spanner.instance "my-instance"
            #
            #   jobs = instance.backup_operations
            #   jobs.all do |job|
            #     puts job.backup.backup_id
            #   end
            #
            # @example Using the enumerator by not passing a block:
            #   require "google/cloud/spanner"
            #
            #   spanner = Google::Cloud::Spanner.new
            #
            #   instance = spanner.instance "my-instance"
            #
            #   jobs = instance.backup_operations
            #   all_backup_ids = jobs.all.map do |job|
            #     job.backup.backup_id
            #   end
            #
            def all &block
              return enum_for :all unless block_given?

              results = self
              loop do
                results.each(&block)
                break unless next?
                grpc.next_page
                results = self.class.from_grpc grpc, service
              end
            end

            ##
            # @private
            #
            # New Backup::Job::List from a
            # `Gapic::PagedEnumerable<Google::Longrunning::Operation>`
            # object. Operation object is a backup operation.
            #
            def self.from_grpc grpc, service
              operations_client = \
                service.databases.instance_variable_get "@operations_client"
              jobs = new(Array(grpc.response.operations).map do |job_grpc|
                Job.from_grpc \
                  Gapic::Operation.new(job_grpc, operations_client),
                  service
              end)
              jobs.grpc = grpc
              jobs.service = service
              jobs
            end

            protected

            ##
            # Raise an error unless an active service is available.
            def ensure_service!
              raise "Must have active connection" unless @service
            end
          end
        end
      end
    end
  end
end