# frozen_string_literal: true

module Gitlab
  module BitbucketImport
    module ParallelScheduling
      include Loggable

      attr_reader :project, :already_enqueued_cache_key, :job_waiter_cache_key

      # The base cache key to use for tracking already enqueued objects.
      ALREADY_ENQUEUED_CACHE_KEY =
        'bitbucket-importer/already-enqueued/%{project}/%{collection}'

      # The base cache key to use for storing job waiter key
      JOB_WAITER_CACHE_KEY =
        'bitbucket-importer/job-waiter/%{project}/%{collection}'

      BATCH_SIZE = 100

      # project - An instance of `Project`.
      def initialize(project)
        @project = project

        @already_enqueued_cache_key =
          format(ALREADY_ENQUEUED_CACHE_KEY, project: project.id, collection: collection_method)
        @job_waiter_cache_key =
          format(JOB_WAITER_CACHE_KEY, project: project.id, collection: collection_method)
      end

      private

      def client
        @client ||= Bitbucket::Client.new(project.import_data.credentials)
      end

      # Returns the ID to use for the cache used for checking if an object has
      # already been enqueued or not.
      #
      # object - The object we may want to import.
      def id_for_already_enqueued_cache(object)
        raise NotImplementedError
      end

      # The Sidekiq worker class used for scheduling the importing of objects in
      # parallel.
      def sidekiq_worker_class
        raise NotImplementedError
      end

      # The name of the method to call to retrieve the data to import.
      def collection_method
        raise NotImplementedError
      end

      def job_waiter
        @job_waiter ||= begin
          key = Gitlab::Cache::Import::Caching.read(job_waiter_cache_key)
          key ||= Gitlab::Cache::Import::Caching.write(job_waiter_cache_key, JobWaiter.generate_key)

          JobWaiter.new(0, key)
        end
      end

      def already_enqueued?(object)
        id = id_for_already_enqueued_cache(object)

        Gitlab::Cache::Import::Caching.set_includes?(already_enqueued_cache_key, id)
      end

      # Marks the given object as "already enqueued".
      def mark_as_enqueued(object)
        id = id_for_already_enqueued_cache(object)

        Gitlab::Cache::Import::Caching.set_add(already_enqueued_cache_key, id)
      end

      def calculate_job_delay(job_index)
        multiplier = (job_index / BATCH_SIZE)

        (multiplier * 1.minute) + 1.second
      end

      def track_import_failure!(project, exception:, **args)
        Gitlab::Import::ImportFailureService.track(
          project_id: project.id,
          error_source: self.class.name,
          exception: exception,
          **args
        )
      end
    end
  end
end