# frozen_string_literal: true

# This Karafka component is a Pro component under a commercial license.
# This Karafka component is NOT licensed under LGPL.
#
# All of the commercial components are present in the lib/karafka/pro directory of this
# repository and their usage requires commercial license agreement.
#
# Karafka has also commercial-friendly license, commercial support and commercial components.
#
# By sending a pull request to the pro components, you are agreeing to transfer the copyright of
# your code to Maciej Mensfeld.

module Karafka
  module Pro
    module Processing
      module Strategies
        # Long-Running Job enabled
        module Lrj
          include Default

          # Pause for tops 31 years
          MAX_PAUSE_TIME = 1_000_000_000_000

          # Features for this strategy
          FEATURES = %i[
            long_running_job
          ].freeze

          # We always need to pause prior to doing any jobs for LRJ
          def handle_before_enqueue
            # This ensures that when running LRJ with VP, things operate as expected run only once
            # for all the virtual partitions collectively
            coordinator.on_enqueued do
              # Pause at the first message in a batch. That way in case of a crash, we will not
              # loose any messages.
              #
              # For VP it applies the same way and since VP cannot be used with MOM we should not
              # have any edge cases here.
              pause(coordinator.seek_offset, MAX_PAUSE_TIME, false)
            end
          end

          # LRJ standard flow after consumption
          def handle_after_consume
            coordinator.on_finished do |last_group_message|
              if coordinator.success?
                coordinator.pause_tracker.reset

                return if coordinator.manual_pause?

                mark_as_consumed(last_group_message) unless revoked?
                seek(coordinator.seek_offset) unless revoked?

                resume
              else
                # If processing failed, we need to pause
                # For long running job this will overwrite the default never-ending pause and will
                # cause the processing to keep going after the error backoff
                pause(coordinator.seek_offset, nil, false)
              end
            end
          end

          # We do not un-pause on revokations for LRJ
          def handle_revoked
            coordinator.on_revoked do
              # We do not want to resume on revocation in case of a LRJ.
              # For LRJ we resume after the successful processing or do a backoff pause in case of
              # a failure. Double non-blocking resume could cause problems in coordination.
              coordinator.revoke
            end
          end
        end
      end
    end
  end
end