class CreateDerivativesJob < ActiveJob::Base
  include CurationConcerns::Lockable

  queue_as CurationConcerns.config.ingest_queue_name

  # @param [FileSet] file_set
  # @param [String] file_id identifier for a Hydra::PCDM::File
  # @param [String, NilClass] filepath the cached file within the CurationConcerns.config.working_path
  def perform(file_set, file_id, filepath = nil)
    return if file_set.video? && !CurationConcerns.config.enable_ffmpeg
    filename = CurationConcerns::WorkingDirectory.find_or_retrieve(file_id, file_set.id, filepath)

    # Prevent other jobs from trying to modify the FileSet at the same time
    acquire_lock_for(file_set.id) do
      file_set.create_derivatives(filename)

      # Reload from Fedora and reindex for thumbnail and extracted text
      file_set.reload
      file_set.update_index
      file_set.parent.update_index if parent_needs_reindex?(file_set)
    end
  end

  # If this file_set is the thumbnail for the parent work,
  # then the parent also needs to be reindexed.
  def parent_needs_reindex?(file_set)
    return false unless file_set.parent
    file_set.parent.thumbnail_id == file_set.id
  end
end