module CurationConcerns
  module FileSet
    module BelongsToWorks
      extend ActiveSupport::Concern

      included do
        before_destroy :remove_representative_relationship
      end

      def generic_works
        in_objects # in_objects is provided by Hydra::PCDM::ObjectBehavior
      end

      # OPTIMIZE: We can load this from Solr much faster than loading the objects
      def generic_work_ids
        generic_works.map(&:id)
      end

      # Returns the first parent object
      # This is a hack to handle things like FileSets inheriting access controls from their parent.  (see CurationConcerns::ParentContainer in app/controllers/concerns/curation_concers/parent_container.rb)
      def parent
        in_objects.first
      end

      # Returns the id of first parent object
      # This is a hack to handle things like FileSets inheriting access controls from their parent.  (see CurationConcerns::ParentContainer in app/controllers/concerns/curation_concers/parent_container.rb)
      delegate :id, to: :parent, prefix: true

      # Files with sibling relationships
      # Returns all FileSets aggregated by any of the GenericWorks that aggregate the current object
      def related_files
        generic_works = self.generic_works
        return [] if generic_works.empty?
        generic_works.flat_map { |work| work.file_sets.select { |file_set| file_set.id != id } }
      end

      # If any parent works are pointing at this object as their representative, remove that pointer.
      def remove_representative_relationship
        generic_works = self.generic_works
        return if generic_works.empty?
        generic_works.each do |work|
          work.update(representative_id: nil) if work.representative_id == id
        end
      end
    end
  end
end