# frozen_string_literal: true

module IiifPrint
  module FileSetIndexer
    # Why `.decorate`?  In my tests for Rails 5.2, I'm not able to use the prepended nor included
    # blocks to assign a class_attribute when I "prepend" a module to the base class.  This method
    # allows me to handle that behavior.
    #
    # @param base [Class]
    # @return [Class] the given base, now decorated in all of it's glory
    def self.decorate(base)
      base.prepend(self)
      base.class_attribute :iiif_print_lineage_service, default: IiifPrint::LineageService
      base
    end

    def generate_solr_document
      super.tap do |solr_doc|
        # only UV viewable images should have is_page_of, it is only used for iiif search
        solr_doc['is_page_of_ssim'] = iiif_print_lineage_service.ancestor_ids_for(object) if object.mime_type&.match(/image/)
        # index for full text search
        solr_doc['all_text_timv'] = all_text
        solr_doc['all_text_tsimv'] = all_text
        solr_doc['digest_ssim'] = digest_from_content
      end
    end

    private

    def digest_from_content
      return unless object.original_file
      object.original_file.digest.first.to_s
    end

    def all_text
      text = IiifPrint.config.all_text_generator_function.call(object: object) || ''
      return text if text.empty?

      text.tr("\n", ' ').squeeze(' ')
    end
  end
end