♻️ Extract direct ActiveFedora calls to adapter

With Valkyrie looming large, this change refactors the code towards an
adapter pattern; one that will allow for creating a Valkyrie adapter and
then configuring IIIFPrint accordingly.

We'll also need to consider how we duplicate the actor work within a
transaction and/or publisher/listener setup.

There are likely other places where we're making assumptions about
presenters and/or the data models we're processing.

app/models/concerns/iiif_print/solr/document.rb

@@ -39,7 +39,7 @@ def digest_sha1
 
   def method_missing(method_name, *args, &block)
     super unless iiif_print_solr_field_names.include? method_name.to_s
-    self[::ActiveFedora.index_field_mapper.solr_name(method_name.to_s)]
+    self[IiifPrint.solr_name(method_name.to_s)]
   end
 
   def respond_to_missing?(method_name, include_private = false)

app/services/iiif_print/manifest_builder_service_behavior.rb

@@ -142,7 +142,7 @@ def get_solr_hits(ids)
       results = []
       ids.each_slice(SOLR_QUERY_PAGE_SIZE) do |paged_ids|
         query = "id:(#{paged_ids.join(' OR ')})"
-        results += ActiveFedora::SolrService.query(
+        results += IiifPrint.solr_query(
           query,
           { fq: "-has_model_ssim:FileSet", rows: paged_ids.size, method: :post }
         )

lib/iiif_print.rb

@@ -44,37 +44,8 @@ def self.config(&block)
   end
 
   class << self
-    delegate :skip_splitting_pdf_files_that_end_with_these_texts, to: :config
-  end
-
-  ##
-  # Return the immediate parent of the given :file_set.
-  #
-  # @param file_set [FileSet]
-  # @return [#work?, Hydra::PCDM::Work]
-  # @return [NilClass] when no parent is found.
-  def self.parent_for(file_set)
-    # fallback to Fedora-stored relationships if work's aggregation of
-    #   file set is not indexed in Solr
-    file_set.parent || file_set.member_of.find(&:work?)
-  end
-
-  ##
-  # Return the parent's parent of the given :file_set.
-  #
-  # @param file_set [FileSet]
-  # @return [#work?, Hydra::PCDM::Work]
-  # @return [NilClass] when no grand parent is found.
-  def self.grandparent_for(file_set)
-    parent_of_file_set = parent_for(file_set)
-    # HACK: This is an assumption about the file_set structure, namely that an image page split from
-    # a PDF is part of a file set that is a child of a work that is a child of a single work.  That
-    # is, it only has one grand parent.  Which is a reasonable assumption for IIIF Print but is not
-    # valid when extended beyond IIIF Print.  That is GenericWork does not have a parent method but
-    # does have a parents method.
-    parent_of_file_set.try(:parent_works).try(:first) ||
-      parent_of_file_set.try(:parents).try(:first) ||
-      parent_of_file_set&.member_of&.find(&:work?)
+    delegate :skip_splitting_pdf_files_that_end_with_these_texts, :persistence_layer, to: :config
+    delegate :parent_for, :grandparent_for, :solr_construct_query, :solr_query, :solr_name, :clean_for_tests!, to: :persistence_layer
   end
 
   DEFAULT_MODEL_CONFIGURATION = {

lib/iiif_print/catalog_search_builder.rb

@@ -25,9 +25,9 @@ class CatalogSearchBuilder < Hyrax::CatalogSearchBuilder
     # rubocop:enable Naming/PredicateName
     def show_parents_only(solr_parameters)
       query = if blacklight_params["include_child_works"] == 'true'
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: 'true')
+                IiifPrint.solr_construct_query(is_child_bsi: 'true')
               else
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: nil)
+                IiifPrint.solr_construct_query(is_child_bsi: nil)
               end
       solr_parameters[:fq] += [query]
     end

lib/iiif_print/configuration.rb

@@ -3,6 +3,22 @@ module IiifPrint
   class Configuration
     attr_writer :after_create_fileset_handler
 
+    attr_writer :persistence_adapter
+    def persistence_adapter
+      @persistent_adapter || default_persistence_adapter
+    end
+
+    def default_persistence_adapter
+      # There's probably some configuration of Hyrax we could use to better refine this; but it's
+      # likely a reasonable guess.  The main goal is to not break existing implementations and
+      # maintain an upgrade path.
+      if Gem::Version.new(Hyrax::VERSION) >= Gem::Version.new('6.0.0')
+        IiifPrint::PersistenceLayer::ValkyrieAdapter
+      else
+        IiifPrint::PersistenceLayer::ActiveFedoraAdapter
+      end
+    end
+
     # @param file_set [FileSet]
     # @param user [User]
     def handle_after_create_fileset(file_set, user)

lib/iiif_print/engine.rb

@@ -11,6 +11,12 @@ module IiifPrint
   class Engine < ::Rails::Engine
     isolate_namespace IiifPrint
 
+    initializer 'requires' do
+      require 'iiif_print/persistence_layer'
+      require 'iiif_print/persistence_layer/active_fedora_adapter' if defined?(ActiveFedora)
+      require 'iiif_print/persistence_layer/valkyrie_adapter' if defined?(Valkyrie)
+    end
+
     # rubocop:disable Metrics/BlockLength
     config.to_prepare do
       require "iiif_print/jobs/create_relationships_job"

lib/iiif_print/homepage_search_builder.rb

@@ -7,9 +7,9 @@ class HomepageSearchBuilder < Hyrax::HomepageSearchBuilder
 
     def show_parents_only(solr_parameters)
       query = if blacklight_params["include_child_works"] == 'true'
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: 'true')
+                IiifPrint.solr_construct_query(is_child_bsi: 'true')
               else
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: nil)
+                IiifPrint.solr_construct_query(is_child_bsi: nil)
               end
       solr_parameters[:fq] += [query]
     end

lib/iiif_print/persistence_layer.rb

@@ -0,0 +1,20 @@
+module IiifPrint
+  module PersistenceLayer
+    class AbstractAdapter
+      def self.parent_for(*); end
+
+      def self.grandparent_for(*); end
+
+      def self.solr_field_query(*); end
+
+      def self.clean_for_tests!
+        return false unless Rails.env.test?
+        yield
+      end
+
+      def self.solr_query(*args); end
+
+      def self.solr_name(*args); end
+    end
+  end
+end

lib/iiif_print/persistence_layer/active_fedora_adapter.rb

@@ -0,0 +1,65 @@
+module IiifPrint
+  module PersistenceLayer
+    class ActiveFedoraAdapter < AbstractAdapter
+      ##
+      # Return the immediate parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no parent is found.
+      def self.parent_for(file_set)
+        # fallback to Fedora-stored relationships if work's aggregation of
+        #   file set is not indexed in Solr
+        file_set.parent || file_set.member_of.find(&:work?)
+      end
+
+      ##
+      # Return the parent's parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no grand parent is found.
+      def self.grandparent_for(file_set)
+        parent_of_file_set = parent_for(file_set)
+        # HACK: This is an assumption about the file_set structure, namely that an image page split from
+        # a PDF is part of a file set that is a child of a work that is a child of a single work.  That
+        # is, it only has one grand parent.  Which is a reasonable assumption for IIIF Print but is not
+        # valid when extended beyond IIIF Print.  That is GenericWork does not have a parent method but
+        # does have a parents method.
+        parent_of_file_set.try(:parent_works).try(:first) ||
+          parent_of_file_set.try(:parents).try(:first) ||
+          parent_of_file_set&.member_of&.find(&:work?)
+      end
+
+      def self.solr_construct_query(*args)
+        if defined?(Hyrax::SolrQueryBuilderService)
+          Hyrax::SolrQueryBuilderService.construct_query(*args)
+        else
+          ActiveFedora::SolrQueryBuilderService.construct_query(*args)
+        end
+      end
+
+      def self.clean_for_tests!
+        super do
+          ActiveFedora::Cleaner.clean!
+        end
+      end
+
+      def self.solr_query(*args)
+        if defined?(Hyrax::SolrService)
+          Hyrax::SolrService.query(*args)
+        else
+          ActiveFedora::SolrService.query(*args)
+        end
+      end
+
+      def self.solr_name(field_name)
+        if defined?(Hyrax) && Hyrax.config.respond_to?(:index_field_mapper)
+          Hyrax.config.index_field_mapper.solr_name(field_name.to_s)
+        else
+          ::ActiveFedora.index_field_mapper.solr_name(field_name.to_s)
+        end
+      end
+    end
+  end
+end

lib/iiif_print/persistence_layer/valkyrie_adapter.rb

@@ -0,0 +1,43 @@
+module IiifPrint
+  module PersistenceLayer
+    class ValkyrieAdapter < AbstractAdapter
+      ##
+      # Return the immediate parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no parent is found.
+      def self.parent_for(file_set)
+        raise NotImplementedError
+      end
+
+      ##
+      # Return the parent's parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no grand parent is found.
+      def self.grandparent_for(file_set)
+        raise NotImplementedError
+      end
+
+      def self.solr_construct_query(*args)
+        Hyrax::SolrQueryBuilderService.construct_query(*args)
+      end
+
+      def self.clean_for_tests!
+        # For Fedora backed repositories, we'll want to consider some cleaning mechanism.  For
+        # database backed repositories, we can rely on the database_cleaner gem.
+        raise NotImplementedError
+      end
+
+      def self.solr_query(*args)
+        Hyrax::SolrService.query(*args)
+      end
+
+      def self.solr_name(field_name)
+        Hyrax.config.index_field_mapper.solr_name(field_name.to_s)
+      end
+    end
+  end
+end

spec/iiif_print/configuration_spec.rb

@@ -3,6 +3,12 @@
 RSpec.describe IiifPrint::Configuration do
   let(:config) { described_class.new }
 
+  describe '#persistence_adapter' do
+    subject { config.persistence_adapter }
+
+    it { is_expected.to be_a PersistenceLayer::AbstractAdapter }
+  end
+
   describe '#ancestory_identifier_function' do
     subject(:function) { config.ancestory_identifier_function }
     it "is expected to be a lambda with an arity of one" do

spec/spec_helper.rb

@@ -50,7 +50,7 @@
     ::Noid::Rails.config.minter_class = minter_class
     Hyrax.config.noid_minter_class = minter_class
 
-    ActiveFedora::Cleaner.clean!
+    IiifPrint.clean_for_tests!
     DatabaseCleaner.clean_with(:truncation)
 
     begin