Merge pull request #244 from scientist-softserv/stenciling-in-the-der…

…ivative-rodeo-integration

🎁 Adding IiifPrint::DerivativeRodeoService

app/services/iiif_print/derivative_rodeo_service.rb

@@ -0,0 +1,157 @@
+module IiifPrint
+  ##
+  # This class implements the interface of a Hyrax::DerivativeService.
+  #
+  # That means three important methods are:
+  #
+  # - {#valid?}
+  # - {#create_derivatives}
+  # - {#cleanup_derivatives}
+  #
+  # And the object initializes with a FileSet.
+  #
+  # It is a companion to {IiifPrint::PluggableDerivativeService}.
+  #
+  # @see https://github.com/samvera/hyrax/blob/main/app/services/hyrax/derivative_service.rb Hyrax::DerivativesService
+  class DerivativeRodeoService
+    ##
+    # @!group Class Attributes
+    #
+    # @attr parent_work_identifier_property_name [String] the property we use to identify the unique
+    #       identifier of the parent work as it went through the SpaceStone pre-process.
+    #
+    # TODO: The default of :aark_id is a quick hack for adventist.  By exposing a configuration
+    # value, my hope is that this becomes easier to configure.
+    class_attribute :parent_work_identifier_property_name, default: 'aark_id'
+
+    ##
+    # @attr input_location_adapter_name [String] The name of a derivative rodeo storage location;
+    #       this will must be a registered with the DerivativeRodeo::StorageLocations::BaseLocation.
+    class_attribute :input_location_adapter_name, default: 's3'
+
+    ##
+    # @attr named_derivatives_and_generators_by_type [Hash<Symbol, #constantize>] the named derivative and it's
+    #       associated generator.  The "name" is important for Hyrax.  The generator is one that
+    #       exists in the DerivativeRodeo.
+    #
+    # TODO: Could be nice to have a registry for the DerivativeRodeo::Generators; but that's a
+    # tomorrow wish.
+    class_attribute(:named_derivatives_and_generators_by_type, default: {
+                      pdf: { thumbnail: "DerivativeRodeo::Generators::ThumbnailGenerator" }
+                    })
+    # @!endgroup Class Attributes
+    ##
+
+    ##
+    # This method "hard-codes" some existing assumptions about the input_uri based on
+    # implementations for Adventist.  Those are reasonable assumptions but time will tell how
+    # reasonable.
+    #
+    # @param file_set [FileSet]
+    # @return [String]
+    def self.derivative_rodeo_input_uri(file_set:)
+      return @derivative_rodeo_input_uri if defined?(@derivative_rodeo_input_uri)
+
+      # TODO: URGENT For a child work (e.g. an image split off of a PDF) we will know that the file_set's
+      # parent is a child, and the rules of the URI for those derivatives are different from the
+      # original ingested PDF or the original ingested Image.
+
+      # TODO: This logic will work for an attached PDF; but not for each of the split pages of that
+      # PDF.  How to do that?
+
+      # TODO: This is duplicated logic for another service, consider extracting a helper module;
+      # better yet wouldn't it be nice if Hyrax did this right and proper.
+      parent = file_set.parent || file_set.member_of.find(&:work?)
+      raise IiifPrint::DataError, "Parent not found for #{file_set.class} ID=#{file_set.id}" unless parent
+
+      dirname = parent.public_send(parent_work_identifier_property_name)
+
+      # TODO: This is a hack that knows about the inner workings of Hydra::Works, but for
+      # expendiency, I'm using it.  See
+      # https://github.com/samvera/hydra-works/blob/c9b9dd0cf11de671920ba0a7161db68ccf9b7f6d/lib/hydra/works/services/add_file_to_file_set.rb#L49-L53
+      # TODO: Could we get away with filename that is passed in the create_derivatives process?
+      filename = Hydra::Works::DetermineOriginalName.call(file_set.original_file)
+
+      # TODO: What kinds of exceptions might we raise if the location is not configured?  Do we need
+      # to "validate" it in another step.
+      location = DerivativeRodeo::StorageLocations::BaseLocation.load_location(input_location_adapter_name)
+
+      # TODO: This is based on the provided output template in
+      # https://github.com/scientist-softserv/space_stone-serverless/blob/0dbe2b6fa13b9f4bf8b9580ec14d0af5c98e2b00/awslambda/bin/sample_post.rb#L1
+      # and is very much hard-coded.  We likely want to "store" the template in a common place for
+      # the application.
+      #
+      # s3://s3-antics/:aark_id/:file_name_with_extension
+      # s3://s3-antics/12345/hello-world.pdf
+      @derivative_rodeo_input_uri = File.join(location.adapter_prefix, dirname, File.basename(filename))
+    end
+
+    def initialize(file_set)
+      @file_set = file_set
+    end
+
+    attr_reader :file_set
+    delegate :uri, :mime_type, to: :file_set
+
+    ##
+    # @return
+    # @see https://github.com/samvera/hyrax/blob/426575a9065a5dd3b30f458f5589a0a705ad7be2/app/services/hyrax/file_set_derivatives_service.rb#L18-L20 Hyrax::FileSetDerivativesService#valid?
+    def valid?
+      if in_the_rodeo?
+        Rails.logger.info("🤠🐮 Using the DerivativeRodeo for FileSet ID=#{file_set.id} with mime_type of #{mime_type}")
+        true
+      else
+        Rails.logger.info("Skipping the DerivativeRodeo for FileSet ID=#{file_set.id} with mime_type of #{mime_type}")
+        false
+      end
+    end
+
+    ##
+    # @api public
+    #
+    # The file_set.class.*_mime_types are carried over from Hyrax.
+    def create_derivatives(filename)
+      # TODO: Do we need to handle "impending derivatives?"  as per {IiifPrint::PluggableDerivativeService}?
+      case mime_type
+      when file_set.class.pdf_mime_types
+        lasso_up_some_derivatives(filename: filename, type: :pdf)
+      when file_set.class.image_mime_types
+        lasso_up_some_derivatives(filename: filename, type: :image)
+      else
+        # TODO: add more mime types but for now image and PDF are the two we accept.
+        raise "Unexpected mime_type #{mime_type} for filename #{filename}"
+      end
+    end
+
+    private
+
+    def lasso_up_some_derivatives(type:, **)
+      # TODO: Can we use the filename instead of the antics of the original_file on the file_set?
+      # We have the filename in create_derivatives.
+      named_derivatives_and_generators_by_type.fetch(type).flat_map do |named_derivative, generator_name|
+        # This is the location that Hyrax expects us to put files that will be added to Fedora.
+        output_location_template = "file://#{Hyrax::DerivativePath.derivative_path_for_reference(file_set, named_derivative)}"
+        generator = generator_name.constantize
+        generator.new(input_uris: [derivative_rodeo_input_uri], output_location_template: output_location_template).generate_uris
+      end
+    end
+
+    def supported_mime_types
+      # If we've configured the rodeo
+      named_derivatives_and_generators_by_type.keys.flat_map { |type| file_set.class.public_send("#{type}_mime_types") }
+    end
+
+    def derivative_rodeo_input_uri
+      @derivative_rodeo_input_uri ||= self.class.derivative_rodeo_input_uri(file_set: file_set)
+    end
+
+    def in_the_rodeo?
+      # We can assume that we are not going to process a supported mime type; and there is a cost
+      # for looking in the rodeo.
+      return false unless supported_mime_types.include?(mime_type)
+
+      location = DerivativeRodeo::StorageLocations::BaseLocation.from_uri(derivative_rodeo_input_uri)
+      location.exist?
+    end
+  end
+end

lib/iiif_print/engine.rb

@@ -1,6 +1,7 @@
 require 'active_fedora'
 require 'hyrax'
 require 'blacklight_iiif_search'
+require 'derivative_rodeo'
 
 module IiifPrint
   # module constants:

lib/iiif_print/jobs/child_works_from_pdf_job.rb

@@ -48,6 +48,8 @@ def perform(candidate_for_parency, pdf_paths, user, admin_set_id, *)
 
       # rubocop:disable Metrics/ParameterLists
       def split_pdf(original_pdf_path, user, child_model)
+        # TODO: This is the place to change out the existing service and instead use the derivative
+        # rodeo; we will likely need to look at method signatures to tighten this interface.
         image_files = @parent_work.iiif_print_config.pdf_splitter_service.call(original_pdf_path)
         return if image_files.blank?
 

spec/services/iiif_print/derivative_rodeo_service_spec.rb

@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe IiifPrint::DerivativeRodeoService do
+  let(:work) { double({ described_class.parent_work_identifier_property_name => 'hello-1234-id' }) }
+  let(:file_set) { FileSet.new.tap { |fs| fs.save!(validate: false) } }
+  let(:generator) { DerivativeRodeo::Generators::CopyGenerator }
+  let(:output_extension) { "rb" }
+
+  let(:instance) { described_class.new(file_set) }
+
+  subject(:klass) { described_class }
+
+  describe '.input_location_adapter_name' do
+    subject { described_class.input_location_adapter_name }
+    it { is_expected.to eq 's3' }
+  end
+
+  describe '.parent_work_identifier_property_name' do
+    subject { described_class.parent_work_identifier_property_name }
+    it { is_expected.to be_a String }
+  end
+
+  describe '.named_derivatives_and_generators_by_type' do
+    subject { described_class.named_derivatives_and_generators_by_type }
+    it { is_expected.to be_a Hash }
+  end
+
+  describe '.derivative_rodeo_input_uri' do
+    subject { described_class.derivative_rodeo_input_uri(file_set: file_set) }
+
+    context 'when the file_set does not have a parent' do
+      xit 'is expected to raise an error' do
+        expect { subject }.to raise_error(IiifPrint::DataError)
+      end
+    end
+
+    context 'when the file_set has a parent' do
+      before do
+        allow(file_set).to receive(:parent).and_return(work)
+        # TODO: This is a hack that leverages the internals of Hydra::Works; not excited about it but
+        # this part is only one piece of the over all integration.
+        allow(file_set).to receive(:original_file).and_return(double(original_filename: __FILE__))
+      end
+
+      it { is_expected.to start_with("#{described_class.input_location_adapter_name}://") }
+      it { is_expected.to end_with(File.basename(__FILE__)) }
+    end
+  end
+
+  # TODO: Need Faux Bucket for Derivative Rodeo
+  xdescribe '#valid?' do
+    subject { instance.valid? }
+
+    before do
+      allow(file_set).to receive(:mime_type).and_return(mime_type)
+      allow(file_set).to receive(:parent).and_return(work)
+    end
+
+    context 'when the mime_type of the file is not supported' do
+      let(:mime_type) { "text/plain" }
+      it { is_expected.to be_falsey }
+    end
+
+    context 'when derivative rodeo has not pre-processed the file set' do
+      before { instance.input_location_adapter_name = "file" }
+
+      let(:mime_type) { "application/pdf" }
+      it { is_expected.to be_falsey }
+    end
+
+    context 'when the mime type is supported and the derivative rodeo has pre-processed the file set' do
+      before do
+        # TODO: write to the rodeo; consider using AWS's spec support; I want to be able to "fake" S3
+        # with a "fake" bucket.
+        #
+        # Dependent on https://github.com/scientist-softserv/derivative_rodeo/pull/37
+      end
+
+      let(:mime_type) { "application/pdf" }
+      it { is_expected.to be_truthy }
+    end
+  end
+end