add file_converter_service which converts the metadata between AF:Fil…

…e and FileMetadata resource

app/models/hyrax/file_metadata.rb

@@ -11,6 +11,7 @@ class FileMetadata < Valkyrie::Resource
     attribute :original_filename, ::Valkyrie::Types::Set
     attribute :mime_type, ::Valkyrie::Types::Set
     attribute :use, ::Valkyrie::Types::Set # AF::File type
+    attribute :content, ::Valkyrie::Types::Set
 
     # attributes set by fits
     attribute :format_label, ::Valkyrie::Types::Set

lib/wings/services/file_converter_service.rb

@@ -0,0 +1,66 @@
+# Conversion service for going between files on a valkyrie resource and files on an active fedora object
+module Wings
+  class FileConverterService
+    class << self
+      def af_file_to_resource(af_file:)
+        return unless af_file&.id.present?
+        attrs = base_af_file_attributes(af_file: af_file)
+        attrs = metadata_node_to_attributes(metadata_node: af_file.metadata_node,
+                                            attributes: attrs)
+        Hyrax::FileMetadata.new(attrs)
+      end
+
+      def resource_to_af_file(metadata_resource:)
+        return unless metadata_resource&.alternate_id.present?
+        af_file = Hydra::PCDM::File.new(id: metadata_resource.alternate_id.first.to_s)
+        af_file.content = content(metadata_resource)
+        af_file.original_name = metadata_resource.original_filename.first
+        af_file.mime_type = metadata_resource.mime_type.first
+        valkyrie_attributes_to_af_file(attributes: metadata_resource.attributes,
+                                       af_file: af_file)
+        af_file
+      end
+
+      private
+
+        # extracts attributes that come from the af_file
+        def base_af_file_attributes(af_file:)
+          id = ::Valkyrie::ID.new(af_file.id)
+          { id: id,
+            alternate_id: [id],
+            file_identifiers: [id],
+            created_at: af_file.create_date,
+            updated_at: af_file.modified_date,
+            content: af_file.content,
+            size: af_file.size,
+            original_filename: [af_file.original_name],
+            mime_type: [af_file.mime_type] }
+        end
+
+        # extracts attributes that come from the metadata_node
+        def metadata_node_to_attributes(metadata_node:, attributes:)
+          af_attrs = metadata_node.attributes.dup
+          af_attrs.delete('id')
+          af_attrs.each { |k, v| attributes[k.to_sym] = Array(v) unless attributes.key?(k.to_sym) }
+          attributes
+        end
+
+        def valkyrie_attributes_to_af_file(attributes:, af_file:)
+          attributes.each do |k, v|
+            next if [:id, :content].include? k
+            mname = (k.to_s + '=').to_sym
+            if af_file.respond_to? mname
+              af_file.send(mname, v)
+            elsif af_file.metadata_node.respond_to? mname
+              af_file.metadata_node.send(mname, v)
+            end
+          end
+        end
+
+        def content(metadata_resource)
+          return nil if metadata_resource.content.nil? || metadata_resource.content.size.zero?
+          metadata_resource.content.first
+        end
+    end
+  end
+end

spec/wings/services/file_converter_service_spec.rb

@@ -0,0 +1,101 @@
+# frozen_string_literal: true
+require 'wings_helper'
+require 'wings/services/file_converter_service'
+
+RSpec.describe Wings::FileConverterService do
+  let(:af_file_id) { af_file.id }
+  let(:af_attrs) { plain_text_af_attrs }
+  let(:af_file) do
+    aff = Hydra::PCDM::File.new(id: 'af_1')
+    aff.original_name = plain_text_af_attrs[:original_name]
+    aff.mime_type = plain_text_af_attrs[:mime_type]
+    aff.content = plain_text_af_attrs[:content]
+    aff.format_label = plain_text_af_attrs[:format_label]
+    aff.language = plain_text_af_attrs[:language]
+    aff.word_count = plain_text_af_attrs[:content].split(' ').count
+    aff.character_count = plain_text_af_attrs[:content].size
+    aff.save
+    aff
+  end
+
+  describe '#af_file_to_resource' do
+    subject { described_class.af_file_to_resource(af_file: af_file) }
+    it 'copies attributes to resource' do # rubocop:disable RSpec/ExampleLength
+      expect(subject.id.to_s).to eq af_file_id
+      expect(subject.alternate_id).to match_valkyrie_ids_with_active_fedora_ids [af_file_id]
+      expect(subject.file_identifiers).to match_valkyrie_ids_with_active_fedora_ids [af_file_id]
+      expect(subject.created_at).to eq af_file.create_date
+      expect(subject.updated_at).to eq af_file.modified_date
+      expect(subject.original_filename).to eq Array(plain_text_af_attrs[:original_name])
+      expect(subject.mime_type).to eq Array(plain_text_af_attrs[:mime_type])
+      expect(subject.content).to eq Array(plain_text_af_attrs[:content])
+      expect(subject.format_label).to eq Array(plain_text_af_attrs[:format_label])
+      expect(subject.language).to eq Array(plain_text_af_attrs[:language])
+      expect(subject.word_count).to eq Array(plain_text_af_attrs[:content].split(' ').count)
+      expect(subject.size).to eq Array(plain_text_af_attrs[:content].size)
+      expect(subject.character_count).to eq Array(plain_text_af_attrs[:content].size)
+    end
+  end
+
+  describe '#resource_to_af_file' do
+    let(:id) { 'val_2' }
+    let(:valkyrie_id) { ::Valkyrie::ID.new(id) }
+    let(:valkyrie_attrs) { plain_text_valkyrie_attrs }
+    let(:file_metadata) do
+      valkyrie_attrs[:alternate_id] = valkyrie_id
+      valkyrie_attrs[:file_identifiers] = valkyrie_id
+      valkyrie_attrs[:word_count] = plain_text_valkyrie_attrs[:content].split(' ').count
+      valkyrie_attrs[:size] = plain_text_valkyrie_attrs[:content].size
+      valkyrie_attrs[:character_count] = plain_text_valkyrie_attrs[:content].size
+      Hyrax::FileMetadata.new(id: valkyrie_id, **valkyrie_attrs)
+    end
+    subject { described_class.resource_to_af_file(metadata_resource: file_metadata) }
+    it 'copies attributes to af_file' do
+      expect(subject.id.to_s).to eq id
+      expect(subject.original_name).to eq plain_text_valkyrie_attrs[:original_filename]
+      validate_af_file_metadata(plain_text_valkyrie_attrs)
+    end
+  end
+
+  context 'round trip conversion from af_file to resource to af_file' do
+    let(:file_metadata) { described_class.af_file_to_resource(af_file: af_file) }
+    subject { described_class.resource_to_af_file(metadata_resource: file_metadata) }
+    it 'copies attributes to af_file' do
+      expect(subject.id.to_s).to eq af_file_id
+      expect(subject.create_date).to eq af_file.create_date
+      expect(subject.modified_date).not_to eq af_file.modified_date
+      expect(subject.original_name).to eq plain_text_af_attrs[:original_name]
+      validate_af_file_metadata(plain_text_af_attrs)
+    end
+  end
+
+  private
+
+    def validate_af_file_metadata(expected_attrs) # rubocop:disable Metrics/AbcSize
+      expect(subject.mime_type).to eq expected_attrs[:mime_type]
+      expect(subject.content).to eq expected_attrs[:content]
+      expect(subject.format_label).to eq Array(expected_attrs[:format_label])
+      expect(subject.language).to eq Array(expected_attrs[:language])
+      expect(subject.word_count).to eq Array(expected_attrs[:content].split(' ').count)
+      expect(subject.size).to eq expected_attrs[:content].size
+      expect(subject.character_count).to eq Array(expected_attrs[:content].size)
+    end
+
+    def plain_text_af_attrs
+      { original_name: 'my_file.txt',
+        mime_type: 'text/plain',
+        content: 'some text content for af_file_to_resource test',
+        format_label: 'Plain Text',
+        language: 'en' }
+    end
+
+    def plain_text_valkyrie_attrs
+      { original_filename: 'my_file.html',
+        mime_type: 'text/html',
+        content: '<h3>different text content for valkyrie_to_af_file test</h3>',
+        format_label: 'HTML Text',
+        language: 'en',
+        created_at: Time.now.getlocal - 5.days,
+        updated_at: Time.now.getlocal }
+    end
+end