List catalog items with DFC Connector

engines/dfc_provider/app/controllers/dfc_provider/catalog_items_controller.rb

@@ -7,11 +7,14 @@ module DfcProvider
     before_action :check_enterprise
 
     def index
-      # CatalogItem is nested into an entreprise which is also nested into
-      # an user on the DFC specifications, as defined here:
-      # https://datafoodconsortium.gitbook.io/dfc-standard-documentation
-      #  /technical-specification/api-examples
-      render json: current_user, serializer: DfcProvider::PersonSerializer
+      person = PersonBuilder.person(current_user)
+      render json: DfcLoader.connector.export(
+        person,
+        *person.affiliatedOrganizations,
+        *person.affiliatedOrganizations.flat_map(&:catalogItems),
+        *person.affiliatedOrganizations.flat_map(&:catalogItems).map(&:product),
+        *person.affiliatedOrganizations.flat_map(&:catalogItems).flat_map(&:offers),
+      )
     end
 
     def show

engines/dfc_provider/app/services/enterprise_builder.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class EnterpriseBuilder < DfcBuilder
+  def self.enterprise(enterprise)
+    DataFoodConsortium::Connector::Enterprise.new(
+      enterprise.name
+    ).tap do |e|
+      e.semanticId = urls.enterprise_url(enterprise.id)
+      e.catalogItems = catalog_items(enterprise)
+    end
+  end
+
+  def self.catalog_items(enterprise)
+    VariantFetcher.new(enterprise).scope.to_a.map do |variant|
+      catalog_item(variant)
+    end
+  end
+end

engines/dfc_provider/app/services/person_builder.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class PersonBuilder < DfcBuilder
+  def self.person(user)
+    DataFoodConsortium::Connector::Person.new(
+      urls.person_url(user.id),
+      firstName: user.bill_address&.firstname,
+      lastName: user.bill_address&.lastname,
+      affiliatedOrganizations: enterprises(user),
+    )
+  end
+
+  def self.enterprises(user)
+    user.enterprises.map do |enterprise|
+      EnterpriseBuilder.enterprise(enterprise)
+    end
+  end
+end