Add basic match on the root level Product Types

Currently anything but the leaf level is modelled as a
DataFoodConsortium::Connector::SKOSInstance, which isn't supported
by the connector as "hasType" for a product. The lead level is modelled
by DataFoodConsortium::Connector::SKOSConcept which is supported by
connector. On top of is `#narrowers`, `#broaders`and `#prefLabels`
aren't set making it very difficult to travers the Product Type tree.

engines/dfc_provider/app/services/supplied_product_builder.rb

@@ -11,19 +11,13 @@ class SuppliedProductBuilder < DfcBuilder
       id,
       name: variant.product_and_full_name,
       description: variant.description,
-      productType: product_type,
+      productType: product_type(variant),
       quantity: QuantitativeValueBuilder.quantity(variant),
       spree_product_id: variant.product.id,
       image_url: variant.product&.image&.url(:product)
     )
   end
 
-  # OFN product categories (taxons) are currently not standardised.
-  # This is just a dummy value for demos.
-  def self.product_type
-    DfcLoader.connector.PRODUCT_TYPES.VEGETABLE.NON_LOCAL_VEGETABLE
-  end
-
   def self.import_variant(supplied_product)
     product_id = supplied_product.spree_product_id
 
@@ -42,6 +36,7 @@ class SuppliedProductBuilder < DfcBuilder
     end
   end
 
+  # TODO fix the taxon here
   def self.import_product(supplied_product)
     Spree::Product.new(
       name: supplied_product.name,
@@ -62,4 +57,17 @@ class SuppliedProductBuilder < DfcBuilder
     QuantitativeValueBuilder.apply(supplied_product.quantity, variant.product)
     variant.unit_value = variant.product.unit_value
   end
+
+  def self.product_type(variant)
+    taxon_name = variant.product.primary_taxon&.dfc_name
+
+    return nil if taxon_name.nil?
+
+    root_product_types = DfcLoader.connector.PRODUCT_TYPES.methods(false).sort
+    search = root_product_types.index(taxon_name.upcase.to_sym)
+
+    return nil if search.nil?
+
+    DfcLoader.connector.PRODUCT_TYPES.public_send(root_product_types[search])
+  end
 end

engines/dfc_provider/spec/services/supplied_product_builder_spec.rb

@@ -7,8 +7,12 @@ describe SuppliedProductBuilder do
 
   subject(:builder) { described_class }
   let(:variant) {
-    build(:variant, id: 5).tap { |v| v.product.supplier_id = 7 }
+    build(:variant, id: 5).tap do |v|
+      v.product.supplier_id = 7
+      v.product.primary_taxon = taxon
+    end
   }
+  let(:taxon) { build(:taxon, name: "Drink", dfc_name: "drink") }
 
   describe ".supplied_product" do
     it "assigns a semantic id" do
@@ -41,11 +45,33 @@ describe SuppliedProductBuilder do
       expect(product.name).to eq "Apple - Granny Smith"
     end
 
-    it "assigns a product type" do
-      product = builder.supplied_product(variant)
-      vegetable = DfcLoader.connector.PRODUCT_TYPES.VEGETABLE.NON_LOCAL_VEGETABLE
+    context "product_type mapping" do
+      it "assigns a product type" do
+        product = builder.supplied_product(variant)
+        drink = DfcLoader.connector.PRODUCT_TYPES.DRINK
 
-      expect(product.productType).to eq vegetable
+        expect(product.productType).to eq drink
+      end
+
+      context "with non existing product type" do
+        let(:taxon) { build(:taxon, name: "other", dfc_name: "other") }
+
+        it "returns nil" do
+          product = builder.supplied_product(variant)
+
+          expect(product.productType).to be_nil
+        end
+      end
+
+      context "when no taxon set" do
+        let(:taxon) { nil }
+
+        it "returns nil" do
+          product = builder.supplied_product(variant)
+
+          expect(product.productType).to be_nil
+        end
+      end
     end
 
     it "assigns an image_url type" do