Map currency to DFC codes

Probably should have just hardcoded it. Hopefully we can remove this soon anyway.

engines/dfc_provider/app/services/offer_builder.rb

@@ -9,12 +9,7 @@ class OfferBuilder < DfcBuilder
 
     price = DataFoodConsortium::Connector::Price.new(
       value: variant.price.to_f,
-
-      # The DFC measures define only five currencies at the moment.
-      # And they are not standardised enough to align with our ISO 4217
-      # currency codes. So I propose to just use those currency codes instead.
-      # https://github.com/datafoodconsortium/taxonomies/issues/48
-      unit: "dfc-m:#{variant.currency}",
+      unit: price_measure(variant)&.semanticId,
     )
     DataFoodConsortium::Connector::Offer.new(
       id, price:, stockLimitation: stock_limitation(variant),
@@ -39,4 +34,25 @@ class OfferBuilder < DfcBuilder
       offer.price
     end
   end
+
+  # The DFC measures define only five currencies at the moment.
+  # And they are not standardised enough to align with our ISO 4217
+  # currency codes. So I propose to just use those currency codes instead.
+  # https://github.com/datafoodconsortium/taxonomies/issues/48
+  def self.price_measure(variant)
+    measures = DfcLoader.vocabulary("measures")
+
+    case variant.currency
+    when "AUD"
+      measures.AUSTRALIANDOLLAR
+    when "CAD"
+      measures.CANADIANDOLLAR
+    when "EUR"
+      measures.EURO
+    when "GBP"
+      measures.POUNDSTERLING
+    when "USD"
+      measures.USDOLLAR
+    end
+  end
 end

engines/dfc_provider/spec/services/offer_builder_spec.rb

@@ -27,13 +27,19 @@ RSpec.describe OfferBuilder do
       expect(offer.stockLimitation).to eq nil
     end
 
-    it "assigns a price with currency" do
-      variant.id = 5
-
+    it "assigns a price with mapped currency" do
       offer = OfferBuilder.build(variant)
 
       expect(offer.price.value).to eq 19.99
-      expect(offer.price.unit).to eq "dfc-m:AUD"
+      expect(offer.price.unit).to eq "dfc-m:AustralianDollar" # Hopefully change to ISO 4217 soon
+    end
+
+    it "assigns a price when unknown currency" do
+      variant.default_price.currency = "XXX"
+      offer = OfferBuilder.build(variant)
+
+      expect(offer.price.value).to eq 19.99
+      expect(offer.price.unit).to be nil
     end
   end
 end

swagger/dfc.yaml

@@ -189,7 +189,7 @@ paths:
                       dfc-b:hasPrice:
                         "@type": dfc-b:Price
                         dfc-b:value: 19.99
-                        dfc-b:hasUnit: dfc-m:AUD
+                        dfc-b:hasUnit: dfc-m:AustralianDollar
                       dfc-b:stockLimitation: 0
         '401':
           description: unauthorized
@@ -230,7 +230,7 @@ paths:
                       dfc-b:hasPrice:
                         "@type": dfc-b:Price
                         dfc-b:value: 19.99
-                        dfc-b:hasUnit: dfc-m:AUD
+                        dfc-b:hasUnit: dfc-m:AustralianDollar
                       dfc-b:stockLimitation: 0
         '404':
           description: not found
@@ -514,7 +514,7 @@ paths:
                     dfc-b:hasPrice:
                       "@type": dfc-b:Price
                       dfc-b:value: 19.99
-                      dfc-b:hasUnit: dfc-m:AUD
+                      dfc-b:hasUnit: dfc-m:AustralianDollar
                     dfc-b:stockLimitation: 5
     put:
       summary: Update Offer