Calculate fee breakdown

app/models/spree/variant_decorator.rb

@@ -48,6 +48,10 @@ Spree::Variant.class_eval do
     OpenFoodNetwork::EnterpriseFeeCalculator.new(distributor, order_cycle).fees_for self
   end
 
+  def fees_by_type_for(distributor, order_cycle)
+    OpenFoodNetwork::EnterpriseFeeCalculator.new(distributor, order_cycle).fees_by_type_for self
+  end
+
 
   # Copied and modified from Spree::Variant
   def options_text

app/serializers/api/variant_serializer.rb

@@ -7,13 +7,10 @@ class Api::VariantSerializer < ActiveModel::Serializer
   end
 
   def base_price
-    1.00
+    object.price
   end
 
   def fees
-    {admin: 1.23, sales: 4.56, packing: 7.89, transport: 0.12}
+    object.fees_by_type_for(options[:current_distributor], options[:current_order_cycle])
   end
 end
-
-
-# price_without_fees / price

lib/open_food_network/enterprise_fee_calculator.rb

@@ -10,14 +10,19 @@ module OpenFoodNetwork
 
     def fees_for(variant)
       per_item_enterprise_fee_applicators_for(variant).sum do |applicator|
-        # Spree's Calculator interface accepts Orders or LineItems,
-        # so we meet that interface with a struct.
-        # Amount is faked, this is a method on LineItem
-        line_item = OpenStruct.new variant: variant, quantity: 1, amount: variant.price
-        applicator.enterprise_fee.compute_amount(line_item)
+        calculate_fee_for variant, applicator
       end
     end
 
+    def fees_by_type_for(variant)
+      per_item_enterprise_fee_applicators_for(variant).inject({}) do |fees, applicator|
+        fees[applicator.enterprise_fee.fee_type.to_sym] ||= 0
+        fees[applicator.enterprise_fee.fee_type.to_sym] += calculate_fee_for variant, applicator
+        fees
+      end
+    end
+
+
     def create_line_item_adjustments_for(line_item)
       variant = line_item.variant
       @distributor = line_item.order.distributor
@@ -40,6 +45,14 @@ module OpenFoodNetwork
 
     private
 
+    def calculate_fee_for(variant, applicator)
+      # Spree's Calculator interface accepts Orders or LineItems,
+      # so we meet that interface with a struct.
+      # Amount is faked, this is a method on LineItem
+      line_item = OpenStruct.new variant: variant, quantity: 1, amount: variant.price
+      applicator.enterprise_fee.compute_amount(line_item)
+    end
+
     def per_item_enterprise_fee_applicators_for(variant)
       fees = []
 

spec/lib/open_food_network/enterprise_fee_calculator_spec.rb

@@ -8,7 +8,7 @@ module OpenFoodNetwork
       let(:order_cycle) { create(:simple_order_cycle) }
       let(:product) { create(:simple_product, price: 10.00) }
 
-      describe "calculating fees for a variant via a particular distribution" do
+      describe "calculating fees for a variant" do
         it "sums all the per-item fees for the variant in the specified hub + order cycle" do
           enterprise_fee1 = create(:enterprise_fee, amount: 20)
           enterprise_fee2 = create(:enterprise_fee, amount:  3)
@@ -32,6 +32,21 @@ module OpenFoodNetwork
         end
       end
 
+      describe "calculating fees by type" do
+        let!(:ef_admin) { create(:enterprise_fee, fee_type: 'admin', amount: 1.23) }
+        let!(:ef_sales) { create(:enterprise_fee, fee_type: 'sales', amount: 4.56) }
+        let!(:ef_packing) { create(:enterprise_fee, fee_type: 'packing', amount: 7.89) }
+        let!(:ef_transport) { create(:enterprise_fee, fee_type: 'transport', amount: 0.12) }
+        let!(:exchange) { create(:exchange, order_cycle: order_cycle,
+                                 sender: coordinator, receiver: distributor, incoming: false,
+                                 enterprise_fees: [ef_admin, ef_sales, ef_packing, ef_transport],
+                                 variants: [product.master]) }
+
+        it "returns a breakdown of fees" do
+          EnterpriseFeeCalculator.new(distributor, order_cycle).fees_by_type_for(product.master).should == {admin: 1.23, sales: 4.56, packing: 7.89, transport: 0.12}
+        end
+      end
+
       describe "creating adjustments" do
         let(:order) { create(:order, distributor: distributor, order_cycle: order_cycle) }
         let!(:line_item) { create(:line_item, order: order, variant: product.master) }

spec/models/spree/variant_spec.rb

@@ -94,6 +94,20 @@ module Spree
     end
 
 
+    describe "calculating fees broken down by fee type" do
+      it "delegates to EnterpriseFeeCalculator" do
+        distributor = double(:distributor)
+        order_cycle = double(:order_cycle)
+        variant = Variant.new
+        fees = double(:fees)
+
+        OpenFoodNetwork::EnterpriseFeeCalculator.any_instance.should_receive(:fees_by_type_for).with(variant) { fees }
+
+        variant.fees_by_type_for(distributor, order_cycle).should == fees
+      end
+    end
+
+
     context "when the product has variants" do
       let!(:product) { create(:simple_product) }
       let!(:variant) { create(:variant, product: product) }