Variant calculates fees and its price inclusive of fees

app/models/order_cycle.rb

@@ -143,18 +143,27 @@ class OrderCycle < ActiveRecord::Base
 
 
   # -- Fees
+  def fees_for(variant, distributor)
+    enterprise_fees_for(variant, distributor).sum do |fee|
+      # Spree's Calculator interface accepts Orders or LineItems,
+      # so we meet that interface with a struct.
+      line_item = OpenStruct.new variant: variant, quantity: 1
+      fee[:enterprise_fee].compute_amount(line_item)
+    end
+  end
+
   def create_adjustments_for(line_item)
     variant = line_item.variant
     distributor = line_item.order.distributor
 
-    fees_for(variant, distributor).each { |fee| create_adjustment_for_fee line_item, fee[:enterprise_fee], fee[:label], fee[:role] }
+    enterprise_fees_for(variant, distributor).each { |fee| create_adjustment_for_fee line_item, fee[:enterprise_fee], fee[:label], fee[:role] }
   end
 
 
   private
 
   # -- Fees
-  def fees_for(variant, distributor)
+  def enterprise_fees_for(variant, distributor)
     fees = []
 
     exchanges_carrying(variant, distributor).each do |exchange|

app/models/spree/variant_decorator.rb

@@ -12,6 +12,18 @@ Spree::Variant.class_eval do
   after_save :update_units
 
 
+  def price_with_fees(distributor, order_cycle)
+    price + fees_for(distributor, order_cycle)
+  end
+
+  # TODO: This method seems a little redundant. Though perhaps a useful interface.
+  # Consider removing.
+  def fees_for(distributor, order_cycle)
+    order_cycle.fees_for(self, distributor)
+  end
+
+
+
   # Copied and modified from Spree::Variant
   def options_text
     values = self.option_values.joins(:option_type).order("#{Spree::OptionType.table_name}.position asc")

spec/models/order_cycle_spec.rb

@@ -309,6 +309,22 @@ describe OrderCycle do
     end
   end
 
+  describe "calculating fees for a variant via a particular distributor" do
+    it "sums all the fees for the variant in the specified hub + order cycle" do
+      coordinator = create(:distributor_enterprise)
+      distributor = create(:distributor_enterprise)
+      order_cycle = create(:simple_order_cycle)
+      enterprise_fee1 = create(:enterprise_fee, amount: 20)
+      enterprise_fee2 = create(:enterprise_fee, amount:  3)
+      product = create(:simple_product)
+
+      create(:exchange, order_cycle: order_cycle, sender: coordinator, receiver: distributor,
+             enterprise_fees: [enterprise_fee1, enterprise_fee2], variants: [product.master])
+      
+      order_cycle.fees_for(product.master, distributor).should == 23
+    end
+  end
+
   describe "creating adjustments for a line item" do
     let(:oc) { OrderCycle.new }
     let(:variant) { double(:variant) }
@@ -318,7 +334,7 @@ describe OrderCycle do
 
     it "creates adjustment for each fee" do
       fee = {enterprise_fee: 'ef', label: 'label', role: 'role'}
-      oc.should_receive(:fees_for).with(variant, distributor) { [fee] }
+      oc.should_receive(:enterprise_fees_for).with(variant, distributor) { [fee] }
       oc.should_receive(:create_adjustment_for_fee).with(line_item, 'ef', 'label', 'role')
 
       oc.send(:create_adjustments_for, line_item)
@@ -335,7 +351,7 @@ describe OrderCycle do
       oc.stub(:coordinator_fees) { [ef3] }
       oc.stub(:adjustment_label_for) { 'label' }
 
-      oc.send(:fees_for, line_item.variant, distributor).should ==
+      oc.send(:enterprise_fees_for, line_item.variant, distributor).should ==
         [{enterprise_fee: ef1, label: 'label', role: 'supplier'},
          {enterprise_fee: ef2, label: 'label', role: 'distributor'},
          {enterprise_fee: ef3, label: 'label', role: 'coordinator'}]

spec/models/spree/variant_spec.rb

@@ -2,6 +2,30 @@ require 'spec_helper'
 
 module Spree
   describe Variant do
+    describe "calculating the price with enterprise fees" do
+      it "returns the price plus the fees" do
+        distributor = double(:distributor)
+        order_cycle = double(:order_cycle)
+
+        variant = Variant.new price: 100
+        variant.should_receive(:fees_for).with(distributor, order_cycle) { 23 }
+        variant.price_with_fees(distributor, order_cycle).should == 123
+      end
+    end
+
+
+    describe "calculating the fees" do
+      it "delegates to order cycle" do
+        distributor = double(:distributor)
+        order_cycle = double(:order_cycle)
+        variant = Variant.new
+
+        order_cycle.should_receive(:fees_for).with(variant, distributor) { 23 }
+        variant.fees_for(distributor, order_cycle).should == 23
+      end
+    end
+
+
     context "when the product has variants" do
       let!(:product) { create(:simple_product) }
       let!(:variant) { create(:variant, product: product) }