Fix finding producers for shopfront, moving to SQL-land in the process. Woo.

app/helpers/shared_helper.rb

@@ -11,7 +11,7 @@ module SharedHelper
 
   # all suppliers of current distributor's products
   def current_producers
-    Exchange.where(receiver_id: current_distributor.id).map{ |ex| ex.variants.map {|v| v.product.supplier }}.flatten.uniq 
+    variants = current_order_cycle.variants_distributed_by(current_distributor)
+    Enterprise.supplying_variant_in(variants)
   end
 end
-

app/models/enterprise.rb

@@ -32,6 +32,7 @@ class Enterprise < ActiveRecord::Base
   scope :by_name, order('name')
   scope :is_primary_producer, where(:is_primary_producer => true)
   scope :is_distributor, where(:is_distributor => true)
+  scope :supplying_variant_in, lambda { |variants| joins(:supplied_products => :variants_including_master).where('spree_variants.id IN (?)', variants).select('DISTINCT enterprises.*') }
   scope :with_supplied_active_products_on_hand, lambda {
     joins(:supplied_products)
       .where('spree_products.deleted_at IS NULL AND spree_products.available_on <= ? AND spree_products.count_on_hand > 0', Time.now)

spec/models/enterprise_spec.rb

@@ -159,6 +159,40 @@ describe Enterprise do
       end
     end
 
+    describe "supplying_variant_in" do
+      it "finds producers by supply of master variant" do
+        s = create(:supplier_enterprise)
+        p = create(:simple_product, supplier: s)
+
+        Enterprise.supplying_variant_in([p.master]).should == [s]
+      end
+
+      it "finds producers by supply of variant" do
+        s = create(:supplier_enterprise)
+        p = create(:simple_product, supplier: s)
+        v = create(:variant, product: p)
+
+        Enterprise.supplying_variant_in([v]).should == [s]
+      end
+
+      it "returns multiple enterprises when given multiple variants" do
+        s1 = create(:supplier_enterprise)
+        s2 = create(:supplier_enterprise)
+        p1 = create(:simple_product, supplier: s1)
+        p2 = create(:simple_product, supplier: s2)
+
+        Enterprise.supplying_variant_in([p1.master, p2.master]).sort.should == [s1, s2].sort
+      end
+
+      it "does not return duplicates" do
+        s = create(:supplier_enterprise)
+        p1 = create(:simple_product, supplier: s)
+        p2 = create(:simple_product, supplier: s)
+
+        Enterprise.supplying_variant_in([p1.master, p2.master]).should == [s]
+      end
+    end
+
     describe "distributing_product" do
       it "returns enterprises distributing via a product distribution" do
         d = create(:distributor_enterprise)