Find all supplied and distributed taxons

app/models/spree/taxon_decorator.rb

@@ -9,4 +9,40 @@ Spree::Taxon.class_eval do
     #fs << Spree::ProductFilters.distributor_filter if Spree::ProductFilters.respond_to? :distributor_filter
     fs
   end
+
+  # Find all the taxons of supplied products for each enterprise, indexed by enterprise.
+  # Format: {enterprise_id => [taxon_id, ...]}
+  def self.supplied_taxons
+    taxons = {}
+
+    Spree::Taxon.
+      joins(:products => :supplier).
+      select('spree_taxons.*, enterprises.id AS enterprise_id').
+      each do |t|
+
+      taxons[t.enterprise_id.to_i] ||= Set.new
+      taxons[t.enterprise_id.to_i] << t.id
+    end
+
+    taxons
+  end
+
+  # Find all the taxons of distributed products for each enterprise, indexed by enterprise.
+  # Format: {enterprise_id => [taxon_id, ...]}
+  def self.distributed_taxons
+    taxons = {}
+
+    Spree::Taxon.
+      joins(:products).
+      merge(Spree::Product.with_order_cycles_outer).
+      where('o_exchanges.incoming = ?', false).
+      select('spree_taxons.*, o_exchanges.receiver_id AS enterprise_id').
+      each do |t|
+
+      taxons[t.enterprise_id.to_i] ||= Set.new
+      taxons[t.enterprise_id.to_i] << t.id
+    end
+
+    taxons
+  end
 end

spec/models/spree/taxon_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+module Spree
+  describe Taxon do
+    let(:e) { create(:supplier_enterprise) }
+    let(:t0) { p1.taxons.order('id ASC').first }
+    let(:t1) { create(:taxon) }
+    let(:t2) { create(:taxon) }
+
+    describe "finding all supplied taxons" do
+      let!(:p1) { create(:simple_product, supplier: e, taxons: [t1, t2]) }
+
+      it "finds taxons" do
+        Taxon.supplied_taxons.should == {e.id => Set.new([t0.id, t1.id, t2.id])}
+      end
+    end
+
+    describe "finding all distributed taxons" do
+      let!(:oc) { create(:simple_order_cycle, distributors: [e], variants: [p1.master]) }
+      let(:s) { create(:supplier_enterprise) }
+      let(:p1) { create(:simple_product, supplier: s, taxons: [t1, t2]) }
+
+      it "finds taxons" do
+        Taxon.distributed_taxons.should == {e.id => Set.new([t0.id, t1.id, t2.id])}
+      end
+    end
+  end
+end