Bring coordinator from spree_core

app/models/spree/stock/coordinator.rb

@@ -0,0 +1,59 @@
+module Spree
+  module Stock
+    class Coordinator
+      attr_reader :order
+
+      def initialize(order)
+        @order = order
+      end
+
+      def packages
+        packages = build_packages
+        packages = prioritize_packages(packages)
+        packages = estimate_packages(packages)
+      end
+
+      # Build packages as per stock location
+      #
+      # It needs to check whether each stock location holds at least one stock
+      # item for the order. In case none is found it wouldn't make any sense
+      # to build a package because it would be empty. Plus we avoid errors down
+      # the stack because it would assume the stock location has stock items
+      # for the given order
+      # 
+      # Returns an array of Package instances
+      def build_packages(packages = Array.new)
+        StockLocation.active.each do |stock_location|
+          next unless stock_location.stock_items.where(:variant_id => order.line_items.pluck(:variant_id)).exists?
+
+          packer = build_packer(stock_location, order)
+          packages += packer.packages
+        end
+        packages
+      end
+
+      private
+      def prioritize_packages(packages)
+        prioritizer = Prioritizer.new(order, packages)
+        prioritizer.prioritized_packages
+      end
+
+      def estimate_packages(packages)
+        estimator = Estimator.new(order)
+        packages.each do |package|
+          package.shipping_rates = estimator.shipping_rates(package)
+        end
+        packages
+      end
+
+      def build_packer(stock_location, order)
+        Packer.new(stock_location, order, splitters(stock_location))
+      end
+
+      def splitters(stock_location)
+        # extension point to return custom splitters for a location
+        Rails.application.config.spree.stock_splitters
+      end
+    end
+  end
+end

spec/models/spree/stock/coordinator_spec.rb

@@ -0,0 +1,34 @@
+require 'spec_helper'
+
+module Spree
+  module Stock
+    describe Coordinator do
+      let!(:order) { create(:order_with_line_items) }
+
+      subject { Coordinator.new(order) }
+
+      context "packages" do
+        it "builds, prioritizes and estimates" do
+          subject.should_receive(:build_packages).ordered
+          subject.should_receive(:prioritize_packages).ordered
+          subject.should_receive(:estimate_packages).ordered
+          subject.packages
+        end
+      end
+
+      context "build packages" do
+        it "builds a package for every stock location" do
+          subject.packages.count == StockLocation.count
+        end
+
+        context "missing stock items in stock location" do
+          let!(:another_location) { create(:stock_location, propagate_all_variants: false) }
+
+          it "builds packages only for valid stock locations" do
+            subject.build_packages.count.should == (StockLocation.count - 1)
+          end
+        end
+      end
+    end
+  end
+end