Optimize faster l shipment count lookup

lib/planet_express/shipments/shipment_repository.rb

@@ -2,6 +2,16 @@
 
 module PlanetExpress
   class ShipmentRepository < Repository
+    attr_reader :valid_l_shipments_by_month
+
+    def initialize(data:)
+      @data = []
+      @valid_l_shipments_by_month = Hash.new { |hash, key| hash[key] = [] }
+      data.each do |entry|
+        add(entry)
+      end
+    end
+
     def rule_applied_in_month?(month, rule)
       valid_shipments.any? do |shipment|
         shipment.month == month &&
@@ -10,13 +20,20 @@ module PlanetExpress
     end
 
     def l_shipment_count_for_provider_and_month(provider, month)
-      valid_shipments.select do |shipment|
-        shipment.month == month &&
-          shipment.l_shipment? &&
+      valid_l_shipments_by_month[month].select do |shipment|
         shipment.provider == provider
       end.length
     end
 
+    def add(item)
+      data.push(item)
+      item.if_valid do
+        if item.l_shipment?
+          valid_l_shipments_by_month[item.month].push(item)
+        end
+      end
+    end
+
     private
 
     def valid_shipments