Revert "Three plus one as promotion"

This reverts commit e9f8863.

Author: lukaszreszke

ecommerce/pricing/lib/pricing/events.rb

@@ -56,6 +56,12 @@ class PriceItemRemoved < Infra::Event
     attribute :total_value, Infra::Types::Price
   end
 
+  class DiscountApplied < Infra::Event
+    attribute :order_id, Infra::Types::UUID
+    attribute :base_total_value, Infra::Types::Price
+    attribute :total_value, Infra::Types::Price
+  end
+
   class PercentageDiscountRemoved < Infra::Event
     attribute :order_id, Infra::Types::UUID
     attribute :type, Infra::Types::String

ecommerce/pricing/lib/pricing/offer.rb

@@ -10,15 +10,12 @@ def initialize(id)
       @list = List.new
       @discounts = []
       @state = :draft
-    end
 
-    def add_item(product_id, base_price, promotion = Pricing::Discounts::ThreePlusOneGratis.new)
-      if promotion
-        price = promotion.apply(@list.quantities, product_id, base_price)
-      else
-        price = @discounts.inject(Discounts::NoPercentageDiscount.new, :add).apply(base_price)
-      end
+      @three_plus_one_gratis = Discounts::ThreePlusOneGratis.new
+    end
 
+    def add_item(product_id, base_price)
+      price = @discounts.inject(Discounts::NoPercentageDiscount.new, :add).apply(base_price)
       apply PriceItemAdded.new(
         data: {
           order_id: @id,
@@ -29,6 +26,15 @@ def add_item(product_id, base_price, promotion = Pricing::Discounts::ThreePlusOn
           total_value: @list.actual_sum + price
         }
       )
+
+      anything_applied = @three_plus_one_gratis.apply(@list)
+      apply DiscountApplied.new(
+        data: {
+          order_id: @id,
+          base_total_value: @list.base_sum,
+          total_value: @list.actual_sum
+        }
+      ) if anything_applied
     end
 
     def remove_item(product_id)
@@ -167,6 +173,10 @@ def expire
 
     private
 
+    on DiscountApplied do |event|
+      # TODO: Something about discount?
+    end
+
     on PriceItemAdded do |event|
       @list.add_item(event.data.fetch(:product_id), event.data.fetch(:base_price), event.data.fetch(:price))
     end

ecommerce/pricing/test/three_plus_one_test.rb

@@ -99,72 +99,6 @@ def test_given_three_items_are_added_when_forth_item_is_added_then_the_last__ite
         )
       ) { add_item(order_id, product_id) }
 
-      assert_events(
-        stream,
-        PriceItemAdded.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            base_price: 20,
-            price: 0,
-            base_total_value: 80,
-            total_value: 60,
-          }
-        ),
-        OrderTotalValueCalculated.new(
-          data: {
-            order_id: order_id,
-            discounted_amount: 60,
-            total_amount: 80
-          }
-        ),
-        PriceItemValueCalculated.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            quantity: 4,
-            amount: 80,
-            discounted_amount: 60,
-          }
-        )
-      ) { add_item(order_id, product_id) }
-    end
-
-    def test_given_3_plus_one__when_10_percent_discount_for_offer__then_offer_price_includes_both_discounts
-      product_id = SecureRandom.uuid
-      set_price(product_id, 20)
-      order_id = SecureRandom.uuid
-      stream = "Pricing::Offer$#{order_id}"
-      assert_events(
-        stream,
-        PriceItemAdded.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            base_price: 20,
-            price: 20,
-            base_total_value: 20,
-            total_value: 20,
-          }
-        ),
-        OrderTotalValueCalculated.new(
-          data: {
-            order_id: order_id,
-            discounted_amount: 20,
-            total_amount: 20
-          }
-        ),
-        PriceItemValueCalculated.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            quantity: 1,
-            amount: 20,
-            discounted_amount: 20,
-          }
-        )
-      ) { add_item(order_id, product_id) }
-
       assert_events(
         stream,
         PriceItemAdded.new(
@@ -173,74 +107,21 @@ def test_given_3_plus_one__when_10_percent_discount_for_offer__then_offer_price_
             product_id: product_id,
             base_price: 20,
             price: 20,
-            base_total_value: 40,
-            total_value: 40,
-          }
-        ),
-        OrderTotalValueCalculated.new(
-          data: {
-            order_id: order_id,
-            discounted_amount: 40,
-            total_amount: 40
-          }
-        ),
-        PriceItemValueCalculated.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            quantity: 2,
-            amount: 40,
-            discounted_amount: 40,
-          }
-        )
-      ) { add_item(order_id, product_id) }
-
-      assert_events(
-        stream,
-        PriceItemAdded.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            base_price: 20,
-            price: 20,
-            base_total_value: 60,
-            total_value: 60,
-          }
-        ),
-        OrderTotalValueCalculated.new(
-          data: {
-            order_id: order_id,
-            discounted_amount: 60,
-            total_amount: 60
+            base_total_value: 80,
+            total_value: 80,
           }
         ),
-        PriceItemValueCalculated.new(
-          data: {
-            order_id: order_id,
-            product_id: product_id,
-            quantity: 3,
-            amount: 60,
-            discounted_amount: 60,
-          }
-        )
-      ) { add_item(order_id, product_id) }
-
-      assert_events(
-        stream,
-        PriceItemAdded.new(
+        DiscountApplied.new(
           data: {
             order_id: order_id,
-            product_id: product_id,
-            base_price: 20,
-            price: 0,
             base_total_value: 80,
             total_value: 60,
           }
         ),
         OrderTotalValueCalculated.new(
           data: {
             order_id: order_id,
-            discounted_amount: 60,
+            discounted_amount: 80,
             total_amount: 80
           }
         ),
@@ -250,7 +131,7 @@ def test_given_3_plus_one__when_10_percent_discount_for_offer__then_offer_price_
             product_id: product_id,
             quantity: 4,
             amount: 80,
-            discounted_amount: 60,
+            discounted_amount: 80,
           }
         )
       ) { add_item(order_id, product_id) }