Discount system

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## Solidus 3.2.0.alpha (master, unreleased)
 
+- Promotions with a `match_policy` of `any` are deprecated.
 - Monkey patch Authentication Bypass by CSRF Weakness vulnerability on solidus_auth_devise for extra security [GHSA-5629-8855-gf4g](https://github.com/solidusio/solidus/security/advisories/GHSA-5629-8855-gf4g)
 - Fix ReDos vulnerability on Spree::EmailValidator::EMAIL_REGEXP [GHSA-qxmr-qxh6-2cc9](https://github.com/solidusio/solidus/security/advisories/GHSA-qxmr-qxh6-2cc9)
 

backend/app/views/spree/admin/promotions/_rules.html.erb

@@ -19,13 +19,15 @@
 
     <%= form_for @promotion, url: object_url, method: :put do |f| %>
       <fieldset class="no-border-top">
-        <div id="promotion-policy-select" class="align-center row">
-          <% Spree::Promotion::MATCH_POLICIES.each do |policy| %>
-            <div class="col-6">
-              <label><%= f.radio_button :match_policy, policy %> <%= t "spree.promotion_form.match_policies.#{policy}" %></label>
-            </div>
-          <% end %>
-        </div>
+        <% if Spree::Config.allow_promotions_any_match_policy %>
+          <div id="promotion-policy-select" class="align-center row">
+            <% Spree::Promotion::MATCH_POLICIES.each do |policy| %>
+              <div class="col-6">
+                <label><%= f.radio_button :match_policy, policy %> <%= t "spree.promotion_form.match_policies.#{policy}" %></label>
+              </div>
+            <% end %>
+          </div>
+        <% end %>
 
         <div id="rules" class="filter_list">
           <% if @promotion.rules.any? %>

backend/app/views/spree/admin/promotions/rules/_line_item_option_value.html.erb

@@ -0,0 +1,12 @@
+<div class="field promo-rule-option-values">
+  <div class="param-prefix hidden" data-param-prefix="<%= param_prefix %>"></div>
+  <div class="row">
+    <div class="col-6"><%= label_tag nil, Spree::Product.model_name.human %></div>
+    <div class="col-6"><%= label_tag nil, plural_resource_name(Spree::OptionValue) %></div>
+  </div>
+
+  <%= content_tag :div, nil, class: "js-promo-rule-option-values",
+                             data: { :'original-option-values' => promotion_rule.preferred_eligible_values } %>
+
+  <button class="button js-add-promo-rule-option-value"><%= t("spree.actions.add") %></button>
+</div>

backend/app/views/spree/admin/promotions/rules/_line_item_product.html.erb

@@ -0,0 +1,18 @@
+<div class="row">
+  <div class="col-12">
+    <div class="field products_rule_products">
+      <%= label_tag "#{param_prefix}_product_ids_string", t('spree.product_rule.choose_products') %>
+      <%= hidden_field_tag "#{param_prefix}[product_ids_string]", promotion_rule.product_ids.join(","), class: "product_picker fullwidth" %>
+    </div>
+  </div>
+  <div class="col-12">
+    <div class="field">
+        <%= label_tag("#{param_prefix}_preferred_match_policy", promotion_rule.class.human_attribute_name(:preferred_match_policy)) %>
+        <%= select_tag(
+          "#{param_prefix}[preferred_match_policy]",
+          options_for_select(I18n.t("spree.promotion_rules.line_item_product.match_policies").to_a.map(&:reverse), promotion_rule.preferred_match_policy),
+          class: "custom-select fullwidth"
+        ) %>
+    </div>
+  </div>
+</div>

backend/app/views/spree/admin/promotions/rules/_line_item_taxon.html.erb

@@ -0,0 +1,14 @@
+<div class="field taxons_rule_taxons">
+  <%= label_tag "#{param_prefix}_taxon_ids_string", t("spree.taxon_rule.choose_taxons") %>
+  <%= hidden_field_tag "#{param_prefix}[taxon_ids_string]", promotion_rule.taxon_ids.join(","), class: "taxon_picker fullwidth", id: "product_taxon_ids" %>
+</div>
+<div class="field">
+   <div class="field">
+        <%= label_tag("#{param_prefix}_preferred_match_policy", promotion_rule.class.human_attribute_name(:preferred_match_policy)) %>
+        <%= select_tag(
+              "#{param_prefix}[preferred_match_policy]",
+              options_for_select(I18n.t("spree.promotion_rules.line_item_taxon.match_policies").to_a.map(&:reverse), promotion_rule.preferred_match_policy),
+              class: "custom-select fullwidth",
+            ) %>
+    </div>
+</div>

backend/spec/features/admin/promotion_adjustments_spec.rb

@@ -118,7 +118,7 @@
       click_button "Create"
       expect(page).to have_title("SAVE SAVE SAVE - Promotions")
 
-      select "Product(s)", from: "Discount Rules"
+      select "Line Item Product(s)", from: "Discount Rules"
       within("#rule_fields") { click_button "Add" }
       select2_search "RoR Mug", from: "Choose products"
       within('#rule_fields') { click_button "Update" }
@@ -136,7 +136,7 @@
       expect(promotion.codes.first).to be_nil
 
       first_rule = promotion.rules.first
-      expect(first_rule.class).to eq(Spree::Promotion::Rules::Product)
+      expect(first_rule.class).to eq(Spree::Promotion::Rules::LineItemProduct)
       expect(first_rule.products.map(&:name)).to include("RoR Mug")
 
       first_action = promotion.actions.first

backend/spec/features/admin/promotions/product_rule_spec.rb

@@ -18,7 +18,7 @@ def add_promotion_rule_of_type(type)
 
   background do
     visit spree.edit_admin_promotion_path(promotion)
-    add_promotion_rule_of_type("Product(s)")
+    add_promotion_rule_of_type("Order Product(s)")
   end
 
   it "can select by product sku" do

core/app/models/spree/calculator/distributed_amount.rb

@@ -15,18 +15,18 @@ class Calculator::DistributedAmount < Calculator
     def compute_line_item(line_item)
       return 0 unless line_item
       return 0 unless preferred_currency.casecmp(line_item.currency).zero?
-      return 0 unless calculable.promotion.line_item_actionable?(line_item.order, line_item)
+      return 0 unless calculable.promotion.line_item_eligible?(line_item)
       Spree::DistributedAmountsHandler.new(
-        actionable_line_items(line_item.order),
+        eligible_line_items(line_item.order),
         preferred_amount
       ).amount(line_item)
     end
 
     private
 
-    def actionable_line_items(order)
+    def eligible_line_items(order)
       order.line_items.select do |line_item|
-        calculable.promotion.line_item_actionable?(order, line_item)
+        calculable.promotion.line_item_eligible?(line_item)
       end
     end
   end

core/app/models/spree/discounts/chooser.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Spree
+  module Discounts
+    class Chooser
+      def initialize(_discountable)
+        # This signature is here to provide context in case
+        # this needs to be customized
+      end
+
+      def call(discounts)
+        [discounts.min_by(&:amount)].compact
+      end
+    end
+  end
+end

core/app/models/spree/discounts/line_item_discounter.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+module Spree
+  module Discounts
+    class LineItemDiscounter
+      attr_reader :promotions
+
+      def initialize(promotions:)
+        @promotions = promotions
+      end
+
+      def call(line_item)
+        discounts = promotions.select do |promotion|
+          promotion.eligible_rules(line_item)
+        end.flat_map do |promotion|
+          promotion.actions.select do |action|
+            action.can_discount? Spree::LineItem
+          end.map do |action|
+            action.discount(line_item)
+          end
+        end
+
+        chosen_discounts = Spree::Config.discount_chooser_class.new(line_item).call(discounts)
+        line_item.discounts = chosen_discounts
+      end
+    end
+  end
+end

core/app/models/spree/discounts/order_discounter.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+module Spree
+  module Discounts
+    class OrderDiscounter
+      attr_reader :order
+
+      def initialize(order)
+        @order = order
+      end
+
+      def call
+        discount_line_items
+        discount_shipments
+      end
+
+      private
+
+      def discount_line_items
+        line_item_discounter = LineItemDiscounter.new(promotions: promotions)
+        order.line_items.each { |line_item| line_item_discounter.call(line_item) }
+      end
+
+      def discount_shipments
+        shipment_discounter = ShipmentDiscounter.new(promotions: promotions)
+        order.shipments.each { |shipment| shipment_discounter.call(shipment) }
+      end
+
+      def promotions
+        @_promotions ||= begin
+          preloader = ActiveRecord::Associations::Preloader.new
+          (connected_order_promotions | sale_promotions).select do |promotion|
+            promotion.activatable?(order)
+          end.map do |promotion|
+            preloader.preload(promotion.rules.select { |r| r.type == "Spree::Promotion::Rules::Product" }, :products)
+            preloader.preload(promotion.rules.select { |r| r.type == "Spree::Promotion::Rules::Store" }, :stores)
+            preloader.preload(promotion.rules.select { |r| r.type == "Spree::Promotion::Rules::Taxon" }, :taxons)
+            preloader.preload(promotion.rules.select { |r| r.type == "Spree::Promotion::Rules::User" }, :users)
+            preloader.preload(promotion.actions.select { |a| a.respond_to?(:calculator) }, :calculator)
+            promotion
+          end
+        end.select { |promotion| promotion.eligible_rules(order) }
+      end
+
+      def connected_order_promotions
+        order.promotions.includes(promotion_includes).select(&:active?)
+      end
+
+      def sale_promotions
+        Spree::Promotion.where(apply_automatically: true).active.includes(promotion_includes)
+      end
+
+      def promotion_includes
+        [
+          :promotion_rules,
+          :promotion_actions,
+        ]
+      end
+    end
+  end
+end

core/app/models/spree/discounts/shipment_discounter.rb

@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+module Spree
+  module Discounts
+    class ShipmentDiscounter
+      attr_reader :promotions
+
+      def initialize(promotions:)
+        @promotions = promotions
+      end
+
+      def call(shipment)
+        discounts = promotions.select do |promotion|
+          promotion.eligible_rules(shipment)
+        end.flat_map do |promotion|
+          promotion.actions.select do |action|
+            action.can_discount? Spree::Shipment
+          end.map do |action|
+            action.discount(shipment)
+          end
+        end
+
+        chosen_discounts = Spree::Config.discount_chooser_class.new(shipment).call(discounts)
+        shipment.discounts = chosen_discounts
+      end
+    end
+  end
+end

core/app/models/spree/line_item.rb

@@ -16,6 +16,7 @@ class LineItem < Spree::Base
 
     has_one :product, through: :variant
 
+    has_many :discounts, class_name: "Spree::LineItemDiscount", inverse_of: :line_item, dependent: :destroy, autosave: true
     has_many :adjustments, as: :adjustable, inverse_of: :adjustable, dependent: :destroy
     has_many :inventory_units, inverse_of: :line_item
 

core/app/models/spree/line_item_discount.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+module Spree
+  class LineItemDiscount < Spree::Base
+    belongs_to :line_item, inverse_of: :discounts
+    belongs_to :promotion_action, -> { with_discarded }, inverse_of: :line_item_discounts
+  end
+end

core/app/models/spree/order_contents.rb

@@ -38,11 +38,13 @@ def update_cart(params)
       if order.update(params)
         unless order.completed?
           order.line_items = order.line_items.select { |li| li.quantity > 0 }
-          # Update totals, then check if the order is eligible for any cart promotions.
-          # If we do not update first, then the item total will be wrong and ItemTotal
-          # promotion rules would not be triggered.
-          reload_totals
-          PromotionHandler::Cart.new(order).activate
+          if legacy_promotion_system?
+            # Update totals, then check if the order is eligible for any cart promotions.
+            # If we do not update first, then the item total will be wrong and ItemTotal
+            # promotion rules would not be triggered.
+            reload_totals
+            PromotionHandler::Cart.new(order).activate
+          end
           order.ensure_updated_shipments
         end
         reload_totals
@@ -71,14 +73,18 @@ def approve(user: nil, name: nil)
     private
 
     def after_add_or_remove(line_item, options = {})
-      reload_totals
+      reload_totals if legacy_promotion_system?
       shipment = options[:shipment]
       shipment.present? ? shipment.update_amounts : order.ensure_updated_shipments
-      PromotionHandler::Cart.new(order, line_item).activate
+      PromotionHandler::Cart.new(order, line_item).activate if legacy_promotion_system?
       reload_totals
       line_item
     end
 
+    def legacy_promotion_system?
+      Spree::Config.promotion_system == :adjustments
+    end
+
     def reload_totals
       @order.recalculate
     end

core/app/models/spree/order_updater.rb

@@ -110,8 +110,12 @@ def recalculate_adjustments
       # http://www.hmrc.gov.uk/vat/managing/charging/discounts-etc.htm#1
       # It also fits the criteria for sales tax as outlined here:
       # http://www.boe.ca.gov/formspubs/pub113/
-      update_item_promotions
-      update_order_promotions
+      if Spree::Config.promotion_system == :adjustments
+        update_item_promotions
+        update_order_promotions
+      elsif Spree::Promotion.order_activatable?(order)
+        Spree::Config.discounter_class.new(order).call
+      end
       update_taxes
       update_cancellations
       update_item_totals
@@ -246,7 +250,11 @@ def update_item_totals
         item.adjustment_total = item.adjustments.
           select(&:eligible?).
           reject(&:included?).
-          sum(&:amount)
+          sum(&:amount) + item.discounts.sum(&:amount)
+        item.promo_total = item.adjustments.
+          select(&:promotion?).
+          select(&:eligible?).
+          sum(&:amount) + item.discounts.sum(&:amount)
 
         if item.changed?
           item.update_columns(