Merge pull request solidusio#1466 from jordan-brough/split-up-item-ad…

…justments

Break ItemAdjustments apart and put the logic in OrderUpdater

core/app/models/spree/order_updater.rb

@@ -30,12 +30,22 @@ def run_hooks
  update_hooks.each { |hook| order.send hook }
  end
 
+ # This will update and select the best promotion adjustment, update tax
+ # adjustments, update cancellation adjustments, and then update the total
+ # fields (promo_total, included_tax_total, additional_tax_total, and
+ # adjustment_total) on the item.
+ # @return [void]
  def recalculate_adjustments
- adjustables = [*line_items, *shipments, order]
-
- adjustables.each do |adjustable|
- Spree::ItemAdjustments.new(adjustable).update
- end
+ # Promotion adjustments must be applied first, then tax adjustments.
+ # This fits the criteria for VAT tax as outlined here:
+ # http:https://www.hmrc.gov.uk/vat/managing/charging/discounts-etc.htm#1
+ # It also fits the criteria for sales tax as outlined here:
+ # http:https://www.boe.ca.gov/formspubs/pub113/
+ update_item_promotions
+ update_order_promotions
+ update_taxes
+ update_cancellations
+ update_item_totals
  end
 
  # Updates the following Order total values:
@@ -164,5 +174,71 @@ def update_payment_state
  def round_money(n)
  (n * 100).round / 100.0
  end
+
+ def update_item_promotions
+ [*line_items, *shipments].each do |item|
+ promotion_adjustments = item.adjustments.select(&:promotion?)
+
+ promotion_adjustments.each(&:update!)
+ Spree::Config.promotion_chooser_class.new(promotion_adjustments).update
+
+ item.promo_total = promotion_adjustments.select(&:eligible?).sum(&:amount)
+ end
+ end
+
+ # Update and select the best promotion adjustment for the order.
+ # We don't update the order.promo_total yet. Order totals are updated later
+ # in #update_adjustment_total since they include the totals from the order's
+ # line items and/or shipments.
+ def update_order_promotions
+ promotion_adjustments = order.adjustments.select(&:promotion?)
+ promotion_adjustments.each(&:update!)
+ Spree::Config.promotion_chooser_class.new(promotion_adjustments).update
+ end
+
+ def update_taxes
+ [*line_items, *shipments].each do |item|
+ tax_adjustments = item.adjustments.select(&:tax?)
+
+ tax_adjustments.each(&:update!)
+ # Tax adjustments come in not one but *two* exciting flavours:
+ # Included & additional
+
+ # Included tax adjustments are those which are included in the price.
+ # These ones should not affect the eventual total price.
+ #
+ # Additional tax adjustments are the opposite, affecting the final total.
+ item.included_tax_total = tax_adjustments.select(&:included?).sum(&:amount)
+ item.additional_tax_total = tax_adjustments.reject(&:included?).sum(&:amount)
+ end
+ end
+
+ def update_cancellations
+ line_items.each do |line_item|
+ line_item.adjustments.select(&:cancellation?).each(&:update!)
+ end
+ end
+
+ def update_item_totals
+ [*line_items, *shipments].each do |item|
+ # The cancellation_total isn't persisted anywhere but is included in
+ # the adjustment_total
+ item_cancellation_total = item.adjustments.select(&:cancellation?).sum(&:amount)
+
+ item.adjustment_total = item.promo_total +
+ item.additional_tax_total +
+ item_cancellation_total
+
+ if item.changed?
+ item.update_columns(
+ promo_total: item.promo_total,
+ included_tax_total: item.included_tax_total,
+ additional_tax_total: item.additional_tax_total,
+ adjustment_total: item.adjustment_total,
+ updated_at: Time.current,
+ )
+ end
+ end
+ end
  end
 end