From 42266397aab80e376c149c474d073a655315a3b3 Mon Sep 17 00:00:00 2001
From: Rob Harrington <oeoeaio@gmail.com>
Date: Wed, 8 Mar 2017 12:19:50 +1100
Subject: [PATCH] Improving performance of available variant lookup for
 standing orders

Only search the DB for available variants once
---
 app/forms/standing_order_form.rb | 12 +++++++++++-
 app/models/standing_line_item.rb |  6 ------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/app/forms/standing_order_form.rb b/app/forms/standing_order_form.rb
index 213bcd6ac0..88d2158864 100644
--- a/app/forms/standing_order_form.rb
+++ b/app/forms/standing_order_form.rb
@@ -217,14 +217,24 @@ class StandingOrderForm
   end
 
   def standing_line_items_available?
+    available_variant_ids = variant_ids_for_shop_and_schedule
     standing_line_items.each do |sli|
-      unless sli.available_from?(shop_id, schedule_id)
+      unless available_variant_ids.include? sli.variant_id
         name = "#{sli.variant.product.name} - #{sli.variant.full_name}"
         errors.add(:standing_line_items, :not_available, name: name)
       end
     end
   end
 
+  def variant_ids_for_shop_and_schedule
+    Spree::Variant.joins(exchanges: { order_cycle: :schedules})
+    .where(id: standing_line_items.map(&:variant_id))
+    .where(schedules: { id: schedule}, exchanges: { incoming: false, receiver_id: shop })
+    .merge(OrderCycle.not_closed)
+    .select('DISTINCT spree_variants.id')
+    .pluck(:id)
+  end
+
   def build_msg_from(k, msg)
     return msg[1..-1] if msg.starts_with?("^")
     errors.full_message(k,msg)
diff --git a/app/models/standing_line_item.rb b/app/models/standing_line_item.rb
index e1d260e7bf..4c3185e45c 100644
--- a/app/models/standing_line_item.rb
+++ b/app/models/standing_line_item.rb
@@ -6,12 +6,6 @@ class StandingLineItem < ActiveRecord::Base
   validates :variant, presence: true
   validates :quantity, { presence: true, numericality: { only_integer: true } }
 
-  def available_from?(shop, schedule)
-    Spree::Variant.joins(exchanges: { order_cycle: :schedules})
-    .where(id: variant_id, schedules: { id: schedule}, exchanges: { incoming: false, receiver_id: shop })
-    .any?
-  end
-
   def total_estimate
     (price_estimate || 0) * (quantity || 0)
   end