From 801fd1efc80996e5b14f04a773aeda17f7e9a998 Mon Sep 17 00:00:00 2001
From: Preston Choate <preston.choate@classyllama.com>
Date: Fri, 25 Jan 2019 14:32:57 -0600
Subject: [PATCH 1/2] AVS-421-129 - Add config value for calculating tax before
 or after discounts. Add helper method to access new config value. Refactored
 TaxLine class to check for new config value to calculate line amount.

---
 Framework/Interaction/Line.php |  9 ++++++---
 Helper/Config.php              | 15 +++++++++++++++
 etc/adminhtml/system.xml       |  9 +++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/Framework/Interaction/Line.php b/Framework/Interaction/Line.php
index 7c0a37dc..4314f82e 100644
--- a/Framework/Interaction/Line.php
+++ b/Framework/Interaction/Line.php
@@ -260,9 +260,12 @@ protected function convertTaxQuoteDetailsItemToData(\Magento\Tax\Api\Data\QuoteD
         $description = $extensionAttributes ? $extensionAttributes->getAvataxDescription() : '';
         $taxCode = $extensionAttributes ? $extensionAttributes->getAvataxTaxCode() : null;
 
-        // The AvaTax 15 API doesn't support the concept of line-based discounts, so subtract discount amount
-        // from taxable amount
-        $amount = ($item->getUnitPrice() * $quantity) - $item->getDiscountAmount();
+        // Calculate tax with or without discount based on config setting
+        if ($this->config->getCalculateTaxBeforeDiscount($item->getStoreId())) {
+            $amount = $item->getUnitPrice() * $quantity;
+        } else {
+            $amount = ($item->getUnitPrice() * $quantity) - $item->getDiscountAmount();
+        }
 
         $ref1 = $extensionAttributes ? $extensionAttributes->getAvataxRef1() : null;
         $ref2 = $extensionAttributes ? $extensionAttributes->getAvataxRef2() : null;
diff --git a/Helper/Config.php b/Helper/Config.php
index b0841199..d43a0266 100644
--- a/Helper/Config.php
+++ b/Helper/Config.php
@@ -47,6 +47,8 @@ class Config extends AbstractHelper
 
     const XML_PATH_AVATAX_REGION_FILTER_LIST = 'tax/avatax/region_filter_list';
 
+    const XML_PATH_AVATAX_CALCULATE_BEFORE_DISCOUNT = 'tax/avatax/calculate_tax_before_discounts';
+
     const XML_PATH_AVATAX_LIVE_MODE = 'tax/avatax/live_mode';
 
     const XML_PATH_AVATAX_PRODUCTION_ACCOUNT_NUMBER = 'tax/avatax/production_account_number';
@@ -1072,4 +1074,17 @@ public function isSellerImporterOfRecord($originAddress, $destAddress, $storeId)
         }
         return $isSellerImporterOfRecord;
     }
+
+    /**
+     * @param $store
+     * @return mixed
+     */
+    public function getCalculateTaxBeforeDiscount($store)
+    {
+        return $this->scopeConfig->getValue(
+            self::XML_PATH_AVATAX_CALCULATE_BEFORE_DISCOUNT,
+            ScopeInterface::SCOPE_STORE,
+            $store
+        );
+    }
 }
diff --git a/etc/adminhtml/system.xml b/etc/adminhtml/system.xml
index 4a0a6980..81499381 100644
--- a/etc/adminhtml/system.xml
+++ b/etc/adminhtml/system.xml
@@ -79,6 +79,15 @@
                         <field id="filter_tax_by_region">1</field>
                     </depends>
                 </field>
+                <field id="calculate_tax_before_discounts" translate="label" type="select" sortOrder="1008" showInDefault="1" showInWebsite="1" showInStore="1">
+                    <label>Calculate Tax Before Discount</label>
+                    <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
+                    <comment><![CDATA[Should tax be calculated on each item before discounts are applied ]]></comment>
+                    <depends>
+                        <field id="enabled">1</field>
+                        <field id="tax_mode" negative="1">1</field>
+                    </depends>
+                </field>
                 <field id="is_seller_importer_of_record" translate="label comment" type="select" sortOrder="1008" showInDefault="1" showInWebsite="1" showInStore="1">
                     <label>Set Seller as Importer of Record for Global Transactions</label>
                     <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>

From 9afd63cc30870068a5f9deac43db3c9b4ca8da72 Mon Sep 17 00:00:00 2001
From: Preston Choate <preston.choate@classyllama.com>
Date: Fri, 22 Feb 2019 14:36:37 -0600
Subject: [PATCH 2/2] AVS-421_129 - Added default value for new calculate tax
 before discounts config field

---
 etc/config.xml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/etc/config.xml b/etc/config.xml
index 96fdf069..f09ce01f 100644
--- a/etc/config.xml
+++ b/etc/config.xml
@@ -56,6 +56,7 @@
                 <queue_admin_notification_enabled>1</queue_admin_notification_enabled>
                 <queue_failure_notification_enabled>1</queue_failure_notification_enabled>
                 <customer_code_format>id</customer_code_format>
+                <calculate_tax_before_discounts>0</calculate_tax_before_discounts>
             </avatax>
         </tax>
     </default>