Added option to force shipping prices to include tax

Model/Config.php

@@ -313,6 +313,14 @@ public function isFreeShippingEnabled($store = null)
         return $this->getValue(self::API_CONFIG_PATH . '/freeshipping_enabled', $store);
     }
 
+    /**
+     * @return mixed
+     */
+    public function isPriceIncludesTax($store = null)
+    {
+        return $this->getValue(self::API_CONFIG_PATH . '/price_incl_tax', $store);
+    }
+
     /**
      * @param null|Store|int|string $store
      *

Plugin/Tax/Config.php

@@ -0,0 +1,92 @@
+<?php
+/**
+ * Copyright © 2019 Paazl. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Paazl\CheckoutWidget\Plugin\Tax;
+
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Tax\Model\Config as TaxConfigModel;
+use Paazl\CheckoutWidget\Helper\Order as OrderHelper;
+use Paazl\CheckoutWidget\Model\Config as PaazlConfig;
+use Magento\Quote\Api\Data\ShippingMethodInterface;
+use Magento\Checkout\Model\Session;
+use Magento\Quote\Api\CartRepositoryInterface;
+
+/**
+ * Tax Config Plugin
+ */
+class Config
+{
+    /**
+     * @var OrderHelper
+     */
+    private $orderHelper;
+
+    /**
+     * @var PaazlConfig
+     */
+    private $paazlConfig;
+    /**
+     * @var Session
+     */
+    private $session;
+    /**
+     * @var CartRepositoryInterface
+     */
+    private $cartRepository;
+
+    /**
+     * Config constructor.
+     *
+     * @param OrderHelper $orderHelper
+     * @param PaazlConfig $paazlConfig
+     * @param ShippingMethodInterface $shippingMethod
+     * @param Session $session
+     * @param CartRepositoryInterface $cartRepository
+     */
+    public function __construct(
+        OrderHelper $orderHelper,
+        PaazlConfig $paazlConfig,
+        ShippingMethodInterface $shippingMethod,
+        Session $session,
+        CartRepositoryInterface $cartRepository
+    ) {
+        $this->orderHelper = $orderHelper;
+        $this->paazlConfig = $paazlConfig;
+        $this->shippingMethod = $shippingMethod;
+        $this->session = $session;
+        $this->cartRepository = $cartRepository;
+    }
+
+    /**
+     * @param TaxConfigModel $subject
+     * @param bool $result
+     * @param null $store
+     *
+     * @return bool
+     */
+    public function afterShippingPriceIncludesTax(
+        TaxConfigModel $subject,
+        bool $result,
+        $store = null
+    ) {
+        try {
+            $cartId = $this->session->getQuoteId();
+            //we can't use Magento\Checkout\Model\Session::getQuote() because of infinity loop on place order
+            $quote = $this->cartRepository->getActive($cartId);
+            $shippingMethod = $quote->getShippingAddress()->getShippingMethod();
+            if ($shippingMethod
+                && $this->orderHelper->isPaazlShippingMethod($shippingMethod)
+                && $this->paazlConfig->isPriceIncludesTax($store)
+            ) {
+                return true;
+            }
+        } catch (NoSuchEntityException $e) {
+            return $result;
+        }
+
+        return $result;
+    }
+}

etc/adminhtml/system.xml

@@ -267,6 +267,11 @@
                     </depends>
                     <comment><![CDATA[API Matrix letter for free shipping]]></comment>
                 </field>
+                <field id="price_incl_tax" translate="label" type="select" sortOrder="67" showInDefault="1" showInWebsite="1" showInStore="1">
+                    <label>Price Includes Tax</label>
+                    <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
+                    <comment>If yes - shipping price will always includes tax regardless Magento settings</comment>
+                </field>
                 <field id="debug" translate="label" type="select" sortOrder="70" showInDefault="1" showInWebsite="1" showInStore="0">
                     <label>Debug</label>
                     <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>

etc/di.xml

@@ -30,6 +30,10 @@
                 type="Paazl\CheckoutWidget\Plugin\Quote\AfterAddProduct" sortOrder="1" disabled="false" />
     </type>
 
+    <type name="Magento\Tax\Model\Config">
+        <plugin name="tax_config_plugin" type="Paazl\CheckoutWidget\Plugin\Tax\Config" disabled="false"/>
+    </type>
+
     <preference for="Magento\Framework\HTTP\Client\Curl"
                 type="Paazl\CheckoutWidget\Model\Api\CurlExtra"/>