^^&&^^

Edit File: class-kkart-gateway-cod.php

<?php
/**
 * Class KKART_Gateway_COD file.
 *
 * @package Kkart\Gateways
 */

use Automattic\Jetpack\Constants;

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

/**
 * Cash on Delivery Gateway.
 *
 * Provides a Cash on Delivery Payment Gateway.
 *
 * @class       KKART_Gateway_COD
 * @extends     KKART_Payment_Gateway
 * @version     2.1.0
 * @package     Kkart\Classes\Payment
 */
class KKART_Gateway_COD extends KKART_Payment_Gateway {

/**
	 * Constructor for the gateway.
	 */
	public function __construct() {
		// Setup general properties.
		$this->setup_properties();

// Load the settings.
		$this->init_form_fields();
		$this->init_settings();

// Get settings.
		$this->title              = $this->get_option( 'title' );
		$this->description        = $this->get_option( 'description' );
		$this->instructions       = $this->get_option( 'instructions' );
		$this->enable_for_methods = $this->get_option( 'enable_for_methods', array() );
		$this->enable_for_virtual = $this->get_option( 'enable_for_virtual', 'yes' ) === 'yes';

add_action( 'kkart_update_options_payment_gateways_' . $this->id, array( $this, 'process_admin_options' ) );
		add_action( 'kkart_thankyou_' . $this->id, array( $this, 'thankyou_page' ) );
		add_filter( 'kkart_payment_complete_order_status', array( $this, 'change_payment_complete_order_status' ), 10, 3 );

// Customer Emails.
		add_action( 'kkart_email_before_order_table', array( $this, 'email_instructions' ), 10, 3 );
	}

/**
	 * Setup general properties for the gateway.
	 */
	protected function setup_properties() {
		$this->id                 = 'cod';
		$this->icon               = apply_filters( 'kkart_cod_icon', '' );
		$this->method_title       = __( 'Cash on delivery', 'kkart' );
		$this->method_description = __( 'Have your customers pay with cash (or by other means) upon delivery.', 'kkart' );
		$this->has_fields         = false;
	}

/**
	 * Initialise Gateway Settings Form Fields.
	 */
	public function init_form_fields() {
		$this->form_fields = array(
			'enabled'            => array(
				'title'       => __( 'Enable/Disable', 'kkart' ),
				'label'       => __( 'Enable cash on delivery', 'kkart' ),
				'type'        => 'checkbox',
				'description' => '',
				'default'     => 'no',
			),
			'title'              => array(
				'title'       => __( 'Title', 'kkart' ),
				'type'        => 'text',
				'description' => __( 'Payment method description that the customer will see on your checkout.', 'kkart' ),
				'default'     => __( 'Cash on delivery', 'kkart' ),
				'desc_tip'    => true,
			),
			'description'        => array(
				'title'       => __( 'Description', 'kkart' ),
				'type'        => 'textarea',
				'description' => __( 'Payment method description that the customer will see on your website.', 'kkart' ),
				'default'     => __( 'Pay with cash upon delivery.', 'kkart' ),
				'desc_tip'    => true,
			),
			'instructions'       => array(
				'title'       => __( 'Instructions', 'kkart' ),
				'type'        => 'textarea',
				'description' => __( 'Instructions that will be added to the thank you page.', 'kkart' ),
				'default'     => __( 'Pay with cash upon delivery.', 'kkart' ),
				'desc_tip'    => true,
			),
			'enable_for_methods' => array(
				'title'             => __( 'Enable for shipping methods', 'kkart' ),
				'type'              => 'multiselect',
				'class'             => 'kkart-enhanced-select',
				'css'               => 'width: 400px;',
				'default'           => '',
				'description'       => __( 'If COD is only available for certain methods, set it up here. Leave blank to enable for all methods.', 'kkart' ),
				'options'           => $this->load_shipping_method_options(),
				'desc_tip'          => true,
				'custom_attributes' => array(
					'data-placeholder' => __( 'Select shipping methods', 'kkart' ),
				),
			),
			'enable_for_virtual' => array(
				'title'   => __( 'Accept for virtual orders', 'kkart' ),
				'label'   => __( 'Accept COD if the order is virtual', 'kkart' ),
				'type'    => 'checkbox',
				'default' => 'yes',
			),
		);
	}

/**
	 * Check If The Gateway Is Available For Use.
	 *
	 * @return bool
	 */
	public function is_available() {
		$order          = null;
		$needs_shipping = false;

// Test if shipping is needed first.
		if ( KKART()->cart && KKART()->cart->needs_shipping() ) {
			$needs_shipping = true;
		} elseif ( is_page( kkart_get_page_id( 'order_pay' ) ) && 0 < (int) @$_GET['order_id'] ) {
			$order_id = absint( $_GET['order_id'] );
			$order    = kkart_get_order( $order_id );

// Test if order needs shipping.
			if ( 0 < count( $order->get_items() ) ) {
				foreach ( $order->get_items() as $item ) {
					$_product = $item->get_product();
					if ( $_product && $_product->needs_shipping() ) {
						$needs_shipping = true;
						break;
					}
				}
			}
		}

$needs_shipping = apply_filters( 'kkart_cart_needs_shipping', $needs_shipping );

// Virtual order, with virtual disabled.
		if ( ! $this->enable_for_virtual && ! $needs_shipping ) {
			return false;
		}

// Only apply if all packages are being shipped via chosen method, or order is virtual.
		if ( ! empty( $this->enable_for_methods ) && $needs_shipping ) {
			$order_shipping_items            = is_object( $order ) ? $order->get_shipping_methods() : false;
			$chosen_shipping_methods_session = KKART()->session->get( 'chosen_shipping_methods' );

if ( $order_shipping_items ) {
				$canonical_rate_ids = $this->get_canonical_order_shipping_item_rate_ids( $order_shipping_items );
			} else {
				$canonical_rate_ids = $this->get_canonical_package_rate_ids( $chosen_shipping_methods_session );
			}

if ( ! count( $this->get_matching_rates( $canonical_rate_ids ) ) ) {
				return false;
			}
		}

return parent::is_available();
	}

/**
	 * Checks to see whether or not the admin settings are being accessed by the current request.
	 *
	 * @return bool
	 */
	private function is_accessing_settings() {
		if ( is_admin() ) {
			// phpcs:disable WordPress.Security.NonceVerification
			if ( ! isset( $_REQUEST['page'] ) || 'kkart-settings' !== $_REQUEST['page'] ) {
				return false;
			}
			if ( ! isset( $_REQUEST['tab'] ) || 'checkout' !== $_REQUEST['tab'] ) {
				return false;
			}
			if ( ! isset( $_REQUEST['section'] ) || 'cod' !== $_REQUEST['section'] ) {
				return false;
			}
			// phpcs:enable WordPress.Security.NonceVerification

return true;
		}

if ( Constants::is_true( 'REST_REQUEST' ) ) {
			global $wp;
			if ( isset( $wp->query_vars['rest_route'] ) && false !== strpos( $wp->query_vars['rest_route'], '/payment_gateways' ) ) {
				return true;
			}
		}

return false;
	}

/**
	 * Loads all of the shipping method options for the enable_for_methods field.
	 *
	 * @return array
	 */
	private function load_shipping_method_options() {
		// Since this is expensive, we only want to do it if we're actually on the settings page.
		if ( ! $this->is_accessing_settings() ) {
			return array();
		}

$data_store = KKART_Data_Store::load( 'shipping-zone' );
		$raw_zones  = $data_store->get_zones();

foreach ( $raw_zones as $raw_zone ) {
			$zones[] = new KKART_Shipping_Zone( $raw_zone );
		}

$zones[] = new KKART_Shipping_Zone( 0 );

$options = array();
		foreach ( KKART()->shipping()->load_shipping_methods() as $method ) {

$options[ $method->get_method_title() ] = array();

// Translators: %1$s shipping method name.
			$options[ $method->get_method_title() ][ $method->id ] = sprintf( __( 'Any &quot;%1$s&quot; method', 'kkart' ), $method->get_method_title() );

foreach ( $zones as $zone ) {

$shipping_method_instances = $zone->get_shipping_methods();

foreach ( $shipping_method_instances as $shipping_method_instance_id => $shipping_method_instance ) {

if ( $shipping_method_instance->id !== $method->id ) {
						continue;
					}

$option_id = $shipping_method_instance->get_rate_id();

// Translators: %1$s shipping method title, %2$s shipping method id.
					$option_instance_title = sprintf( __( '%1$s (#%2$s)', 'kkart' ), $shipping_method_instance->get_title(), $shipping_method_instance_id );

// Translators: %1$s zone name, %2$s shipping method instance name.
					$option_title = sprintf( __( '%1$s &ndash; %2$s', 'kkart' ), $zone->get_id() ? $zone->get_zone_name() : __( 'Other locations', 'kkart' ), $option_instance_title );

$options[ $method->get_method_title() ][ $option_id ] = $option_title;
				}
			}
		}

return $options;
	}

/**
	 * Converts the chosen rate IDs generated by Shipping Methods to a canonical 'method_id:instance_id' format.
	 *
	 * @since  3.4.0
	 *
	 * @param  array $order_shipping_items  Array of KKART_Order_Item_Shipping objects.
	 * @return array $canonical_rate_ids    Rate IDs in a canonical format.
	 */
	private function get_canonical_order_shipping_item_rate_ids( $order_shipping_items ) {

$canonical_rate_ids = array();

foreach ( $order_shipping_items as $order_shipping_item ) {
			$canonical_rate_ids[] = $order_shipping_item->get_method_id() . ':' . $order_shipping_item->get_instance_id();
		}

return $canonical_rate_ids;
	}

/**
	 * Converts the chosen rate IDs generated by Shipping Methods to a canonical 'method_id:instance_id' format.
	 *
	 * @since  3.4.0
	 *
	 * @param  array $chosen_package_rate_ids Rate IDs as generated by shipping methods. Can be anything if a shipping method doesn't honor KKART conventions.
	 * @return array $canonical_rate_ids  Rate IDs in a canonical format.
	 */
	private function get_canonical_package_rate_ids( $chosen_package_rate_ids ) {

$shipping_packages  = KKART()->shipping()->get_packages();
		$canonical_rate_ids = array();

if ( ! empty( $chosen_package_rate_ids ) && is_array( $chosen_package_rate_ids ) ) {
			foreach ( $chosen_package_rate_ids as $package_key => $chosen_package_rate_id ) {
				if ( ! empty( $shipping_packages[ $package_key ]['rates'][ $chosen_package_rate_id ] ) ) {
					$chosen_rate          = $shipping_packages[ $package_key ]['rates'][ $chosen_package_rate_id ];
					$canonical_rate_ids[] = $chosen_rate->get_method_id() . ':' . $chosen_rate->get_instance_id();
				}
			}
		}

return $canonical_rate_ids;
	}

/**
	 * Indicates whether a rate exists in an array of canonically-formatted rate IDs that activates this gateway.
	 *
	 * @since  3.4.0
	 *
	 * @param array $rate_ids Rate ids to check.
	 * @return boolean
	 */
	private function get_matching_rates( $rate_ids ) {
		// First, match entries in 'method_id:instance_id' format. Then, match entries in 'method_id' format by stripping off the instance ID from the candidates.
		return array_unique( array_merge( array_intersect( $this->enable_for_methods, $rate_ids ), array_intersect( $this->enable_for_methods, array_unique( array_map( 'kkart_get_string_before_colon', $rate_ids ) ) ) ) );
	}

/**
	 * Process the payment and return the result.
	 *
	 * @param int $order_id Order ID.
	 * @return array
	 */
	public function process_payment( $order_id ) {
		$order = kkart_get_order( $order_id );

if ( $order->get_total() > 0 ) {
			// Mark as processing or on-hold (payment won't be taken until delivery).
			$order->update_status( apply_filters( 'kkart_cod_process_payment_order_status', $order->has_downloadable_item() ? 'on-hold' : 'processing', $order ), __( 'Payment to be made upon delivery.', 'kkart' ) );
		} else {
			$order->payment_complete();
		}

// Remove cart.
		KKART()->cart->empty_cart();

// Return thankyou redirect.
		return array(
			'result'   => 'success',
			'redirect' => $this->get_return_url( $order ),
		);
	}

/**
	 * Output for the order received page.
	 */
	public function thankyou_page() {
		if ( $this->instructions ) {
			echo wp_kses_post( wpautop( wptexturize( $this->instructions ) ) );
		}
	}

/**
	 * Change payment complete order status to completed for COD orders.
	 *
	 * @since  3.1.0
	 * @param  string         $status Current order status.
	 * @param  int            $order_id Order ID.
	 * @param  KKART_Order|false $order Order object.
	 * @return string
	 */
	public function change_payment_complete_order_status( $status, $order_id = 0, $order = false ) {
		if ( $order && 'cod' === $order->get_payment_method() ) {
			$status = 'completed';
		}
		return $status;
	}

/**
	 * Add content to the KKART emails.
	 *
	 * @param KKART_Order $order Order object.
	 * @param bool     $sent_to_admin  Sent to admin.
	 * @param bool     $plain_text Email format: plain text or HTML.
	 */
	public function email_instructions( $order, $sent_to_admin, $plain_text = false ) {
		if ( $this->instructions && ! $sent_to_admin && $this->id === $order->get_payment_method() ) {
			echo wp_kses_post( wpautop( wptexturize( $this->instructions ) ) . PHP_EOL );
		}
	}
}