gocodebox/lifterlms

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includes/abstracts/abstract.llms.payment.gateway.php

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<?php
/**
 * LifterLMS Payment Gateways Abstract
 *
 * @package LifterLMS/Abstracts/Classes
 *
 * @since 3.0.0
 * @version 7.5.0
 */

defined( 'ABSPATH' ) || exit;

/**
 * LifterLMS Payment Gateways abstract class
 *
 * @since 3.0.0
 * @since 4.0.0 Removed deprecated completed transaction message parameter output.
 * @since 5.3.0 Extend LLMS_Abstract_Options_Data for improved options interactions.
 */
abstract class LLMS_Payment_Gateway extends LLMS_Abstract_Options_Data {

    /**
     * Optional gateway description for the admin panel
     *
     * @var string
     */
    public $admin_description = '';

    /**
     * Fields the gateway uses on the admin panel when displaying/editing an order
     *
     * @var array
     */
    public $admin_order_fields = array(
        'customer'     => false,
        'subscription' => false,
        'source'       => false,
    );

    /**
     * Optional gateway title for the admin panel
     *
     * @var string
     */
    public $admin_title = '';

    /**
     * Optional gateway description for the frontend
     *
     * @var string
     */
    public $description = '';

    /**
     * Order to display the gateway in on the frontend
     *
     * @var integer
     */
    public $display_order = 1;

    /**
     * Is the gateway enabled for payment processing?
     *
     * @var string
     */
    public $enabled = 'no';

    /**
     * Optional icon displayed on the frontend
     *
     * @var string
     */
    public $icon = '';

    /**
     * ID of the Payment Gateway, used internally
     *
     * @var string
     */
    public $id;

    /**
     * Logging status
     *
     * @var string
     */
    public $logging_enabled = '';

    /**
     * Option name prefix.
     *
     * @var string
     */
    protected $option_prefix = 'llms_gateway_';

    /**
     * Array of supported gateway features.
     *
     * @var array
     */
    public $supports = array(
        'checkout_fields'           => false,
        'cc_save'                   => false,
        'refunds'                   => false,
        'single_payments'           => false,
        'recurring_payments'        => false,
        'recurring_retry'           => false,
        'test_mode'                 => false,
        'modify_recurring_payments' => null,
    );

    /**
     * Description of the gateway's test mode (if supported)
     *
     * @var string
     */
    public $test_mode_description = '';

    /**
     * Is test mode enabled?
     *
     * Can be modified by user on settings page if gateway supports "test_mode".
     *
     * @var string
     */
    public $test_mode_enabled = 'no';

    /**
     * Title of the gateway's test mode (if supported)
     *
     * @var string
     */
    public $test_mode_title = '';

    /**
     * Gateway title for the frontend
     *
     * @var string
     */
    public $title = '';

    /**
     * Strings to mask when writing debug logs.
     *
     * @var string[]
     */
    protected $secure_strings = array();

    /**
     * Option's data version
     *
     * @var integer
     */
    protected $version = 2;

    /**
     * Adds a string to the gateway's list of secure strings.
     *
     * @since 7.0.0
     *
     * @param string $string The string to add.
     * @return void
     */
    public function add_secure_string( $string ) {
        $this->secure_strings[] = (string) $string;
    }

    /**
     * This should be called by the gateway after verifying the transaction was completed successfully
     *
     * @since 3.0.0
     * @since 3.30.0 Added access plan and query string checkout redirect settings.
     * @since 3.34.3 Use `llms_redirect_and_exit()` instead of `wp_redirect()` and `exit()`.
     * @since 3.37.18 Allow redirection to external domains by disabling "safe" redirects.
     *
     * @param LLMS_Order $order      Instance of an LLMS_Order object.
     * @param null       $deprecated Deprecated.
     * @return void
     */
    public function complete_transaction( $order, $deprecated = null ) {

        $this->log( $this->get_admin_title() . ' `complete_transaction()` started', $order );

        $redirect = $this->get_complete_transaction_redirect_url( $order );

        $this->log( $this->get_admin_title() . ' `complete_transaction()` finished', $redirect, $order );

        // Ensure notification processors get dispatched since shutdown wont be called.
        do_action( 'llms_dispatch_notification_processors' );

        // Execute a redirect.
        llms_redirect_and_exit(
            $redirect,
            array(
                'safe' => false,
            )
        );

    }

    /**
     * This should be called by AJAX-powered gateways after verifying that a transaction was completed successfully.
     *
     * @since 7.0.0
     *
     * @param LLMS_Order $order The order being processed.
     * @param array      $data  Data to add to the default success return array.
     * @return array {
     *     An array of return data. The actual return array may include additional data from the payment gateway.
     *
     *     @type string $redirect The complete transaction redirect URL.
     *     @type string $status   The status code, always 'SUCCESS'.
     * }
     */
    public function complete_transaction_ajax( $order, $data = array() ) {

        $data = wp_parse_args(
            $data,
            array(
                'redirect' => $this->get_complete_transaction_redirect_url( $order ),
                'status'   => 'SUCCESS',
            )
        );

        // Ensure notification processors get dispatched since shutdown won't be called.
        do_action( 'llms_dispatch_notification_processors' );

        return $data;

    }

    /**
     * Confirms a Payment.
     *
     * Called by {@see LLMS_Controller_Orders::confirm_pending_order} on confirm form submission.
     *
     * Some validation is performed before passing to this function, gateways should do further validation
     * on their own.
     *
     * This stub is not necessary to implement if the gateway doesn't have a payment confirmation step.
     *
     * For gateways which implement AJAX order processing, this function should return either a WP_Error or
     * a success array from {@see LLMS_Payment_Gateway::complete_transaction_ajax()}.
     *
     * For gateways which implement synchronous order processing through form submission, this function should
     * not return and should instead perform a redirect and / or output notices using {@see llms_add_notice()}.
     *
     * @since 3.0.0
     *
     * @param LLMS_Order $order Instance of the order being processed.
     * @return void|WP_Error|array
     */
    public function confirm_pending_order( $order ) {}

    /**
     * Get admin description for the gateway
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_admin_description() {

        /**
         * Filters a payment gateway's admin description.
         *
         * @since 3.0.0
         *
         * @param string $admin_description The admin description.
         * @param string $gateway_id        The payment gateway ID.
         */
        return apply_filters( 'llms_get_gateway_admin_description', $this->admin_description, $this->id );

    }

    /**
     * Get the admin title for the gateway
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_admin_title() {

        /**
         * Filters a payment gateway's admin title.
         *
         * @since 3.0.0
         *
         * @param string $admin_title The admin title.
         * @param string $gateway_id  The payment gateway ID.
         */
        return apply_filters( 'llms_get_gateway_admin_title', $this->admin_title, $this->id );

    }

    /**
     * Get data about the fields displayed on the admin panel when viewing an order
     *
     * @since 3.10.0
     *
     * @return array[]
     */
    public function get_admin_order_fields() {

        $fields = array(
            'customer'     => array(
                'label'   => __( 'Customer ID', 'lifterlms' ),
                'enabled' => $this->admin_order_fields['customer'],
                'name'    => 'gateway_customer_id',
            ),
            'source'       => array(
                'label'   => __( 'Source ID', 'lifterlms' ),
                'enabled' => $this->admin_order_fields['source'],
                'name'    => 'gateway_source_id',
            ),
            'subscription' => array(
                'label'   => __( 'Subscription ID', 'lifterlms' ),
                'enabled' => $this->admin_order_fields['subscription'],
                'name'    => 'gateway_subscription_id',
            ),
        );

        /**
         * Filters a payment gateway's admin title.
         *
         * @since 3.10.0
         *
         * @param array[] $fields     Array of admin order fields.
         * @param string  $gateway_id The payment gateway ID.
         */
        return apply_filters( 'llms_get_gateway_admin_order_fields', $fields, $this->id );
    }

    /**
     * Get default gateway admin settings fields
     *
     * @since 3.0.0
     * @since 3.29.0 Unknown.
     *
     * @return array[]
     */
    public function get_admin_settings_fields() {

        $fields = array();

        $fields[] = array(
            'type'  => 'custom-html',
            'value' => '
                <h1>' . $this->get_admin_title() . '</h1>
                <p>' . $this->get_admin_description() . '</p>
            ',
        );

        $fields[] = array(
            'autoload'     => true,
            'id'           => $this->get_option_name( 'enabled' ),
            'desc'         => sprintf( _x( 'Enable %s', 'Payment gateway title', 'lifterlms' ), $this->get_admin_title() ),
            'desc_tooltip' => __( 'Checking this box will allow users to use this payment gateway.', 'lifterlms' ),
            'default'      => $this->get_enabled(),
            'title'        => __( 'Enable / Disable', 'lifterlms' ),
            'type'         => 'checkbox',
        );

        $fields[] = array(
            'id'      => $this->get_option_name( 'title' ),
            'desc'    => '<br>' . __( 'The title the user sees during checkout.', 'lifterlms' ),
            'default' => $this->get_title(),
            'title'   => __( 'Title', 'lifterlms' ),
            'type'    => 'text',
        );

        $fields[] = array(
            'id'      => $this->get_option_name( 'description' ),
            'desc'    => '<br>' . __( 'The description the user sees during checkout.', 'lifterlms' ),
            'default' => $this->get_description(),
            'title'   => __( 'Description', 'lifterlms' ),
            'type'    => 'text',
        );

        if ( $this->supports( 'test_mode' ) ) {

            $fields[] = array(
                'id'           => $this->get_option_name( 'test_mode_enabled' ),
                'desc'         => sprintf( _x( 'Enable %s', 'Payment gateway test mode title', 'lifterlms' ), $this->get_test_mode_title() ),
                'desc_tooltip' => $this->get_test_mode_description(),
                'default'      => $this->get_test_mode_enabled(),
                'title'        => $this->get_test_mode_title(),
                'type'         => 'checkbox',
            );

        }

        $fields[] = array(
            'id'           => $this->get_option_name( 'logging_enabled' ),
            'desc'         => __( 'Enable debug logging', 'lifterlms' ),
            'desc_tooltip' => sprintf( __( 'When enabled, debugging information will be logged to "%s"', 'lifterlms' ), llms_get_log_path( $this->get_id() ) ),
            'title'        => __( 'Debug Log', 'lifterlms' ),
            'type'         => 'checkbox',
        );

        /**
         * Filters the gateway's settings fields displayed on the admin panel
         *
         * @since 3.0.0
         *
         * @param array[] $fields     Array of settings fields.
         * @param string  $gateway_id The payment gateway ID.
         */
        return apply_filters( 'llms_get_gateway_settings_fields', $fields, $this->id );

    }

    /**
     * Get API mode
     *
     * If test is not supported will return "live".
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_api_mode() {
        if ( $this->supports( 'test_mode' ) && $this->is_test_mode_enabled() ) {
            return 'test';
        }
        return 'live';
    }

    /**
     * Calculates the url to redirect to on transaction completion.
     *
     * @since 3.30.0
     * @since 7.0.0 Retrieve the redirect URL from the INPUT_POST if not passed via INPUT_GET.
     *
     * @param LLMS_Order $order The order object.
     * @return string
     */
    protected function get_complete_transaction_redirect_url( $order ) {

        // Get the redirect parameter from INPUT_GET.
        $redirect = urldecode( llms_filter_input( INPUT_GET, 'redirect', FILTER_VALIDATE_URL ) ?? '' );

        // Get the redirect parameter from INPUT_POST if not INPUT_GET redirect pased.
        $redirect = $redirect ? $redirect : llms_filter_input( INPUT_POST, 'redirect', FILTER_VALIDATE_URL );

        // Redirect to the product's permalink, if no redirect found yet.
        $redirect = $redirect ? $redirect : get_permalink( $order->get( 'product_id' ) );

        // Fallback to the account page if we don't have a url for some reason.
        $redirect = $redirect ? $redirect : get_permalink( llms_get_page_id( 'myaccount' ) );

        // Add order key to the url.
        $redirect = add_query_arg(
            array(
                'order-complete' => $order->get( 'order_key' ),
            ),
            esc_url( $redirect )
        );

        // Redirection url on free checkout form.
        $quick_enroll_form      = llms_filter_input( INPUT_POST, 'form' );
        $free_checkout_redirect = llms_filter_input( INPUT_POST, 'free_checkout_redirect', FILTER_VALIDATE_URL );

        if ( get_current_user_id() && ( 'free_enroll' === $quick_enroll_form ) && $free_checkout_redirect ) {
            $redirect = $free_checkout_redirect;
        }

        /**
         * Filters the redirect on order completion.
         *
         * @since 3.8.0
         *
         * @param string     $redirect The URL to redirect user to.
         * @param LLMS_Order $order    The order object.
         */
        return esc_url( apply_filters( 'lifterlms_completed_transaction_redirect', $redirect, $order ) );

    }

    /**
     * Gateways can override this to return a URL to a customer permalink on the gateway's website
     *
     * If this is not defined, it will just return the supplied ID.
     *
     * @since 3.0.0
     *
     * @param string $customer_id Gateway's customer ID.
     * @param string $api_mode    Link to either the live or test site for the gateway, where applicable.
     * @return string
     */
    public function get_customer_url( $customer_id, $api_mode = 'live' ) {
        return $customer_id;
    }

    /**
     * Get the frontend description setting
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_description() {
        return $this->get_option( 'description' );
    }

    /**
     * Get the display order setting
     *
     * @since 3.0.0
     *
     * @return int
     */
    public function get_display_order() {
        return absint( $this->get_option( 'display_order' ) );
    }

    /**
     * Get the value of the enabled setting
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_enabled() {
        return $this->get_option( 'enabled' );
    }

    /**
     * Get fields displayed on the checkout form
     *
     * Gateways should define this function if the gateway supports fields.
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_fields() {
        /**
         * Filters the HTML of the gateway's checkout fields
         *
         * @since 3.0.0
         *
         * @param string $fields     Fields HTML string.
         * @param string $gateway_id The payment gateway's ID.
         */
        return apply_filters( 'llms_get_gateway_fields', '', $this->id );
    }

    /**
     * Get the icon displayed on the checkout form
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_icon() {
        /**
         * Filters the HTML of the gateway's checkout icon
         *
         * @since 3.0.0
         *
         * @param string $icon       Icon HTML string.
         * @param string $gateway_id The payment gateway's ID.
         */
        return apply_filters( 'llms_get_gateway_icon', $this->icon, $this->id );
    }

    /**
     * Get the gateway's ID
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_id() {
        return $this->id;
    }

    /**
     * Retrieve an HTML link to a customer, subscription, or source URL
     *
     * If no URL provided returns the item value as string.
     *
     * @since 3.10.0
     *
     * @param string $item_key   The key of the item to retrieve a URL for.
     * @param string $item_value The value of the item to retrieve.
     * @param string $api_mode   The current api mode to retrieve the URL for.
     * @return string
     */
    public function get_item_link( $item_key, $item_value, $api_mode = 'live' ) {

        switch ( $item_key ) {

            case 'customer':
                $url = $this->get_customer_url( $item_value, $api_mode );
                break;

            case 'subscription':
                $url = $this->get_subscription_url( $item_value, $api_mode );
                break;

            case 'source':
                $url = $this->get_source_url( $item_value, $api_mode );
                break;

            default:
                $url = $item_value;

        }

        if ( false === filter_var( $url, FILTER_VALIDATE_URL ) ) {
            return $item_value;
        }

        return sprintf( '<a href="%1$s" target="_blank">%2$s</a>', $url, $item_value );

    }

    /**
     * Get the value of the logging setting
     *
     * @since 3.0.0
     * @since 7.0.0 Added the force filter, `llms_gateway_{$this->id}_logging_enabled`.
     *
     * @return string
     */
    public function get_logging_enabled() {
        /**
         * Enables forcing the logging status for the gateway on or off.
         *
         * The dynamic portion of this hook, `{$this->id}`, refers to the gateway's ID.
         *
         * @since 7.0.0
         *
         * @param null|bool $forced The forced status. If `null`, the default status derived from the gateway options will be used.
         */
        $forced = apply_filters( "llms_gateway_{$this->id}_logging_enabled", null );
        if ( ! is_null( $forced ) ) {
            return $forced ? 'yes' : 'no';
        }
        return $this->get_option( 'logging_enabled' );
    }

    /**
     * Adds the gateway's registered secured strings to the default list of site-wide secure strings.
     *
     * This is the callback for the `llms_secure_strings` filter (called via `llms_log()`).
     *
     * @since 6.4.0
     * @since 7.0.0 Load strings from `retrieve_secure_strings()`.
     *
     * @param string[] $strings Array of secure strings.
     * @param string   $handle  The log handle.
     * @return string[]
     */
    public function get_secure_strings( $strings, $handle ) {

        // Don't add our strings to other log files.
        if ( $this->id !== $handle ) {
            return $strings;
        }

        return array_merge( $strings, $this->retrieve_secure_strings() );

    }

    /**
     * Gateways can override this to return a URL to a source permalink on the gateway's website
     *
     * If this is not defined, it will just return the supplied ID.
     *
     * @since 3.0.0
     *
     * @param string $source_id Gateway's source ID.
     * @param string $api_mode  Link to either the live or test site for the gateway, where applicable.
     * @return string
     */
    public function get_source_url( $source_id, $api_mode = 'live' ) {
        return $source_id;
    }

    /**
     * Gateways can override this to return a URL to a subscription permalink on the gateway's website
     *
     * If this is not defined, it will just return the supplied ID.
     *
     * @since 3.0.0
     *
     * @param string $subscription_id Gateway's subscription ID.
     * @param string $api_mode        Link to either the live or test site for the gateway, where applicable.
     * @return string
     */
    public function get_subscription_url( $subscription_id, $api_mode = 'live' ) {
        return $subscription_id;
    }

    /**
     * Get an array of features the gateway supports.
     *
     * @since 3.0.0
     * @since 7.0.0 Handle `modify_recurring_payments` depending on `recurring_payments`.
     *
     * @return array
     */
    public function get_supported_features() {

        if ( ! isset( $this->supports['modify_recurring_payments'] ) || is_null( $this->supports['modify_recurring_payments'] ) ) {
            $this->supports['modify_recurring_payments'] = $this->supports['recurring_payments'] ?? false;
        }

        /**
         * Filters the gateway's supported features array
         *
         * @since 3.0.0
         *
         * @param array  $supports   Array of feature support.
         * @param string $gateway_id The payment gateway's ID.
         */
        return apply_filters( 'llms_get_gateway_supported_features', $this->supports, $this->id );
    }

    /**
     * Get the description of test mode displayed on the admin panel
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_test_mode_description() {
        return $this->test_mode_description;
    }

    /**
     * Get value of the test mode enabled setting
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_test_mode_enabled() {
        return $this->get_option( 'test_mode_enabled' );
    }

    /**
     * Get the title of test mode displayed on the admin panel
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_test_mode_title() {
        return $this->test_mode_title;
    }

    /**
     * Get gateway title setting
     *
     * @since 3.0.0
     *
     * @return string
     */
    public function get_title() {
        return $this->get_option( 'title' );
    }

    /**
     * Gateways can override this to return a URL to a transaction permalink on the gateway's website
     *
     * If this is not defined, it will just return the supplied ID.
     *
     * @since 3.0.0
     *
     * @param string $transaction_id Gateway's transaction ID.
     * @param string $api_mode       Link to either the live or test site for the gateway, where applicable.
     *
     * @return string
     */
    public function get_transaction_url( $transaction_id, $api_mode = 'live' ) {
        return $transaction_id;
    }

    /**
     * Called when the Update Payment Method form is submitted from a single order view on the student dashboard
     *
     * Gateways should do whatever the gateway needs to do to validate the new payment method and save it to the order
     * so that future payments on the order will use this new source.
     *
     * This should be an abstract function but experience has taught me that no one will upgrade follow our instructions
     * and they'll end up with 500 errors and debug mode disabled and send me giant frustrated question marks.
     *
     * @since 3.10.0
     *
     * @param LLMS_Order $order     Order object.
     * @param array      $form_data Additional data passed from the submitted form (EG $_POST).
     *
     * @return null
     */
    public function handle_payment_source_switch( $order, $form_data = array() ) {
        return llms_add_notice(
            sprintf(
                // Translatos: %s = the title of the payment gateway.
                esc_html__( 'The selected payment gateway "%s" does not support payment method switching.', 'lifterlms' ),
                $this->get_title()
            ),
            'error'
        );
    }

    /**
     * Handle a Pending Order
     *
     * Called by LLMS_Controller_Orders->create_pending_order() on checkout form submission.
     *
     * All data will be validated before it's passed to this function.
     *
     * @since 3.0.0
     *
     * @param LLMS_Order        $order  The order being processed.
     * @param LLMS_Access_Plan  $plan   Access plan the order is built from.
     * @param LLMS_Student      $person The purchasing customer.
     * @param LLMS_Coupon|false $coupon Coupon used during order processing or `false` if none supplied.
     * @return void
     */
    abstract public function handle_pending_order( $order, $plan, $person, $coupon = false );

    /**
     * Called by scheduled actions to charge an order for a scheduled recurring transaction
     *
     * This function must be defined by gateways which support recurring transactions.
     *
     * @since 3.0.0
     *
     * @param LLMS_Order $order The order being processed.
     * @return mixed
     */
    public function handle_recurring_transaction( $order ) {}

    /**
     * Determine if the gateway is the default gateway
     *
     * This will be the FIRST gateway in the gateways that are enabled.
     *
     * @since 3.0.0
     * @since 5.3.0 Use `llms()` in favor of deprecated `LLMS()`.
     *
     * @return boolean
     */
    public function is_default_gateway() {
        return ( $this->get_id() === llms()->payment_gateways()->get_default_gateway() );
    }

    /**
     * Determine if the gateway is enabled according to admin settings checkbox
     *
     * @since 3.0.0
     *
     * @return boolean
     */
    public function is_enabled() {
        return ( 'yes' === $this->get_enabled() ) ? true : false;
    }

    /**
     * Determine if test mode is enabled
     *
     * Returns false if gateway doesn't support test mode.
     *
     * @since 3.0.0
     *
     * @return boolean
     */
    public function is_test_mode_enabled() {
        return ( 'yes' === $this->get_test_mode_enabled() ) ? true : false;
    }

    /**
     * Log messages if logging is enabled
     *
     * @since 3.0.0
     * @since 6.4.0 Load the gateway's `secure_option` settings into `llms_secure_strings` hook when logging.
     *
     * @return void
     */
    public function log() {

        if ( ! llms_parse_bool( $this->get_logging_enabled() ) ) {
            return;
        }

        add_filter( 'llms_secure_strings', array( $this, 'get_secure_strings' ), 10, 2 );

        foreach ( func_get_args() as $data ) {
            llms_log( $data, $this->get_id() );
        }

        remove_filter( 'llms_secure_strings', array( $this, 'get_secure_strings' ), 10, 2 );

    }

    /**
     * Get the value of an option from the database & fallback to default value if none found
     *
     * Optionally attempts to retrieve a secure key first, if secure key is provided.
     *
     * The behavior of this function differs slightly from the parent method in that the second argument
     * in this method allows lookup of the secure key value.
     *
     * Default options are autoloaded via the get_option_default_value() method.
     *
     * @since 3.0.0
     * @since 3.29.0 Added secure option lookup via option second parameter.
     *
     * @param string $key option Option name / key, eg: "title".
     * @param string $secure_key Secure option name / key, eg: "TITLE".
     * @return mixed
     */
    public function get_option( $key, $secure_key = false ) {

        if ( $secure_key ) {
            $secure_val = llms_get_secure_option( $secure_key );
            if ( false !== $secure_val ) {
                return $secure_val; // Intentionally not filtered here.
            }
        }

        $val = parent::get_option( $key );

        /**
         * Filters the value of a gateway option
         *
         * The dynamic portion of the hook, `{$key}`, refers to the unprefixed
         * option name.
         *
         * @since Unknown
         *
         * @param mixed  $val        Option value.
         * @param string $gateway_id Payment gateway ID.
         */
        return apply_filters( "llms_get_gateway_{$key}", $val, $this->id );

    }

    /**
     * Option default value autoloader
     *
     * This is a callback function for the WP core filter `default_option_{$option}`.
     *
     * @since 5.3.0
     *
     * @param mixed  $default_value        The default value. If no value is passed to `get_option()`, this will be an empty string.
     *                                     Otherwise it will be the default value passed to the method.
     * @param string $full_option_name     The full (prefixed) option name.
     * @param bool   $passed_default_value Whether or not a default value was passed to `get_option()`.
     * @return mixed The default option value.
     */
    public function get_option_default_value( $default_value, $full_option_name, $passed_default_value ) {
        $unprefixed = str_replace( $this->get_option_prefix(), '', $full_option_name );
        return isset( $this->$unprefixed ) ? $this->$unprefixed : '';
    }

    /**
     * Retrieve a prefix for options
     *
     * Appends the gateway's ID to the default option prefix, eg: "llms_gateway_manual_".
     *
     * @since 5.3.0
     *
     * @return string
     */
    protected function get_option_prefix() {
        return parent::get_option_prefix() . $this->id . '_';
    }

    /**
     * Called when refunding via a Gateway
     *
     * This function must be defined by gateways which support refunds.
     *
     * This function is called by LLMS_Transaction->process_refund().
     *
     * @since 3.0.0
     *
     * @param LLMS_Transaction $transaction The transaction being refunded.
     * @param float            $amount      Amount to refund.
     * @param string           $note        Optional refund note to pass to the gateway.
     * @return mixed
     */
    public function process_refund( $transaction, $amount = 0, $note = '' ) {}

    /**
     * Retrieves a list of "secure" strings which should be anonymized if they're found within debug logs.
     *
     * This method will load the values of any gateway options with a `secure_option` declaration. Additional
     * strings can be added to the list using the `llms_get_gateway_secure_strings` filter or via the
     * gateway's `add_secure_string()` method.
     *
     * @since 7.0.0
     *
     * @return string[]
     */
    public function retrieve_secure_strings() {

        $gateway_strings = $this->secure_strings;
        foreach ( $this->get_admin_settings_fields() as $field ) {

            if ( empty( $field['id'] ) || empty( $field['secure_option'] ) ) {
                continue;
            }

            $string = llms_get_secure_option( $field['secure_option'], '', $field['id'] );
            if ( empty( $string ) ) {
                continue;
            }

            $gateway_strings[] = $string;

        }

        /**
         * Filters the list of the gateway's secure strings.
         *
         * @since 6.4.0
         *
         * @param string[] $gateway_strings List of secure strings for the payment gateway.
         * @param string   $id              The gateway ID.
         */
        $gateway_strings = apply_filters( 'llms_get_gateway_secure_strings', $gateway_strings, $this->id );

        return array_values( array_unique( $gateway_strings ) );

    }

    /**
     * Determine if a feature is supported by the gateway.
     *
     * Looks at the $this->supports and ensures the submitted feature exists and is true.
     *
     * @since 3.0.0
     * @since 7.0.0 Added `$order` param, to be used when the feature also depends on an order property.
     *
     * @param string     $feature Name of the supported feature.
     * @param LLMS_Order $order   Instance of an LLMS_Order.
     * @return boolean
     */
    public function supports( $feature, $order = null ) {

        $supports = $this->get_supported_features();

        if ( isset( $supports[ $feature ] ) && $supports[ $feature ] ) {
            return true;
        }

        return false;

    }

    /**
     * Determine if an access plan can be processed by the gateway.
     *
     * @since 7.5.0
     *
     * @param LLMS_Access_Plan $plan  Instance of an LLMS_Access_Plan.
     * @param LLMS_Order       $order Instance of an LLMS_Order. Used to check whether a payment can be switched using this gateway.
     *                                In that case, in fact, we have to rely on the access plan information contained in the order
     *                                at the moment of its creation.
     * @return boolean
     */
    public function can_process_access_plan( $plan, $order = null ) {
        /**
         * Filters whether or not a gateway can process a specific access plan.
         *
         * @since 7.5.0
         *
         * @param bool             $can_process_plan Whether or not the gateway can process a specific access plan.
         * @param LLMS_Access_Plan $plan             Access plan object.
         * @param LLMS_Order       $plan             Order object.
         * @param string           $id               The gateway ID.
         */
        return apply_filters( 'llms_can_gateway_process_access_plan', $plan || $order, $plan, $order, $this->id );
    }

}