Pronamic\WordPress\Pay\Plugin

Complexity

Total Complexity

96

Size/Duplication

Total Lines	833
Duplicated Lines	0 %

Importance

Changes

0

21 Methods

Rating	Name	Duplication	Size	Complexity
A	get_default_error_message()	0	2	1
A	get_pages()	0	18	2
B	get_config_select_options()	0	27	3
C	start_payment()	0	59	9
A	plugins_loaded()	0	15	1
A	datetime_format()	0	2	1
A	get_plugin_dir_path()	0	2	1
C	maybe_redirect()	0	76	14
A	maybe_set_active_payment_methods()	0	8	2
A	get_file()	0	2	1
A	get_version()	0	2	1
D	update_payment()	0	39	10
D	handle_returns()	0	42	9
A	start_recurring()	0	2	1
B	start()	0	40	3
A	plugin_locale()	0	14	4
A	instance()	0	10	2
D	get_gateway()	0	107	24
A	__construct()	0	75	2
A	render_errors()	0	7	3
A	get_number_payments()	0	10	2

<?php
/**
 * Plugin
 *
 * @author    Pronamic <info@pronamic.eu>
 * @copyright 2005-2018 Pronamic
 * @license   GPL-3.0-or-later
 * @package   Pronamic\WordPress\Pay
 */

namespace Pronamic\WordPress\Pay;

use Pronamic\WordPress\Pay\Core\Gateway;
use Pronamic\WordPress\Pay\Core\PaymentMethods;
use Pronamic\WordPress\Pay\Core\Recurring;
use Pronamic\WordPress\Pay\Core\Statuses;
use Pronamic\WordPress\Pay\Payments\Payment;
use Pronamic\WordPress\Pay\Payments\PaymentDataInterface;
use Pronamic\WordPress\Pay\Payments\PaymentPostType;
use Pronamic\WordPress\Pay\Payments\StatusChecker;
use Pronamic\WordPress\Pay\Subscriptions\Subscription;
use Pronamic\WordPress\Pay\Subscriptions\SubscriptionPostType;
use WP_Query;

/**
 * Title: WordPress iDEAL plugin
 *
 * @author Remco Tolsma
 * @version 4.5.3
 * @since 1.0.0
 */
class Plugin {
	/**
	 * Version.
	 *
	 * @var string
	 */
	private $version = '5.0.0';

	/**
	 * The root file of this WordPress plugin
	 *
	 * @var string
	 */
	public static $file;

	/**
	 * The plugin dirname
	 *
	 * @var string
	 */
	public static $dirname;

	/**
	 * The timezone
	 *
	 * @var string
	 */
	const TIMEZONE = 'UTC';

	/**
	 * Instance.
	 *
	 * @var Plugin
	 */
	protected static $instance = null;

	/**
	 * Instance.
	 *
	 * @param string $file The plugin file.
	 */
	public static function instance( $file = null ) {
		if ( is_null( self::$instance ) ) {
			self::$instance = new self();

			// Backward compatibility.
			self::$file    = $file;
			self::$dirname = dirname( $file );
		}

		return self::$instance;
	}

	/**
	 * Plugin settings.
	 *
	 * @var Settings
	 */
	public $settings;

	/**
	 * Payment data storing.
	 *
	 * @var Payments\PaymentsDataStoreCPT
	 */
	public $payments_data_store;

	/**
	 * Subscription data storing.
	 *
	 * @var Subscriptions\SubscriptionsDataStoreCPT
	 */
	public $subscriptions_data_store;

	/**
	 * Gateway post type.
	 *
	 * @var GatewayPostType
	 */
	public $gateway_post_type;

	/**
	 * Payment post type.
	 *
	 * @var PaymentPostType
	 */
	public $payment_post_type;

	/**
	 * Subscription post type.
	 *
	 * @var SubscriptionPostType
	 */
	public $subscription_post_type;

	/**
	 * Licence manager.
	 *
	 * @var LicenseManager
	 */
	public $license_manager;

	/**
	 * Forms module.
	 *
	 * @var Forms\FormsModule
	 */
	public $forms_module;

	/**
	 * Payments module.
	 *
	 * @var Payments\PaymentsModule
	 */
	public $payments_module;

	/**
	 * Subsciptions module.
	 *
	 * @var Subscriptions\SubscriptionsModule
	 */
	public $subscriptions_module;

	/**
	 * Google analytics ecommerce.
	 *
	 * @var GoogleAnalyticsEcommerce
	 */
	public $google_analytics_ecommerce;

	/**
	 * Construct and initialize an Pronamic Pay plugin object
	 */
	public function __construct() {
		// Bootstrap the add-ons.
		Extensions\Charitable\Extension::bootstrap();
		Extensions\Give\Extension::bootstrap();
		Extensions\WooCommerce\Extension::bootstrap();
		Extensions\GravityForms\Extension::bootstrap();
		Extensions\Shopp\Extension::bootstrap();
		Extensions\Jigoshop\Extension::bootstrap();
		Extensions\WPeCommerce\Extension::bootstrap();
		Extensions\ClassiPress\Extension::bootstrap();
		Extensions\EventEspressoLegacy\Extension::bootstrap();
		Extensions\EventEspresso\Extension::bootstrap();
		Extensions\AppThemes\Extension::bootstrap();
		Extensions\S2Member\Extension::bootstrap();
		Extensions\Membership\Extension::bootstrap();
		Extensions\EasyDigitalDownloads\Extension::bootstrap();
		Extensions\IThemesExchange\Extension::bootstrap();
		Extensions\MemberPress\Extension::bootstrap();
		Extensions\FormidableForms\Extension::bootstrap();
		Extensions\RestrictContentPro\Extension::bootstrap();

		// Settings.
		$this->settings = new Settings( $this );

		// Data Stores.
		$this->payments_data_store      = new Payments\PaymentsDataStoreCPT();
		$this->subscriptions_data_store = new Subscriptions\SubscriptionsDataStoreCPT();

		// Post Types.
		$this->gateway_post_type      = new GatewayPostType();
		$this->payment_post_type      = new PaymentPostType();
		$this->subscription_post_type = new SubscriptionPostType();

		// License Manager.
		$this->license_manager = new LicenseManager( $this );

		// Modules.
		$this->forms_module         = new Forms\FormsModule( $this );
		$this->payments_module      = new Payments\PaymentsModule( $this );
		$this->subscriptions_module = new Subscriptions\SubscriptionsModule( $this );

		// Google Analytics Ecommerce.
		$this->google_analytics_ecommerce = new GoogleAnalyticsEcommerce();

		// Admin.
		if ( is_admin() ) {
			$this->admin = new Admin\AdminModule( $this );

The property admin does not exist. Although not strictly required by PHP, it is generally a best practice to declare properties explicitly.

		}

		/*
		 * Plugins loaded.
		 *
		 * Priority should be at least lower then 8 to support the "WP eCommerce" plugin.
		 *
		 * new WP_eCommerce()
		 * add_action( 'plugins_loaded' , array( $this, 'init' ), 8 );
		 * $this->load();
		 * wpsc_core_load_gateways();
		 *
		 * @see https://github.com/wp-e-commerce/WP-e-Commerce/blob/branch-3.11.2/wp-shopping-cart.php#L342-L343
		 * @see https://github.com/wp-e-commerce/WP-e-Commerce/blob/branch-3.11.2/wp-shopping-cart.php#L26-L35
		 * @see https://github.com/wp-e-commerce/WP-e-Commerce/blob/branch-3.11.2/wp-shopping-cart.php#L54
		 * @see https://github.com/wp-e-commerce/WP-e-Commerce/blob/branch-3.11.2/wp-shopping-cart.php#L296-L297
		 */
		add_action( 'plugins_loaded', array( $this, 'plugins_loaded' ), 5 );

		// Plugin locale.
		add_filter( 'plugin_locale', array( $this, 'plugin_locale' ), 10, 2 );

		// If WordPress is loaded check on returns and maybe redirect requests.
		add_action( 'wp_loaded', array( $this, 'handle_returns' ) );
		add_action( 'wp_loaded', array( $this, 'maybe_redirect' ) );

		// Default date time format.
		add_filter( 'pronamic_datetime_default_format', array( $this, 'datetime_format' ), 10, 1 );
	}

	/**
	 * Get the version number of this plugin.
	 *
	 * @return string The version number of this plugin.
	 */
	public function get_version() {
		return $this->version;
	}

	/**
	 * Get plugin file path.
	 *
	 * @return string
	 */
	public function get_file() {
		return self::$file;
	}

	/**
	 * Get the plugin dir path.
	 *
	 * @return string
	 */
	public function get_plugin_dir_path() {
		return plugin_dir_path( $this->get_file() );
	}

	/**
	 * Update payment.
	 *
	 * @param Payment $payment      The payment to update.
	 * @param bool    $can_redirect Flag to indicate if redirect is allowed after the payment update.
	 */
	public static function update_payment( $payment = null, $can_redirect = true ) {
		if ( empty( $payment ) ) {
			return;
		}

		$gateway = Plugin::get_gateway( $payment->config_id );

		if ( empty( $gateway ) ) {
			return;
		}

		$amount = $payment->get_amount()->get_amount();

		if ( empty( $amount ) ) {
			$payment->set_status( Core\Statuses::SUCCESS );
		} else {
			$gateway->update_status( $payment );

			if ( $gateway->has_error() ) {
				foreach ( $gateway->error->get_error_codes() as $code ) {
					$payment->add_note( sprintf( '%s: %s', $code, $gateway->error->get_error_message( $code ) ) );
				}
			}
		}

		// Update payment in data store.
		$payment->save();

		// Maybe redirect.
		if ( defined( 'DOING_CRON' ) && ( empty( $payment->status ) || Statuses::OPEN === $payment->status ) ) {
			$can_redirect = false;
		}

		if ( $can_redirect ) {
			$url = $payment->get_return_redirect_url();

			wp_redirect( $url );

			exit;

Using exit here is not recommended.

		}
	}

	/**
	 * Handle returns.
	 */
	public function handle_returns() {
		if ( ! filter_has_var( INPUT_GET, 'payment' ) ) {
			return;
		}

		$payment_id = filter_input( INPUT_GET, 'payment', FILTER_SANITIZE_NUMBER_INT );

		$payment = get_pronamic_payment( $payment_id );

		// Check if payment key is valid.
		$valid_key = false;

		if ( empty( $payment->key ) ) {
			$valid_key = true;
		} elseif ( filter_has_var( INPUT_GET, 'key' ) ) {
			$key = filter_input( INPUT_GET, 'key', FILTER_SANITIZE_STRING );

			$valid_key = ( $key === $payment->key );
		}

		if ( ! $valid_key ) {
			wp_redirect( home_url() );

			exit;

Using exit here is not recommended.

		}

		// Check if we should redirect.
		$should_redirect = true;

		// Check if the request is an callback request.
		// Sisow gatway will extend callback requests with querystring "callback=true".
		if ( filter_has_var( INPUT_GET, 'callback' ) && filter_input( INPUT_GET, 'callback', FILTER_VALIDATE_BOOLEAN ) ) {
			$should_redirect = false;
		}

		// Check if the request is an notify request.
		// Sisow gatway will extend callback requests with querystring "notify=true".
		if ( filter_has_var( INPUT_GET, 'notify' ) && filter_input( INPUT_GET, 'notify', FILTER_VALIDATE_BOOLEAN ) ) {
			$should_redirect = false;
		}

		self::update_payment( $payment, $should_redirect );
	}

	/**
	 * Maybe redirect.
	 */
	public function maybe_redirect() {
		if ( ! filter_has_var( INPUT_GET, 'payment_redirect' ) ) {
			return;
		}

		$payment_id = filter_input( INPUT_GET, 'payment_redirect', FILTER_SANITIZE_NUMBER_INT );

		$payment = get_pronamic_payment( $payment_id );

		// HTML Answer.
		$html_answer = $payment->get_meta( 'ogone_directlink_html_answer' );

		if ( ! empty( $html_answer ) ) {
			echo $html_answer; // WPCS: XSS ok.

			exit;

Using exit here is not recommended.

		}

		$redirect_message = $payment->get_meta( 'payment_redirect_message' );

		if ( ! empty( $redirect_message ) ) {
			$key = filter_input( INPUT_GET, 'key', FILTER_SANITIZE_STRING );

			if ( $key !== $payment->key ) {
				wp_redirect( home_url() );

				exit;

Using exit here is not recommended.

			}

			// @see https://github.com/woothemes/woocommerce/blob/2.3.11/includes/class-wc-cache-helper.php
			// @see https://www.w3-edge.com/products/w3-total-cache/
			if ( ! defined( 'DONOTCACHEPAGE' ) ) {
				define( 'DONOTCACHEPAGE', true );
			}

			if ( ! defined( 'DONOTCACHEDB' ) ) {
				define( 'DONOTCACHEDB', true );
			}

			if ( ! defined( 'DONOTMINIFY' ) ) {
				define( 'DONOTMINIFY', true );
			}

			if ( ! defined( 'DONOTCDN' ) ) {
				define( 'DONOTCDN', true );
			}

			if ( ! defined( 'DONOTCACHEOBJECT' ) ) {
				define( 'DONOTCACHEOBJECT', true );
			}

			nocache_headers();

			include Plugin::$dirname . '/views/redirect-message.php';

			exit;

Using exit here is not recommended.

		}

		$gateway = Plugin::get_gateway( $payment->config_id );

		if ( $gateway && $gateway->is_html_form() ) {
			$gateway->start( $payment );

			$error = $gateway->get_error();

			if ( is_wp_error( $error ) ) {
				Plugin::render_errors( $error );
			} else {
				$gateway->redirect( $payment );
			}
		}

		if ( ! empty( $payment->action_url ) ) {
			wp_redirect( $payment->action_url );

			exit;

Using exit here is not recommended.

		}
	}

	/**
	 * Get number payments.
	 *
	 * @return int
	 */
	public static function get_number_payments() {
		$number = false;

		$count = wp_count_posts( 'pronamic_payment' );

		if ( isset( $count, $count->payment_completed ) ) {
			$number = intval( $count->payment_completed );
		}

		return $number;
	}

	/**
	 * Setup, creates or updates database tables. Will only run when version changes.
	 */
	public function plugins_loaded() {
		// Load plugin text domain.
		$rel_path = dirname( plugin_basename( self::$file ) );

		load_plugin_textdomain( 'pronamic_ideal', false, $rel_path . '/languages' );

false of type false is incompatible with the type string expected by parameter $deprecated of load_plugin_textdomain().

		load_plugin_textdomain( 'pronamic-money', false, $rel_path . '/vendor/pronamic/wp-money/languages' );

		// Gateway Integrations.
		$integrations = new GatewayIntegrations();

		$this->gateway_integrations = $integrations->register_integrations();

The property gateway_integrations does not exist. Although not strictly required by PHP, it is generally a best practice to declare properties explicitly.

		// Maybes.
		self::maybe_set_active_payment_methods();
	}

	/**
	 * Filter plugin locale.
	 *
	 * @param string $locale A WordPress locale identifier.
	 * @param string $domain A WordPress text domain indentifier.
	 *
	 * @return string
	 */
	public function plugin_locale( $locale, $domain ) {
		if ( 'pronamic_ideal' !== $domain ) {
			return $locale;
		}

		if ( 'nl_NL_formal' === $locale ) {
			return 'nl_NL';
		}

		if ( 'nl_BE' === $locale ) {
			return 'nl_NL';
		}

		return $locale;
	}

	/**
	 * Default date time format.
	 *
	 * @param string $format Format.
	 *
	 * @return string|void
	 */
	public function datetime_format( $format ) {

The parameter $format is not used and could be removed.

		return _x( 'D j M Y \a\t H:i', 'default datetime format', 'pronamic_ideal' );
	}

	/**
	 * Get default error message.
	 *
	 * @return string
	 */
	public static function get_default_error_message() {
		return __( 'Something went wrong with the payment. Please try again later or pay another way.', 'pronamic_ideal' );
	}

	/**
	 * Get config select options.
	 *
	 * @param null|string $payment_method The gateway configuration options for the specified payment method.
	 *
	 * @return array
	 */
	public static function get_config_select_options( $payment_method = null ) {
		$args = array(
			'post_type' => 'pronamic_gateway',
			'orderby'   => 'post_title',
			'order'     => 'ASC',
			'nopaging'  => true,
		);

		if ( $payment_method ) {
			$args['post__in'] = PaymentMethods::get_config_ids( $payment_method );
		}

		$query = new WP_Query( $args );

		$options = array( __( '— Select Configuration —', 'pronamic_ideal' ) );

		foreach ( $query->posts as $post ) {
			$id = $post->ID;

			$options[ $id ] = sprintf(
				'%s (%s)',
				get_the_title( $id ),
				get_post_meta( $id, '_pronamic_gateway_mode', true )

It seems like get_post_meta($id, '_pronamic_gateway_mode', true) can also be of type false; however, parameter $args of sprintf() does only seem to accept string, maybe add an additional type check?

			);
		}

		return $options;
	}

	/**
	 * Maybe set active payment methods option.
	 *
	 * @since unreleased
	 */
	public static function maybe_set_active_payment_methods() {
		$active_methods = get_option( 'pronamic_pay_active_payment_methods' );

		if ( is_array( $active_methods ) ) {
			return;
		}

		PaymentMethods::update_active_payment_methods();
	}

	/**
	 * Render errors.
	 *
	 * @param array|WP_Error $errors An array with errors to render.

The type Pronamic\WordPress\Pay\WP_Error was not found. Did you mean WP_Error? If so, make sure to prefix the type with \.

	 */
	public static function render_errors( $errors = array() ) {
		if ( ! is_array( $errors ) ) {
			$errors = array( $errors );
		}

		foreach ( $errors as $error ) {
			include Plugin::$dirname . '/views/error.php';
		}
	}

	/**
	 * Get gateway.
	 *
	 * @param string|integer|boolean $config_id A gateway configuration ID.
	 *
	 * @return Gateway|null
	 */
	public static function get_gateway( $config_id ) {
		if ( empty( $config_id ) ) {
			return null;
		}

		$gateway_id = get_post_meta( $config_id, '_pronamic_gateway_id', true );

It seems like $config_id can also be of type string and boolean; however, parameter $post_id of get_post_meta() does only seem to accept integer, maybe add an additional type check?

		$mode       = get_post_meta( $config_id, '_pronamic_gateway_mode', true );
		$is_utf8    = strcasecmp( get_bloginfo( 'charset' ), 'UTF-8' ) === 0;

		$config = Core\ConfigProvider::get_config( $gateway_id, $config_id );

		switch ( $gateway_id ) {
			case 'abnamro-ideal-easy':
			case 'abnamro-ideal-only-kassa':
			case 'abnamro-internetkassa':
				$config->form_action_url = sprintf(
					'https://internetkassa.abnamro.nl/ncol/%s/orderstandard%s.asp',
					'test' === $mode ? 'test' : 'prod',
					$is_utf8 ? '_utf8' : ''
				);

				break;
			case 'abnamro-ideal-zelfbouw-v3':
				$config->payment_server_url = 'https://abnamro.ideal-payment.de/ideal/iDEALv3';

				if ( 'test' === $mode ) {
					$config->payment_server_url = 'https://abnamro-test.ideal-payment.de/ideal/iDEALv3';
				}

				$config->certificates = array();

				break;
			case 'deutschebank-ideal-expert-v3':
				$config->payment_server_url = 'https://myideal.db.com/ideal/iDealv3';

				$config->certificates = array();

				break;
			case 'ideal-simulator-ideal-basic':
				$config->url = 'https://www.ideal-simulator.nl/lite/';

				break;
			case 'ideal-simulator-ideal-advanced-v3':
				$config->payment_server_url = 'https://www.ideal-checkout.nl/simulator/';

				$config->certificates = array();

				break;
			case 'ing-ideal-basic':
				$config->url = 'https://ideal.secure-ing.com/ideal/mpiPayInitIng.do';

				if ( 'test' === $mode ) {
					$config->url = 'https://idealtest.secure-ing.com/ideal/mpiPayInitIng.do';
				}

				break;
			case 'ing-ideal-advanced-v3':
				$config->payment_server_url = 'https://ideal.secure-ing.com/ideal/iDEALv3';

				if ( 'test' === $mode ) {
					$config->payment_server_url = 'https://idealtest.secure-ing.com/ideal/iDEALv3';
				}

				$config->certificates = array();

				break;
			case 'mollie-ideal-basic':
				$config->url = 'https://secure.mollie.nl/xml/idealAcquirer/lite/';

				if ( 'test' === $mode ) {
					$config->url = 'https://secure.mollie.nl/xml/idealAcquirer/testmode/lite/';
				}

				break;
			case 'postcode-ideal':
				$config->payment_server_url = 'https://ideal.postcode.nl/ideal';

				if ( 'test' === $mode ) {
					$config->payment_server_url = 'https://ideal-test.postcode.nl/ideal';
				}

				$config->certificates = array();

				break;
			case 'rabobank-ideal-professional-v3':
				$config->payment_server_url = 'https://ideal.rabobank.nl/ideal/iDEALv3';

				if ( 'test' === $mode ) {
					$config->payment_server_url = 'https://idealtest.rabobank.nl/ideal/iDEALv3';
				}

				$config->certificates = array();

				break;
			case 'sisow-ideal-basic':
				$config->url = 'https://www.sisow.nl/Sisow/iDeal/IssuerHandler.ashx';

				if ( 'test' === $mode ) {
					$config->url = 'https://www.sisow.nl/Sisow/iDeal/IssuerHandler.ashx/test';
				}

				break;
		}

		$gateway = Core\GatewayFactory::create( $config );

		return $gateway;
	}

	/**
	 * Start a payment.
	 *
	 * @param string               $config_id      A gateway configuration ID.
	 * @param Gateway              $gateway        The gateway to start the payment at.
	 * @param PaymentDataInterface $data           A payment data interface object with all the required payment info.
	 * @param string|null          $payment_method The payment method to use to start the payment.
	 *
	 * @return Payment
	 */
	public static function start( $config_id, Gateway $gateway, PaymentDataInterface $data, $payment_method = null ) {
		$payment = new Payments\Payment();

		$payment->title               = sprintf( __( 'Payment for %s', 'pronamic_ideal' ), $data->get_title() );
		$payment->user_id             = $data->get_user_id();

The method get_user_id() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

The property user_id does not exist on Pronamic\WordPress\Pay\Payments\Payment. Did you mean user_ip?

		$payment->config_id           = $config_id;

The property $config_id was declared of type integer, but $config_id is of type string. Maybe add a type cast?

		$payment->key                 = uniqid( 'pay_' );
		$payment->order_id            = $data->get_order_id();

The method get_order_id() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->language            = $data->get_language();

The method get_language() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->locale              = $data->get_language_and_country();

The method get_language_and_country() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->entrance_code       = $data->get_entrance_code();

The method get_entrance_code() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->description         = $data->get_description();

The method get_description() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Did you maybe mean get_subscription()?

		$payment->source              = $data->get_source();

The method get_source() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->source_id           = $data->get_source_id();

The method get_source_id() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->email               = $data->get_email();

The method get_email() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->status              = null;
		$payment->method              = $payment_method;
		$payment->issuer              = $data->get_issuer( $payment_method );

The method get_issuer() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->first_name          = $data->get_first_name();

The method get_first_name() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. It seems like you code against a sub-type of Pronamic\WordPress\Pay\Payments\PaymentDataInterface such as Pronamic\WordPress\Pay\Payments\PaymentData.

		$payment->last_name           = $data->get_last_name();

The method get_last_name() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. It seems like you code against a sub-type of Pronamic\WordPress\Pay\Payments\PaymentDataInterface such as Pronamic\WordPress\Pay\Payments\PaymentData.

		$payment->customer_name       = $data->get_customer_name();

The method get_customer_name() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->address             = $data->get_address();

The method get_address() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->zip                 = $data->get_zip();

The method get_zip() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->city                = $data->get_city();

The method get_city() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->country             = $data->get_country();

The method get_country() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->telephone_number    = $data->get_telephone_number();

The method get_telephone_number() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->analytics_client_id = $data->get_analytics_client_id();

The method get_analytics_client_id() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. It seems like you code against a sub-type of Pronamic\WordPress\Pay\Payments\PaymentDataInterface such as Pronamic\WordPress\Pay\Payments\PaymentData.

		$payment->recurring           = $data->get_recurring();

The method get_recurring() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->subscription        = $data->get_subscription();
		$payment->subscription_id     = $data->get_subscription_id();

The method get_subscription_id() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Did you maybe mean get_subscription()?

		$payment->set_amount( $data->get_amount() );

The method get_amount() does not exist on Pronamic\WordPress\Pay\Payments\PaymentDataInterface. Since it exists in all sub-types, consider adding an abstract or default implementation to Pronamic\WordPress\Pay\Payments\PaymentDataInterface.

		$payment->set_credit_card( $data->get_credit_card() );

		// User Agent (@see https://github.com/WordPress/WordPress/blob/4.9.4/wp-includes/comment.php#L1962-L1965).
		$payment->user_agent = isset( $_SERVER['HTTP_USER_AGENT'] ) ? $_SERVER['HTTP_USER_AGENT'] : null;

		// IP (@see https://github.com/WordPress/WordPress/blob/4.9.4/wp-includes/comment.php#L1957-L1960).
		$payment->user_ip = isset( $_SERVER['REMOTE_ADDR'] ) ? $_SERVER['REMOTE_ADDR'] : null;

		return self::start_payment( $payment, $gateway );
	}

	/**
	 * Start recurring payment.
	 *
	 * @param Subscription $subscription Subscription.
	 * @param Gateway      $gateway      Gateway.
	 *
	 * @return Payment
	 */
	public static function start_recurring( Subscription $subscription, Gateway $gateway ) {
		return pronamic_pay_plugin()->subscriptions_module->start_recurring( $subscription, $gateway );
	}

	/**
	 * Start payment.
	 *
	 * @param Payment $payment The payment to start at the specified gateway.
	 * @param Gateway $gateway The gateway to start the payment at.
	 *
	 * @return Payment
	 */
	public static function start_payment( Payment $payment, Gateway $gateway ) {
		global $pronamic_ideal;

		$pronamic_ideal->payments_data_store->create( $payment );

		// Prevent payment start at gateway if amount is empty.
		$amount = $payment->get_amount()->get_amount();

		if ( empty( $amount ) ) {
			// Keep track of free payments to update during shutdown.
			pronamic_pay_plugin()->payments_module->free[] = $payment->get_id();

			return $payment;
		}

		// Start payment at the gateway.
		$result = $gateway->start( $payment );

Are you sure the assignment to $result is correct as $gateway->start($payment) targeting Pronamic\WordPress\Pay\Core\Gateway::start() seems to always return null.

		// Add gateway errors as payment notes.
		if ( $gateway->has_error() ) {
			foreach ( $gateway->error->get_error_codes() as $code ) {
				$payment->add_note( sprintf( '%s: %s', $code, $gateway->error->get_error_message( $code ) ) );
			}
		}

		// Set payment status.
		if ( false === $result ) {

The condition false === $result is always true.

			$payment->set_status( Statuses::FAILURE );
		} else {
			$payment->set_status( Statuses::OPEN );
		}

		// Save payment.
		$payment->save();

		// Update subscription status for failed payments.
		if ( false === $result && $payment->get_subscription() ) {
			// Reload payment, so subscription is available.
			$payment = new Payment( $payment->get_id() );

			$subscription = $payment->get_subscription();

			if ( Recurring::FIRST === $payment->recurring_type ) {
				// First payment - cancel subscription to prevent unwanted recurring payments
				// in the future, when a valid customer ID might be set for the user.
				$subscription->set_status( Statuses::CANCELLED );
			} else {
				$subscription->set_status( Statuses::FAILURE );
			}

			$subscription->save();
		}

		// Schedule payment status check.
		if ( $gateway->supports( 'payment_status_request' ) ) {
			StatusChecker::schedule_event( $payment );
		}

		return $payment;
	}

	/**
	 * Get pages.
	 *
	 * @return array
	 */
	public function get_pages() {
		$return = array();

		$pages = array(
			'completed' => __( 'Completed', 'pronamic_ideal' ),
			'cancel'    => __( 'Canceled', 'pronamic_ideal' ),
			'expired'   => __( 'Expired', 'pronamic_ideal' ),
			'error'     => __( 'Error', 'pronamic_ideal' ),
			'unknown'   => __( 'Unknown', 'pronamic_ideal' ),
		);

		foreach ( $pages as $key => $label ) {
			$id = sprintf( 'pronamic_pay_%s_page_id', $key );

			$return[ $id ] = $label;
		}

		return $return;
	}
}