Simple plugin to add multiple gateways for WooCommerce POS Pro

woocommerce-pos-gateways.php

<?php
/**
 * Plugin Name:       WooCommerce POS Gateways
 * Plugin URI:        https://wordpress.org/plugins/woocommerce-pos/
 * Description:       Extends WooCommerce with multiple POS gateways.
 * Version:           1.0.0
 * Author:            kilbot
 * Author URI:        http://wcpos.com
 * License:           GPL-3.0+
 * License URI:       http://www.gnu.org/licenses/gpl-3.0.txt
 */

namespace WCPOS;

use WC_Payment_Gateway;

/**
 * Gateway class.
 *
 * Requires WooCommerce to be loaded first.
 */
add_action(
	'woocommerce_loaded',
	function () {
		/**
		 * Gateway 1
		 */
		class POS_Gateway_1 extends WC_Payment_Gateway {
			/**
			 * Constructor for the gateway.
			 */
			public function __construct() {
				$this->id          = 'pos_gateway_1';
				$this->title       = 'POS Gateway 1';
				$this->description = '';
				$this->has_fields  = false;
				$this->enabled     = 'no';
			}

			/**
			 * Process the payment and return the result.
			 */
			public function process_payment( $order_id ) {
				$order = wc_get_order( $order_id );
				$order->payment_complete();

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

		/**
		 * Gateway 2
		 */
		class POS_Gateway_2 extends WC_Payment_Gateway {
			/**
			 * Constructor for the gateway.
			 */
			public function __construct() {
				$this->id          = 'pos_gateway_2';
				$this->title       = 'POS Gateway 2';
				$this->description = '';
				$this->has_fields  = false;
				$this->enabled     = 'no';
			}

			/**
			 * Process the payment and return the result.
			 */
			public function process_payment( $order_id ) {
				$order = wc_get_order( $order_id );
				$order->payment_complete();

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

		/**
		 * Gateway 3
		 */
		class POS_Gateway_3 extends WC_Payment_Gateway {
			/**
			 * Constructor for the gateway.
			 */
			public function __construct() {
				$this->id          = 'pos_gateway_3';
				$this->title       = 'POS Gateway 3';
				$this->description = '';
				$this->has_fields  = false;
				$this->enabled     = 'no';
			}

			/**
			 * Process the payment and return the result.
			 */
			public function process_payment( $order_id ) {
				$order = wc_get_order( $order_id );
				$order->payment_complete();

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

		/**
		 * Add the Gateways to WooCommerce.
		 */
		add_filter(
			'woocommerce_payment_gateways',
			function ( $gateways ) {
				$gateways[] = 'WCPOS\POS_Gateway_1';
				$gateways[] = 'WCPOS\POS_Gateway_2';
				$gateways[] = 'WCPOS\POS_Gateway_3';
				return $gateways;
			}
		);
	}
);