WooCommerce - Filter payment methods based on custom field

/**
 * WooCommerce customisation
 * Filter the list of available payment gateways based on a custom
 * field (in the example, "billing_customer_type").
 *
 * This customisation is compatible with the Aelia Currency Switcher
 * (https://aelia.co/shop/currency-switcher-woocommerce/) and the other
 * plugins developed by Aelia (https://aelia.co/shop/product-category/woocommerce/).
 *
 * @author Aelia <support@aelia.co>
 * @link https://aelia.co
 */


/**
 * Filters the availabel payment gateways based on the value of the
 * "billing_customer_type" field.
 *
 * @param array gateways The array of gateways passed by WooCommerce.
 * @return array The filtered array of gateways.
 * @author Aelia <support@aelia.co>
 * @link https://aelia.co
 */
add_filter('woocommerce_available_payment_gateways', function ($gateways) {
    if(!empty($_POST['post_data'])) {
        parse_str($_POST['post_data'], $post_data);

        $customer_type = strtolower(!empty($post_data['billing_customer_type']) ? $post_data['billing_customer_type'] : 'company');
        switch($customer_type) {
            case 'company':
                unset($gateways['paypal']);
                break;
            case 'private':
                unset($gateways['cod']);
                break;
        }
    }

    return $gateways;
}, 30);

/**
 * Adds a script to ensure that, when the "customer type" field changes,
 * the list of available payment gateways is updated.
 * @author Aelia <support@aelia.co>
 * @link https://aelia.co
 */
add_action('wp_footer', function() {
  // The script is only needed on the checkout page
  if(!is_checkout()) {
    return;
  }
  ?>
  <script type="text/javascript">
    // When the "billing_customer_type" field changes,
    // refresh the checkout data. This will update the
    // list of payment gateways
    jQuery(document).ready(function($) {
      $('#billing_customer_type').on('change', function() {
        $('#billing_country').change();
      });
    });
  </script>
  <?php
});