/*--------------------------------------
Woocommerce - Allow Guest Checkout on Certain products
----------------------------------------*/

// Display Guest Checkout Field
add_action( 'woocommerce_product_options_general_product_data', 'woo_add_custom_general_fields' );
function woo_add_custom_general_fields() {
  global $woocommerce, $post;

  echo '<div class="options_group">';

  // Checkbox
  woocommerce_wp_checkbox(
  array(
	'id'            => '_allow_guest_checkout',
	'wrapper_class' => 'show_if_simple',
	'label'         => __('Checkout', 'woocommerce' ),
	'description'   => __('Allow Guest Checkout', 'woocommerce' )
	)
   );

  echo '</div>';
}

// Save Guest Checkout Field
add_action( 'woocommerce_process_product_meta', 'woo_add_custom_general_fields_save' );
function woo_add_custom_general_fields_save( $post_id ){
	$woocommerce_checkbox = isset( $_POST['_allow_guest_checkout'] ) ? 'yes' : 'no';
	update_post_meta( $post_id, '_allow_guest_checkout', $woocommerce_checkbox );
}

// Enable Guest Checkout on Certain products
add_filter( 'pre_option_woocommerce_enable_guest_checkout', 'enable_guest_checkout_based_on_product' );
function enable_guest_checkout_based_on_product( $value ) {

  if ( WC()->cart ) {
    $cart = WC()->cart->get_cart();
    foreach ( $cart as $item ) {
      if ( get_post_meta( $item['product_id'], '_allow_guest_checkout', true ) == 'yes' ) {
        $value = "yes";
      } else {
        $value = "no";
        break;
      }
    }
  }

  return $value;
}