Cancel WooCommerce Bookings when an order status changes from Pending to Failed.

cancel_bookings_if_payment_fails.php

/**
 * Cancel WooCommerce Bookings when an order status changes from Pending to Failed.
 */
add_action('woocommerce_order_status_changed', 'wc_cancel_bookings_on_failed_order', 10, 4);

function wc_cancel_bookings_on_failed_order($order_id, $from_status, $to_status, $order) {
    // Check if the transition is from 'pending' to 'failed'
    if ($from_status === 'pending' && $to_status === 'failed') {
        
        // Ensure the Bookings classes exist
        if (!class_exists('WC_Booking_Data_Store')) {
            return;
        }

        // Get all bookings associated with this order
        $booking_ids = WC_Booking_Data_Store::get_booking_ids_from_order_id($order_id);

        if (!empty($booking_ids)) {
            foreach ($booking_ids as $booking_id) {
                $booking = new WC_Booking($booking_id);
                
                // Update booking status to cancelled
                // This also triggers the availability to be released
                $booking->update_status('cancelled');
            }
        }
    }
}