using System; namespace AIK.ViewModels.Integral { public static class PaymentLaunchHelper { public static string BuildPaypalLaunchUrl(string tokenOrUrl) { if (string.IsNullOrWhiteSpace(tokenOrUrl)) { return string.Empty; } if (Uri.TryCreate(tokenOrUrl, UriKind.Absolute, out var absoluteUri)) { return absoluteUri.ToString(); } return $"https://www.paypal.com/checkoutnow?token={tokenOrUrl}"; } } }