AuthenticationBehavior.cs

public class AuthenticationBehavior : IActionBehavior
{
    private readonly IUrlRegistry _registry;
    private readonly CurrentRequest _request;
    private readonly IOutputWriter _writer;
    private readonly IActionBehavior _actionBehavior;
    private readonly ISecureSession _secureSession;

    public AuthenticationBehavior(IUrlRegistry registry, CurrentRequest request, IOutputWriter writer, IActionBehavior actionBehavior, ISecureSession secureSession)
    {
        _registry = registry;
        _request = request;
        _writer = writer;
        _actionBehavior = actionBehavior;
        _secureSession = secureSession;
    }

    public void Invoke()
    {
        var loginPageUrl = _registry.UrlFor<LoginHandler>(x => x.Query(null));
        var requestingLoginPage = _request.Path.Equals(loginPageUrl, StringComparison.OrdinalIgnoreCase);
        var loggedIn = _secureSession.IsLoggedIn();

        if (loggedIn && requestingLoginPage) _writer.RedirectToUrl(_registry.UrlFor<DashboardHandler>(x => x.Query()));
        else if (loggedIn) _actionBehavior.Invoke();
        else if (requestingLoginPage) _actionBehavior.Invoke();
        else _writer.RedirectToUrl(loginPageUrl);
    }

    public void InvokePartial()
    {
        if (_secureSession.IsLoggedIn()) _actionBehavior.InvokePartial();
    }
}