convert iOS to MAC

Hello,
I'm using the following class for auth in xamarin-ios, but I'm unable to use it xamarin-macos because SFSafariViewController, SFSafariViewControllerDelegate and UIViewController cannot be resolved.
Can anyone help me and tell me what classes should I use to convert this for mac support

public class PlatformWebView : SFSafariViewControllerDelegate, IBrowser
    {
    private SafariServices.SFSafariViewController m_Safari;
    private readonly UIViewController r_Controller;

    public PlatformWebView(UIViewController i_Controller)
    {
        r_Controller = i_Controller;
    }

    public override void DidFinish(SFSafariViewController i_Controller)
    {
        ActivityMediator.Instance.Send("UserCancel");
    }

    public Task<BrowserResult> InvokeAsync(BrowserOptions i_Options)
    {
        if (string.IsNullOrWhiteSpace(i_Options.StartUrl))
        {
            throw new ArgumentException("Missing StartUrl", nameof(i_Options));
        }

        if (string.IsNullOrWhiteSpace(i_Options.EndUrl))
        {
            throw new ArgumentException("Missing EndUrl", nameof(i_Options));
        }

        // must be able to wait for the intent to be finished to continue
        // with setting the task result
        TaskCompletionSource<BrowserResult> tcs = new TaskCompletionSource<BrowserResult>();

        // create Safari controller
        m_Safari = new SafariServices.SFSafariViewController(new NSUrl(i_Options.StartUrl));
        m_Safari.Delegate = this;

        ActivityMediator.MessageReceivedEventHandler callback = null;
        callback = async (i_Response) =>
        {
            // remove handler
            ActivityMediator.Instance.ActivityMessageReceived -= callback;

            if (i_Response == "UserCancel")
            {
                tcs.SetResult(new BrowserResult
                {
                    ResultType = BrowserResultType.UserCancel
                });
            }
            else
            {
                // Close Safari
                await m_Safari.DismissViewControllerAsync(true);

                // set result
                tcs.SetResult(new BrowserResult
                {
                    Response = i_Response,
                    ResultType = BrowserResultType.Success
                });
            }
        };

        // attach handler
        ActivityMediator.Instance.ActivityMessageReceived += callback;

        // launch Safari
        r_Controller.PresentViewController(m_Safari, true, null);

        // need an intent to be triggered when browsing to the "io.identitymodel.native://callback"
        // scheme/URI => CallbackInterceptorActivity
        return tcs.Task;
    }
}

public class ActivityMediator
    {
    public delegate void MessageReceivedEventHandler(string i_Message);

    private static ActivityMediator s_Instance;

    public static ActivityMediator Instance
    {
        get
        {
            if (s_Instance == null)
            {
                s_Instance = new ActivityMediator();
            }

            return s_Instance;
        }
    }

    private ActivityMediator()
    {
    }

    public event MessageReceivedEventHandler ActivityMessageReceived;

    public void Send(string i_Response)
    {
        ActivityMessageReceived?.Invoke(i_Response);
    }
}