keepass2android/src/keepass2android-app/Utils/MessagePresenter.cs

using Android.OS;
using Android.Views;
using Google.Android.Material.Snackbar;

namespace keepass2android.Utils
{
    public struct Message
    {
        public Message()
        {
            Text = null;
            Severity = MessageSeverity.Info;
        }

        public string Text { get; set; }
        public MessageSeverity Severity { get; set; }
        public bool ShowOnSubsequentScreens { get; set; } = true;
    }
    public interface IMessagePresenter
    {
        void ShowMessage(Message message);

        List<Message> PendingMessages
        {
            get;
        }

    }

    internal class NonePresenter : IMessagePresenter
    {
        public void ShowMessage(Message message)
        {
            PendingMessages.Add(message);
        }

        public List<Message> PendingMessages
        {
            get;
            set;
        } = new List<Message>();
    }


    internal class ToastPresenter : IMessagePresenter
    {
        public void ShowMessage(Message message)
        {
            new Handler(Looper.MainLooper).Post(() =>
            {
                Toast.MakeText(App.Context, message.Text, ToastLength.Long).Show();
            });
        }

        public List<Message> PendingMessages => new();
    }

    internal class ChainedSnackbarPresenter: IMessagePresenter
    {
        internal ChainedSnackbarPresenter(View anchorView)
        {
            this.AnchorView = anchorView;
            
        }

        private DateTime nextSnackbarShowTime = DateTime.Now;
        private List<Message> queuedMessages = new List<Message>();

        public View AnchorView { get; set; }

        private TimeSpan chainingTime = TimeSpan.FromSeconds(1.5);
        private Snackbar snackbar;
        private Message lastMessage;

        public void ShowMessage(Message message)
        {
            if (DateTime.Now <= nextSnackbarShowTime)
            {
                var waitDuration = nextSnackbarShowTime - DateTime.Now;
                nextSnackbarShowTime = nextSnackbarShowTime.Add(chainingTime);

                if (!queuedMessages.Any())
                {
                    if (Looper.MainLooper != null)
                    {
                        new Handler(Looper.MainLooper).PostDelayed(ShowNextSnackbar,
                            (long)waitDuration.TotalMilliseconds);
                    }
                    else
                    {
                        Kp2aLog.Log("Currently cannot show message");
                    }
                }
                
                queuedMessages.Add(message);

                return;
            }
            ShowSnackbarNow(message);
            nextSnackbarShowTime = DateTime.Now.Add(chainingTime);

        }

        public List<Message> PendingMessages
        {
            get
            {
                List<Message> pendingMessages = new List<Message>();
                if (snackbar?.IsShown == true)
                {
                    pendingMessages.Add(lastMessage);
                }

                pendingMessages.AddRange(queuedMessages);
                return pendingMessages;
            }
        }

        private void ShowNextSnackbar()
        {
            if (!queuedMessages.Any())
            {
                return;
            }

            ShowSnackbarNow(queuedMessages.First());
            queuedMessages.RemoveAt(0);

            if (!queuedMessages.Any())
            {
                new Handler().PostDelayed(() => { ShowNextSnackbar(); }, (long)chainingTime.TotalMilliseconds);
            }
        }

        private void ShowSnackbarNow(Message message)
        {
            snackbar = Snackbar
                .Make(AnchorView, message.Text,
                    Snackbar.LengthLong);
            snackbar.SetTextMaxLines(10);
            if ((int)Build.VERSION.SdkInt >= 23)
            {
                if (message.Severity == MessageSeverity.Error)
                {
                    snackbar.SetBackgroundTint(App.Context.GetColor(Resource.Color.md_theme_errorContainer));
                    snackbar.SetTextColor(App.Context.GetColor(Resource.Color.md_theme_onErrorContainer));
                }
                else if (message.Severity == MessageSeverity.Warning)
                {
                    snackbar.SetBackgroundTint(App.Context.GetColor(Resource.Color.md_theme_inverseSurface));
                    snackbar.SetTextColor(App.Context.GetColor(Resource.Color.md_theme_inverseOnSurface));
                }
                else
                {
                    snackbar.SetBackgroundTint(App.Context.GetColor(Resource.Color.md_theme_secondaryContainer));
                    snackbar.SetTextColor(App.Context.GetColor(Resource.Color.md_theme_onSecondaryContainer));
                }
            }

            snackbar.Show();
            lastMessage = message;

        }
    }
}