using Telerik.Blazor;
using Telerik.Blazor.Components;

namespace Prefab.Web.Client.Services;

/// <summary>
/// Defines a contract for displaying notifications of various types, such as errors, successes, and warnings, within an
/// application.
/// </summary>
/// <remarks>Implementations of this interface provide methods to present user-facing messages in a consistent
/// manner. The interface supports attaching a notification component and displaying messages with different severity
/// levels. This is typically used to inform users about the outcome of operations or to alert them to important
/// events.</remarks>
public interface INotificationService
{
    void Attach(TelerikNotification notification);
    void ShowError(string message);
    void ShowSuccess(string message);
    void ShowWarning(string message);
}

/// <summary>
/// Provides functionality to display error, success, and warning notifications using a Telerik notification component.
/// </summary>
/// <remarks>This service queues notifications if the Telerik notification component is not yet attached, and
/// displays them once the component becomes available. It is intended to be used as an abstraction for showing
/// user-facing notifications in applications that utilize Telerik UI components.</remarks>
public class NotificationService : INotificationService
{
    private readonly Queue<NotificationModel> _pending = new();
    private TelerikNotification? _notification;

    public void Attach(TelerikNotification notification)
    {
        _notification = notification ?? throw new ArgumentNullException(nameof(notification));
        FlushPending();
    }

    public void ShowError(string message) =>
        Show(message, ThemeConstants.Notification.ThemeColor.Error);

    public void ShowSuccess(string message) =>
        Show(message, ThemeConstants.Notification.ThemeColor.Success);

    public void ShowWarning(string message) =>
        Show(message, ThemeConstants.Notification.ThemeColor.Warning);

    private void Show(string message, string themeColor)
    {
        var model = new NotificationModel
        {
            Text = message,
            ThemeColor = themeColor,
            CloseAfter = 3000
        };

        if (_notification is { } notification)
        {
            notification.Show(model);
            return;
        }

        _pending.Enqueue(model);
    }

    private void FlushPending()
    {
        if (_notification is not { } notification)
        {
            return;
        }

        while (_pending.Count > 0)
        {
            notification.Show(_pending.Dequeue());
        }
    }
}