using System;
using System.Threading;
using System.Threading.Tasks;
using AsbCloudApp.Repositories;
using AsbCloudApp.Services;
using AsbCloudWebApi.Options.Notifications;
using AsbCloudWebApi.SignalR.ConnectionManager;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;

namespace AsbCloudWebApi.SignalR.BackgroundServices;

public class SignalRNotificationSender : BackgroundService
{
	private readonly IConnectionManager connectionManager;
	private readonly INotificationSendingQueueService notificationSendingQueueService;
	private readonly IHubContext<NotificationHub> notificationHubContext;
	private readonly NotificationsOptionsSignalR notificationsOptionsSignalR;
	private readonly IServiceProvider serviceProvider;

	public SignalRNotificationSender(IConnectionManager connectionManager,
		INotificationSendingQueueService notificationSendingQueueService,
		IHubContext<NotificationHub> notificationHubContext,
		IOptions<NotificationsOptionsSignalR> notificationsOptionsSignalR,
		IServiceProvider serviceProvider)
	{
		this.connectionManager = connectionManager;
		this.notificationSendingQueueService = notificationSendingQueueService;
		this.notificationHubContext = notificationHubContext;
		this.notificationsOptionsSignalR = notificationsOptionsSignalR.Value;
		this.serviceProvider = serviceProvider;
	}

	protected override async Task ExecuteAsync(CancellationToken stoppingToken)
	{
		await Task.Run( async () =>
		{
			await SendAsync(stoppingToken);
		}, stoppingToken);
	}

	private async Task SendAsync(CancellationToken cancellationToken)
	{
		while (!cancellationToken.IsCancellationRequested)
		{
			notificationSendingQueueService.Wait(cancellationToken);
		
			while (!notificationSendingQueueService.IsEmpty)
			{
				if (notificationSendingQueueService.TryDequeue(out var notification))
				{
					string userId = notification.IdUser.ToString();
		
					var connectionId = connectionManager.GetConnectionIdByUserId(userId);
					
					if (!string.IsNullOrWhiteSpace(connectionId))
					{
						await notificationHubContext.Clients.Client(connectionId)
							.SendAsync(notificationsOptionsSignalR.Method,
								notification,
								cancellationToken);
		
						notification.SentDateAtUtc = DateTime.UtcNow;
						notification.IsRead = false;
					}
		
					var scope = serviceProvider.CreateScope();
		
					var notificationRepository = scope.ServiceProvider.GetService<INotificationRepository>();
		
					if (notificationRepository != null)
					{
						await notificationRepository.UpdateAsync(notification,
							cancellationToken);
					}
				}
			}
		}
	}
}