DD.WellWorkover.Cloud/AsbCloudWebApi/SignalR/ReportsHub.cs

using AsbCloudApp.Data;
using AsbCloudInfrastructure.Background;
using AsbCloudWebApi.SignalR.Clients;
using Microsoft.AspNetCore.Authorization;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace AsbCloudWebApi.SignalR
{
    // SignalR manual:
    // https://docs.microsoft.com/ru-ru/aspnet/core/signalr/introduction?view=aspnetcore-5.0
    //[SignalRHub]
    /// <summary>
    /// ReportsHub
    /// </summary>
    [Authorize]
    public class ReportsHub : BaseHub<IReportHubClient>
    {
        private readonly BackgroundWorker backgroundWorker;

        public ReportsHub(BackgroundWorker backgroundWorker)
        {
            this.backgroundWorker = backgroundWorker;
        }

        /// <summary>
        /// Добавление в группу, отправка данных о формировании отчета
        /// </summary>
        /// <param name="groupName"></param>
        /// <returns></returns>
        public override async Task AddToGroup(string groupName)
        {
            await base.AddToGroup(groupName);

            var workId = groupName.Replace("Report_", "");
            var work = backgroundWorker.Works.FirstOrDefault(work => work.Id == workId);

            var progress = new ReportProgressDto()
            {
                Operation = "Ожидает начала в очереди.",
                Progress = 0f,
            };

            var state = work?.CurrentState;
            if (state is not null)
            {
                progress.Operation = state.State;
                progress.Progress = (float)state.Progress;
            }

            await Clients.Group(groupName).GetReportProgress(progress, CancellationToken.None);
        }
    }
}