ClientApiPoC/OnPremiseApp/Services/ClientDataService.cs

using Microsoft.AspNetCore.SignalR.Client;
using ClientApiPoC.Shared.Models;

namespace ClientApiPoC.OnPremiseApp.Services {
    public class ClientDataService {
        public string? ClientData { get; set; } = null;

        public async Task<ClientDataModel> GetClientDataAsync(DateTime timestampServer) {
            return new ClientDataModel() {
                Data = this.ClientData,
                TimestampServerUtc = timestampServer,
                TimestampClientUtc = DateTime.UtcNow
            };
        }

        public void ConfigureTunnelActions(HubConnection tunnelConnection) {
            if (tunnelConnection == null) throw new ArgumentNullException(nameof(tunnelConnection));
            tunnelConnection.On<DateTime, ClientDataModel>("GetClientData", GetClientDataAsync);
        }
    }
}