TruckerWebAppHub

TruckerWebAppHub.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.SignalR;
using Newtonsoft.Json;
using TruckerWebApp.RestApi.Manager;

namespace TruckerWebApp.RestApi.Hub
{
    public class TruckerWebAppHub : Microsoft.AspNetCore.SignalR.Hub
    {
        private readonly MetricsManagerHelper _metricsManagerHelper;
        private static readonly List<HubUser> HubUsers;
        private const string SystemName = "_TRUCKERAPP_SYSTEM_";

        static TruckerWebAppHub()
        {
            HubUsers = new List<HubUser>();
        }

        public TruckerWebAppHub(MetricsManagerHelper metricsManagerHelper)
        {
            _metricsManagerHelper = metricsManagerHelper;
        }

        public void Join(int truckerWebAppId, string name)
        {
            try
            {
                string connectionId = Context.ConnectionId;
                HubUser currentHubUser = HubUsers.FirstOrDefault(user => user.UserId == truckerWebAppId);

                if (currentHubUser == null)
                {
                    // add new Hub User
                    currentHubUser = new HubUser
                    {
                        UserId = truckerWebAppId,
                        Name = name
                    };
                    currentHubUser.ConnectionIds.Add(connectionId);
                    HubUsers.Add(currentHubUser);

                    IDictionary<string, string> properties = new Dictionary<string, string>
                    {
                        {"User", JsonConvert.SerializeObject(currentHubUser)}
                    };
                    _metricsManagerHelper.TrackEvent("SignalR-User-Joined", properties);
                }
                else
                {
                    // update existing Hub User with the newly added connectionid. A user can be logged in in
                    // several browsers or SignalR clients. So the truckerWebAppId is either the AuftraggeberId (AG)
                    // or the LieferantId (SUB) and that truckerWebAppId has a 1:many relationship to the ConnectionId(s).
                    currentHubUser.ConnectionIds.Add(connectionId);

                    IDictionary<string, string> properties = new Dictionary<string, string>
                    {
                        {"User", JsonConvert.SerializeObject(currentHubUser)}
                    };
                    _metricsManagerHelper.TrackEvent("SignalR-User-Updated", properties);
                }
            }
            catch (Exception e)
            {
                _metricsManagerHelper.TrackException(e);
            }
        }


        public void Leave(int truckerWebAppId, string name)
        {
            try
            {
                HubUser removableHubUser = HubUsers.FirstOrDefault(user => user.UserId == truckerWebAppId);

                if (removableHubUser == null)
                    return;

                HubUsers.Remove(removableHubUser);

                IDictionary<string, string> properties = new Dictionary<string, string>
                {
                    {" User", JsonConvert.SerializeObject(removableHubUser)}
                };
                _metricsManagerHelper.TrackEvent("SignalR-User-Left", properties);
            }
            catch (Exception e)
            {
                _metricsManagerHelper.TrackException(e);
            }
        }

        public void SendDirectMessage(int senderId, int receiverId, string message)
        {
            try
            {
                HubUser receiver = HubUsers.FirstOrDefault(user => user.UserId == receiverId);
                HubUser sender = HubUsers.FirstOrDefault(user => user.UserId == senderId);
                string senderName = sender?.Name ?? SystemName;

                if (receiver != null)
                {
                    foreach (string receiverConnectionId in receiver.ConnectionIds)
                    {
                        Clients.Client(receiverConnectionId).SendAsync("broadcastMessage", senderName, message);
                        IDictionary<string, string> properties = new Dictionary<string, string>
                        {
                            {"sender", senderId.ToString()},
                            {"receiverId", receiverId.ToString()},
                            {"connectionId", receiverConnectionId},
                            {"client-method", "broadcastMessage"},
                            {"message", message}
                        };
                        _metricsManagerHelper.TrackEvent("SignalR-Message-Sent", properties);
                    }
                }
                else
                {
                    // No receiver joined with that Id.
                    Clients.Client(Context.ConnectionId).SendAsync("broadcastMessage", SystemName, $"No Receiver registered with Id={receiverId}");
                    IDictionary<string, string> properties = new Dictionary<string, string>
                    {
                        {"sender", senderId.ToString()},
                        {"receiver", receiverId.ToString()},
                        {"client-method", "broadcastMessage"},
                        {"message", $"No Receiver registered with Id={receiverId}"}
                    };
                    _metricsManagerHelper.TrackEvent("SignalR-Message-No-Receiver", properties);
                }
            }
            catch (Exception e)
            {
                _metricsManagerHelper.TrackException(e);
            }
        }
    }
}