Warn on Refresh Metadata (#610)

* Warn the user about the dangers of refresh metadata and promote them to use a scan instead.

* Removed presence hub and moved it over to message hub.

When a library scan is in progress, now a spinner will show on manage libraries page.

* Code cleanup

API/Services/Tasks/ScannerService.cs

@@ -185,6 +185,9 @@ namespace API.Services.Tasks
            }
 
            _logger.LogInformation("[ScannerService] Beginning file scan on {LibraryName}", library.Name);
+           await _messageHub.Clients.All.SendAsync(SignalREvents.ScanLibraryProgress,
+               MessageFactory.ScanLibraryProgressEvent(libraryId, 0, string.Empty));
+
            var scanner = new ParseScannedFiles(_bookService, _logger);
            var series = scanner.ScanLibrariesForSeries(library.Type, library.Folders.Select(fp => fp.Path), out var totalFiles, out var scanElapsedTime);
 
@@ -212,7 +215,8 @@ namespace API.Services.Tasks
            await CleanupAbandonedChapters();
 
            BackgroundJob.Enqueue(() => _metadataService.RefreshMetadata(libraryId, false));
-           await _messageHub.Clients.All.SendAsync(SignalREvents.ScanLibrary, MessageFactory.ScanLibraryEvent(libraryId, "complete"));
+           await _messageHub.Clients.All.SendAsync(SignalREvents.ScanLibraryProgress,
+               MessageFactory.ScanLibraryProgressEvent(libraryId, 100, string.Empty));
        }
 
        /// <summary>
@@ -277,7 +281,10 @@ namespace API.Services.Tasks
 
               // Now, we only have to deal with series that exist on disk. Let's recalculate the volumes for each series
               var librarySeries = cleanedSeries.ToList();
-              Parallel.ForEach(librarySeries, (series) => { UpdateSeries(series, parsedSeries); });
+              Parallel.ForEach(librarySeries, (series) =>
+              {
+                  UpdateSeries(series, parsedSeries);
+              });
 
               await _unitOfWork.CommitAsync();
               _logger.LogInformation(

API/SignalR/MessageFactory.cs

@@ -59,6 +59,22 @@ namespace API.SignalR
             };
         }
 
+        public static SignalRMessage ScanLibraryProgressEvent(int libraryId, int progress, string seriesName)
+        {
+            return new SignalRMessage()
+            {
+                Name = SignalREvents.ScanLibrary,
+                Body = new
+                {
+                    LibraryId = libraryId,
+                    Progress = progress,
+                    SeriesName = seriesName
+                }
+            };
+        }
+
+
+
         public static SignalRMessage RefreshMetadataEvent(int libraryId, int seriesId)
         {
             return new SignalRMessage()

API/SignalR/MessageHub.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using API.Extensions;
+using API.SignalR.Presence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.SignalR;
 
@@ -13,8 +15,14 @@ namespace API.SignalR
     [Authorize]
     public class MessageHub : Hub
     {
+        private readonly IPresenceTracker _tracker;
         private static readonly HashSet<string> Connections = new HashSet<string>();
 
+        public MessageHub(IPresenceTracker tracker)
+        {
+            _tracker = tracker;
+        }
+
         public static bool IsConnected
         {
             get
@@ -33,6 +41,12 @@ namespace API.SignalR
                 Connections.Add(Context.ConnectionId);
             }
 
+            await _tracker.UserConnected(Context.User.GetUsername(), Context.ConnectionId);
+
+            var currentUsers = await PresenceTracker.GetOnlineUsers();
+            await Clients.All.SendAsync(SignalREvents.OnlineUsers, currentUsers);
+
+
             await base.OnConnectedAsync();
         }
 
@@ -43,6 +57,12 @@ namespace API.SignalR
                 Connections.Remove(Context.ConnectionId);
             }
 
+            await _tracker.UserDisconnected(Context.User.GetUsername(), Context.ConnectionId);
+
+            var currentUsers = await PresenceTracker.GetOnlineUsers();
+            await Clients.All.SendAsync(SignalREvents.OnlineUsers, currentUsers);
+
+
             await base.OnDisconnectedAsync(exception);
         }
     }

API/SignalR/SignalREvents.cs

@@ -8,6 +8,7 @@
         public const string ScanLibrary = "ScanLibrary";
         public const string SeriesAdded = "SeriesAdded";
         public const string SeriesRemoved = "SeriesRemoved";
-
+        public const string ScanLibraryProgress = "ScanLibraryProgress";
+        public const string OnlineUsers = "OnlineUsers";
     }
 }

API/Startup.cs

@@ -147,7 +147,6 @@ namespace API
             {
                 endpoints.MapControllers();
                 endpoints.MapHub<MessageHub>("hubs/messages");
-                endpoints.MapHub<PresenceHub>("hubs/presence");
                 endpoints.MapHangfireDashboard();
                 endpoints.MapFallbackToController("Index", "Fallback");
             });