Made serveral presence improvements and additions.

src/Discord.Net/DiscordClient.API.cs

@@ -420,12 +420,23 @@ namespace Discord
 							else
 								msg = _messages[x.Id] ?? new Message(this, x.Id, x.ChannelId, x.Author.Id);
 							if (msg != null)
-								msg.Update(x);
-							if (_config.TrackActivity)
 							{
-								var user = _users[x.Author.Id];
-								if (user != null)
-									user.UpdateActivity(x.Timestamp);
+								msg.Update(x);
+								if (_config.TrackActivity)
+								{
+									if (channel.IsPrivate)
+									{
+										var user = msg.User;
+										if (user != null)
+											user.UpdateActivity(msg.EditedTimestamp ?? msg.Timestamp);
+									}
+									else
+									{
+										var member = msg.Member;
+										if (member != null)
+											member.UpdateActivity(msg.EditedTimestamp ?? msg.Timestamp);
+									}
+								}
 							}
 							return msg;
 						})

src/Discord.Net/DiscordClient.cs

@@ -118,18 +118,14 @@ namespace Discord
 				{
 					if (_voiceSocket.CurrentVoiceServerId != null)
 					{
-						if (_config.TrackActivity)
-						{
-							var user = _users[e.UserId];
-							if (user != null)
-								user.UpdateActivity();
-						}
 						var member = _members[e.UserId, _voiceSocket.CurrentVoiceServerId];
 						bool value = e.IsSpeaking;
                         if (member.IsSpeaking != value)
 						{
 							member.IsSpeaking = value;
 							RaiseUserIsSpeaking(member, value);
+							if (_config.TrackActivity)
+								member.UpdateActivity();
 						}
 					}
 				};
@@ -359,10 +355,10 @@ namespace Discord
 							var data = e.Payload.ToObject<Events.GuildMemberAdd>(_serializer);
 							var user = _users.GetOrAdd(data.User.Id);
 							user.Update(data.User);
-							if (_config.TrackActivity)
-								user.UpdateActivity();
 							var member = _members.GetOrAdd(data.User.Id, data.GuildId);
 							member.Update(data);
+							if (_config.TrackActivity)
+								member.UpdateActivity();
 							RaiseUserAdded(member);
 						}
 						break;
@@ -455,7 +451,21 @@ namespace Discord
 								msg = _messages.GetOrAdd(data.Id, data.ChannelId, data.Author.Id);
 							msg.Update(data);
 							if (_config.TrackActivity)
-								msg.User.UpdateActivity(data.Timestamp);
+							{
+								var channel = msg.Channel;
+								if (channel == null || channel.IsPrivate)
+								{
+									var user = msg.User;
+									if (user != null)
+										user.UpdateActivity(data.Timestamp);
+								}
+								else
+								{
+									var member = msg.Member;
+									if (member != null)
+										member.UpdateActivity(data.Timestamp);
+								}
+							}
 							if (wasLocal)
 								RaiseMessageSent(msg);
 							RaiseMessageCreated(msg);
@@ -537,11 +547,23 @@ namespace Discord
 
 							if (user != null)
 							{
-								if (_config.TrackActivity)
-									user.UpdateActivity();
 								if (channel != null)
 									RaiseUserIsTyping(user, channel);
 							}
+							if (_config.TrackActivity)
+							{
+								if (channel.IsPrivate)
+								{
+									if (user != null)
+										user.UpdateActivity();
+								}
+								else
+								{
+									var member = _members[data.UserId, channel.ServerId];
+									if (member != null)
+										member.UpdateActivity();
+								}
+							}
 						}
 						break;
 

src/Discord.Net/DiscordClientConfig.cs

@@ -41,7 +41,7 @@ namespace Discord
 		private bool _useMessageQueue = false;
 		/// <summary> (Experimental) Maintains the LastActivity property for users, showing when they last made an action (sent message, joined server, typed, etc). </summary>
 		public bool TrackActivity { get { return _trackActivity; } set { SetValue(ref _trackActivity, value); } }
-		private bool _trackActivity = false;
+		private bool _trackActivity = true;
 
 		//Lock
 		private bool _isLocked;

src/Discord.Net/Models/Member.cs

@@ -20,11 +20,18 @@ namespace Discord
 
 		public string SessionId { get; internal set; }
 		public string Token { get; internal set; }
+
 		/// <summary> Returns the id for the game this user is currently playing. </summary>
 		public string GameId { get; internal set; }
 		/// <summary> Returns the current status for this user. </summary>
 		public string Status { get; internal set; }
+		/// <summary> Returns the time this user's status was last changed in this server. </summary>
 		public DateTime StatusSince { get; internal set; }
+		/// <summary> Returns the time this user last sent/edited a message, started typing or sent voice data in this server. </summary>
+		public DateTime? LastActivity { get; private set; }
+		/// <summary> Returns the time this user was last seen online in this server. </summary>
+		public DateTime? LastOnline => Status != UserStatus.Offline ? DateTime.UtcNow : _lastOnline;
+		private DateTime _lastOnline;
 
 		public string UserId { get; }
 		[JsonIgnore]
@@ -50,7 +57,8 @@ namespace Discord
 			_client = client;
 			UserId = userId;
 			ServerId = serverId;
-		}
+			Status = UserStatus.Offline;
+        }
 
 		public override string ToString() => UserId;
 
@@ -70,8 +78,11 @@ namespace Discord
 		{
 			if (Status != model.Status)
 			{
-				Status = model.Status;
-				StatusSince = DateTime.UtcNow;
+				var now = DateTime.UtcNow;
+                Status = model.Status;
+				StatusSince = now;
+				if (Status == UserStatus.Offline)
+					_lastOnline = now;
             }
 			GameId = model.GameId;
 		}
@@ -90,5 +101,11 @@ namespace Discord
 			if (model.IsSuppressed.HasValue)
 				IsSuppressed = model.IsSuppressed.Value;
 		}
-    }
+
+		internal void UpdateActivity(DateTime? activity = null)
+		{
+			if (LastActivity == null || activity > LastActivity.Value)
+				LastActivity = activity ?? DateTime.UtcNow;
+		}
+	}
 }

src/Discord.Net/Models/User.cs

@@ -11,6 +11,7 @@ namespace Discord
 	{
 		private readonly DiscordClient _client;
 		private int _refs;
+		private DateTime? _lastPrivateActivity;
 
 		/// <summary> Returns the unique identifier for this user. </summary>
 		public string Id { get; }
@@ -44,9 +45,27 @@ namespace Discord
 		public IEnumerable<Server> Servers => _client.Servers.Where(x => x.HasMember(Id));
 		/// <summary> Returns a collection of all messages this user has sent that are still in cache. </summary>
 		public IEnumerable<Message> Messages => _client.Messages.Where(x => x.UserId == Id);
-		
-		/// <summary> Returns the time this user last sent a message. </summary>
-		public DateTime? LastActivity { get; private set; }
+
+		/// <summary> Returns the id for the game this user is currently playing. </summary>
+		public string GameId => Memberships.Where(x => x.GameId != null).Select(x => x.GameId).FirstOrDefault();
+		/// <summary> Returns the current status for this user. </summary>
+		public string Status => Memberships.OrderByDescending(x => x.StatusSince).Select(x => x.Status).FirstOrDefault();
+		/// <summary> Returns the time this user's status was last changed. </summary>
+		public DateTime StatusSince => Memberships.OrderByDescending(x => x.StatusSince).Select(x => x.StatusSince).First();
+		/// <summary> Returns the time this user last sent/edited a message, started typing or sent voice data. </summary>
+		public DateTime? LastActivity
+		{
+			get
+			{
+				var lastServerActivity = Memberships.OrderByDescending(x => x.LastActivity).Select(x => x.LastActivity).FirstOrDefault();
+				if (lastServerActivity == null || (_lastPrivateActivity != null && _lastPrivateActivity.Value > lastServerActivity.Value))
+					return _lastPrivateActivity;
+				else
+					return lastServerActivity;
+			}
+		}
+		/// <summary> Returns the time this user was last seen online. </summary>
+		public DateTime? LastOnline => Memberships.OrderByDescending(x => x.LastOnline).Select(x => x.LastOnline).FirstOrDefault();
 
 		internal User(DiscordClient client, string id)
 		{
@@ -66,11 +85,10 @@ namespace Discord
 			Email = model.Email;
 			IsVerified = model.IsVerified;
 		}
-
 		internal void UpdateActivity(DateTime? activity = null)
 		{
-			if (LastActivity == null || activity > LastActivity.Value)
-				LastActivity = activity ?? DateTime.UtcNow;
+			if (_lastPrivateActivity == null || activity > _lastPrivateActivity.Value)
+				_lastPrivateActivity = activity ?? DateTime.UtcNow;
 		}
 
 		public override string ToString() => Name;