[Feature] Support for the new username system (#2696)

* update a lot of stuff

* update CDN for new avatar calculation

* whoops, forgot to commit

* handle `null` values

* Remove duplicate line

Co-authored-by: Dmitry <dimson-n@users.noreply.github.com>

* updates

* Apply suggestions from code review

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

* Apply suggestion

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

* update `SocketThreadUSer`

---------

Co-authored-by: Dmitry <dimson-n@users.noreply.github.com>
Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

src/Discord.Net.WebSocket/Entities/Users/SocketGlobalUser.cs

@@ -48,7 +48,10 @@ namespace Discord.WebSocket
             }
         }
 
-        private string DebuggerDisplay => $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Global)";
+        private string DebuggerDisplay => DiscriminatorValue != 0
+            ? $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Guild)"
+            : $"{Username} ({Id}{(IsBot ? ", Bot" : "")}, Guild)";
+
         internal new SocketGlobalUser Clone() => MemberwiseClone() as SocketGlobalUser;
     }
 }

src/Discord.Net.WebSocket/Entities/Users/SocketGroupUser.cs

@@ -48,7 +48,10 @@ namespace Discord.WebSocket
             return entity;
         }
 
-        private string DebuggerDisplay => $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Group)";
+        private string DebuggerDisplay => DiscriminatorValue != 0
+            ? $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Group)"
+            : $"{Username} ({Id}{(IsBot ? ", Bot" : "")}, Group)";
+
         internal new SocketGroupUser Clone() => MemberwiseClone() as SocketGroupUser;
         #endregion
 

src/Discord.Net.WebSocket/Entities/Users/SocketGuildUser.cs

@@ -29,8 +29,10 @@ namespace Discord.WebSocket
         ///     Gets the guild the user is in.
         /// </summary>
         public SocketGuild Guild { get; }
-        /// <inheritdoc />
-        public string DisplayName => Nickname ?? Username;
+
+        /// <inheritdoc cref="IGuildUser.DisplayName"/>
+        public string DisplayName => Nickname ?? GlobalName ?? Username;
+
         /// <inheritdoc />
         public string Nickname { get; private set; }
         /// <inheritdoc/>
@@ -265,7 +267,9 @@ namespace Discord.WebSocket
         public string GetGuildAvatarUrl(ImageFormat format = ImageFormat.Auto, ushort size = 128)
             => CDN.GetGuildUserAvatarUrl(Id, Guild.Id, GuildAvatarId, size, format);
 
-        private string DebuggerDisplay => $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Guild)";
+        private string DebuggerDisplay => DiscriminatorValue != 0
+            ? $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Guild)"
+            : $"{Username} ({Id}{(IsBot ? ", Bot" : "")}, Guild)";
 
         internal new SocketGuildUser Clone()
         {

src/Discord.Net.WebSocket/Entities/Users/SocketSelfUser.cs

@@ -91,7 +91,10 @@ namespace Discord.WebSocket
         public Task ModifyAsync(Action<SelfUserProperties> func, RequestOptions options = null)
             => UserHelper.ModifyAsync(this, Discord, func, options);
 
-        private string DebuggerDisplay => $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Self)";
+        private string DebuggerDisplay => DiscriminatorValue != 0
+            ? $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Self)"
+            : $"{Username} ({Id}{(IsBot ? ", Bot" : "")}, Self)";
+
         internal new SocketSelfUser Clone() => MemberwiseClone() as SocketSelfUser;
     }
 }

src/Discord.Net.WebSocket/Entities/Users/SocketThreadUser.cs

@@ -31,7 +31,7 @@ namespace Discord.WebSocket
 
         /// <inheritdoc/>
         public string DisplayName
-            => GuildUser.Nickname ?? GuildUser.Username;
+            => GuildUser.Nickname ?? GuildUser.GlobalName ?? GuildUser.Username;
 
         /// <inheritdoc/>
         public string Nickname

src/Discord.Net.WebSocket/Entities/Users/SocketUnknownUser.cs

@@ -42,7 +42,10 @@ namespace Discord.WebSocket
             return entity;
         }
 
-        private string DebuggerDisplay => $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Unknown)";
+        private string DebuggerDisplay => DiscriminatorValue != 0
+            ? $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Unknown)"
+            : $"{Username} ({Id}{(IsBot ? ", Bot" : "")}, Unknown)";
+
         internal new SocketUnknownUser Clone() => MemberwiseClone() as SocketUnknownUser;
     }
 }

src/Discord.Net.WebSocket/Entities/Users/SocketUser.cs

@@ -32,6 +32,9 @@ namespace Discord.WebSocket
         internal abstract SocketGlobalUser GlobalUser { get; set; }
         internal abstract SocketPresence Presence { get; set; }
 
+        /// <inheritdoc />
+        public string GlobalName { get; internal set; }
+
         /// <inheritdoc />
         public DateTimeOffset CreatedAt => SnowflakeUtils.FromSnowflake(Id);
         /// <inheritdoc />
@@ -68,10 +71,10 @@ namespace Discord.WebSocket
             }
             if (model.Discriminator.IsSpecified)
             {
-                var newVal = ushort.Parse(model.Discriminator.Value, NumberStyles.None, CultureInfo.InvariantCulture);
+                var newVal = ushort.Parse(model.Discriminator.GetValueOrDefault(null) ?? "0", NumberStyles.None, CultureInfo.InvariantCulture);
                 if (newVal != DiscriminatorValue)
                 {
-                    DiscriminatorValue = ushort.Parse(model.Discriminator.Value, NumberStyles.None, CultureInfo.InvariantCulture);
+                    DiscriminatorValue = ushort.Parse(model.Discriminator.GetValueOrDefault(null) ?? "0", NumberStyles.None, CultureInfo.InvariantCulture);
                     hasChanges = true;
                 }
             }
@@ -90,6 +93,11 @@ namespace Discord.WebSocket
                 PublicFlags = model.PublicFlags.Value;
                 hasChanges = true;
             }
+            if (model.GlobalName.IsSpecified)
+            {
+                GlobalName = model.GlobalName.Value;
+                hasChanges = true;
+            }
             return hasChanges;
         }
 
@@ -109,7 +117,9 @@ namespace Discord.WebSocket
 
         /// <inheritdoc />
         public string GetDefaultAvatarUrl()
-            => CDN.GetDefaultUserAvatarUrl(DiscriminatorValue);
+            => DiscriminatorValue != 0
+                ? CDN.GetDefaultUserAvatarUrl(DiscriminatorValue)
+                : CDN.GetDefaultUserAvatarUrl(Id);
 
         /// <summary>
         ///     Gets the full name of the user (e.g. Example#0001).

src/Discord.Net.WebSocket/Entities/Users/SocketWebhookUser.cs

@@ -49,7 +49,10 @@ namespace Discord.WebSocket
             return entity;
         }
 
-        private string DebuggerDisplay => $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Webhook)";
+        private string DebuggerDisplay => DiscriminatorValue != 0
+            ? $"{Username}#{Discriminator} ({Id}{(IsBot ? ", Bot" : "")}, Webhook)"
+            : $"{Username} ({Id}{(IsBot ? ", Bot" : "")}, Webhook)";
+
         internal new SocketWebhookUser Clone() => MemberwiseClone() as SocketWebhookUser;
         #endregion