Introduce the foundation for the new username system

DiscordChatExporter.Core/Discord/Data/Channel.cs

@@ -42,7 +42,7 @@ public partial record Channel
             json.GetPropertyOrNull("recipients")?
                 .EnumerateArrayOrNull()?
                 .Select(User.Parse)
-                .Select(u => u.Name)
+                .Select(u => u.DisplayName)
                 .Pipe(s => string.Join(", ", s)) ??
 
             // Fallback

DiscordChatExporter.Core/Discord/Data/Member.cs

@@ -11,7 +11,7 @@ namespace DiscordChatExporter.Core.Discord.Data;
 // https://discord.com/developers/docs/resources/guild#guild-member-object
 public partial record Member(
     User User,
-    string? Nick,
+    string? DisplayName,
     string? AvatarUrl,
     IReadOnlyList<Snowflake> RoleIds) : IHasId
 {
@@ -25,7 +25,7 @@ public partial record Member
     public static Member Parse(JsonElement json, Snowflake? guildId = null)
     {
         var user = json.GetProperty("user").Pipe(User.Parse);
-        var nick = json.GetPropertyOrNull("nick")?.GetNonWhiteSpaceStringOrNull();
+        var displayName = json.GetPropertyOrNull("nick")?.GetNonWhiteSpaceStringOrNull();
 
         var roleIds = json
             .GetPropertyOrNull("roles")?
@@ -43,7 +43,7 @@ public partial record Member
 
         return new Member(
             user,
-            nick,
+            displayName,
             avatarUrl,
             roleIds
         );

DiscordChatExporter.Core/Discord/Data/User.cs

@@ -9,13 +9,24 @@ namespace DiscordChatExporter.Core.Discord.Data;
 public partial record User(
     Snowflake Id,
     bool IsBot,
-    int Discriminator,
+    // Remove after Discord migrates all accounts to the new system.
+    // With that, also remove the DiscriminatorFormatted and FullName properties.
+    // Replace existing calls to FullName with Name (not DisplayName).
+    int? Discriminator,
     string Name,
+    string DisplayName,
     string AvatarUrl) : IHasId
 {
-    public string DiscriminatorFormatted => $"{Discriminator:0000}";
+    public string DiscriminatorFormatted => Discriminator is not null
+        ? $"{Discriminator:0000}"
+        : "0000";
 
-    public string FullName => $"{Name}#{DiscriminatorFormatted}";
+    // This effectively represents the user's true identity.
+    // In the old system, this is formed from the username and discriminator.
+    // In the new system, the username is already the user's unique identifier.
+    public string FullName => Discriminator is not null
+        ? $"{Name}#{DiscriminatorFormatted}"
+        : Name;
 }
 
 public partial record User
@@ -24,16 +35,23 @@ public partial record User
     {
         var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
         var isBot = json.GetPropertyOrNull("bot")?.GetBooleanOrNull() ?? false;
-        var discriminator = json.GetProperty("discriminator").GetNonWhiteSpaceString().Pipe(int.Parse);
+
+        var discriminator = json
+            .GetPropertyOrNull("discriminator")?
+            .GetNonWhiteSpaceStringOrNull()?
+            .Pipe(int.Parse)
+            .NullIfDefault();
+
         var name = json.GetProperty("username").GetNonNullString();
+        var displayName = json.GetPropertyOrNull("global_name")?.GetNonWhiteSpaceStringOrNull() ?? name;
 
         var avatarUrl =
             json
                 .GetPropertyOrNull("avatar")?
                 .GetNonWhiteSpaceStringOrNull()?
                 .Pipe(h => ImageCdn.GetUserAvatarUrl(id, h)) ??
-            ImageCdn.GetFallbackUserAvatarUrl(discriminator);
+            ImageCdn.GetFallbackUserAvatarUrl(discriminator ?? 0);
 
-        return new User(id, isBot, discriminator, name, avatarUrl);
+        return new User(id, isBot, discriminator, name, displayName, avatarUrl);
     }
 }

DiscordChatExporter.Core/Exporting/Filtering/FromMessageFilter.cs

@@ -11,6 +11,7 @@ internal class FromMessageFilter : MessageFilter
 
     public override bool IsMatch(Message message) =>
         string.Equals(_value, message.Author.Name, StringComparison.OrdinalIgnoreCase) ||
+        string.Equals(_value, message.Author.DisplayName, StringComparison.OrdinalIgnoreCase) ||
         string.Equals(_value, message.Author.FullName, StringComparison.OrdinalIgnoreCase) ||
         string.Equals(_value, message.Author.Id.ToString(), StringComparison.OrdinalIgnoreCase);
 }

DiscordChatExporter.Core/Exporting/Filtering/MentionsMessageFilter.cs

@@ -12,6 +12,7 @@ internal class MentionsMessageFilter : MessageFilter
 
     public override bool IsMatch(Message message) => message.MentionedUsers.Any(user =>
         string.Equals(_value, user.Name, StringComparison.OrdinalIgnoreCase) ||
+        string.Equals(_value, user.DisplayName, StringComparison.OrdinalIgnoreCase) ||
         string.Equals(_value, user.FullName, StringComparison.OrdinalIgnoreCase) ||
         string.Equals(_value, user.Id.ToString(), StringComparison.OrdinalIgnoreCase)
     );

DiscordChatExporter.Core/Exporting/HtmlMarkdownVisitor.cs

@@ -249,12 +249,12 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
 
             var member = mention.TargetId?.Pipe(_context.TryGetMember);
             var fullName = member?.User.FullName ?? "Unknown";
-            var nick = member?.Nick ?? member?.User.Name ?? "Unknown";
+            var displayName = member?.DisplayName ?? member?.User.DisplayName ?? "Unknown";
 
             _buffer.Append(
                 // lang=html
                 $"""
-                <span class="chatlog__markdown-mention" title="{HtmlEncode(fullName)}">@{HtmlEncode(nick)}</span>
+                <span class="chatlog__markdown-mention" title="{HtmlEncode(fullName)}">@{HtmlEncode(displayName)}</span>
                 """
             );
         }

DiscordChatExporter.Core/Exporting/JsonMessageWriter.cs

@@ -44,7 +44,7 @@ internal class JsonMessageWriter : MessageWriter
         _writer.WriteString("id", user.Id.ToString());
         _writer.WriteString("name", user.Name);
         _writer.WriteString("discriminator", user.DiscriminatorFormatted);
-        _writer.WriteString("nickname", Context.TryGetMember(user.Id)?.Nick ?? user.Name);
+        _writer.WriteString("nickname", Context.TryGetMember(user.Id)?.DisplayName ?? user.DisplayName);
         _writer.WriteString("color", Context.TryGetUserColor(user.Id)?.ToHex());
         _writer.WriteBoolean("isBot", user.IsBot);
 

DiscordChatExporter.Core/Exporting/MessageGroupTemplate.cshtml

@@ -40,9 +40,9 @@
 
     var authorMember = Context.TryGetMember(message.Author.Id);
     var authorColor = Context.TryGetUserColor(message.Author.Id);
-    var authorNick = message.Author.IsBot
+    var authorDisplayName = message.Author.IsBot
-        ? message.Author.Name
+        ? message.Author.DisplayName
-        : authorMember?.Nick ?? message.Author.Name;
+        : authorMember?.DisplayName ?? message.Author.DisplayName;
 
     <div id="chatlog__message-container-@message.Id" class="chatlog__message-container @(message.IsPinned ? "chatlog__message-container--pinned" : null)" data-message-id="@message.Id">
         <div class="chatlog__message">
@@ -71,7 +71,7 @@
 
                 <div class="chatlog__message-primary">
                     @* Author name *@
-                    <span class="chatlog__system-notification-author" style="@(authorColor is not null ? $"color: rgb({authorColor.Value.R}, {authorColor.Value.G}, {authorColor.Value.B})" : null)" title="@message.Author.FullName" data-user-id="@message.Author.Id">@authorNick</span>
+                    <span class="chatlog__system-notification-author" style="@(authorColor is not null ? $"color: rgb({authorColor.Value.R}, {authorColor.Value.G}, {authorColor.Value.B})" : null)" title="@message.Author.FullName" data-user-id="@message.Author.Id">@authorDisplayName</span>
 
                     @* Space out the content *@
                     <span> </span>
@@ -81,7 +81,7 @@
                         @if (message.Kind == MessageKind.RecipientAdd && message.MentionedUsers.Any())
                         {
                             <span>added </span>
-                            <a class="chatlog__system-notification-link" title="@message.MentionedUsers.First().FullName">@message.MentionedUsers.First().Name</a>
+                            <a class="chatlog__system-notification-link" title="@message.MentionedUsers.First().FullName">@message.MentionedUsers.First().DisplayName</a>
                             <span> to the group.</span>
                         }
                         else if (message.Kind == MessageKind.RecipientRemove && message.MentionedUsers.Any())
@@ -93,7 +93,7 @@
                             else
                             {
                                 <span>removed </span>
-                                <a class="chatlog__system-notification-link" title="@message.MentionedUsers.First().FullName">@message.MentionedUsers.First().Name</a>
+                                <a class="chatlog__system-notification-link" title="@message.MentionedUsers.First().FullName">@message.MentionedUsers.First().DisplayName</a>
                                 <span> from the group.</span>
                             }
                         }
@@ -168,12 +168,12 @@
                                 {
                                     var referencedUserMember = Context.TryGetMember(message.ReferencedMessage.Author.Id);
                                     var referencedUserColor = Context.TryGetUserColor(message.ReferencedMessage.Author.Id);
-                                    var referencedUserNick = message.ReferencedMessage.Author.IsBot
+                                    var referencedUserDisplayName = message.ReferencedMessage.Author.IsBot
-                                        ? message.ReferencedMessage.Author.Name
+                                        ? message.ReferencedMessage.Author.DisplayName
-                                        : referencedUserMember?.Nick ?? message.ReferencedMessage.Author.Name;
+                                        : referencedUserMember?.DisplayName ?? message.ReferencedMessage.Author.DisplayName;
 
                                     <img class="chatlog__reply-avatar" src="@await ResolveAssetUrlAsync(referencedUserMember?.AvatarUrl ?? message.ReferencedMessage.Author.AvatarUrl)" alt="Avatar" loading="lazy">
-                                    <div class="chatlog__reply-author" style="@(referencedUserColor is not null ? $"color: rgb({referencedUserColor.Value.R}, {referencedUserColor.Value.G}, {referencedUserColor.Value.B})" : null)" title="@message.ReferencedMessage.Author.FullName">@referencedUserNick</div>
+                                    <div class="chatlog__reply-author" style="@(referencedUserColor is not null ? $"color: rgb({referencedUserColor.Value.R}, {referencedUserColor.Value.G}, {referencedUserColor.Value.B})" : null)" title="@message.ReferencedMessage.Author.FullName">@referencedUserDisplayName</div>
                                     <div class="chatlog__reply-content">
                                         <span class="chatlog__reply-link" onclick="scrollToMessage(event, '@message.ReferencedMessage.Id')">
                                             @if (!string.IsNullOrWhiteSpace(message.ReferencedMessage.Content) && !message.ReferencedMessage.IsContentHidden())
@@ -201,12 +201,12 @@
                                 {
                                     var interactionUserMember = Context.TryGetMember(message.Interaction.User.Id);
                                     var interactionUserColor = Context.TryGetUserColor(message.Interaction.User.Id);
-                                    var interactionUserNick = message.Interaction.User.IsBot
+                                    var interactionUserDisplayName = message.Interaction.User.IsBot
-                                        ? message.Interaction.User.Name
+                                        ? message.Interaction.User.DisplayName
-                                        : interactionUserMember?.Nick ?? message.Interaction.User.Name;
+                                        : interactionUserMember?.DisplayName ?? message.Interaction.User.DisplayName;
 
                                     <img class="chatlog__reply-avatar" src="@await ResolveAssetUrlAsync(interactionUserMember?.AvatarUrl ?? message.Interaction.User.AvatarUrl)" alt="Avatar" loading="lazy">
-                                    <div class="chatlog__reply-author" style="@(interactionUserColor is not null ? $"color: rgb({interactionUserColor.Value.R}, {interactionUserColor.Value.G}, {interactionUserColor.Value.B})" : null)" title="@message.Interaction.User.FullName">@interactionUserNick</div>
+                                    <div class="chatlog__reply-author" style="@(interactionUserColor is not null ? $"color: rgb({interactionUserColor.Value.R}, {interactionUserColor.Value.G}, {interactionUserColor.Value.B})" : null)" title="@message.Interaction.User.FullName">@interactionUserDisplayName</div>
                                     <div class="chatlog__reply-content">
                                         used /@message.Interaction.Name
                                     </div>
@@ -223,7 +223,7 @@
                         // Header
                         <div class="chatlog__header">
                             @* Author name *@
-                            <span class="chatlog__author" style="@(authorColor is not null ? $"color: rgb({authorColor.Value.R}, {authorColor.Value.G}, {authorColor.Value.B})" : null)" title="@message.Author.FullName" data-user-id="@message.Author.Id">@authorNick</span>
+                            <span class="chatlog__author" style="@(authorColor is not null ? $"color: rgb({authorColor.Value.R}, {authorColor.Value.G}, {authorColor.Value.B})" : null)" title="@message.Author.FullName" data-user-id="@message.Author.Id">@authorDisplayName</span>
 
                             @* Bot tag *@
                             @if (message.Author.IsBot)

DiscordChatExporter.Core/Exporting/PlainTextMarkdownVisitor.cs

@@ -59,9 +59,9 @@ internal partial class PlainTextMarkdownVisitor : MarkdownVisitor
                 await _context.PopulateMemberAsync(mention.TargetId.Value, cancellationToken);
 
             var member = mention.TargetId?.Pipe(_context.TryGetMember);
-            var name = member?.User.Name ?? "Unknown";
+            var displayName = member?.DisplayName ?? member?.User.DisplayName ?? "Unknown";
 
-            _buffer.Append($"@{name}");
+            _buffer.Append($"@{displayName}");
         }
         else if (mention.Kind == MentionKind.Channel)
         {

DiscordChatExporter.Core/Exporting/PlainTextMessageExtensions.cs

@@ -9,13 +9,13 @@ internal static class PlainTextMessageExtensions
     public static string GetFallbackContent(this Message message) => message.Kind switch
     {
         MessageKind.RecipientAdd => message.MentionedUsers.Any()
-            ? $"Added {message.MentionedUsers.First().Name} to the group."
+            ? $"Added {message.MentionedUsers.First().DisplayName} to the group."
             : "Added a recipient.",
 
         MessageKind.RecipientRemove => message.MentionedUsers.Any()
             ? message.Author.Id == message.MentionedUsers.First().Id
                 ? "Left the group."
-                : $"Removed {message.MentionedUsers.First().Name} from the group."
+                : $"Removed {message.MentionedUsers.First().DisplayName} from the group."
             : "Removed a recipient.",
 
         MessageKind.Call =>

DiscordChatExporter.Core/Utils/Extensions/GenericExtensions.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 
 namespace DiscordChatExporter.Core.Utils.Extensions;
 
@@ -10,4 +11,7 @@ public static class GenericExtensions
         !predicate(value)
             ? value
             : null;
+
+    public static T? NullIfDefault<T>(this T value) where T : struct =>
+        value.NullIf(v => EqualityComparer<T>.Default.Equals(v, default));
 }