Add support for group DMs in invite embeds

DiscordChatExporter.Core/Discord/Data/Invite.cs

@@ -8,7 +8,7 @@ namespace DiscordChatExporter.Core.Discord.Data;
 // https://discord.com/developers/docs/resources/invite#invite-object
 public record Invite(
     string Code,
-    Guild? Guild,
+    Guild Guild,
     Channel? Channel)
 {
     public static string? TryGetCodeFromUrl(string url) =>
@@ -17,7 +17,7 @@ public record Invite(
     public static Invite Parse(JsonElement json)
     {
         var code = json.GetProperty("code").GetNonWhiteSpaceString();
-        var guild = json.GetPropertyOrNull("guild")?.Pipe(Guild.Parse);
+        var guild = json.GetPropertyOrNull("guild")?.Pipe(Guild.Parse) ?? Guild.DirectMessages;
         var channel = json.GetPropertyOrNull("channel")?.Pipe(c => Channel.Parse(c));
 
         return new Invite(code, guild, channel);

DiscordChatExporter.Core/Exporting/MessageGroupTemplate.cshtml

@@ -329,15 +329,15 @@
 
                             <div class="chatlog__embed">
                                 <div class="chatlog__embed-invite-container">
-                                    <div class="chatlog__embed-invite-title">Invite to join a server</div>
+                                    <div class="chatlog__embed-invite-title">@(invite.Channel?.Kind.IsDirect() == true ? "Invite to join a group DM" : "Invite to join a server")</div>
                                     <div class="chatlog__embed-invite">
                                         <div class="chatlog__embed-invite-guild-icon-container">
-                                            <img class="chatlog__embed-invite-guild-icon" src="@await ResolveAssetUrlAsync(invite.Guild?.IconUrl ?? Guild.DirectMessages.IconUrl)" alt="Guild icon" loading="lazy">
+                                            <img class="chatlog__embed-invite-guild-icon" src="@await ResolveAssetUrlAsync(invite.Channel?.IconUrl ?? invite.Guild.IconUrl)" alt="Guild icon" loading="lazy">
                                         </div>
                                         <div class="chatlog__embed-invite-info">
                                             <div class="chatlog__embed-invite-guild-name">
                                                 <a href="https://discord.gg/@invite.Code">
-                                                    @(invite.Guild?.Name ?? "Unknown Guild")
+                                                    @(invite.Guild.Name)
                                                 </a>
                                             </div>
                                             <div class="chatlog__embed-invite-channel-name">