Preliminary support for APIv9 and threads

Myriad/Cache/DiscordCacheExtensions.cs

@@ -38,6 +38,14 @@ namespace Myriad.Cache
                     return cache.TrySaveDmChannelStub(md.GuildId, md.ChannelId);
                 case MessageDeleteBulkEvent md:
                     return cache.TrySaveDmChannelStub(md.GuildId, md.ChannelId);
+                case ThreadCreateEvent tc:
+                    return cache.SaveChannel(tc);
+                case ThreadUpdateEvent tu:
+                    return cache.SaveChannel(tu);
+                case ThreadDeleteEvent td:
+                    return cache.RemoveChannel(td.Id);
+                case ThreadListSyncEvent tls:
+                    return cache.SaveThreadListSync(tls);
             }
 
             return default;
@@ -53,6 +61,9 @@ namespace Myriad.Cache
 
             foreach (var member in guildCreate.Members)
                 await cache.SaveUser(member.User);
+
+            foreach (var thread in guildCreate.Threads)
+                await cache.SaveChannel(thread);
         }
 
         private static async ValueTask SaveMessageCreate(this IDiscordCache cache, MessageCreateEvent evt)
@@ -70,5 +81,11 @@ namespace Myriad.Cache
             // some kind of stub channel object until we get the real one
             return guildId != null ? default : cache.SaveDmChannelStub(channelId);
         }
+
+        private static async ValueTask SaveThreadListSync(this IDiscordCache cache, ThreadListSyncEvent evt)
+        {
+            foreach (var thread in evt.Threads) 
+                await cache.SaveChannel(thread);
+        }
     }
 }

Myriad/Extensions/CacheExtensions.cs

@@ -75,5 +75,15 @@ namespace Myriad.Extensions
             await cache.SaveChannel(restChannel);
             return restChannel;
         }
+
+        public static Channel GetRootChannel(this IDiscordCache cache, ulong channelOrThread)
+        {
+            var channel = cache.GetChannel(channelOrThread);
+            if (!channel.IsThread()) 
+                return channel;
+            
+            var parent = cache.GetChannel(channel.ParentId!.Value);
+            return parent;
+        }
     }
 }

Myriad/Extensions/ChannelExtensions.cs

@@ -5,5 +5,12 @@ namespace Myriad.Extensions
     public static class ChannelExtensions
     {
         public static string Mention(this Channel channel) => $"<#{channel.Id}>";
+
+        public static bool IsThread(this Channel channel) => channel.Type.IsThread();
+
+        public static bool IsThread(this Channel.ChannelType type) =>
+            type is Channel.ChannelType.GuildPublicThread
+                or Channel.ChannelType.GuildPrivateThread
+                or Channel.ChannelType.GuildNewsThread;
     }
 }

Myriad/Extensions/PermissionExtensions.cs

@@ -11,7 +11,7 @@ namespace Myriad.Extensions
     public static class PermissionExtensions
     {
         public static PermissionSet PermissionsFor(this IDiscordCache cache, MessageCreateEvent message) =>
-            PermissionsFor(cache, message.ChannelId, message.Author.Id, message.Member?.Roles, isWebhook: message.Author.Discriminator == "0000");
+            PermissionsFor(cache, message.ChannelId, message.Author.Id, message.Member?.Roles, isWebhook: message.WebhookId != null);
 
         public static PermissionSet PermissionsFor(this IDiscordCache cache, ulong channelId, GuildMember member) =>
             PermissionsFor(cache, channelId, member.User.Id, member.Roles);
@@ -21,16 +21,21 @@ namespace Myriad.Extensions
 
         public static PermissionSet PermissionsFor(this IDiscordCache cache, ulong channelId, ulong userId, ICollection<ulong>? userRoles, bool isWebhook = false)
         {
-            var channel = cache.GetChannel(channelId);
+            if (!cache.TryGetChannel(channelId, out var channel))
+                // todo: handle channel not found better
+                return PermissionSet.Dm;
+            
             if (channel.GuildId == null)
                 return PermissionSet.Dm;
 
+            var rootChannel = cache.GetRootChannel(channelId);
+            
             var guild = cache.GetGuild(channel.GuildId.Value);
 
             if (isWebhook)
                 return EveryonePermissions(guild);
 
-            return PermissionsFor(guild, channel, userId, userRoles);
+            return PermissionsFor(guild, rootChannel, userId, userRoles);
         }
         
         public static PermissionSet EveryonePermissions(this Guild guild) =>

Myriad/Gateway/Events/GuildCreateEvent.cs

@@ -6,5 +6,6 @@ namespace Myriad.Gateway
     {
         public Channel[] Channels { get; init; }
         public GuildMember[] Members { get; init; }
+        public Channel[] Threads { get; init; }
     }
 }

Myriad/Gateway/Events/IGatewayEvent.cs

@@ -21,6 +21,10 @@ namespace Myriad.Gateway
             {"CHANNEL_CREATE", typeof(ChannelCreateEvent)},
             {"CHANNEL_UPDATE", typeof(ChannelUpdateEvent)},
             {"CHANNEL_DELETE", typeof(ChannelDeleteEvent)},
+            {"THREAD_CREATE", typeof(ThreadCreateEvent)},
+            {"THREAD_UPDATE", typeof(ThreadUpdateEvent)},
+            {"THREAD_DELETE", typeof(ThreadDeleteEvent)},
+            {"THREAD_LIST_SYNC", typeof(ThreadListSyncEvent)},
             {"MESSAGE_CREATE", typeof(MessageCreateEvent)},
             {"MESSAGE_UPDATE", typeof(MessageUpdateEvent)},
             {"MESSAGE_DELETE", typeof(MessageDeleteEvent)},

Myriad/Gateway/Events/ThreadCreateEvent.cs

@@ -0,0 +1,6 @@
+using Myriad.Types;
+
+namespace Myriad.Gateway
+{
+    public record ThreadCreateEvent: Channel, IGatewayEvent;
+}

Myriad/Gateway/Events/ThreadDeleteEvent.cs

@@ -0,0 +1,12 @@
+using Myriad.Types;
+
+namespace Myriad.Gateway
+{
+    public record ThreadDeleteEvent: IGatewayEvent
+    {
+        public ulong Id { get; init; }
+        public ulong? GuildId { get; init; }
+        public ulong? ParentId { get; init; }
+        public Channel.ChannelType Type { get; init; }
+    }
+}

Myriad/Gateway/Events/ThreadListSyncEvent.cs

@@ -0,0 +1,11 @@
+using Myriad.Types;
+
+namespace Myriad.Gateway
+{
+    public record ThreadListSyncEvent: IGatewayEvent
+    {
+        public ulong GuildId { get; init; }
+        public ulong[]? ChannelIds { get; init; }
+        public Channel[] Threads { get; init; }
+    }
+}

Myriad/Gateway/Events/ThreadUpdateEvent.cs

@@ -0,0 +1,6 @@
+using Myriad.Types;
+
+namespace Myriad.Gateway
+{
+    public record ThreadUpdateEvent: Channel, IGatewayEvent;
+}

Myriad/Gateway/ShardConnection.cs

@@ -82,7 +82,7 @@ namespace Myriad.Gateway
         
         private Uri GetConnectionUri(string baseUri) => new UriBuilder(baseUri)
         {
-            Query = "v=8&encoding=json"
+            Query = "v=9&encoding=json"
         }.Uri;
 
         private async Task CloseInner(WebSocketCloseStatus closeStatus, string? description)

Myriad/Rest/BaseRestClient.cs

@@ -22,7 +22,7 @@ namespace Myriad.Rest
 {
     public class BaseRestClient: IAsyncDisposable
     {
-        private const string ApiBaseUrl = "https://discord.com/api/v8";
+        private const string ApiBaseUrl = "https://discord.com/api/v9";
 
         private readonly Version _httpVersion = new(2, 0);
         private readonly JsonSerializerOptions _jsonSerializerOptions;

Myriad/Rest/DiscordApiClient.cs

@@ -116,9 +116,15 @@ namespace Myriad.Rest
             _client.Get<Webhook[]>($"/channels/{channelId}/webhooks", ("GetChannelWebhooks", channelId))!;
 
         public Task<Message> ExecuteWebhook(ulong webhookId, string webhookToken, ExecuteWebhookRequest request,
-                                            MultipartFile[]? files = null) =>
+                                            MultipartFile[]? files = null, ulong? threadId = null)
-            _client.PostMultipart<Message>($"/webhooks/{webhookId}/{webhookToken}?wait=true",
+        {
+            var url = $"/webhooks/{webhookId}/{webhookToken}?wait=true";
+            if (threadId != null)
+                url += $"&thread_id={threadId}";
+            
+            return _client.PostMultipart<Message>(url,
                 ("ExecuteWebhook", webhookId), request, files)!;
+        }
 
         public Task<Message> EditWebhookMessage(ulong webhookId, string webhookToken, ulong messageId,
                                                 WebhookMessageEditRequest request) =>

PluralKit.Bot/Bot.cs

@@ -78,7 +78,7 @@ namespace PluralKit.Bot
 
         public PermissionSet PermissionsIn(ulong channelId)
         {
-            var channel = _cache.GetChannel(channelId);
+            var channel = _cache.GetRootChannel(channelId);
 
             if (channel.GuildId != null)
             {

PluralKit.Bot/Handlers/MessageCreated.cs

@@ -63,6 +63,7 @@ namespace PluralKit.Bot
 
             var guild = evt.GuildId != null ? _cache.GetGuild(evt.GuildId.Value) : null;
             var channel = _cache.GetChannel(evt.ChannelId);
+            var rootChannel = _cache.GetRootChannel(evt.ChannelId);
             
             // Log metrics and message info
             _metrics.Measure.Meter.Mark(BotMetrics.MessagesReceived);
@@ -72,7 +73,7 @@ namespace PluralKit.Bot
             MessageContext ctx;
             await using (var conn = await _db.Obtain())
             using (_metrics.Measure.Timer.Time(BotMetrics.MessageContextQueryTime))
-                ctx = await _repo.GetMessageContext(conn, evt.Author.Id, evt.GuildId ?? default, evt.ChannelId);
+                ctx = await _repo.GetMessageContext(conn, evt.Author.Id, evt.GuildId ?? default, rootChannel.Id);
             
             // Try each handler until we find one that succeeds
             if (await TryHandleLogClean(evt, ctx)) 

PluralKit.Bot/Proxy/ProxyService.cs

@@ -57,6 +57,8 @@ namespace PluralKit.Bot
             // Fetch members and try to match to a specific member
             await using var conn = await _db.Obtain();
 
+            var rootChannel = _cache.GetRootChannel(message.ChannelId);
+
             List<ProxyMember> members;
             using (_metrics.Measure.Timer.Time(BotMetrics.ProxyMembersQueryTime))
                 members = (await _repo.GetProxyMembers(conn, message.Author.Id, message.GuildId!.Value)).ToList();
@@ -68,7 +70,7 @@ namespace PluralKit.Bot
             if (message.Content != null && message.Content.Length > 2000) throw new PKError("PluralKit cannot proxy messages over 2000 characters in length.");
 
             // Permission check after proxy match so we don't get spammed when not actually proxying
-            if (!await CheckBotPermissionsOrError(botPermissions, message.ChannelId)) 
+            if (!await CheckBotPermissionsOrError(botPermissions, rootChannel.Id)) 
                 return false;
 
             // this method throws, so no need to wrap it in an if statement
@@ -76,7 +78,7 @@ namespace PluralKit.Bot
             
             // Check if the sender account can mention everyone/here + embed links
             // we need to "mirror" these permissions when proxying to prevent exploits
-            var senderPermissions = PermissionExtensions.PermissionsFor(guild, channel, message);
+            var senderPermissions = PermissionExtensions.PermissionsFor(guild, rootChannel, message);
             var allowEveryone = senderPermissions.HasFlag(PermissionSet.MentionEveryone);
             var allowEmbeds = senderPermissions.HasFlag(PermissionSet.EmbedLinks);
 
@@ -131,10 +133,15 @@ namespace PluralKit.Bot
             var content = match.ProxyContent;
             if (!allowEmbeds) content = content.BreakLinkEmbeds();
 
+            var messageChannel = _cache.GetChannel(trigger.ChannelId);
+            var rootChannel = _cache.GetRootChannel(trigger.ChannelId);
+            var threadId = messageChannel.IsThread() ? messageChannel.Id : (ulong?)null; 
+
             var proxyMessage = await _webhookExecutor.ExecuteWebhook(new ProxyRequest
             {
                 GuildId = trigger.GuildId!.Value,
-                ChannelId = trigger.ChannelId,
+                ChannelId = rootChannel.Id,
+                ThreadId = threadId,
                 Name = match.Member.ProxyName(ctx),
                 AvatarUrl = match.Member.ProxyAvatar(ctx),
                 Content = content,

PluralKit.Bot/Services/WebhookExecutorService.cs

@@ -33,6 +33,7 @@ namespace PluralKit.Bot
     {
         public ulong GuildId { get; init; }
         public ulong ChannelId { get; init; }
+        public ulong? ThreadId { get; init; }
         public string Name { get; init; }
         public string? AvatarUrl { get; init; }
         public string? Content { get; init; }
@@ -70,8 +71,8 @@ namespace PluralKit.Bot
             
             // Log the relevant metrics
             _metrics.Measure.Meter.Mark(BotMetrics.MessagesProxied);
-            _logger.Information("Invoked webhook {Webhook} in channel {Channel}", webhook.Id,
+            _logger.Information("Invoked webhook {Webhook} in channel {Channel} (thread {ThreadId}", webhook.Id,
-                req.ChannelId);
+                req.ChannelId, req.ThreadId);
             
             return webhookMessage;
         }
@@ -122,7 +123,7 @@ namespace PluralKit.Bot
             using (_metrics.Measure.Timer.Time(BotMetrics.WebhookResponseTime)) {
                 try
                 {
-                    webhookMessage = await _rest.ExecuteWebhook(webhook.Id, webhook.Token, webhookReq, files);
+                    webhookMessage = await _rest.ExecuteWebhook(webhook.Id, webhook.Token, webhookReq, files, req.ThreadId);
                 }
                 catch (JsonReaderException)
                 {
@@ -136,7 +137,8 @@ namespace PluralKit.Bot
                     {
                         // Error 10015 = "Unknown Webhook" - this likely means the webhook was deleted
                         // but is still in our cache. Invalidate, refresh, try again
-                        _logger.Warning("Error invoking webhook {Webhook} in channel {Channel}", webhook.Id, webhook.ChannelId);
+                        _logger.Warning("Error invoking webhook {Webhook} in channel {Channel} (thread {ThreadId}",
+                            webhook.Id, webhook.ChannelId, req.ThreadId);
                         
                         var newWebhook = await _webhookCache.InvalidateAndRefreshWebhook(req.ChannelId, webhook);
                         return await ExecuteWebhookInner(newWebhook, req, hasRetried: true);
@@ -147,12 +149,12 @@ namespace PluralKit.Bot
             } 
 
             // We don't care about whether the sending succeeds, and we don't want to *wait* for it, so we just fork it off
-            var _ = TrySendRemainingAttachments(webhook, req.Name, req.AvatarUrl, attachmentChunks);
+            var _ = TrySendRemainingAttachments(webhook, req.Name, req.AvatarUrl, attachmentChunks, req.ThreadId);
 
             return webhookMessage;
         }
 
-        private async Task TrySendRemainingAttachments(Webhook webhook, string name, string avatarUrl, IReadOnlyList<IReadOnlyCollection<Message.Attachment>> attachmentChunks)
+        private async Task TrySendRemainingAttachments(Webhook webhook, string name, string avatarUrl, IReadOnlyList<IReadOnlyCollection<Message.Attachment>> attachmentChunks, ulong? threadId)
         {
             if (attachmentChunks.Count <= 1) return;
 
@@ -160,7 +162,7 @@ namespace PluralKit.Bot
             {
                 var files = await GetAttachmentFiles(attachmentChunks[i]);
                 var req = new ExecuteWebhookRequest {Username = name, AvatarUrl = avatarUrl};
-                await _rest.ExecuteWebhook(webhook.Id, webhook.Token!, req, files);
+                await _rest.ExecuteWebhook(webhook.Id, webhook.Token!, req, files, threadId);
             }
         }
         

PluralKit.Bot/Utils/DiscordUtils.cs

@@ -194,6 +194,11 @@ namespace PluralKit.Bot
         }
 
         public static bool IsValidGuildChannel(Channel channel) =>
-            channel.Type == Channel.ChannelType.GuildText || channel.Type == Channel.ChannelType.GuildNews;
+            channel.Type is 
+                Channel.ChannelType.GuildText or
+                Channel.ChannelType.GuildNews or 
+                Channel.ChannelType.GuildPublicThread or
+                Channel.ChannelType.GuildPrivateThread or
+                Channel.ChannelType.GuildNewsThread;
     }
 }

PluralKit.Bot/Utils/SerilogGatewayEnricherFactory.cs

@@ -36,11 +36,14 @@ namespace PluralKit.Bot
             
             if (channel != null)
             {
-                props.Add(new("GuildId", new ScalarValue(channel.Value)));
+                props.Add(new("ChannelId", new ScalarValue(channel.Value)));
 
+                if (_cache.TryGetChannel(channel.Value, out _))
+                {
                     var botPermissions = _bot.PermissionsIn(channel.Value);
                     props.Add(new("BotPermissions", new ScalarValue(botPermissions)));
                 }
+            }
             
             if (message != null)
                 props.Add(new("MessageId", new ScalarValue(message.Value)));