refactor: cache own user ID in IDiscordCache

- remove Cluster.User
- remove Cluster.Application (it was only being used as an alternative to Cluster.User for some reason)
- move Bot.PermissionsIn to DiscordCacheExtensions

Myriad/Cache/DiscordCacheExtensions.cs

@@ -1,7 +1,9 @@
 using System.Linq;
 using System.Threading.Tasks;
 
+using Myriad.Extensions;
 using Myriad.Gateway;
+using Myriad.Types;
 
 namespace Myriad.Cache
 {
@@ -11,6 +13,8 @@ namespace Myriad.Cache
         {
             switch (evt)
             {
+                case ReadyEvent ready:
+                    return cache.SaveOwnUser(ready.User.Id);
                 case GuildCreateEvent gc:
                     return cache.SaveGuildCreate(gc);
                 case GuildUpdateEvent gu:
@@ -102,5 +106,20 @@ namespace Myriad.Cache
             foreach (var thread in evt.Threads)
                 await cache.SaveChannel(thread);
         }
+
+        public static async Task<PermissionSet> PermissionsIn(this IDiscordCache cache, ulong channelId)
+        {
+            var channel = await cache.GetRootChannel(channelId);
+
+            if (channel.GuildId != null)
+            {
+                var userId = await cache.GetOwnUser();
+                var member = await cache.TryGetSelfMember(channel.GuildId.Value);
+                return await cache.PermissionsFor(channelId, userId, member);
+            }
+
+            return PermissionSet.Dm;
+        }
+
     }
 }

Myriad/Cache/IDiscordCache.cs

@@ -7,6 +7,7 @@ namespace Myriad.Cache
 {
     public interface IDiscordCache
     {
+        public ValueTask SaveOwnUser(ulong userId);
         public ValueTask SaveGuild(Guild guild);
         public ValueTask SaveChannel(Channel channel);
         public ValueTask SaveUser(User user);
@@ -19,6 +20,7 @@ namespace Myriad.Cache
         public ValueTask RemoveUser(ulong userId);
         public ValueTask RemoveRole(ulong guildId, ulong roleId);
 
+        public Task<ulong> GetOwnUser();
         public Task<Guild?> TryGetGuild(ulong guildId);
         public Task<Channel?> TryGetChannel(ulong channelId);
         public Task<Channel?> TryGetDmChannel(ulong userId);

Myriad/Cache/MemoryDiscordCache.cs

@@ -16,6 +16,7 @@ namespace Myriad.Cache
         private readonly ConcurrentDictionary<ulong, Role> _roles = new();
         private readonly ConcurrentDictionary<ulong, User> _users = new();
         private readonly ConcurrentDictionary<ulong, GuildMemberPartial> _guildMembers = new();
+        private ulong? _ownUserId { get; set; }
 
         public ValueTask SaveGuild(Guild guild)
         {
@@ -46,6 +47,15 @@ namespace Myriad.Cache
             }
         }
 
+        public ValueTask SaveOwnUser(ulong userId)
+        {
+            // this (hopefully) never changes at runtime, so we skip out on re-assigning it
+            if (_ownUserId == null)
+                _ownUserId = userId;
+
+            return default;
+        }
+
         public ValueTask SaveUser(User user)
         {
             _users[user.Id] = user;
@@ -125,6 +135,8 @@ namespace Myriad.Cache
             return default;
         }
 
+        public Task<ulong> GetOwnUser() => Task.FromResult(_ownUserId!.Value);
+
         public ValueTask RemoveRole(ulong guildId, ulong roleId)
         {
             _roles.TryRemove(roleId, out _);

Myriad/Gateway/Cluster.cs

@@ -28,8 +28,6 @@ namespace Myriad.Gateway
         public event Action<Shard>? ShardCreated;
 
         public IReadOnlyDictionary<int, Shard> Shards => _shards;
-        public User? User => _shards.Values.Select(s => s.User).FirstOrDefault(s => s != null);
-        public ApplicationPartial? Application => _shards.Values.Select(s => s.Application).FirstOrDefault(s => s != null);
 
         public async Task Start(GatewayInfo.Bot info)
         {

PluralKit.Bot/Bot.cs

@@ -77,19 +77,6 @@ namespace PluralKit.Bot
             }, null, timeTillNextWholeMinute, TimeSpan.FromMinutes(1));
         }
 
-        public async Task<PermissionSet> PermissionsIn(ulong channelId)
-        {
-            var channel = await _cache.GetRootChannel(channelId);
-
-            if (channel.GuildId != null)
-            {
-                var member = await _cache.TryGetSelfMember(channel.GuildId.Value);
-                return await _cache.PermissionsFor(channelId, _cluster.User?.Id ?? default, member);
-            }
-
-            return PermissionSet.Dm;
-        }
-
         private async Task OnEventReceived(Shard shard, IGatewayEvent evt)
         {
             await _cache.TryUpdateSelfMember(shard, evt);
@@ -249,7 +236,7 @@ namespace PluralKit.Bot
                 if (reportChannel == null)
                     return;
 
-                var botPerms = await PermissionsIn(reportChannel.Value);
+                var botPerms = await _cache.PermissionsIn(reportChannel.Value);
                 if (botPerms.HasFlag(PermissionSet.SendMessages | PermissionSet.EmbedLinks))
                     await _errorMessageService.SendErrorMessage(reportChannel.Value, sentryEvent.EventId.ToString());
             }

PluralKit.Bot/CommandSystem/Context.cs

@@ -71,7 +71,7 @@ namespace PluralKit.Bot
         public Cluster Cluster => _cluster;
         public MessageContext MessageContext => _messageContext;
 
-        public Task<PermissionSet> BotPermissions => _provider.Resolve<Bot>().PermissionsIn(_channel.Id);
+        public Task<PermissionSet> BotPermissions => _provider.Resolve<IDiscordCache>().PermissionsIn(_channel.Id);
         public Task<PermissionSet> UserPermissions => _cache.PermissionsFor(_message);
 
         public DiscordApiClient Rest => _rest;

PluralKit.Bot/Commands/Checks.cs

@@ -87,7 +87,7 @@ namespace PluralKit.Bot
             var missingEmojiPermissions = false;
             foreach (var channel in await _rest.GetGuildChannels(guild.Id))
             {
-                var botPermissions = await _bot.PermissionsIn(channel.Id);
+                var botPermissions = await _cache.PermissionsIn(channel.Id);
                 var webhookPermissions = await _cache.EveryonePermissions(channel);
                 var userPermissions = PermissionExtensions.PermissionsFor(guild, channel, ctx.Author.Id, senderGuildUser);
 
@@ -176,7 +176,7 @@ namespace PluralKit.Bot
             if (!await ctx.CheckPermissionsInGuildChannel(channel, PermissionSet.ViewChannel))
                 throw new PKError(error);
 
-            var botPermissions = await _bot.PermissionsIn(channel.Id);
+            var botPermissions = await _cache.PermissionsIn(channel.Id);
             var webhookPermissions = await _cache.EveryonePermissions(channel);
 
             // We use a bitfield so we can set individual permission bits

PluralKit.Bot/Commands/Lists/ContextListExt.cs

@@ -61,7 +61,7 @@ namespace PluralKit.Bot
                 p.IncludeLastSwitch = true;
             if (ctx.MatchFlag("with-last-message", "with-last-proxy", "wlm", "wlp"))
                 throw new PKError("Sorting by last message is temporarily disabled due to database issues, sorry.");
-                // p.IncludeLastMessage = true;
+            // p.IncludeLastMessage = true;
             if (ctx.MatchFlag("with-message-count", "wmc"))
                 p.IncludeMessageCount = true;
             if (ctx.MatchFlag("with-created", "wc"))

PluralKit.Bot/Commands/Misc.cs

@@ -59,7 +59,7 @@ namespace PluralKit.Bot
 
         public async Task Invite(Context ctx)
         {
-            var clientId = _botConfig.ClientId ?? _cluster.Application?.Id;
+            var clientId = _botConfig.ClientId ?? await _cache.GetOwnUser();
 
             var permissions =
                 PermissionSet.AddReactions |

PluralKit.Bot/Commands/ServerConfig.cs

@@ -59,7 +59,7 @@ namespace PluralKit.Bot
             if (channel.Type != Channel.ChannelType.GuildText)
                 throw new PKError("PluralKit cannot log messages to this type of channel.");
 
-            var perms = await _bot.PermissionsIn(channel.Id);
+            var perms = await _cache.PermissionsIn(channel.Id);
             if (!perms.HasFlag(PermissionSet.SendMessages))
                 throw new PKError("PluralKit is missing **Send Messages** permissions in the new log channel.");
             if (!perms.HasFlag(PermissionSet.EmbedLinks))

PluralKit.Bot/Handlers/MessageCreated.cs

@@ -54,7 +54,9 @@ namespace PluralKit.Bot
         // for now, only return error messages for explicit commands
         public ulong? ErrorChannelFor(MessageCreateEvent evt)
         {
-            if (!HasCommandPrefix(evt.Content, _cluster.User?.Id ?? default, out var cmdStart) || cmdStart == evt.Content.Length)
+            // todo: fix @mention prefix
+            // it only breaks error reporting so I'm not *too* worried about it, but should be fixed eventually
+            if (!HasCommandPrefix(evt.Content, default, out var cmdStart) || cmdStart == evt.Content.Length)
                 return null;
 
             return evt.ChannelId;
@@ -156,7 +158,7 @@ namespace PluralKit.Bot
 
         private async ValueTask<bool> TryHandleProxy(Shard shard, MessageCreateEvent evt, Guild guild, Channel channel, MessageContext ctx)
         {
-            var botPermissions = await _bot.PermissionsIn(channel.Id);
+            var botPermissions = await _cache.PermissionsIn(channel.Id);
 
             try
             {

PluralKit.Bot/Handlers/MessageEdited.cs

@@ -45,7 +45,7 @@ namespace PluralKit.Bot
 
         public async Task Handle(Shard shard, MessageUpdateEvent evt)
         {
-            if (evt.Author.Value?.Id == _client.User?.Id) return;
+            if (evt.Author.Value?.Id == await _cache.GetOwnUser()) return;
 
             // Edit message events sometimes arrive with missing data; double-check it's all there
             if (!evt.Content.HasValue || !evt.Author.HasValue || !evt.Member.HasValue)
@@ -67,7 +67,7 @@ namespace PluralKit.Bot
                 ctx = await _repo.GetMessageContext(evt.Author.Value!.Id, channel.GuildId!.Value, evt.ChannelId);
 
             var equivalentEvt = await GetMessageCreateEvent(evt, lastMessage, channel);
-            var botPermissions = await _bot.PermissionsIn(channel.Id);
+            var botPermissions = await _cache.PermissionsIn(channel.Id);
 
             try
             {
@@ -112,7 +112,7 @@ namespace PluralKit.Bot
             if (referencedMessageId == null)
                 return null;
 
-            var botPermissions = await _bot.PermissionsIn(channelId);
+            var botPermissions = await _cache.PermissionsIn(channelId);
             if (!botPermissions.HasFlag(PermissionSet.ReadMessageHistory))
             {
                 _logger.Warning("Tried to get referenced message in channel {ChannelId} to reply but bot does not have Read Message History",

PluralKit.Bot/Handlers/ReactionAdded.cs

@@ -54,7 +54,7 @@ namespace PluralKit.Bot
                 return;
 
             // ignore any reactions added by *us*
-            if (evt.UserId == _cluster.User?.Id)
+            if (evt.UserId == await _cache.GetOwnUser())
                 return;
 
             // Ignore reactions from bots (we can't DM them anyway)
@@ -121,7 +121,7 @@ namespace PluralKit.Bot
 
         private async ValueTask HandleProxyDeleteReaction(MessageReactionAddEvent evt, FullMessage msg)
         {
-            if (!(await _bot.PermissionsIn(evt.ChannelId)).HasFlag(PermissionSet.ManageMessages))
+            if (!(await _cache.PermissionsIn(evt.ChannelId)).HasFlag(PermissionSet.ManageMessages))
                 return;
 
             var system = await _repo.GetSystemByAccount(evt.UserId);
@@ -185,7 +185,7 @@ namespace PluralKit.Bot
 
         private async ValueTask HandlePingReaction(MessageReactionAddEvent evt, FullMessage msg)
         {
-            if (!(await _bot.PermissionsIn(evt.ChannelId)).HasFlag(PermissionSet.ManageMessages))
+            if (!(await _cache.PermissionsIn(evt.ChannelId)).HasFlag(PermissionSet.ManageMessages))
                 return;
 
             // Check if the "pinger" has permission to send messages in this channel
@@ -240,7 +240,7 @@ namespace PluralKit.Bot
 
         private async Task TryRemoveOriginalReaction(MessageReactionAddEvent evt)
         {
-            if ((await _bot.PermissionsIn(evt.ChannelId)).HasFlag(PermissionSet.ManageMessages))
+            if ((await _cache.PermissionsIn(evt.ChannelId)).HasFlag(PermissionSet.ManageMessages))
                 await _rest.DeleteUserReaction(evt.ChannelId, evt.MessageId, evt.Emoji, evt.UserId);
         }
     }

PluralKit.Bot/Services/LogChannelService.cs

@@ -78,7 +78,7 @@ namespace PluralKit.Bot
             if (logChannel == null || logChannel.Type != Channel.ChannelType.GuildText) return null;
 
             // Check bot permissions
-            var perms = await _bot.PermissionsIn(logChannel.Id);
+            var perms = await _cache.PermissionsIn(logChannel.Id);
             if (!perms.HasFlag(PermissionSet.SendMessages | PermissionSet.EmbedLinks))
             {
                 _logger.Information(

PluralKit.Bot/Services/LoggerCleanService.cs

@@ -89,7 +89,7 @@ namespace PluralKit.Bot
             var channel = await _cache.GetChannel(msg.ChannelId);
 
             if (channel.Type != Channel.ChannelType.GuildText) return;
-            if (!(await _bot.PermissionsIn(channel.Id)).HasFlag(PermissionSet.ManageMessages)) return;
+            if (!(await _cache.PermissionsIn(channel.Id)).HasFlag(PermissionSet.ManageMessages)) return;
 
             // If this message is from a *webhook*, check if the name matches one of the bots we know
             // TODO: do we need to do a deeper webhook origin check, or would that be too hard on the rate limit?

PluralKit.Bot/Services/WebhookCacheService.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 using App.Metrics;
 
-using Myriad.Gateway;
+using Myriad.Cache;
 using Myriad.Rest;
 using Myriad.Rest.Types.Requests;
 using Myriad.Types;
@@ -24,13 +24,13 @@ namespace PluralKit.Bot
 
         private readonly IMetrics _metrics;
         private readonly ILogger _logger;
-        private readonly Cluster _cluster;
+        private readonly IDiscordCache _cache;
 
-        public WebhookCacheService(ILogger logger, IMetrics metrics, DiscordApiClient rest, Cluster cluster)
+        public WebhookCacheService(ILogger logger, IMetrics metrics, DiscordApiClient rest, IDiscordCache cache)
         {
             _metrics = metrics;
             _rest = rest;
-            _cluster = cluster;
+            _cache = cache;
             _logger = logger.ForContext<WebhookCacheService>();
             _webhooks = new ConcurrentDictionary<ulong, Lazy<Task<Webhook>>>();
         }
@@ -86,7 +86,8 @@ namespace PluralKit.Bot
             var webhooks = await FetchChannelWebhooks(channelId);
 
             // If the channel has a webhook created by PK, just return that one
-            var ourWebhook = webhooks.FirstOrDefault(IsWebhookMine);
+            var ourUserId = await _cache.GetOwnUser();
+            var ourWebhook = webhooks.FirstOrDefault(hook => IsWebhookMine(ourUserId, hook));
             if (ourWebhook != null)
                 return ourWebhook;
 
@@ -120,7 +121,7 @@ namespace PluralKit.Bot
             return await _rest.CreateWebhook(channelId, new CreateWebhookRequest(WebhookName));
         }
 
-        private bool IsWebhookMine(Webhook arg) => arg.User?.Id == _cluster.User?.Id && arg.Name == WebhookName;
+        private bool IsWebhookMine(ulong userId, Webhook arg) => arg.User?.Id == userId && arg.Name == WebhookName;
 
         public int CacheSize => _webhooks.Count;
     }

PluralKit.Bot/Utils/SerilogGatewayEnricherFactory.cs

@@ -42,7 +42,7 @@ namespace PluralKit.Bot
 
                 if (await _cache.TryGetChannel(channel.Value) != null)
                 {
-                    var botPermissions = await _bot.PermissionsIn(channel.Value);
+                    var botPermissions = await _cache.PermissionsIn(channel.Value);
                     props.Add(new("BotPermissions", new ScalarValue(botPermissions)));
                 }
             }