feat: emoji update event

Catalogger.Backend/Bot/Commands/MetaCommands.cs

@@ -46,6 +46,7 @@ public class MetaCommands(
     ContextInjectionService contextInjection,
     GuildCache guildCache,
     ChannelCache channelCache,
+    EmojiCache emojiCache,
     IDiscordRestChannelAPI channelApi
 ) : CommandGroup
 {
@@ -107,7 +108,7 @@ public class MetaCommands(
         embed.AddField(
             "Numbers",
             $"{CataloggerMetrics.MessagesStored.Value:N0} messages "
-                + $"from {guildCache.Size:N0} servers\nCached {channelCache.Size:N0} channels",
+                + $"from {guildCache.Size:N0} servers\nCached {channelCache.Size:N0} channels, {emojiCache.Size:N0}",
             false
         );
 

Catalogger.Backend/Bot/Responders/Guilds/GuildCreateResponder.cs

@@ -16,13 +16,13 @@
 using Catalogger.Backend.Cache;
 using Catalogger.Backend.Cache.InMemoryCache;
 using Catalogger.Backend.Database;
-using Catalogger.Backend.Database.Models;
 using Catalogger.Backend.Extensions;
 using Catalogger.Backend.Services;
 using Remora.Discord.API.Abstractions.Gateway.Events;
 using Remora.Discord.Extensions.Embeds;
 using Remora.Discord.Gateway.Responders;
 using Remora.Results;
+using Guild = Catalogger.Backend.Database.Models.Guild;
 
 namespace Catalogger.Backend.Bot.Responders.Guilds;
 
@@ -33,6 +33,7 @@ public class GuildCreateResponder(
     GuildCache guildCache,
     RoleCache roleCache,
     ChannelCache channelCache,
+    EmojiCache emojiCache,
     WebhookExecutorService webhookExecutor,
     IMemberCache memberCache,
     GuildFetchService guildFetchService
@@ -55,6 +56,7 @@ public class GuildCreateResponder(
             guildName = guild.Name;
 
             guildCache.Set(guild);
+            emojiCache.Set(guild.ID, guild.Emojis);
             foreach (var c in guild.Channels)
                 channelCache.Set(c, guild.ID);
             foreach (var r in guild.Roles)

Catalogger.Backend/Bot/Responders/Guilds/GuildEmojisUpdateResponder.cs

@@ -0,0 +1,128 @@
+// Copyright (C) 2021-present sam (starshines.gay)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+using Catalogger.Backend.Cache.InMemoryCache;
+using Catalogger.Backend.Database;
+using Catalogger.Backend.Database.Queries;
+using Catalogger.Backend.Extensions;
+using Catalogger.Backend.Services;
+using Remora.Discord.API;
+using Remora.Discord.API.Abstractions.Gateway.Events;
+using Remora.Discord.API.Abstractions.Objects;
+using Remora.Discord.Extensions.Embeds;
+using Remora.Discord.Gateway.Responders;
+using Remora.Results;
+
+namespace Catalogger.Backend.Bot.Responders.Guilds;
+
+public class GuildEmojisUpdateResponder(
+    ILogger logger,
+    DatabaseContext db,
+    EmojiCache emojiCache,
+    WebhookExecutorService webhookExecutor
+) : IResponder<IGuildEmojisUpdate>
+{
+    private readonly ILogger _logger = logger.ForContext<GuildEmojisUpdateResponder>();
+
+    public async Task<Result> RespondAsync(IGuildEmojisUpdate evt, CancellationToken ct = default)
+    {
+        try
+        {
+            if (!emojiCache.TryGet(evt.GuildID, out var oldEmoji))
+            {
+                _logger.Information(
+                    "Previous emoji for {GuildId} were not in cache, ignoring event",
+                    evt.GuildID
+                );
+                return Result.Success;
+            }
+
+            IEmbed embed;
+
+            // As far as I know, only one emoji can be added or removed at once.
+            var added = evt.Emojis.FirstOrDefault(e => oldEmoji.All(o => o.ID != e.ID));
+            var removed = oldEmoji.FirstOrDefault(o => evt.Emojis.All(e => o.ID != e.ID));
+            var updated = evt.Emojis.FirstOrDefault(e =>
+                oldEmoji.Any(o => o.ID == e.ID && o.Name != e.Name)
+            );
+            if (added != null)
+            {
+                var url = CDN.GetEmojiUrl(added).GetOrThrow().ToString();
+                embed = new EmbedBuilder()
+                    .WithTitle("Emoji created")
+                    .WithDescription($"{FormatEmoji(added)} [{added.Name}]({url})")
+                    .WithThumbnailUrl(url)
+                    .WithFooter($"ID: {added.ID}")
+                    .WithColour(DiscordUtils.Green)
+                    .WithCurrentTimestamp()
+                    .Build()
+                    .GetOrThrow();
+            }
+            else if (removed != null)
+            {
+                var url = CDN.GetEmojiUrl(removed).GetOrThrow().ToString();
+                embed = new EmbedBuilder()
+                    .WithTitle("Emoji removed")
+                    .WithDescription($"[{removed.Name}]({url})")
+                    .WithThumbnailUrl(url)
+                    .WithFooter($"ID: {removed.ID}")
+                    .WithColour(DiscordUtils.Red)
+                    .WithCurrentTimestamp()
+                    .Build()
+                    .GetOrThrow();
+            }
+            else if (updated != null)
+            {
+                var url = CDN.GetEmojiUrl(updated).GetOrThrow().ToString();
+                var previous = oldEmoji.First(o => o.ID == updated.ID);
+                embed = new EmbedBuilder()
+                    .WithTitle("Emoji renamed")
+                    .WithDescription(
+                        $"""
+                        {FormatEmoji(updated)} [{updated.Name}]({url})
+                        {previous.Name} → {updated.Name}
+                        """
+                    )
+                    .WithThumbnailUrl(url)
+                    .WithFooter($"ID: {updated.ID}")
+                    .WithColour(DiscordUtils.Green)
+                    .WithCurrentTimestamp()
+                    .Build()
+                    .GetOrThrow();
+            }
+            else
+            {
+                _logger.Warning(
+                    "Received emoji update event for {GuildId} but all emoji were identical, not logging",
+                    evt.GuildID
+                );
+                return Result.Success;
+            }
+
+            var guildConfig = await db.GetGuildAsync(evt.GuildID, ct);
+            webhookExecutor.QueueLog(guildConfig, LogChannelType.GuildEmojisUpdate, embed);
+            return Result.Success;
+        }
+        finally
+        {
+            emojiCache.Set(evt.GuildID, evt.Emojis);
+        }
+    }
+
+    private static string FormatEmoji(IEmoji emoji) =>
+        emoji.IsAnimated.OrDefault(false)
+            ? $"<a:{emoji.Name}:{emoji.ID}>"
+            : $"<:{emoji.Name}:{emoji.ID}>";
+}

Catalogger.Backend/Cache/InMemoryCache/EmojiCache.cs

@@ -0,0 +1,33 @@
+// Copyright (C) 2021-present sam (starshines.gay)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+using System.Collections.Concurrent;
+using System.Diagnostics.CodeAnalysis;
+using Remora.Discord.API.Abstractions.Objects;
+using Remora.Rest.Core;
+
+namespace Catalogger.Backend.Cache.InMemoryCache;
+
+public class EmojiCache
+{
+    private readonly ConcurrentDictionary<Snowflake, IReadOnlyList<IEmoji>> _emojis = new();
+
+    public void Set(Snowflake guildId, IReadOnlyList<IEmoji> emoji) => _emojis[guildId] = emoji;
+
+    public bool TryGet(Snowflake guildId, [NotNullWhen(true)] out IReadOnlyList<IEmoji>? emoji) =>
+        _emojis.TryGetValue(guildId, out emoji);
+
+    public int Size => _emojis.Select(kv => kv.Value.Count).Sum();
+}

Catalogger.Backend/CataloggerMetrics.cs

@@ -44,6 +44,11 @@ public static class CataloggerMetrics
         "Number of users in the cache"
     );
 
+    public static readonly Gauge EmojiCached = Metrics.CreateGauge(
+        "catalogger_cache_emoji",
+        "Number of custom emoji in the cache"
+    );
+
     public static readonly Gauge MessagesStored = Metrics.CreateGauge(
         "catalogger_stored_messages",
         "Number of users in the cache"

Catalogger.Backend/Extensions/StartupExtensions.cs

@@ -105,6 +105,7 @@ public static class StartupExtensions
             .AddSingleton<ChannelCache>()
             .AddSingleton<UserCache>()
             .AddSingleton<AuditLogCache>()
+            .AddSingleton<EmojiCache>()
             .AddSingleton<PluralkitApiService>()
             .AddScoped<IEncryptionService, EncryptionService>()
             .AddSingleton<MetricsCollectionService>()

Catalogger.Backend/Services/MetricsCollectionService.cs

@@ -27,6 +27,7 @@ public class MetricsCollectionService(
     GuildCache guildCache,
     ChannelCache channelCache,
     UserCache userCache,
+    EmojiCache emojiCache,
     IServiceProvider services
 )
 {
@@ -44,6 +45,7 @@ public class MetricsCollectionService(
         CataloggerMetrics.GuildsCached.Set(guildCache.Size);
         CataloggerMetrics.ChannelsCached.Set(channelCache.Size);
         CataloggerMetrics.UsersCached.Set(userCache.Size);
+        CataloggerMetrics.EmojiCached.Set(emojiCache.Size);
         CataloggerMetrics.MessagesStored.Set(messageCount);
         CataloggerMetrics.MessageRateMinute = messageCount - CataloggerMetrics.MessageRateMinute;