start channel update responder

Catalogger.Backend/Bot/Responders/Channels/ChannelUpdateResponder.cs

@@ -0,0 +1,120 @@
+using System.Diagnostics;
+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.Abstractions.Gateway.Events;
+using Remora.Discord.API.Abstractions.Objects;
+using Remora.Discord.Extensions.Embeds;
+using Remora.Discord.Gateway.Responders;
+using Remora.Rest.Core;
+using Remora.Results;
+
+namespace Catalogger.Backend.Bot.Responders.Channels;
+
+public class ChannelUpdateResponder(
+    ILogger logger,
+    DatabaseContext db,
+    ChannelCache channelCache,
+    RoleCache roleCache,
+    UserCache userCache,
+    WebhookExecutorService webhookExecutor)
+    : IResponder<IChannelUpdate>
+{
+    private readonly ILogger _logger = logger.ForContext<ChannelUpdateResponder>();
+
+    public async Task<Result> RespondAsync(IChannelUpdate evt, CancellationToken ct = default)
+    {
+        try
+        {
+            if (!channelCache.TryGet(evt.ID, out var oldChannel))
+            {
+                _logger.Debug("Updated channel {ChannelId} wasn't in the cache", evt.ID);
+                return Result.Success;
+            }
+
+            var guildConfig = await db.GetGuildAsync(evt.GuildID.Value, ct);
+
+            var builder = new EmbedBuilder()
+                .WithTitle(evt.Type switch
+                {
+                    ChannelType.GuildVoice => "Voice channel created",
+                    ChannelType.GuildCategory => "Category channel created",
+                    ChannelType.GuildAnnouncement or ChannelType.GuildText => "Text channel created",
+                    _ => "Channel created"
+                })
+                .WithColour(DiscordUtils.Blue)
+                .WithFooter($"ID: {evt.ID} | Name: {evt.Name}")
+                .WithCurrentTimestamp();
+
+            if (oldChannel.ParentID != evt.ParentID)
+                builder.AddField("Category",
+                    CategoryUpdate(oldChannel.ParentID.OrDefault(), evt.ParentID.OrDefault()));
+
+            if (oldChannel.Name != evt.Name)
+                builder.AddField("Name", $"**Before:** {oldChannel.Name}\n**After:** {evt.Name}");
+
+            if (oldChannel.Topic != evt.Topic)
+            {
+                var oldTopic = oldChannel.Topic.OrDefault() ?? "(none)";
+                var newTopic = evt.Topic.OrDefault() ?? "(none)";
+
+                var topicField = $"**Before:** {oldTopic}\n\n**After:** {newTopic}";
+                if (topicField.Length > 1000) topicField = topicField[..1000] + "…";
+
+                builder.AddField("Description", topicField);
+            }
+
+            var oldOverrides = oldChannel.PermissionOverwrites.OrDefault() ?? [];
+            var newOverrides = evt.PermissionOverwrites.OrDefault() ?? [];
+
+            var addedOverrides = newOverrides.Where(o => oldOverrides.All(o2 => o.ID != o2.ID));
+            var removedOverrides = oldOverrides.Where(o => newOverrides.All(o2 => o.ID != o2.ID)).ToList();
+            // Overrides filtered to ones that exist in both lists, but have different allow or deny values
+            var editedOverrides = newOverrides.Where(o => oldOverrides.Any(o2 =>
+                o.ID == o2.ID && (o.Allow.Value != o2.Allow.Value || o.Deny.Value != o2.Deny.Value)));
+
+            if (removedOverrides.Count != 0)
+            {
+                var removedOverrideNames = new List<string>();
+                foreach (var o in removedOverrides)
+                {
+                    if (o.Type is PermissionOverwriteType.Member)
+                    {
+                        var user = await userCache.GetUserAsync(o.ID);
+                        removedOverrideNames.Add(user != null ? $"<@{user.ID}>" : $"user {o.ID}");
+                    }
+                    else
+                    {
+                        removedOverrideNames.Add(roleCache.TryGet(o.ID, out var role) ? role.Name : $"role {o.ID}");
+                        break;
+                    }
+                }
+
+                builder.AddField("Removed overrides", string.Join(", ", removedOverrideNames));
+            }
+            
+            
+
+            await webhookExecutor.QueueLogAsync(guildConfig, LogChannelType.ChannelUpdate,
+                builder.Build().GetOrThrow());
+        }
+        finally
+        {
+            channelCache.Set(evt);
+        }
+
+        throw new NotImplementedException();
+    }
+
+    private string CategoryUpdate(Snowflake? oldCategory, Snowflake? newCategory)
+    {
+        var value = "";
+        if (oldCategory != null && channelCache.TryGet(oldCategory.Value, out var oldChannel))
+            value += $"**Before:** {oldChannel.Name}";
+        if (newCategory != null && channelCache.TryGet(newCategory.Value, out var newChannel))
+            value += $"\n**After:** {newChannel.Name}";
+        return value.Trim();
+    }
+}