Merge pull request #1003 from 13xforever/vnext

Some anti-spam enhancements

CompatBot/Commands/Processors/CommandErroredHandler.cs

@@ -42,6 +42,16 @@ internal static partial class CommandErroredHandler
                 {
                     Config.Log.Warn(e, "Failed to remove message with unknown text command");
                 }
+                try
+                {
+                    var dm = await tctx.CreateDmAsync().ConfigureAwait(false);
+                    await dm.SendMessageAsync("""
+                        You have tried to use an outdated bot command, please use Discord Application Command instead.
+                        You can access them through `⊕` > `Use Apps` on desktop, or the gamepad button on mobile.
+                        Alternately you can open the list of App Commands by typing `/` prefix.
+                        """
+                    ).ConfigureAwait(false);
+                } catch {}
             }
             else
             {

CompatBot/Database/Providers/ContentFilter.cs

@@ -260,9 +260,14 @@ internal static class ContentFilter
         {
             try
             {
-                if (await client.GetMemberAsync(message.Channel.Guild, message.Author).ConfigureAwait(false) is DiscordMember mem
+                if (await client.GetMemberAsync(message.Channel?.Guild, message.Author).ConfigureAwait(false) is DiscordMember mem
                     && !mem.Roles.Any())
                 {
+                    try
+                    {
+                        await mem.SendMessageAsync("You have been kicked from the server for posting undesirable content. Please do not post it again.").ConfigureAwait(false);
+                    }
+                    catch {}
                     await mem.RemoveAsync("Filter action for trigger " + trigger.String).ConfigureAwait(false);
                     completedActions.Add(FilterAction.Kick);
                 }

CompatBot/EventHandlers/AntiSpamMessageHandler.cs

@@ -0,0 +1,66 @@
+using CompatBot.Utils.Extensions;
+using Microsoft.Extensions.Caching.Memory;
+
+namespace CompatBot.EventHandlers;
+
+public static class AntiSpamMessageHandler
+{
+    private static readonly MemoryCache MessageCache = new(new MemoryCacheOptions{ ExpirationScanFrequency = TimeSpan.FromMinutes(1) });
+    private static readonly TimeSpan DefaultExpiration = TimeSpan.FromSeconds(10);
+
+    public static async Task<bool> OnMessageCreated(DiscordClient client, MessageCreatedEventArgs args)
+    {
+        var author = args.Author;
+        if (author.IsBotSafeCheck())
+            return true;
+
+#if !DEBUG
+        if (await author.IsSmartlistedAsync(client, args.Guild).ConfigureAwait(false)
+            || await author.IsWhitelistedAsync(client, args.Guild).ConfigureAwait(false))
+            return true;
+#endif
+
+        var msg = args.Message;
+        if (msg.Content is not { Length: > 0 })
+            return true;
+
+        if (MessageCache.TryGetValue(author.Id, out var item)
+            && item is (DiscordMessage { Content.Length: >0 } lastMessage, bool isWarned)
+            && lastMessage.Content == msg.Content
+            && lastMessage.ChannelId != msg.ChannelId)
+        {
+            var removedSpam = false;
+            try
+            {
+                await msg.DeleteAsync("spam").ConfigureAwait(false);
+                Config.Log.Debug($"""
+                    Removed spam message from user {author.Username} ({author.Id}) in #{msg.Channel?.Name}:
+                    {msg.Content.Trim()}
+                    """
+                );
+                removedSpam = true;
+            }
+            catch (Exception e)
+            {
+                Config.Log.Warn(e, $"Faled to delete spam message from user {author.Username} ({author.Id}) in #{msg.Channel?.Name} {msg.JumpLink}");
+            }
+            try
+            {
+                if (!isWarned)
+                {
+                    await author.SendMessageAsync("Please do not spam the same message in multiple channels. Thank you.").ConfigureAwait(false);
+                    isWarned = true;
+                }
+            }
+            catch (Exception e)
+            {
+                Config.Log.Warn(e, $"Faled to send DM to user {author.Username} ({author.Id})");
+            }
+            MessageCache.Set(author.Id, (lastMessage, isWarned), DefaultExpiration);
+            return !removedSpam; // couldn't remove, need to check with filters etc
+        }
+
+        MessageCache.Set(author.Id, (msg, false), DefaultExpiration);
+        return true;
+    }
+}

CompatBot/Program.cs

@@ -236,6 +236,7 @@ internal static class Program
                     ]));
                     config.HandleMessageCreated(new MultiEventHandlerWrapper<MessageCreatedEventArgs>(
                         [
+                            AntiSpamMessageHandler.OnMessageCreated,
                             ContentFilterMonitor.OnMessageCreated, // should be first
                             DiscordInviteFilter.OnMessageCreated,
                         ],