Fix mass mention filter for AutoMod-blocked messages

Author: FloatingMilkshake

Constants/RegexConstants.cs

@@ -9,6 +9,7 @@ public class RegexConstants
         readonly public static Regex bold_rx = new("\\*\\*(.*?)\\*\\*");
         readonly public static Regex discord_link_rx = new(@".*discord(?:app)?.com\/channels\/((?:@)?[a-z0-9]*)\/([0-9]*)(?:\/)?([0-9]*)");
         readonly public static Regex channel_rx = new("<#([0-9]+)>");
+        readonly public static Regex user_rx = new("<@([0-9]+)>");
         readonly public static Regex warn_msg_rx = new($"{Program.cfgjson.Emoji.Warning} <@!?[0-9]+> was warned");
         readonly public static Regex auto_warn_msg_rx = new($"{Program.cfgjson.Emoji.Denied} <@!?[0-9]+> was automatically warned");
         readonly public static Regex mute_msg_rx = new($"{Program.cfgjson.Emoji.Muted} <@!?[0-9]+> has been muted");

Events/AutoModEvents.cs

@@ -16,7 +16,17 @@ public static async Task AutoModerationRuleExecuted(DiscordClient client, AutoMo
                 var channel = await client.GetChannelAsync(e.Rule.ChannelId!.Value);
 
                 // Create a "mock" message object to pass to the message handler, since we don't have the actual message object
-                var message = new MockDiscordMessage(author: author, channel: channel, channelId: channel.Id, content: e.Rule.Content);
+                var mentionedUsers = new List<ulong>();
+                if (e.Rule.Content is not null)
+                {
+                    foreach (var match in Constants.RegexConstants.user_rx.Matches(e.Rule.Content))
+                    {
+                        var id = Convert.ToUInt64(((Match)match).Groups[1].ToString());
+                        if (!mentionedUsers.Contains(id))
+                            mentionedUsers.Add(id);
+                    }
+                }
+                var message = new MockDiscordMessage(author: author, channel: channel, channelId: channel.Id, content: e.Rule.Content, mentionedUsersCount: mentionedUsers.Count);
 
                 // Pass to the message handler
                 await MessageEvent.MessageHandlerAsync(client, message, channel, false, true, true);

Events/MessageEvent.cs

@@ -285,7 +285,7 @@ public static async Task MessageHandlerAsync(DiscordClient client, MockDiscordMe
                         }
                     }
 
-                    if (message.MentionedUsers is not null && message.MentionedUsers.Count > Program.cfgjson.MassMentionBanThreshold)
+                    if ((message.MentionedUsers is not null && message.MentionedUsers.Count > Program.cfgjson.MassMentionBanThreshold) || (message.MentionedUsersCount > Program.cfgjson.MassMentionBanThreshold))
                     {
                         if (wasAutoModBlock)
                         {
@@ -298,7 +298,8 @@ public static async Task MessageHandlerAsync(DiscordClient client, MockDiscordMe
                         }
 
                         _ = channel.Guild.BanMemberAsync(message.Author, TimeSpan.FromDays(7), $"Mentioned more than {Program.cfgjson.MassMentionBanThreshold} users in one message.");
-                        string content = $"{Program.cfgjson.Emoji.Banned} {message.Author.Mention} was automatically banned for mentioning **{message.MentionedUsers.Count}** users.";
+                        var mentionCount = message.MentionedUsers is not null && message.MentionedUsers.Count > 0 ? message.MentionedUsers.Count : message.MentionedUsersCount;
+                        string content = $"{Program.cfgjson.Emoji.Banned} {message.Author.Mention} was automatically banned for mentioning **{mentionCount}** users.";
                         var chatMsg = await channel.SendMessageAsync(content);
                         _ = InvestigationsHelpers.SendInfringingMessaageAsync("investigations", message, "Mass mentions (Ban threshold)", DiscordHelpers.MessageLink(chatMsg), content: content, wasAutoModBlock: wasAutoModBlock);
                         _ = InvestigationsHelpers.SendInfringingMessaageAsync("mod", message, "Mass mentions (Ban threshold)", DiscordHelpers.MessageLink(chatMsg), content: content, wasAutoModBlock: wasAutoModBlock);
@@ -666,7 +667,7 @@ public static async Task MessageHandlerAsync(DiscordClient client, MockDiscordMe
                     }
 
                     // Mass mentions
-                    if (message.MentionedUsers is not null && message.MentionedUsers.Count >= Program.cfgjson.MassMentionThreshold && (await GetPermLevelAsync(member)) < ServerPermLevel.Tier3)
+                    if (((message.MentionedUsers is not null && message.MentionedUsers.Count >= Program.cfgjson.MassMentionThreshold) || (message.MentionedUsersCount >= Program.cfgjson.MassMentionThreshold)) && (await GetPermLevelAsync(member)) < ServerPermLevel.Tier3)
                     {
                         if (wasAutoModBlock)
                         {

Events/MockDiscordMessage.cs

@@ -19,13 +19,14 @@ public MockDiscordMessage(DiscordMessage baseMessage)
             Id = baseMessage.Id;
             JumpLink = baseMessage.JumpLink;
             MentionedUsers = baseMessage.MentionedUsers;
+            MentionedUsersCount = baseMessage.MentionedUsers.Count;
             Reactions = baseMessage.Reactions;
             ReferencedMessage = baseMessage.ReferencedMessage;
             Stickers = baseMessage.Stickers;
             Timestamp = baseMessage.Timestamp;
         }
 
-        public MockDiscordMessage(IReadOnlyList<DiscordAttachment> attachments = default, DiscordUser author = default, DiscordChannel channel = default, ulong channelId = default, string content = default, IReadOnlyList<DiscordEmbed> embeds = default, ulong id = default, Uri jumpLink = default, IReadOnlyList<DiscordUser> mentionedUsers = default, IReadOnlyList<DiscordReaction> reactions = default, DiscordMessage referencedMessage = default, IReadOnlyList<DiscordMessageSticker> stickers = default, DateTimeOffset? timestamp = default)
+        public MockDiscordMessage(IReadOnlyList<DiscordAttachment> attachments = default, DiscordUser author = default, DiscordChannel channel = default, ulong channelId = default, string content = default, IReadOnlyList<DiscordEmbed> embeds = default, ulong id = default, Uri jumpLink = default, IReadOnlyList<DiscordUser> mentionedUsers = default, int mentionedUsersCount = default, IReadOnlyList<DiscordReaction> reactions = default, DiscordMessage referencedMessage = default, IReadOnlyList<DiscordMessageSticker> stickers = default, DateTimeOffset? timestamp = default)
         {
             Attachments = attachments;
             Author = author;
@@ -36,6 +37,7 @@ public MockDiscordMessage(IReadOnlyList<DiscordAttachment> attachments = default
             Id = id;
             JumpLink = jumpLink;
             MentionedUsers = mentionedUsers;
+            MentionedUsersCount = mentionedUsersCount;
             Reactions = reactions;
             ReferencedMessage = referencedMessage;
             Stickers = stickers;
@@ -52,6 +54,7 @@ public MockDiscordMessage(IReadOnlyList<DiscordAttachment> attachments = default
         public ulong Id { get; }
         public Uri JumpLink { get; set; }
         public IReadOnlyList<DiscordUser> MentionedUsers { get; }
+        public int MentionedUsersCount { get; }
         public IReadOnlyList<DiscordReaction> Reactions { get; set; }
         public DiscordMessage ReferencedMessage { get; set; }
         public IReadOnlyList<DiscordMessageSticker> Stickers { get; set; }