Ignore "scam" send by trusted users (#1282)

* Ignore "scam" send by trusted users
* added extra "trustedUserRolePattern" config entry

Author: Zabuzard

application/config.json.template

@@ -22,6 +22,7 @@
         "mode": "AUTO_DELETE_BUT_APPROVE_QUARANTINE",
         "reportChannelPattern": "commands",
         "botTrapChannelPattern": "bot-trap",
+        "trustedUserRolePattern": "Top Helpers .+|Moderator|Community Ambassador|Expert",
         "suspiciousKeywords": [
             "nitro",
             "boob",

application/src/main/java/org/togetherjava/tjbot/config/ScamBlockerConfig.java

@@ -18,6 +18,7 @@ public final class ScamBlockerConfig {
     private final Mode mode;
     private final String reportChannelPattern;
     private final String botTrapChannelPattern;
+    private final String trustedUserRolePattern;
     private final Set<String> suspiciousKeywords;
     private final Set<String> hostWhitelist;
     private final Set<String> hostBlacklist;
@@ -32,6 +33,8 @@ private ScamBlockerConfig(@JsonProperty(value = "mode", required = true) Mode mo
                     required = true) String reportChannelPattern,
             @JsonProperty(value = "botTrapChannelPattern",
                     required = true) String botTrapChannelPattern,
+            @JsonProperty(value = "trustedUserRolePattern",
+                    required = true) String trustedUserRolePattern,
             @JsonProperty(value = "suspiciousKeywords",
                     required = true) Set<String> suspiciousKeywords,
             @JsonProperty(value = "hostWhitelist", required = true) Set<String> hostWhitelist,
@@ -47,6 +50,7 @@ private ScamBlockerConfig(@JsonProperty(value = "mode", required = true) Mode mo
         this.mode = Objects.requireNonNull(mode);
         this.reportChannelPattern = Objects.requireNonNull(reportChannelPattern);
         this.botTrapChannelPattern = Objects.requireNonNull(botTrapChannelPattern);
+        this.trustedUserRolePattern = Objects.requireNonNull(trustedUserRolePattern);
         this.suspiciousKeywords = new HashSet<>(Objects.requireNonNull(suspiciousKeywords));
         this.hostWhitelist = new HashSet<>(Objects.requireNonNull(hostWhitelist));
         this.hostBlacklist = new HashSet<>(Objects.requireNonNull(hostBlacklist));
@@ -86,6 +90,15 @@ public String getBotTrapChannelPattern() {
         return botTrapChannelPattern;
     }
 
+    /**
+     * Gets the REGEX pattern used to identify roles that will be ignored for scam detection.
+     *
+     * @return the REGEX pattern
+     */
+    public String getTrustedUserRolePattern() {
+        return trustedUserRolePattern;
+    }
+
     /**
      * Gets the set of keywords that are considered suspicious if they appear in a message.
      *

application/src/main/java/org/togetherjava/tjbot/features/moderation/scam/ScamDetector.java

@@ -1,6 +1,8 @@
 package org.togetherjava.tjbot.features.moderation.scam;
 
+import net.dv8tion.jda.api.entities.Member;
 import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.Role;
 
 import org.togetherjava.tjbot.config.Config;
 import org.togetherjava.tjbot.config.ScamBlockerConfig;
@@ -25,6 +27,7 @@ public final class ScamDetector {
     private static final Pattern TOKENIZER = Pattern.compile("[\\s,]");
     private final ScamBlockerConfig config;
     private final Predicate<String> isSuspiciousAttachmentName;
+    private final Predicate<String> hasTrustedRole;
 
     /**
      * Creates a new instance with the given configuration
@@ -33,9 +36,12 @@ public final class ScamDetector {
      */
     public ScamDetector(Config config) {
         this.config = config.getScamBlocker();
+
         isSuspiciousAttachmentName =
-                Pattern.compile(config.getScamBlocker().getSuspiciousAttachmentNamePattern())
+                Pattern.compile(this.config.getSuspiciousAttachmentNamePattern())
                     .asMatchPredicate();
+        hasTrustedRole =
+                Pattern.compile(this.config.getTrustedUserRolePattern()).asMatchPredicate();
     }
 
     /**
@@ -45,6 +51,13 @@ public ScamDetector(Config config) {
      * @return Whether the message classifies as scam
      */
     public boolean isScam(Message message) {
+        Member author = message.getMember();
+        boolean isTrustedUser = author != null
+                && author.getRoles().stream().map(Role::getName).noneMatch(hasTrustedRole);
+        if (isTrustedUser) {
+            return false;
+        }
+
         String content = message.getContentDisplay();
         List<Message.Attachment> attachments = message.getAttachments();
 

application/src/test/java/org/togetherjava/tjbot/features/moderation/scam/ScamDetectorTest.java

@@ -1,6 +1,8 @@
 package org.togetherjava.tjbot.features.moderation.scam;
 
+import net.dv8tion.jda.api.entities.Member;
 import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.Role;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -50,6 +52,8 @@ void setUp() {
         when(scamConfig.getSuspiciousAttachmentNamePattern())
             .thenReturn(SUSPICIOUS_ATTACHMENT_NAME);
 
+        when(scamConfig.getTrustedUserRolePattern()).thenReturn("Moderator");
+
         scamDetector = new ScamDetector(config);
     }
 
@@ -205,6 +209,23 @@ void ignoresHarmlessAttachments() {
         assertFalse(isScamResult);
     }
 
+    @Test
+    @DisplayName("Suspicious messages send by trusted users are not flagged")
+    void ignoreTrustedUser() {
+        // GIVEN a scam message send by a trusted user
+        String content = "Checkout https://bit.ly/3IhcLiO to get your free nitro !";
+        Member trustedUser = createAuthorMock(List.of("Moderator"));
+        Message message = createMessageMock(content, List.of());
+
+        when(message.getMember()).thenReturn(trustedUser);
+
+        // WHEN analyzing it
+        boolean isScamResult = scamDetector.isScam(message);
+
+        // THEN flags it as harmless
+        assertTrue(isScamResult);
+    }
+
     private static Message createMessageMock(String content, List<Message.Attachment> attachments) {
         Message message = mock(Message.class);
         when(message.getContentRaw()).thenReturn(content);
@@ -220,6 +241,19 @@ private static Message.Attachment createImageAttachmentMock(String name) {
         return attachment;
     }
 
+    private static Member createAuthorMock(List<String> roleNames) {
+        List<Role> roles = new ArrayList<>();
+        for (String roleName : roleNames) {
+            Role role = mock(Role.class);
+            when(role.getName()).thenReturn(roleName);
+            roles.add(role);
+        }
+
+        Member member = mock(Member.class);
+        when(member.getRoles()).thenReturn(roles);
+        return member;
+    }
+
     private static List<String> provideRealScamMessages() {
         return List.of("""
                 🤩bro steam gived nitro - https://nitro-ds.online/LfgUfMzqYyx12""",