button correctly dis- and enables iff instructor logs in

src/main/java/edu/kit/kastel/sdq/intelligrade/extensions/guis/ExercisePanel.java

@@ -62,6 +62,7 @@ public class ExercisePanel extends SimpleToolWindowPanel {
     private JPanel generalPanel;
     private JButton startGradingRound1Button;
     private JButton startGradingRound2Button;
+    private JButton startGradingRound3Button;
     private TextFieldWithBrowseButton gradingConfigPathInput;
 
     private JPanel statisticsPanel;
@@ -142,10 +143,21 @@ private void createGeneralPanel() {
                 a -> PluginState.getInstance().startNextAssessment(1));
         generalPanel.add(startGradingRound2Button, "growx");
 
-        //only add the third grading round button iff the permissions are sufficient
-        PluginState.getInstance().registerConnectedListener(connectionOptional -> {
-            connectionOptional.flatMap(PermissionUtils::getAssessorPermissionLevel).ifPresent(System.out::println);
-        });
+        //add button for third correction round but disable it by default
+        startGradingRound3Button = new JButton("Start Grading Round 3");
+        startGradingRound3Button.setForeground(JBColor.GREEN);
+        startGradingRound3Button.addActionListener(
+                a -> PluginState.getInstance().startNextAssessment(3));
+        startGradingRound3Button.setEnabled(false);
+        generalPanel.add(startGradingRound3Button, "growx");
+
+        //only enable the third grading round button iff the permissions are sufficient
+        PluginState.getInstance().registerConnectedListener(connectionOptional -> connectionOptional.ifPresent(connection -> {
+            List<PermissionUtils.PermissionLevel> perms = PermissionUtils.getAssessorPermissionLevel(connection);
+            if (perms.contains(PermissionUtils.PermissionLevel.INSTRUCTOR)) {
+                startGradingRound3Button.setEnabled(true);
+            }
+        }));
 
         gradingConfigPathInput = new TextFieldWithBrowseButton();
         gradingConfigPathInput.addBrowseFolderListener(

src/main/java/edu/kit/kastel/sdq/intelligrade/utils/PermissionUtils.java

@@ -2,7 +2,6 @@
 
 import edu.kit.kastel.sdq.artemis4j.ArtemisNetworkException;
 import edu.kit.kastel.sdq.artemis4j.grading.ArtemisConnection;
-import edu.kit.kastel.sdq.intelligrade.state.PluginState;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -54,14 +53,14 @@ public static List<PermissionLevel> getAssessorPermissionLevel(ArtemisConnection
             permissionLevels.add(PermissionLevel.NONE);
         }
 
-        return permissionLevels;
+        return permissionLevels.stream().distinct().toList();
     }
 
     /**
      * Map the string based permission level from the groups
      * to some cleanly switchable enum
      */
-    public enum PermissionLevel implements Comparable<PermissionLevel> {
+    public enum PermissionLevel {
         INSTRUCTOR,
         TUTOR,
         STUDENT,