Refine distractor selection logic in VocabLessonView to enhance vocabulary options

- Updated the logic for generating distractors by collecting unique vocabulary entries from both learning and reference directions, ensuring no duplicates are included.
- Increased the maximum attempts for finding distractors and adjusted fallback mechanisms to ensure a minimum of two options are provided, improving the overall user experience.

frontend/src/views/social/VocabLessonView.vue

@@ -1046,16 +1046,36 @@ export default {
         normalizedExcludeSet.add(this.normalizeVocab(excludePrompt));
       }
       
-      // Füge 3 Distraktoren hinzu
-      let attempts = 0;
-      const maxAttempts = 100; // Erhöht, da wir mehr Filter haben
+      // Sammle alle verfügbaren Distraktoren aus beiden Richtungen
+      const allDistractors = [];
+      allVocabs.forEach(vocab => {
+        // Füge beide Richtungen hinzu (learning und reference)
+        if (vocab.learning && vocab.learning.trim()) {
+          const normalized = this.normalizeVocab(vocab.learning);
+          if (!normalizedExcludeSet.has(normalized)) {
+            allDistractors.push(vocab.learning);
+          }
+        }
+        if (vocab.reference && vocab.reference.trim()) {
+          const normalized = this.normalizeVocab(vocab.reference);
+          if (!normalizedExcludeSet.has(normalized)) {
+            allDistractors.push(vocab.reference);
+          }
+        }
+      });
       
-      while (options.size < 4 && allVocabs.length > 1 && attempts < maxAttempts) {
+      // Entferne Duplikate
+      const uniqueDistractors = [...new Set(allDistractors)];
+      
+      // Füge Distraktoren hinzu, bis wir 4 Optionen haben
+      let attempts = 0;
+      const maxAttempts = 200;
+      
+      while (options.size < 4 && uniqueDistractors.length > 0 && attempts < maxAttempts) {
         attempts++;
-        const randomVocab = allVocabs[Math.floor(Math.random() * allVocabs.length)];
-        const distractor = this.vocabTrainerDirection === 'L2R' ? randomVocab.reference : randomVocab.learning;
+        const randomIndex = Math.floor(Math.random() * uniqueDistractors.length);
+        const distractor = uniqueDistractors[randomIndex];
         
-        // Prüfe: Distraktor darf nicht gleich correctAnswer oder excludePrompt sein (mit Normalisierung)
         if (distractor && distractor.trim()) {
           const normalizedDistractor = this.normalizeVocab(distractor);
           if (!normalizedExcludeSet.has(normalizedDistractor) && !options.has(distractor)) {
@@ -1064,17 +1084,25 @@ export default {
         }
       }
       
-      // Falls nicht genug Optionen gefunden wurden, füge generische Optionen hinzu
-      if (options.size < 4) {
-        const genericOptions = ['Option A', 'Option B', 'Option C', 'Option D'];
-        let index = 0;
-        while (options.size < 4 && index < genericOptions.length) {
-          const option = genericOptions[index];
-          if (!normalizedExcludeSet.has(this.normalizeVocab(option)) && !options.has(option)) {
-            options.add(option);
+      // Falls immer noch nicht genug Optionen: Verwende auch die andere Richtung der aktuellen Vokabeln
+      if (options.size < 4 && allVocabs.length > 0) {
+        allVocabs.forEach(vocab => {
+          if (options.size >= 4) return;
+          
+          // Verwende die andere Richtung als Distraktor
+          const otherDirection = this.vocabTrainerDirection === 'L2R' ? vocab.learning : vocab.reference;
+          if (otherDirection && otherDirection.trim()) {
+            const normalized = this.normalizeVocab(otherDirection);
+            if (!normalizedExcludeSet.has(normalized) && !options.has(otherDirection)) {
+              options.add(otherDirection);
+            }
           }
-          index++;
-        }
+        });
+      }
+      
+      // Falls immer noch nicht genug Optionen: Verwende weniger Optionen (mindestens 2)
+      if (options.size < 2) {
+        console.warn('[buildChoiceOptions] Nicht genug Optionen gefunden, verwende nur', options.size, 'Optionen');
       }
       
       // Shuffle