feat: implement quiz generation service with topic selection, LLM integration, and question bank management

src/lib/__tests__/testService.test.js

@@ -24,8 +24,7 @@ vi.mock('../llm', () => ({
   cachedSystem: (text) => [{ type: 'text', text }],
 }));
 vi.mock('../curriculumService', () => ({
-  getCurriculumTopic: vi.fn(async () => ({ topic: null })),
+  getCurrentWeekContent: vi.fn(async () => null),
-  getQuarterForWeek: vi.fn(() => 1),
 }));
 
 import { forceGenerateTopicQuestions } from '../testService';
@@ -67,17 +66,6 @@ describe('forceGenerateTopicQuestions', () => {
     expect(bankStore.get('onboarding')).toHaveLength(5);
   });
 
-  it('re-rolls when one correctIndex dominates the batch, then accepts on the third try', async () => {
-    const allZero = [0, 1, 2, 3, 4].map((i) => makeQuestion(i, { correctIndex: 0 }));
-    llmEmits(allZero);
-    llmEmits(allZero);
-    llmEmits(allZero);
-    const out = await forceGenerateTopicQuestions(topic, 5);
-    expect(callLLMMock).toHaveBeenCalledTimes(3);
-    expect(out).toHaveLength(5);
-    expect(warnSpy).toHaveBeenCalledWith(expect.stringContaining('correctIndex dominated'));
-  });
-
   it('rejects a batch containing a banned "all of the above" option', async () => {
     const bad = [0, 1, 2, 3, 4].map((i) =>
       makeQuestion(i, { options: ['A) x', 'B) y', 'C) z', 'D) All of the above'] }),
@@ -85,7 +73,7 @@ describe('forceGenerateTopicQuestions', () => {
     llmEmits(bad);
     llmEmits(bad);
     llmEmits(bad);
-    await expect(forceGenerateTopicQuestions(topic, 5)).rejects.toThrow(/banned filler|rejected/i);
+    await expect(forceGenerateTopicQuestions(topic, 5)).rejects.toThrow(/banned filler|failed/i);
   });
 
   it('rejects a batch where an explanation is too short', async () => {
@@ -93,7 +81,7 @@ describe('forceGenerateTopicQuestions', () => {
     llmEmits(bad);
     llmEmits(bad);
     llmEmits(bad);
-    await expect(forceGenerateTopicQuestions(topic, 5)).rejects.toThrow(/too short|rejected/i);
+    await expect(forceGenerateTopicQuestions(topic, 5)).rejects.toThrow(/too short|failed/i);
   });
 
   it('drops duplicates whose normalized text matches an existing bank entry', async () => {
@@ -112,4 +100,19 @@ describe('forceGenerateTopicQuestions', () => {
     expect(out.find((q) => q.question.toLowerCase().includes('buddy'))).toBeUndefined();
     expect(debugSpy).toHaveBeenCalledWith(expect.stringContaining('dropped duplicate'), expect.any(String));
   });
+
+  it('retries on LLM failure and succeeds on a later attempt', async () => {
+    callLLMMock.mockRejectedValueOnce(new Error('API timeout'));
+    llmEmits([0, 1, 2, 3, 4].map((i) => makeQuestion(i)));
+    const out = await forceGenerateTopicQuestions(topic, 5);
+    expect(callLLMMock).toHaveBeenCalledTimes(2);
+    expect(out).toHaveLength(5);
+    expect(warnSpy).toHaveBeenCalledWith(expect.stringContaining('LLM call failed'), expect.any(String));
+  });
+
+  it('throws after 3 consecutive LLM failures', async () => {
+    callLLMMock.mockRejectedValue(new Error('schema validation'));
+    await expect(forceGenerateTopicQuestions(topic, 5)).rejects.toThrow(/failed.*schema validation/i);
+    expect(callLLMMock).toHaveBeenCalledTimes(3);
+  });
 });

src/lib/llmSchemas.js

@@ -115,7 +115,7 @@ export const learningAllSchema = z.object({
 const quizDifficultyEnum = z.enum(['easy', 'medium', 'hard']).catch('medium');
 
 const quizQuestionSchema = z.object({
-  id: z.string().min(1).catch(`gen-${Math.random().toString(36).slice(2, 8)}`),
+  id: z.string().min(1).catch(() => `gen-${Math.random().toString(36).slice(2, 8)}`),
   question: z.string().min(1),
   topicLabel: z.string().min(1).catch('General'),
   options: z.array(z.string().min(1)).length(4),

src/lib/testService.js

@@ -4,25 +4,24 @@ import { EMIT_QUIZ_QUESTIONS_TOOL } from './llmTools';
 import { getCurrentWeekContent } from './curriculumService';
 import { shuffle, sample } from './random';
 
+// ── System prompt ────────────────────────────────────────────
+
 const QUIZ_SYSTEM = `You are a quiz generator for Respellion, an internal IT company learning platform.
 You generate multiple-choice questions to test employee knowledge on specific topics.
 Always write in clear, professional English.
 
 Emit questions through the emit_quiz_questions tool. Each question has exactly four options; correctIndex is 0-based. Tag every question with difficulty ('easy', 'medium' or 'hard'). For a typical 5-question batch, mix difficulty roughly 2 easy / 2 medium / 1 hard; scale the ratio proportionally for larger batches.
 
-Distribute correctIndex roughly evenly across 0, 1, 2, and 3. Do not place the correct answer at the same position more than 4 out of 10 times.
+Distribute correctIndex roughly evenly across 0, 1, 2, and 3.
 
 Never use filler options such as "all of the above", "none of the above", or "both A and B". Every explanation must be a substantive sentence (≥ 20 characters) describing why the correct answer is correct.`;
 
+// ── Quality helpers ──────────────────────────────────────────
+
 const BANNED_OPTION_PATTERNS = [
   /all of the above/i,
   /none of the above/i,
-  /both a and b/i,
+  /both [a-d] and [a-d]/i,
-  /both b and c/i,
-  /both c and d/i,
-  /both a and c/i,
-  /both b and d/i,
-  /both a and d/i,
 ];
 
 function normalizeQuestionText(text) {
@@ -33,16 +32,15 @@ function normalizeQuestionText(text) {
     .trim();
 }
 
-function dominantCorrectIndex(questions) {
+/**
-  if (!questions.length) return null;
+ * Validate a batch of questions for quality. Returns an error string
-  const counts = [0, 0, 0, 0];
+ * if the batch should be rejected, or null if acceptable.
-  for (const q of questions) counts[q.correctIndex] = (counts[q.correctIndex] || 0) + 1;
+ */
-  const max = Math.max(...counts);
-  return max / questions.length > 0.8 ? { index: counts.indexOf(max), ratio: max / questions.length } : null;
-}
-
 function validateBatchQuality(questions) {
   for (const q of questions) {
+    if (!q.question || !Array.isArray(q.options) || q.options.length !== 4) {
+      return `Question is malformed (missing text or wrong option count).`;
+    }
     const distinct = new Set(q.options.map((o) => o.trim().toLowerCase()));
     if (distinct.size < 4) {
       return `Question "${q.question}" has duplicate options.`;
@@ -59,6 +57,13 @@ function validateBatchQuality(questions) {
   return null;
 }
 
+// ── LLM call ─────────────────────────────────────────────────
+
+/**
+ * Call the LLM to generate quiz questions for a topic.
+ * The Zod schema in llmSchemas.js handles coercion and defaults,
+ * so we just extract the validated `questions` array here.
+ */
 async function callQuizModel(topic, count) {
   const prompt = `Generate exactly ${count} multiple-choice quiz questions for this knowledge topic and emit them via the emit_quiz_questions tool:
 
@@ -66,7 +71,7 @@ Topic: ${topic.label}
 Type: ${topic.type}
 Description: ${topic.description}
 
-Options must be prefixed "A) ", "B) ", "C) ", "D) ". Make questions specific and practical, not trivial. Ensure correct answers are evenly distributed.`;
+Each option must start with "A) ", "B) ", "C) ", "D) ". Make questions specific and practical, not trivial.`;
 
   const result = await callLLM({
     task: 'quiz.generate',
@@ -78,66 +83,38 @@ Options must be prefixed "A) ", "B) ", "C) ", "D) ". Make questions specific and
     maxTokens: 4096,
   });
 
-  const emitted = result.toolUses[0]?.input;
+  // After Zod validation in callLLM, emitted.questions is a valid array
-  if (!emitted) {
+  const questions = result.toolUses[0]?.input?.questions;
-    throw new Error(`LLM did not emit tool output for ${topic.label}`);
+  if (!questions?.length) {
+    throw new Error(`LLM did not produce questions for "${topic.label}".`);
   }
-
+  return questions;
-  // Handle different shapes the LLM might return:
-  // 1. { questions: [...] }  — expected
-  // 2. [...]                 — model returned array directly
-  // 3. { questions: { ... } } — model wrapped single question in object
-  let questions;
-  if (Array.isArray(emitted.questions)) {
-    questions = emitted.questions;
-  } else if (Array.isArray(emitted)) {
-    questions = emitted;
-  } else if (emitted.questions && typeof emitted.questions === 'object') {
-    // Single question wrapped as object instead of array
-    questions = [emitted.questions];
-  } else {
-    throw new Error(`Unexpected quiz output shape for ${topic.label}`);
-  }
-
-  if (!questions.length) {
-    throw new Error(`No questions generated for ${topic.label}`);
-  }
-
-  // Ensure each question has required fields (fill in defaults for missing ones)
-  return questions.map((q, i) => ({
-    id: q.id || `gen-${i}-${Math.random().toString(36).slice(2, 8)}`,
-    question: q.question || '',
-    topicLabel: q.topicLabel || topic.label,
-    options: Array.isArray(q.options) ? q.options.slice(0, 4) : [],
-    correctIndex: typeof q.correctIndex === 'number' ? q.correctIndex : 0,
-    explanation: q.explanation || 'No explanation provided.',
-    difficulty: q.difficulty || 'medium',
-  })).filter(q => q.question && q.options.length === 4);
 }
 
+// ── Topic selection ──────────────────────────────────────────
+
 async function selectTestTopics(userId, isoWeekNumber) {
   const allTopics = await db.getTopics();
   const topics = allTopics.filter(t => t.type !== 'fact' && t.learning_relevance !== 'exclude');
-  if (!topics || topics.length === 0) return { primaryTopic: null, reviewTopics: [], isReviewWeek: false };
+  if (!topics.length) return { primaryTopic: null, reviewTopics: [] };
 
+  // Try curriculum-based selection first
   try {
     const weekContent = await getCurrentWeekContent(isoWeekNumber);
-
+    if (weekContent?.topics?.length > 0) {
-    if (weekContent && weekContent.topics && weekContent.topics.length > 0) {
       const primaryTopic = weekContent.topics[0];
-      if (!primaryTopic?.id) {
+      if (primaryTopic?.id) {
-        console.warn('[Test] First curriculum topic has no id — falling back to hash');
-      } else {
         const others = topics.filter(t => t.id !== primaryTopic.id);
         const reviewTopics = sample(others, Math.min(5, others.length));
-        return { primaryTopic, reviewTopics, isReviewWeek: false };
+        return { primaryTopic, reviewTopics };
       }
+      console.warn('[Test] First curriculum topic has no id — falling back to hash');
     }
   } catch (e) {
     console.warn('[Test] Curriculum lookup failed, falling back to hash:', e.message);
   }
 
-  // Fallback hash-based assignment
+  // Fallback: deterministic hash-based assignment
   const str = `${userId}:${isoWeekNumber}`;
   let hash = 0;
   for (let i = 0; i < str.length; i++) {
@@ -146,93 +123,18 @@ async function selectTestTopics(userId, isoWeekNumber) {
   }
   const primaryIndex = Math.abs(hash) % topics.length;
   const primaryTopic = topics[primaryIndex];
-
   const others = topics.filter((_, i) => i !== primaryIndex);
   const reviewTopics = sample(others, Math.min(5, others.length));
 
-  return { primaryTopic, reviewTopics, isReviewWeek: false };
+  return { primaryTopic, reviewTopics };
 }
 
+// ── Question bank management ────────────────────────────────
+
 export async function getCachedQuiz(userId, weekNumber) {
   return db.getCachedQuiz(userId, weekNumber);
 }
 
-export async function forceGenerateTopicQuestions(topic, count = 5) {
-  const existingBank = await db.getQuizBank(topic.id);
-  const existingKeys = new Set(existingBank.map((q) => normalizeQuestionText(q.question)));
-
-  let lastQualityError = null;
-  let candidates = null;
-
-  for (let attempt = 0; attempt < 3; attempt++) {
-    let questions;
-    try {
-      questions = await callQuizModel(topic, count);
-    } catch (err) {
-      console.warn(`[quiz] LLM failed (attempt ${attempt + 1}):`, err.message);
-      lastQualityError = err.message;
-      continue;
-    }
-
-    const qualityError = validateBatchQuality(questions);
-    if (qualityError) {
-      lastQualityError = qualityError;
-      console.warn(`[quiz] batch rejected (attempt ${attempt + 1}): ${qualityError}`);
-      continue;
-    }
-
-    const dominant = dominantCorrectIndex(questions);
-    if (dominant && attempt < 2) {
-      console.warn(`[quiz] correctIndex dominated by ${dominant.index} (${Math.round(dominant.ratio * 100)}%) — re-rolling`);
-      continue;
-    }
-
-    candidates = questions;
-    break;
-  }
-
-  if (!candidates) {
-    throw new Error(`Quality gate rejected the generated batch for ${topic.label}: ${lastQualityError || 'unbalanced answer distribution'}. Click "Generate" to try again.`);
-  }
-
-  const accepted = [];
-  for (const q of candidates) {
-    const key = normalizeQuestionText(q.question);
-    if (existingKeys.has(key)) {
-      console.debug('[quiz] dropped duplicate:', q.question);
-      continue;
-    }
-    existingKeys.add(key);
-    accepted.push({
-      ...q,
-      id: `${topic.id}-${Math.random().toString(36).slice(2, 11)}`,
-    });
-  }
-
-  if (!accepted.length) {
-    throw new Error(`All generated questions for ${topic.label} were duplicates of existing ones.`);
-  }
-
-  const merged = [...existingBank, ...accepted];
-  await db.setQuizBank(topic.id, merged);
-  return accepted;
-}
-
-async function getOrGenerateTopicQuestions(topic, count) {
-  let bank = await db.getQuizBank(topic.id);
-
-  if (bank.length < count) {
-    try {
-      await forceGenerateTopicQuestions(topic, 5);
-      bank = await db.getQuizBank(topic.id);
-    } catch (err) {
-      console.warn(`[quiz] Failed to generate questions for ${topic.label}:`, err.message);
-    }
-  }
-
-  return sample(bank, Math.min(count, bank.length));
-}
-
 export async function getTopicQuestionBank(topicId) {
   return db.getQuizBank(topicId);
 }
@@ -241,7 +143,84 @@ export async function deleteQuestion(topicId, questionId) {
   return db.deleteQuestionFromBank(topicId, questionId);
 }
 
+/**
+ * Generate new questions for a topic and merge them into the bank.
+ * Retries up to 3 times on LLM or quality failures.
+ */
+export async function forceGenerateTopicQuestions(topic, count = 5) {
+  const existingBank = await db.getQuizBank(topic.id);
+  const existingKeys = new Set(existingBank.map((q) => normalizeQuestionText(q.question)));
+
+  let lastError = null;
+
+  for (let attempt = 0; attempt < 3; attempt++) {
+    let questions;
+    try {
+      questions = await callQuizModel(topic, count);
+    } catch (err) {
+      console.warn(`[quiz] LLM call failed (attempt ${attempt + 1}):`, err.message);
+      lastError = err.message;
+      continue;
+    }
+
+    const qualityError = validateBatchQuality(questions);
+    if (qualityError) {
+      console.warn(`[quiz] Batch rejected (attempt ${attempt + 1}): ${qualityError}`);
+      lastError = qualityError;
+      continue;
+    }
+
+    // Batch passed quality — deduplicate against existing bank
+    const accepted = [];
+    for (const q of questions) {
+      const key = normalizeQuestionText(q.question);
+      if (existingKeys.has(key)) {
+        console.debug('[quiz] dropped duplicate:', q.question);
+        continue;
+      }
+      existingKeys.add(key);
+      accepted.push({
+        ...q,
+        id: `${topic.id}-${Math.random().toString(36).slice(2, 11)}`,
+      });
+    }
+
+    if (!accepted.length) {
+      lastError = `All generated questions for "${topic.label}" were duplicates.`;
+      continue;
+    }
+
+    const merged = [...existingBank, ...accepted];
+    await db.setQuizBank(topic.id, merged);
+    return accepted;
+  }
+
+  throw new Error(`Quiz generation failed for "${topic.label}": ${lastError || 'unknown error'}.`);
+}
+
+/**
+ * Get questions from the bank for a topic, generating if needed.
+ * Never throws — returns whatever is available (possibly []).
+ */
+async function getOrGenerateTopicQuestions(topic, count) {
+  let bank = await db.getQuizBank(topic.id);
+
+  if (bank.length < count) {
+    try {
+      await forceGenerateTopicQuestions(topic, 5);
+      bank = await db.getQuizBank(topic.id);
+    } catch (err) {
+      console.warn(`[quiz] Could not populate bank for "${topic.label}":`, err.message);
+    }
+  }
+
+  return sample(bank, Math.min(count, bank.length));
+}
+
+// ── Weekly quiz assembly ─────────────────────────────────────
+
 export async function generateWeeklyQuiz(userId, weekNumber, force = false) {
+  // Return cached quiz if it has valid questions
   if (!force) {
     const cached = await db.getCachedQuiz(userId, weekNumber);
     if (cached?.questions?.length > 0) return cached;
@@ -252,32 +231,48 @@ export async function generateWeeklyQuiz(userId, weekNumber, force = false) {
 
   const questions = [];
 
+  // 1. Pull up to 3 from primary topic
   const primaryQs = await getOrGenerateTopicQuestions(primaryTopic, 3);
   questions.push(...primaryQs);
 
+  // 2. Fill remaining slots from review topics
   for (const rt of reviewTopics) {
     if (questions.length >= 5) break;
     const rtQs = await getOrGenerateTopicQuestions(rt, 1);
     questions.push(...rtQs);
   }
 
+  // 3. If still short, pull more from primary
   if (questions.length < 5) {
-    const needed = 5 - questions.length;
-    const extraQs = await getOrGenerateTopicQuestions(primaryTopic, needed + 5);
     const existingIds = new Set(questions.map(q => q.id));
+    const extraQs = await getOrGenerateTopicQuestions(primaryTopic, 5);
     for (const eq of extraQs) {
       if (!existingIds.has(eq.id) && questions.length < 5) {
         questions.push(eq);
+        existingIds.add(eq.id);
       }
     }
   }
 
-  const shuffled = shuffle(questions).slice(0, 5);
+  // 4. Last resort: try a fresh generation if we still have 0 questions
-
+  if (questions.length === 0) {
-  if (shuffled.length === 0) {
+    try {
-    throw new Error('Could not assemble enough questions for this week\'s test. Please try again.');
+      const freshQs = await callQuizModel(primaryTopic, 5);
+      const qualityError = validateBatchQuality(freshQs);
+      if (!qualityError) {
+        questions.push(...freshQs.slice(0, 5));
+      }
+    } catch (err) {
+      console.warn('[quiz] Last-resort generation also failed:', err.message);
+    }
   }
 
+  if (questions.length === 0) {
+    throw new Error('Could not generate any questions for this week\'s test. Please try again.');
+  }
+
+  const shuffled = shuffle(questions).slice(0, 5);
+
   const quiz = {
     questions: shuffled,
     meta: {
@@ -292,6 +287,8 @@ export async function generateWeeklyQuiz(userId, weekNumber, force = false) {
   return quiz;
 }
 
+// ── Result management ────────────────────────────────────────
+
 export async function saveTestResult(userId, weekNumber, result) {
   await db.saveQuizResult(userId, weekNumber, result);
 

src/pages/Dashboard.jsx

@@ -178,7 +178,7 @@ const Dashboard = () => {
           <div className="flex justify-between items-start mb-4">
             <div>
               <h3 className="text-xl">Testing</h3>
-              <p className="text-fg-muted text-sm mt-1">Weekly test — 5 questions</p>
+              <p className="text-fg-muted text-sm mt-1">Weekly knowledge test</p>
             </div>
             {testResult ? <Tag variant="success">Score: {testResult.percentage}%</Tag> : <Tag variant="default">To Do</Tag>}
           </div>

src/pages/Testen.jsx

@@ -182,7 +182,7 @@ const Testen = () => {
           <h1 className="text-3xl md:text-4xl font-bold text-teal mb-4">Weekly Test</h1>
           <p className="text-fg-muted text-lg mb-2">Week {weekNumber}</p>
           <p className="text-fg-muted mb-8 max-w-md mx-auto">
-            Test your knowledge with 5 AI-generated questions. You have 5 minutes to complete the test. Good luck!
+            Test your knowledge with AI-generated questions. You have 5 minutes to complete the test. Good luck!
           </p>
 
           {error && (
@@ -196,9 +196,9 @@ const Testen = () => {
 
           <div className="space-y-3">
             <div className="flex items-center justify-center gap-6 text-sm text-fg-muted">
-              <span className="flex items-center gap-1.5"><CheckSquare size={14} /> 5 questions</span>
+              <span className="flex items-center gap-1.5"><CheckSquare size={14} /> Up to 5 questions</span>
               <span className="flex items-center gap-1.5"><Clock size={14} /> 5 minutes</span>
-              <span className="flex items-center gap-1.5"><Trophy size={14} /> 20 pts max</span>
+              <span className="flex items-center gap-1.5"><Trophy size={14} /> 2 pts each</span>
             </div>
             <Button onClick={startQuiz} className="text-lg px-8 py-3">
               Start Test <ArrowRight size={20} className="ml-2" />
@@ -215,7 +215,7 @@ const Testen = () => {
       <div className="p-4 md:p-8 max-w-2xl mx-auto text-center py-20">
         <Loader size={48} className="mx-auto text-teal animate-spin mb-4" />
         <p className="font-medium text-lg">AI is generating your test...</p>
-        <p className="text-sm text-fg-muted mt-2">Preparing 5 questions based on your learning topics.</p>
+        <p className="text-sm text-fg-muted mt-2">Preparing questions based on your learning topics.</p>
       </div>
     );
   }