feat(interview): 모르겠습니다/부연 요청 처리 (PR2)

ai/src/ai_server/chain/followup_generation_chain.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Protocol
+from typing import Literal, Protocol
 
 from langchain_core.output_parsers import PydanticOutputParser
 from langchain_core.prompts import ChatPromptTemplate
@@ -17,6 +17,8 @@
 class FollowupResult(BaseModel):
     followup_question: str = Field(..., description="한국어 꼬리질문 1개")
     answer_evaluation: AnswerEvaluation
+    # 답변 의도. NORMAL=정상답변, DONT_KNOW=모름/포기, CLARIFICATION=질문 재설명 요청.
+    answer_intent: Literal["NORMAL", "DONT_KNOW", "CLARIFICATION"] = "NORMAL"
 
 
 class FollowupGenerator(Protocol):

ai/src/ai_server/chain/prompts/followup_generation.py

@@ -20,6 +20,12 @@
     "- 꼬리질문은 가장 약한 축을 겨냥합니다 (예: 구체성 낮음→수치/사례 요구, "
     "correctness 의심→자료와의 불일치 확인).\n"
     "- '이미 나눈 대화'에서 다룬 내용을 그대로 반복하지 말고 새로운 각도로 파고드세요.\n"
+    "- answer_intent 로 답변 의도를 분류하세요:\n"
+    "  - DONT_KNOW: '모르겠습니다/잘 모릅니다/패스' 등 사실상 답을 못 한 경우.\n"
+    "  - CLARIFICATION: 답변 대신 '질문을 다시/쉽게 설명해 달라'고 요청한 경우. "
+    "이때 followup_question 에는 새 꼬리질문이 아니라 **직전 질문을 더 쉽고 구체적으로 다시 설명한 문장**을 담으세요.\n"
+    "  - NORMAL: 그 외 정상 답변. followup_question 은 평소처럼 가장 약한 축을 파는 꼬리질문.\n"
+    "  - DONT_KNOW/CLARIFICATION 이면 채점(specificity/logic/correctness)은 보수적으로(낮게/null) 둡니다.\n"
     "- 응답은 반드시 지정된 JSON 스키마를 따릅니다."
 )
 

ai/src/ai_server/messaging/consumers/followup_consumer.py

@@ -91,6 +91,7 @@ async def handle(self, message: AbstractIncomingMessage) -> None:
                 answer_message_id=req.answer_message_id,
                 followup_question=result.followup_question,
                 answer_evaluation=result.answer_evaluation,
+                answer_intent=result.answer_intent,
             )
 
             await self._publisher.publish(

ai/src/ai_server/model/messages/followup.py

@@ -56,3 +56,5 @@ class FollowupCallbackPayload(BaseModel):
     answer_message_id: int  # 평가가 달릴 답변 메시지 (Core 가 평가 영속에 사용)
     followup_question: str
     answer_evaluation: AnswerEvaluation | None = None
+    # 답변 의도: NORMAL | DONT_KNOW | CLARIFICATION. Core 가 흐름 분기에 사용.
+    answer_intent: str = "NORMAL"

backend/src/main/java/com/stackup/stackup/session/application/QuestionsCallbackService.java

@@ -158,34 +158,43 @@ private void endSession(InterviewSession session, String reason) {
     }
 
     private void applyFollowup(InterviewSession session, QuestionsCallbackPayload payload) {
-        if (payload.followupQuestion() == null || payload.followupQuestion().isBlank()) {
-            log.warn("callback.questions FOLLOWUP empty question. sessionId={}", session.getId());
-            return;
-        }
         InterviewMessage parent = payload.parentMessageId() == null
             ? null
             : messageRepository.findById(payload.parentMessageId()).orElse(null);
+        String intent = payload.answerIntent() == null ? "NORMAL" : payload.answerIntent();
 
-        // 답변 평가를 해당 답변 메시지에 영속 (피드백 롤업 재활용). 평가/대상 없으면 skip.
-        recordAnswerEvaluation(payload);
+        // 모르겠음 → 이 주제 더 안 파고 다음 일반질문으로(없으면 종료). 답변평가는 기록(낮은 점수 의미 있음).
+        if ("DONT_KNOW".equalsIgnoreCase(intent)) {
+            recordAnswerEvaluation(payload);
+            log.info("callback.questions DONT_KNOW — advancing to next general. sessionId={}", session.getId());
+            advanceToNextGeneral(session.getId());
+            return;
+        }
 
-        long currentMsgs = messageRepository.countBySession_Id(session.getId());
-        int nextSeq = (int) currentMsgs + 1;
+        if (payload.followupQuestion() == null || payload.followupQuestion().isBlank()) {
+            log.warn("callback.questions FOLLOWUP empty question. sessionId={}", session.getId());
+            return;
+        }
+
+        // 부연 요청 → 같은 질문 재설명. 질문 수(k)·깊이(m) 미반영, 답변평가 기록 안 함.
+        if ("CLARIFICATION".equalsIgnoreCase(intent)) {
+            int seq = (int) messageRepository.countBySession_Id(session.getId()) + 1;
+            InterviewMessage clar = messageRepository.save(
+                InterviewMessage.clarification(session, seq, payload.followupQuestion(), parent));
+            publishQuestionEvents(session, clar, "CLARIFICATION");
+            log.info("callback.questions CLARIFICATION — re-explained question. sessionId={}, msg={}",
+                session.getId(), clar.getId());
+            return;
+        }
 
+        // 정상 답변 → 꼬리질문 삽입.
+        recordAnswerEvaluation(payload);
+        int nextSeq = (int) messageRepository.countBySession_Id(session.getId()) + 1;
         InterviewMessage message = messageRepository.save(
             InterviewMessage.followup(session, nextSeq, payload.followupQuestion(), parent)
         );
         session.incrementQuestionCount();
-
-        events.publishEvent(new QuestionPersistedEvent(
-            session.getUser().getId(), session.getId(), message.getId()));
-
-        events.publishEvent(RealtimeNotifyEvent.session(session.getId(), SseEventType.SESSION_MESSAGE, message.getId()));
-        events.publishEvent(RealtimeNotifyEvent.user(
-            session.getUser().getId(),
-            SseEventType.SESSION_MESSAGE,
-            new SessionMessageNotice(session.getId(), message.getId(), "FOLLOWUP_READY")
-        ));
+        publishQuestionEvents(session, message, "FOLLOWUP_READY");
 
         // maxQuestions(k) 도달 시 자동 종료.
         maybeAutoEnd(session);

backend/src/main/java/com/stackup/stackup/session/application/SessionFollowupRequester.java

@@ -101,8 +101,8 @@ public void onAnswerSubmitted(AnswerSubmittedEvent event) {
     private int currentFollowupDepth(List<InterviewMessage> ordered) {
         int depth = 0;
         for (InterviewMessage m : ordered) {
-            if (m.getRole() != MessageRole.INTERVIEWER) {
-                continue;
+            if (m.getRole() != MessageRole.INTERVIEWER || m.isClarification()) {
+                continue;             // 부연 메시지는 깊이에 미반영
             }
             if (m.getParentMessage() == null) {
                 depth = 0;            // 일반질문 → 리셋

backend/src/main/java/com/stackup/stackup/session/application/dto/QuestionsCallbackPayload.java

@@ -11,7 +11,8 @@ public record QuestionsCallbackPayload(
     Long parentMessageId,              // FOLLOWUP 시 사용 (직전 질문)
     Long answerMessageId,              // FOLLOWUP 시 평가 대상 답변 메시지
     String followupQuestion,           // FOLLOWUP 시 사용
-    AnswerEvaluation answerEvaluation  // FOLLOWUP 시 옵션
+    AnswerEvaluation answerEvaluation, // FOLLOWUP 시 옵션
+    String answerIntent                // NORMAL | DONT_KNOW | CLARIFICATION (FOLLOWUP)
 ) {
     public boolean isPool() {
         return "POOL".equals(kind);

backend/src/main/java/com/stackup/stackup/session/domain/InterviewMessage.java

@@ -102,6 +102,10 @@ public class InterviewMessage extends BaseTimeEntity {
     @Column(name = "answer_correctness")
     private Double answerCorrectness;
 
+    // 부연(질문 재설명) 메시지 여부. true 면 총 질문 수·꼬리 깊이에 카운트하지 않는다.
+    @Column(nullable = false)
+    private boolean clarification = false;
+
     private InterviewMessage(InterviewSession session, Integer sequenceNumber, MessageRole role,
                              String content, InterviewMessage parentMessage,
                              MessageStatus initialStatus, String idempotencyKey) {
@@ -147,6 +151,16 @@ public static InterviewMessage followup(InterviewSession session, int seq, Strin
         return m;
     }
 
+    // 부연: 직전 질문을 다시 설명해 같은 차례를 유지. 질문 수/깊이에 카운트 안 함.
+    public static InterviewMessage clarification(InterviewSession session, int seq, String content,
+                                                 InterviewMessage parent) {
+        InterviewMessage m = new InterviewMessage(session, seq, MessageRole.INTERVIEWER, content, parent,
+            MessageStatus.CREATED, null);
+        m.clarification = true;
+        m.markTtsPending();
+        return m;
+    }
+
     public static InterviewMessage interviewee(InterviewSession session, int seq, String content,
                                                InterviewMessage parent, String idempotencyKey) {
         return new InterviewMessage(session, seq, MessageRole.INTERVIEWEE, content, parent,

backend/src/main/resources/db/migration/V13__add_clarification_to_interview_messages.sql

@@ -0,0 +1,4 @@
+-- 부연(질문 재설명) 메시지 표시. clarification 메시지는 총 질문 수(k)·꼬리 깊이(m)에
+-- 카운트되지 않는다. 같은 질문을 다시 제시하는 용도.
+ALTER TABLE interview_messages
+    ADD COLUMN clarification BOOLEAN NOT NULL DEFAULT FALSE;

backend/src/test/java/com/stackup/stackup/session/application/QuestionsCallbackServiceTest.java

@@ -139,7 +139,7 @@ void apply_followupPersistsAnswerEvaluationOntoAnswerMessage() {
 
         QuestionsCallbackPayload payload = new QuestionsCallbackPayload(
             11L, "FOLLOWUP", null, 500L, 600L, "다음 질문?",
-            new QuestionsCallbackPayload.AnswerEvaluation(2.0, 3.0, "PARTIAL_STAR", 1.5)
+            new QuestionsCallbackPayload.AnswerEvaluation(2.0, 3.0, "PARTIAL_STAR", 1.5), "NORMAL"
         );
         QuestionsCallbackEnvelope env = new QuestionsCallbackEnvelope(
             "m-eval", "callback.questions", "1", "t", null, "ai", payload, null);
@@ -160,16 +160,41 @@ void apply_followupPersistsAnswerEvaluationOntoAnswerMessage() {
         assertThat(answer.getAnswerCorrectness()).isEqualTo(1.5);
     }
 
+    @Test
+    void apply_clarificationReExplainsWithoutCountingQuestion() {
+        InterviewSession session = sessionFixture(11L, SessionStatus.IN_PROGRESS);
+        QuestionsCallbackPayload payload = new QuestionsCallbackPayload(
+            11L, "FOLLOWUP", null, 500L, 600L, "쉽게 다시 설명: 트랜잭션이란…",
+            null, "CLARIFICATION"
+        );
+        QuestionsCallbackEnvelope env = new QuestionsCallbackEnvelope(
+            "m-clar", "callback.questions", "1", "t", null, "ai", payload, null);
+
+        when(processedMessageRepository.existsById("m-clar")).thenReturn(false);
+        when(sessionRepository.findById(11L)).thenReturn(Optional.of(session));
+        when(messageRepository.findById(500L)).thenReturn(Optional.empty());
+        when(messageRepository.countBySession_Id(11L)).thenReturn(2L);
+        when(messageRepository.save(any(InterviewMessage.class))).thenAnswer(inv -> inv.getArgument(0));
+
+        service.apply(env);
+
+        ArgumentCaptor<InterviewMessage> cap = ArgumentCaptor.forClass(InterviewMessage.class);
+        verify(messageRepository).save(cap.capture());
+        assertThat(cap.getValue().isClarification()).isTrue();
+        // 부연은 질문 수(k)에 카운트되지 않는다.
+        assertThat(session.getTotalQuestionCount()).isEqualTo(0);
+    }
+
     private QuestionsCallbackEnvelope poolEnvelope(Long sessionId, List<GeneratedQuestion> questions) {
         QuestionsCallbackPayload payload = new QuestionsCallbackPayload(
-            sessionId, "POOL", questions, null, null, null, null
+            sessionId, "POOL", questions, null, null, null, null, null
         );
         return new QuestionsCallbackEnvelope("m-1", "callback.questions", "1", "t", null, "ai", payload, null);
     }
 
     private QuestionsCallbackEnvelope followupEnvelope(Long sessionId, Long parentId, String followup) {
         QuestionsCallbackPayload payload = new QuestionsCallbackPayload(
-            sessionId, "FOLLOWUP", null, parentId, null, followup, null
+            sessionId, "FOLLOWUP", null, parentId, null, followup, null, "NORMAL"
         );
         return new QuestionsCallbackEnvelope("m-2", "callback.questions", "1", "t", null, "ai", payload, null);
     }