修复错题一直显示处理中：超时、自动刷新与状态更新。

backend/app/core/config.py

@@ -19,6 +19,9 @@ class Settings(BaseSettings):
     FRONTEND_DIST: str = "../frontend/dist"
     ADMIN_DEFAULT_USERNAME: str = "admin"
     ADMIN_DEFAULT_PASSWORD: str = "admin123"
+    OCR_TIMEOUT_SECONDS: int = 300
+    AI_TIMEOUT_SECONDS: int = 600
+    PROCESS_STALE_MINUTES: int = 20
 
     class Config:
         env_file = ".env"

backend/app/routers/wrong_questions.py

@@ -1,5 +1,7 @@
 import json
 import uuid
+from concurrent.futures import ThreadPoolExecutor, TimeoutError as FuturesTimeout
+from datetime import datetime, timedelta, timezone
 from pathlib import Path
 
 from fastapi import APIRouter, BackgroundTasks, Depends, File, Form, HTTPException, Query, UploadFile, status
@@ -26,6 +28,28 @@ def _short_error(exc: BaseException, prefix: str = "") -> str:
     return f"{prefix}{msg}" if prefix else msg
 
 
+def _is_still_processing(wq: WrongQuestion) -> bool:
+    if wq.status == WrongQuestionStatus.pending:
+        return True
+    if wq.status == WrongQuestionStatus.ocr_done and not wq.question_text and not wq.error_message:
+        return True
+    return False
+
+
+def _expire_stale_processing(wq: WrongQuestion, db: Session) -> None:
+    if not _is_still_processing(wq):
+        return
+    created = wq.created_at
+    if created.tzinfo is None:
+        created = created.replace(tzinfo=timezone.utc)
+    age = datetime.now(timezone.utc) - created
+    if age <= timedelta(minutes=settings.PROCESS_STALE_MINUTES):
+        return
+    wq.status = WrongQuestionStatus.failed
+    wq.error_message = f"处理超时（超过 {settings.PROCESS_STALE_MINUTES} 分钟），请点击「重新识别标注」重试"
+    db.commit()
+
+
 def _parse_mark_regions(raw: str | None) -> list[dict] | None:
     if not raw:
         return None
@@ -57,25 +81,41 @@ def _wq_to_out(wq: WrongQuestion) -> WrongQuestionOut:
 
 
 async def _run_ai_pipeline(wq: WrongQuestion, db: Session, ocr_lines: list[dict], ocr_text: str):
+    import asyncio
+
     subject_name = wq.subject.name if wq.subject else "综合"
     school_level = wq.student.school_level if wq.student else None
     olympiad = wq.category == WrongQuestionCategory.olympiad
     ai_cfg = llm_service.load_ai_config(db)
     image_full = str(Path(settings.UPLOAD_DIR) / wq.image_path)
+    timeout = settings.AI_TIMEOUT_SECONDS
+
+    try:
+        detect_resp = await asyncio.wait_for(
+            llm_service.detect_wrong_line_ids(ai_cfg, subject_name, ocr_lines, school_level),
+            timeout=min(90, timeout),
+        )
+        wrong_ids = annotation_service.parse_wrong_line_ids(detect_resp, ocr_lines)
+    except Exception:
+        wrong_ids = annotation_service.heuristic_wrong_line_ids(ocr_lines)
 
-    detect_resp = await llm_service.detect_wrong_line_ids(ai_cfg, subject_name, ocr_lines, school_level)
-    wrong_ids = annotation_service.parse_wrong_line_ids(detect_resp, ocr_lines)
     regions = annotation_service.regions_from_lines(ocr_lines, wrong_ids)
     wq.mark_regions_json = json.dumps(regions, ensure_ascii=False)
-
     ann_rel = ocr_service.annotated_rel_path(wq.image_path)
     wq.annotated_image_path = annotation_service.draw_annotated_image(
         image_full, ocr_lines, wrong_ids, ann_rel
     )
+    db.commit()
 
-    question_text = await llm_service.format_question(ai_cfg, subject_name, ocr_text, school_level)
-    solution_full = await llm_service.generate_solution(
-        ai_cfg, subject_name, question_text, school_level, olympiad=olympiad
+    question_text = await asyncio.wait_for(
+        llm_service.format_question(ai_cfg, subject_name, ocr_text, school_level),
+        timeout=timeout,
+    )
+    solution_full = await asyncio.wait_for(
+        llm_service.generate_solution(
+            ai_cfg, subject_name, question_text, school_level, olympiad=olympiad
+        ),
+        timeout=timeout,
     )
     approach, solution_body = annotation_service.split_solution_sections(solution_full)
     wq.question_text = question_text
@@ -87,6 +127,7 @@ async def _run_ai_pipeline(wq: WrongQuestion, db: Session, ocr_lines: list[dict]
 
 def _process_wrong_question(question_id: uuid.UUID):
     db = SessionLocal()
+    wq = None
     try:
         wq = (
             db.query(WrongQuestion)
@@ -100,7 +141,9 @@ def _process_wrong_question(question_id: uuid.UUID):
         wq.error_message = None
         image_full = Path(settings.UPLOAD_DIR) / wq.image_path
         try:
-            ocr_result = ocr_service.run_ocr_with_regions(str(image_full))
+            with ThreadPoolExecutor(max_workers=1) as pool:
+                future = pool.submit(ocr_service.run_ocr_with_regions, str(image_full))
+                ocr_result = future.result(timeout=settings.OCR_TIMEOUT_SECONDS)
             ocr_text = ocr_result["text"]
             ocr_lines = ocr_result["lines"]
             wq.ocr_raw_text = ocr_text or None
@@ -111,6 +154,14 @@ def _process_wrong_question(question_id: uuid.UUID):
                 return
             wq.status = WrongQuestionStatus.ocr_done
             db.commit()
+        except FuturesTimeout:
+            wq.status = WrongQuestionStatus.failed
+            wq.error_message = (
+                f"OCR 识别超时（>{settings.OCR_TIMEOUT_SECONDS}秒）。"
+                " 首次加载模型较慢，请稍后点「重新识别标注」重试"
+            )
+            db.commit()
+            return
         except Exception as exc:
             wq.status = WrongQuestionStatus.failed
             msg = _short_error(exc, "OCR 识别失败：")
@@ -129,10 +180,18 @@ def _process_wrong_question(question_id: uuid.UUID):
             db.commit()
         except Exception as exc:
             wq.status = WrongQuestionStatus.failed
-            wq.error_message = _short_error(exc, "AI 处理失败：")
+            detail = _short_error(exc, "AI 处理失败：")
+            if "Timeout" in type(exc).__name__ or "timeout" in str(exc).lower():
+                detail = "AI 处理超时，请检查 Ollama/OpenAI 是否可用后重试"
+            wq.error_message = detail
             db.commit()
         finally:
             loop.close()
+    except Exception as exc:
+        if wq is not None:
+            wq.status = WrongQuestionStatus.failed
+            wq.error_message = _short_error(exc, "处理失败：")
+            db.commit()
     finally:
         db.close()
 
@@ -164,6 +223,8 @@ def list_wrong_questions(
             | (WrongQuestion.ocr_raw_text.ilike(pattern))
         )
     items = query.order_by(WrongQuestion.created_at.desc()).all()
+    for w in items:
+        _expire_stale_processing(w, db)
     return [_wq_to_out(w) for w in items]
 
 
@@ -233,6 +294,7 @@ def get_wrong_question(
     )
     if wq is None or wq.student.user_id != current_user.id:
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="错题不存在")
+    _expire_stale_processing(wq, db)
     return _wq_to_out(wq)