fix(avatar): ground replies in recognized images

Reviewed-on: #13

digital-avatar-app/backend/database.py

@@ -1,16 +1,30 @@
 import os
 
-from sqlalchemy import create_engine
+from sqlalchemy import create_engine, event
 from sqlalchemy.orm import sessionmaker, declarative_base, Session
 
 BASE_DIR = os.path.dirname(os.path.abspath(__file__))
 DB_FILE = os.path.join(BASE_DIR, "avatar.db")
 DATABASE_URL = os.getenv("DATABASE_URL", f"sqlite:///{DB_FILE}")
 
+IS_SQLITE = DATABASE_URL.startswith("sqlite:")
 engine = create_engine(
     DATABASE_URL,
-    connect_args={"check_same_thread": False} if DATABASE_URL.startswith("sqlite:") else {},
+    connect_args={"check_same_thread": False, "timeout": 30} if IS_SQLITE else {},
 )
+
+
+if IS_SQLITE:
+    @event.listens_for(engine, "connect")
+    def _configure_sqlite_connection(dbapi_connection, _connection_record):
+        cursor = dbapi_connection.cursor()
+        try:
+            cursor.execute("PRAGMA synchronous=NORMAL")
+            cursor.execute("PRAGMA busy_timeout=30000")
+        finally:
+            cursor.close()
+
+
 SessionLocal = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)
 Base = declarative_base()
 
@@ -26,6 +40,10 @@ def get_db():
 def init_db():
     import models
 
+    if IS_SQLITE:
+        with engine.connect() as conn:
+            conn.exec_driver_sql("PRAGMA journal_mode=WAL")
+            conn.commit()
     Base.metadata.create_all(bind=engine)
 
     # 轻量迁移：为已存在的表补充新列（SQLite 不支持自动 ALTER，逐列尝试）

digital-avatar-app/backend/routers/chat.py

@@ -47,6 +47,25 @@ QA_SEMANTIC_THRESHOLD = 0.72
 QA_MATCH_MARGIN = 0.06
 KNOWLEDGE_MIN_SCORE = float(os.getenv("KNOWLEDGE_MIN_SCORE", "0.42"))
 
+_IMAGE_ACCESS_DENIAL_PATTERNS = (
+    re.compile(
+        r"(?:我|目前|暂时|这里|本身|系统)?\s*(?:无法|不能|没法|不支持)\s*"
+        r"(?:直接)?\s*(?:查看|看到|看见|识别|读取|访问|打开|分析|理解)"
+        r"(?:\s*(?:或|、|/)\s*(?:查看|看到|看见|识别|读取|访问|打开|分析|理解))*\s*"
+        r"(?:你(?:发|提供|上传)的|这张|该|当前)?\s*(?:图片|图像|照片|影像|文件)"
+    ),
+    re.compile(
+        r"(?:我|这里|目前|暂时)?\s*(?:看不到|看不见|未看到|没有看到|没收到|未收到)\s*"
+        r"(?:你(?:发|提供|上传)的|这张|该|当前)?\s*(?:图片|图像|照片|影像)"
+    ),
+    re.compile(
+        r"\b(?:i\s+)?(?:can(?:not|'t)|am\s+unable\s+to)\s+(?:directly\s+)?"
+        r"(?:view|see|access|read|analy[sz]e|recogni[sz]e)\s+"
+        r"(?:the\s+|this\s+|your\s+)?(?:image|photo|picture|scan)\b",
+        re.IGNORECASE,
+    ),
+)
+
 _WRITING_SYSTEM_PATTERNS = {
     "han": re.compile(r"[\u3400-\u4dbf\u4e00-\u9fff]"),
     "latin": re.compile(r"[A-Za-z\u00c0-\u024f]"),
@@ -178,6 +197,75 @@ def _image_retrieval_question(question: str, image_contexts: list[dict]) -> str:
     return "\n".join(part for part in parts if part).strip()
 
 
+def _answer_denies_available_image(answer: str) -> bool:
+    """Reject only whole-image access denials, not uncertainty about one field."""
+    value = re.sub(r"\s+", " ", answer or "").strip()
+    return any(pattern.search(value) for pattern in _IMAGE_ACCESS_DENIAL_PATTERNS)
+
+
+def _compact_context_text(value: Any, limit: int) -> str:
+    lines = [re.sub(r"\s+", " ", line).strip() for line in str(value or "").splitlines()]
+    text = "\n".join(line for line in lines if line).strip()
+    return text[:limit].rstrip()
+
+
+def _grounded_image_fallback(question: str, image_contexts: list[dict]) -> str:
+    """Build a safe answer from completed vision data when the chat model contradicts it."""
+    summaries: list[str] = []
+    facts: list[str] = []
+    excerpts: list[str] = []
+    warnings: list[str] = []
+    for context in image_contexts:
+        summary = _compact_context_text(context.get("summary"), 500)
+        if summary:
+            summaries.append(summary)
+        structured = context.get("structuredData") or {}
+        if isinstance(structured, dict):
+            for fact in structured.get("key_facts") or []:
+                value = _compact_context_text(fact, 300)
+                if value:
+                    facts.append(value)
+        extracted = _compact_context_text(context.get("extractedText"), 900)
+        if extracted:
+            excerpts.append(extracted)
+        warning = _compact_context_text(context.get("warning"), 300)
+        if warning:
+            warnings.append(warning)
+
+    summaries = list(dict.fromkeys(summaries))
+    facts = list(dict.fromkeys(facts))[:6]
+    excerpts = list(dict.fromkeys(excerpts))
+    warnings = list(dict.fromkeys(warnings))
+    writing_system = _dominant_writing_system(question)
+
+    if writing_system == "latin":
+        parts = []
+        if summaries:
+            parts.append("From the image, I can confirm: " + " ".join(summaries))
+        if facts:
+            parts.append("Key details:\n" + "\n".join(
+                f"{index}. {fact}" for index, fact in enumerate(facts, 1)
+            ))
+        elif excerpts:
+            parts.append("Visible text:\n" + excerpts[0])
+        if warnings:
+            parts.append("Please note: " + " ".join(warnings))
+        return "\n".join(parts).strip() or "The image is available, but there is not enough clear detail to confirm more."
+
+    parts = []
+    if summaries:
+        parts.append("从这张图中可以确认：" + "；".join(summaries).rstrip("。；") + "。")
+    if facts:
+        parts.append("其中比较明确的信息有：\n" + "\n".join(
+            f"{index}. {fact}" for index, fact in enumerate(facts, 1)
+        ))
+    elif excerpts:
+        parts.append("图中可见的主要文字是：\n" + excerpts[0])
+    if warnings:
+        parts.append("需要注意：" + "；".join(warnings).rstrip("。；") + "。")
+    return "\n".join(parts).strip() or "这张图已经看到了，但目前能确认的清晰信息比较有限。"
+
+
 def _run_billed_vision_call(
     db: Session,
     avatar: Avatar,
@@ -553,8 +641,10 @@ def _build_prompt(
     if image_contexts:
         image_material = json.dumps(image_contexts, ensure_ascii=False, default=str)
         system += (
-            "\n以下是当前会话图片经过视觉识别后得到的资料：\n"
+            "\n当前会话图片已经成功读取并完成内容识别，以下资料就是可直接使用的图片内容：\n"
             f"{image_material}"
+            "\n必须直接依据这些图片内容回答当前问题。禁止声称无法查看、看不到、未收到、无法识别、"
+            "无法读取或不能访问图片，也不要要求对方重新上传；只有资料明确标记读取失败时才可以请对方重发。"
             "\n图片资料可能包含 OCR 错字、模糊内容或用户尚未确认的信息，只能按可见内容谨慎表达。"
             "标准答题对中的事实优先级高于图片资料，知识库事实优先级高于模型推测；发生冲突时遵循更高优先级资料，"
             "并自然提醒对方核对原图。不得声称看到了图片中不存在的内容。"
@@ -815,6 +905,14 @@ def _resolve_reply(
         except Exception as exc:
             release_reservation(db, reservation, str(exc))
             raise
+    answer = str(answer or "").strip()
+    if image_contexts and _answer_denies_available_image(answer):
+        logger.warning(
+            "chat model contradicted ready image context avatar=%s source=%s",
+            avatar.id,
+            usage_source,
+        )
+        answer = _grounded_image_fallback(question, image_contexts)
     result = {
         "answer": answer,
         "source": "qa" if matched else (

digital-avatar-app/backend/services/takeover_service.py

@@ -49,6 +49,15 @@ BOXIM_TEXT_MESSAGE_TYPE = 0
 BOXIM_IMAGE_MESSAGE_TYPE = 1
 BOXIM_IMAGE_PROMPT = "请看看这张图片。"
 BOXIM_IMAGE_UNAVAILABLE_REPLY = "这张图片我暂时没看清，麻烦重新发送一张清晰的原图。"
+IMAGE_CONTEXT_LOOKBACK_SECONDS = 1800
+IMAGE_REFERENCE_LOOKBACK_SECONDS = 172_800
+MAX_RECENT_IMAGE_CONTEXTS = 3
+
+_IMAGE_REFERENCE_PATTERN = re.compile(
+    r"(?:图片|图像|照片|截图|这张图|刚才.{0,8}图|病例|病历|检查单|检验单|化验单|报告|影像|"
+    r"\b(?:image|photo|picture|screenshot|scan|report)\b)",
+    re.IGNORECASE,
+)
 
 
 def _utcnow() -> datetime:
@@ -127,6 +136,10 @@ def _event_prompt(event: TakeoverMessage) -> str:
     return ""
 
 
+def _references_recent_image(value: str) -> bool:
+    return bool(_IMAGE_REFERENCE_PATTERN.search(value or ""))
+
+
 class TakeoverService:
     """Poll BOXIM, honor the owner grace period, then generate and send one reply."""
 
@@ -149,6 +162,7 @@ class TakeoverService:
         self._sessions: dict[str, dict] = {}
         self._poll_lock = asyncio.Lock()
         self._process_lock = asyncio.Lock()
+        self._persist_lock = asyncio.Lock()
 
     async def poll_and_process_messages(self):
         """Run one complete cycle for callers that do not use the split scheduler."""
@@ -409,13 +423,6 @@ class TakeoverService:
             max_message_id = _numeric_id(cursor.last_message_id)
             read_receipts: dict[str, int] = {}
             for message in messages:
-                self._record_message(
-                    db,
-                    avatar,
-                    cursor.boxim_owner_id,
-                    message,
-                    schedule_reply=not priming,
-                )
                 message_id = _numeric_id(message.get("id"))
                 max_message_id = max(max_message_id, message_id)
                 send_id = str(message.get("sendId") or "")
@@ -430,11 +437,22 @@ class TakeoverService:
                     session["access_token"], peer_id, message_id
                 )
 
-            cursor.last_message_id = str(max_message_id)
-            cursor.initialized = True
-            cursor.last_polled_at = self.now()
-            cursor.last_error = ""
-            db.commit()
+            # Keep SQLite write transactions short. The read-receipt request above
+            # can block on the network and must not hold the database write lock.
+            async with self._persist_lock:
+                for message in messages:
+                    self._record_message(
+                        db,
+                        avatar,
+                        cursor.boxim_owner_id,
+                        message,
+                        schedule_reply=not priming,
+                    )
+                cursor.last_message_id = str(max_message_id)
+                cursor.initialized = True
+                cursor.last_polled_at = self.now()
+                cursor.last_error = ""
+                db.commit()
             return True
         except Exception:
             db.rollback()
@@ -645,6 +663,15 @@ class TakeoverService:
                 task.status = "cancelled"
                 task.cancel_reason = "newer_incoming_message"
                 task.locked_at = None
+        if event.message_type == BOXIM_TEXT_MESSAGE_TYPE:
+            for image_event in self._recent_unhandled_images(
+                db,
+                avatar,
+                event,
+                source_ids,
+            ):
+                prompt_parts.append(_event_prompt(image_event))
+                source_ids.append(image_event.boxim_message_id)
         prompt_parts.append(_event_prompt(event))
         source_ids.append(event.boxim_message_id)
         prompt = "\n".join(part for part in prompt_parts if part).strip()[-MAX_PROMPT_LENGTH:]
@@ -670,6 +697,68 @@ class TakeoverService:
             )
         )
 
+    @staticmethod
+    def _recent_unhandled_images(
+        db: Session,
+        avatar: Avatar,
+        event: TakeoverMessage,
+        current_source_ids: list[str],
+    ) -> list[TakeoverMessage]:
+        """Recover missed images, or reuse a referenced image from the last two days."""
+        references_image = _references_recent_image(event.content)
+        lookback_seconds = (
+            IMAGE_REFERENCE_LOOKBACK_SECONDS
+            if references_image
+            else IMAGE_CONTEXT_LOOKBACK_SECONDS
+        )
+        threshold = event.send_time - timedelta(seconds=lookback_seconds)
+        candidates = (
+            db.query(TakeoverMessage)
+            .filter(
+                TakeoverMessage.avatar_id == avatar.id,
+                TakeoverMessage.owner_id == avatar.owner_id,
+                TakeoverMessage.peer_id == event.peer_id,
+                TakeoverMessage.direction == "incoming",
+                TakeoverMessage.message_type == BOXIM_IMAGE_MESSAGE_TYPE,
+                TakeoverMessage.is_avatar.is_(False),
+                TakeoverMessage.send_time >= threshold,
+                TakeoverMessage.send_time <= event.send_time,
+            )
+            .order_by(TakeoverMessage.send_time.desc())
+            .limit(MAX_RECENT_IMAGE_CONTEXTS)
+            .all()
+        )
+        if not candidates:
+            return []
+
+        current_ids = set(current_source_ids)
+        if references_image:
+            return [
+                image
+                for image in reversed(candidates)
+                if image.boxim_message_id not in current_ids
+            ]
+
+        handled_ids = set(current_ids)
+        task_sources = (
+            db.query(TakeoverReplyTask.source_message_ids)
+            .filter(
+                TakeoverReplyTask.avatar_id == avatar.id,
+                TakeoverReplyTask.owner_id == avatar.owner_id,
+                TakeoverReplyTask.peer_id == event.peer_id,
+                TakeoverReplyTask.created_at >= threshold,
+            )
+            .all()
+        )
+        for (source_message_ids,) in task_sources:
+            handled_ids.update(source_message_ids or [])
+
+        return [
+            image
+            for image in reversed(candidates)
+            if image.boxim_message_id not in handled_ids
+        ]
+
     async def _prepare_replies(self) -> int:
         db = self.session_factory()
         try:
@@ -766,6 +855,21 @@ class TakeoverService:
             db.commit()
 
             excluded_ids = set(task.source_message_ids or [])
+            source_events = {
+                event.boxim_message_id: event
+                for event in (
+                    db.query(TakeoverMessage)
+                    .filter(
+                        TakeoverMessage.owner_id == task.owner_id,
+                        TakeoverMessage.peer_id == task.peer_id,
+                        TakeoverMessage.avatar_id == task.avatar_id,
+                        TakeoverMessage.boxim_message_id.in_(excluded_ids),
+                    )
+                    .all()
+                    if excluded_ids
+                    else []
+                )
+            }
             events = (
                 db.query(TakeoverMessage)
                 .filter(
@@ -777,11 +881,6 @@ class TakeoverService:
                 .limit(30)
                 .all()
             )
-            source_events = {
-                event.boxim_message_id: event
-                for event in events
-                if event.boxim_message_id in excluded_ids
-            }
             image_attachments = []
             image_failed = False
             for message_id in (task.source_message_ids or [])[-3:]:
@@ -821,11 +920,7 @@ class TakeoverService:
             from routers.chat import _attachment_contexts, _resolve_reply
 
             image_contexts = _attachment_contexts(image_attachments)
-            has_source_text = any(
-                event.message_type == BOXIM_TEXT_MESSAGE_TYPE and event.content.strip()
-                for event in source_events.values()
-            )
-            if image_failed and not image_contexts and not has_source_text:
+            if image_failed and not image_contexts:
                 answer = BOXIM_IMAGE_UNAVAILABLE_REPLY
             else:
                 result = _resolve_reply(

digital-avatar-app/backend/tests/test_chat_images.py

@@ -12,6 +12,7 @@ from main import app
 from models import ChatAttachment
 from routers.chat import (
     ChatIn,
+    _answer_denies_available_image,
     _attachment_contexts,
     _load_chat_attachments,
     _resolve_reply,
@@ -274,6 +275,47 @@ def test_image_context_keeps_standard_answer_authoritative():
     assert "标准答题对中的事实优先级高于图片资料" in system
 
 
+def test_ready_image_context_never_returns_whole_image_access_denial():
+    avatar = SimpleNamespace(
+        id="avatar-vision",
+        name="测试分身",
+        description="产品顾问",
+        config={},
+    )
+    model = Mock(return_value="抱歉，我无法查看或识别图片，请重新上传。")
+    result = _resolve_reply(
+        None,
+        avatar,
+        "请看看这张图片",
+        [],
+        qa_pairs=[],
+        search_fn=Mock(return_value=[]),
+        model_client=model,
+        image_contexts=[{
+            "id": "attachment",
+            "filename": "report.jpg",
+            "category": "medical_document",
+            "summary": "一份耳鼻喉科门诊记录",
+            "extractedText": "主诉：咽痛三天",
+            "structuredData": {"key_facts": ["主诉为咽痛三天"]},
+            "warning": "请核对原始资料",
+        }],
+    )
+
+    assert result["source"] == "vision"
+    assert "一份耳鼻喉科门诊记录" in result["answer"]
+    assert "主诉为咽痛三天" in result["answer"]
+    assert "无法查看" not in result["answer"]
+    system = model.call_args.kwargs["messages"][0]["content"]
+    assert "当前会话图片已经成功读取" in system
+    assert "禁止声称无法查看" in system
+
+
+def test_image_denial_detector_allows_uncertain_field_in_ready_image():
+    assert _answer_denies_available_image("我无法查看这张图片") is True
+    assert _answer_denies_available_image("图片中患者姓名无法辨认，主诉为咽痛三天。") is False
+
+
 def test_attachment_context_does_not_expose_internal_fields():
     row = SimpleNamespace(
         id="attachment",

digital-avatar-app/backend/tests/test_takeover_service.py

@@ -85,6 +85,29 @@ class ConcurrentPollingBoxIM(FakeBoxIM):
         return []
 
 
+class ConcurrentMessagePollingBoxIM(ConcurrentPollingBoxIM):
+    async def fetch_private_messages(self, access_token, min_id="0"):
+        await super().fetch_private_messages(access_token, min_id)
+        owner_id = 100 if access_token == "prod-huihui-token" else 101
+        return [
+            {
+                "id": owner_id,
+                "localId": owner_id,
+                "sendId": owner_id + 100,
+                "recvId": owner_id,
+                "sendTime": 1_700_000_000_000,
+                "type": 0,
+                "content": "并发写入测试",
+            }
+        ]
+
+    async def mark_private_messages_read(self, access_token, friend_id, message_id):
+        await asyncio.sleep(0.05)
+        self.read_receipts.append(
+            {"friendId": str(friend_id), "messageId": str(message_id)}
+        )
+
+
 @pytest.fixture
 def service_context(tmp_path):
     engine = create_engine(
@@ -202,6 +225,7 @@ async def test_incoming_image_is_analyzed_and_used_in_takeover_reply(service_con
         assert scheduled.prompt == "请看看这张图片。"
     finally:
         db.close()
+
     clock.advance(3)
 
     def analyze(db, avatar, content, **kwargs):
@@ -262,6 +286,131 @@ async def test_incoming_image_is_analyzed_and_used_in_takeover_reply(service_con
         db.close()
 
 
+@pytest.mark.asyncio
+async def test_followup_text_recovers_recent_image_recorded_without_task(service_context):
+    session_factory, service, boxim, clock = service_context
+    await service.poll_and_process_messages()
+    image_message = {
+        "id": 113,
+        "localId": 113,
+        "sendId": 200,
+        "recvId": 100,
+        "sendTime": clock.millis(),
+        "type": 1,
+        "content": json.dumps(
+            {
+                "originUrl": "https://cdn.example/case.png",
+                "thumbUrl": "https://cdn.example/case-thumb.png",
+            }
+        ),
+    }
+
+    db = session_factory()
+    try:
+        avatar = db.get(Avatar, "avatar-1")
+        service._record_message(db, avatar, "100", image_message, schedule_reply=False)
+        cursor = db.query(TakeoverCursor).one()
+        cursor.last_message_id = "113"
+        db.commit()
+    finally:
+        db.close()
+
+    clock.advance(60)
+    boxim.messages.extend(
+        [
+            image_message,
+            {
+                "id": 114,
+                "localId": 114,
+                "sendId": 200,
+                "recvId": 100,
+                "sendTime": clock.millis(),
+                "type": 0,
+                "content": "请帮我看看这张图",
+            },
+        ]
+    )
+    await service.poll_messages()
+
+    db = session_factory()
+    try:
+        task = db.query(TakeoverReplyTask).filter_by(trigger_message_id="114").one()
+        assert task.source_message_ids == ["113", "114"]
+        assert task.prompt == "请看看这张图片。\n请帮我看看这张图"
+    finally:
+        db.close()
+
+    clock.advance(1)
+    boxim.messages.append(
+        {
+            "id": 115,
+            "localId": 115,
+            "sendId": 200,
+            "recvId": 100,
+            "sendTime": clock.millis(),
+            "type": 0,
+            "content": "图里写了什么",
+        }
+    )
+    await service.poll_messages()
+
+    db = session_factory()
+    try:
+        latest = db.query(TakeoverReplyTask).filter_by(trigger_message_id="115").one()
+        assert latest.source_message_ids == ["113", "114", "115"]
+        assert latest.source_message_ids.count("113") == 1
+    finally:
+        db.close()
+
+
+@pytest.mark.asyncio
+async def test_explicit_followup_reuses_handled_image_within_two_days(service_context):
+    session_factory, service, boxim, clock = service_context
+    await service.poll_and_process_messages()
+    image_message = {
+        "id": 116,
+        "localId": 116,
+        "sendId": 200,
+        "recvId": 100,
+        "sendTime": clock.millis(),
+        "type": 1,
+        "content": json.dumps({"originUrl": "https://cdn.example/handled-case.png"}),
+    }
+    boxim.messages.append(image_message)
+    await service.poll_messages()
+
+    db = session_factory()
+    try:
+        image_task = db.query(TakeoverReplyTask).filter_by(trigger_message_id="116").one()
+        image_task.status = "sent"
+        image_task.sent_at = clock.now()
+        db.commit()
+    finally:
+        db.close()
+
+    clock.advance(47 * 60 * 60)
+    boxim.messages.append(
+        {
+            "id": 117,
+            "localId": 117,
+            "sendId": 200,
+            "recvId": 100,
+            "sendTime": clock.millis(),
+            "type": 0,
+            "content": "重新看一下刚才那张病例图片",
+        }
+    )
+    await service.poll_messages()
+
+    db = session_factory()
+    try:
+        task = db.query(TakeoverReplyTask).filter_by(trigger_message_id="117").one()
+        assert task.source_message_ids == ["116", "117"]
+        assert task.prompt == "请看看这张图片。\n重新看一下刚才那张病例图片"
+    finally:
+        db.close()
+
+
 @pytest.mark.asyncio
 async def test_invalid_image_message_is_recorded_but_not_scheduled(service_context):
     session_factory, service, boxim, clock = service_context
@@ -347,7 +496,7 @@ async def test_multiple_avatar_owners_are_polled_concurrently(service_context):
     finally:
         db.close()
 
-    boxim = ConcurrentPollingBoxIM()
+    boxim = ConcurrentMessagePollingBoxIM()
     service = TakeoverService(
         session_factory,
         boxim,
@@ -361,6 +510,8 @@ async def test_multiple_avatar_owners_are_polled_concurrently(service_context):
     db = session_factory()
     try:
         assert db.query(TakeoverCursor).filter(TakeoverCursor.initialized.is_(True)).count() == 2
+        assert db.query(TakeoverMessage).count() == 2
+        assert len(boxim.read_receipts) == 2
     finally:
         db.close()