fix: speed up chat detail pagination

ai_knowledge_base_v2/apps/backend/app/api/admin_records.py

@@ -80,6 +80,28 @@ def export_chats(
     )
 
 
+@router.get("/chat/{session_id}/messages")
+def chat_messages(
+    session_id: int,
+    page: int = Query(default=1, ge=1),
+    pageSize: int = Query(default=20, ge=10, le=100),
+    db: Session = Depends(get_db),
+    current_admin: Admin = Depends(get_current_admin),
+) -> dict:
+    exists_session = db.scalar(select(ChatSession.id).where(ChatSession.id == session_id))
+    if exists_session is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="会话不存在")
+    message_query = select(ChatMessage).where(ChatMessage.session_id == session_id)
+    total = db.scalar(select(func.count()).select_from(message_query.subquery())) or 0
+    messages = db.scalars(
+        message_query
+        .order_by(ChatMessage.created_at.asc(), ChatMessage.id.asc())
+        .offset((page - 1) * pageSize)
+        .limit(pageSize)
+    ).all()
+    return api_success(page_result([_message_dict(item) for item in messages], total=total, page=page, page_size=pageSize))
+
+
 @router.get("/chat/{session_id}")
 def chat_detail(
     session_id: int,

ai_knowledge_base_v2/apps/backend/tests/test_admin_pagination.py

@@ -3,7 +3,7 @@ from sqlalchemy.orm import Session
 from sqlalchemy.pool import StaticPool
 
 from app.api.admin_agent_records import attention_list, retrieval_logs
-from app.api.admin_records import ai_logs, chat_detail
+from app.api.admin_records import ai_logs, chat_detail, chat_messages
 from app.api.admin_users import list_users
 from app.models import Base
 from app.models.chat import ChatMessage, ChatSession
@@ -65,6 +65,27 @@ def test_chat_detail_messages_are_paginated():
         assert data["messages"][0]["content"] == "消息11"
 
 
+def test_chat_messages_endpoint_returns_only_message_page():
+    with _database() as db:
+        user = User(id=1, phone="13800000000", name="学员", daily_chat_limit=10)
+        session = ChatSession(id=1, user_id=1, title="长会话", message_count=12)
+        db.add_all([user, session])
+        db.add_all([
+            ChatMessage(id=index + 1, session_id=1, user_id=1, role="user", content=f"消息{index + 1}")
+            for index in range(12)
+        ])
+        db.add(AiRequestLog(session_id=1, status="success", prompt="p" * 5000, retrieved_chunks='[{"content":"large"}]'))
+        db.commit()
+
+        response = chat_messages(1, page=2, pageSize=10, db=db, current_admin=object())
+
+        data = response["data"]
+        assert data["total"] == 12
+        assert len(data["items"]) == 2
+        assert data["items"][0]["content"] == "消息11"
+        assert "aiLogs" not in data
+
+
 def test_retrieval_and_attention_lists_are_paginated():
     with _database() as db:
         for index in range(21):