添加rag置信度判断

backend/app/main_graph/nodes/fast_paths.py

@@ -7,7 +7,7 @@ from typing import Optional
 from langchain_core.runnables.config import RunnableConfig
 
 from ..state import MainGraphState
-from ...logger import info, debug
+from backend.app.logger import info, debug
 from ...model_services.chat_services import get_small_llm_service, get_chat_service
 from .rag_nodes import rag_retrieve_node
 from ._utils import dispatch_custom_event
@@ -113,10 +113,18 @@ async def fast_rag_node(state: MainGraphState, config: Optional[RunnableConfig]
 
 
 def _has_valid_rag_results(state: MainGraphState) -> bool:
-    """检查 RAG 结果是否有效"""
-    rag_docs = getattr(state, "rag_docs", [])
+    """检查 RAG 结果是否有效（基于置信度）"""
+    from .rag_nodes import RAG_CONFIDENCE_THRESHOLD
     rag_context = getattr(state, "rag_context", "")
-    return (rag_docs and len(rag_docs) > 0) or (rag_context and len(rag_context) > 10)
+    rag_confidence = getattr(state, "rag_confidence", 0.0)
+
+    # 有结果且置信度足够
+    has_content = rag_context and len(rag_context) > 0
+    has_confidence = rag_confidence >= RAG_CONFIDENCE_THRESHOLD
+
+    info(f"[Fast RAG Check] has_content={has_content}, rag_confidence={rag_confidence:.2f}, threshold={RAG_CONFIDENCE_THRESHOLD}")
+
+    return has_content and has_confidence
 
 
 async def _generate_fast_answer(state: MainGraphState, query: str) -> MainGraphState: