feat: routing

backend/main.py

@@ -1,4 +1,4 @@
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Literal, Tuple
 from fastapi import FastAPI, HTTPException
 from fastapi.encoders import jsonable_encoder
 from fastapi.responses import StreamingResponse
@@ -6,6 +6,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from pydantic import BaseModel
 import asyncio
 import json
+import re
 from datetime import datetime
 
 from app.api import upload, llm, skills, users, datasources, projects, semantic
@@ -83,13 +84,58 @@ class ChatRequest(BaseModel):
     source: str = "postgres"
     prefer_sql_chart: bool = False
     file_url: Optional[str] = None
+    route_mode: Literal["auto", "chat", "sql"] = "auto"
 
 
-def _should_use_nl2sql(request: ChatRequest) -> bool:
+def _session_context_for_routing(session_id: str) -> Dict[str, Any]:
+    if not nanobot_service.agent:
+        return {}
+    session = nanobot_service.agent.sessions.get_or_create(session_id)
+    return session.metadata or {}
+
+
+def _looks_like_sql_intent(message: str) -> bool:
+    text = (message or "").strip().lower()
+    if not text:
+        return False
+    deny_patterns = [
+        r"\b(sql|query)\b.*(解释|说明|改写|优化|翻译)",
+        r"(解释|说明|改写|优化|翻译).*\b(sql|query)\b",
+        r"(写|生成).*(python|脚本|代码)",
+    ]
+    for pattern in deny_patterns:
+        if re.search(pattern, text, re.IGNORECASE):
+            return False
+    positive_patterns = [
+        r"\b(select|from|where|group by|order by|having|join|union|limit)\b",
+        r"(统计|汇总|分组|排序|筛选|过滤|环比|同比|趋势|top\s*\d+|前\d+|占比|均值|平均|最大|最小|总数|总量|明细)",
+        r"(多少|几条|多少条|有多少|查询|检索|按.*(天|周|月|年))",
+        r"(chart|plot|visuali[sz]e|dashboard)",
+    ]
+    for pattern in positive_patterns:
+        if re.search(pattern, text, re.IGNORECASE):
+            return True
+    return False
+
+
+def _should_use_nl2sql(request: ChatRequest) -> Tuple[bool, str]:
+    if request.route_mode == "sql":
+        return True, "route_mode=sql"
+    if request.route_mode == "chat":
+        return False, "route_mode=chat"
     if request.prefer_sql_chart:
-        return True
+        return True, "prefer_sql_chart=true"
+    has_sql_intent = _looks_like_sql_intent(request.message)
+    if not has_sql_intent:
+        return False, "message_non_sql_intent"
+    session_ctx = _session_context_for_routing(request.session_id)
+    selected_data_source = (session_ctx.get("selected_data_source") or "").strip().lower()
+    if selected_data_source.startswith("ds:") or selected_data_source == "upload":
+        return True, "message_sql_intent_with_session_datasource"
     source = (request.source or "").strip().lower()
-    return source == "upload" or source.startswith("ds:")
+    if source == "upload" or source.startswith("ds:"):
+        return True, "message_sql_intent_with_request_datasource"
+    return True, "message_sql_intent"
 
 
 class SessionAliasUpdateRequest(BaseModel):
@@ -146,7 +192,8 @@ def _persist_session_turn(
 @app.post("/nanobot/chat")
 async def nanobot_chat(request: ChatRequest):
     try:
-        if _should_use_nl2sql(request):
+        use_nl2sql, route_reason = _should_use_nl2sql(request)
+        if use_nl2sql:
             nl2sql_result = await process_nl2sql(
                 NL2SQLRequest(query=request.message, source=request.source, file_url=request.file_url)
             )
@@ -156,6 +203,7 @@ async def nanobot_chat(request: ChatRequest):
             return {
                 "response": text,
                 "viz": viz_payload,
+                "routing": {"selected": "sql", "reason": route_reason},
             }
         response = await nanobot_service.process_message(
             request.message,
@@ -163,7 +211,7 @@ async def nanobot_chat(request: ChatRequest):
             skill_ids=request.skill_ids,
             model_id=request.model_id,
         )
-        return {"response": response}
+        return {"response": response, "routing": {"selected": "chat", "reason": route_reason}}
     except Exception as e:
         raise HTTPException(status_code=500, detail=str(e))
 
@@ -171,7 +219,9 @@ async def nanobot_chat(request: ChatRequest):
 async def nanobot_chat_stream(request: ChatRequest):
     async def event_generator():
         try:
-            if _should_use_nl2sql(request):
+            use_nl2sql, route_reason = _should_use_nl2sql(request)
+            yield f"data: {json.dumps({'type': 'routing', 'selected': 'sql' if use_nl2sql else 'chat', 'reason': route_reason}, ensure_ascii=False)}\n\n"
+            if use_nl2sql:
                 nl2sql_result = await process_nl2sql(
                     NL2SQLRequest(query=request.message, source=request.source, file_url=request.file_url)
                 )