added RAG, Multiuser, TG bot

backend/app/api/routes/chat.py.refactor_bak

@@ -0,0 +1,70 @@
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import StreamingResponse
+from sqlalchemy.orm import Session
+
+from app.api.schemas import MessageCreate, MessageOut, SessionCreate, SessionDetailOut, SessionOut
+from app.chat.service import ChatService
+from app.db.base import get_db
+
+router = APIRouter()
+
+
+@router.post("/sessions", response_model=SessionOut)
+def create_session(payload: SessionCreate, db: Session = Depends(get_db)) -> SessionOut:
+    service = ChatService(db)
+    return service.create_session(title=payload.title)
+
+
+@router.get("/sessions", response_model=list[SessionOut])
+def list_sessions(db: Session = Depends(get_db)) -> list[SessionOut]:
+    service = ChatService(db)
+    return service.list_sessions()
+
+
+@router.get("/sessions/{session_id}", response_model=SessionDetailOut)
+def get_session(session_id: int, db: Session = Depends(get_db)) -> SessionDetailOut:
+    service = ChatService(db)
+    session = service.get_session(session_id)
+    if not session:
+        raise HTTPException(status_code=404, detail="Session not found")
+    return session
+
+
+@router.delete("/sessions/{session_id}")
+def delete_session(session_id: int, db: Session = Depends(get_db)) -> dict[str, bool]:
+    service = ChatService(db)
+    if not service.delete_session(session_id):
+        raise HTTPException(status_code=404, detail="Session not found")
+    return {"ok": True}
+
+
+@router.post("/sessions/{session_id}/messages")
+async def send_message(
+    session_id: int,
+    payload: MessageCreate,
+    db: Session = Depends(get_db),
+) -> StreamingResponse:
+    service = ChatService(db)
+    if not service.get_session(session_id):
+        raise HTTPException(status_code=404, detail="Session not found")
+
+    # Сохраняем user до стрима: иначе при обрыве SSE сообщение не попадает в БД.
+    service.save_user_message(session_id, payload.content)
+
+    async def event_stream():
+        async for chunk in service.stream_response(
+            session_id,
+            payload.content,
+            user_message_saved=True,
+        ):
+            yield chunk
+
+    return StreamingResponse(
+        event_stream(),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",
+        },
+    )