优化目录结构

routes.py

@@ -0,0 +1,66 @@
+from fastapi import APIRouter, HTTPException, Request, status
+
+from schemas import (
+    CreateSessionRequest,
+    CreateSessionResponse,
+    SendMessageRequest,
+    SendMessageResponse,
+    SessionHistoryResponse,
+)
+from service import ChatProviderError, ChatService
+from storage import SessionNotFoundError, SessionStorageError
+
+
+router = APIRouter(prefix="/sessions", tags=["sessions"])
+
+
+def get_chat_service(request: Request) -> ChatService:
+    return request.app.state.chat_service
+
+
+@router.post(
+    "",
+    response_model=CreateSessionResponse,
+    status_code=status.HTTP_201_CREATED,
+)
+async def create_session(
+    request: Request,
+    body: CreateSessionRequest | None = None,
+) -> CreateSessionResponse:
+    try:
+        return await get_chat_service(request).create_session(
+            body.system_prompt if body is not None else None
+        )
+    except SessionStorageError as exc:
+        raise HTTPException(status_code=500, detail=str(exc)) from exc
+
+
+@router.post("/{session_id}/messages", response_model=SendMessageResponse)
+async def send_message(
+    session_id: str,
+    body: SendMessageRequest,
+    request: Request,
+) -> SendMessageResponse:
+    try:
+        return await get_chat_service(request).generate_response(
+            session_id, body.content
+        )
+    except SessionNotFoundError as exc:
+        raise HTTPException(status_code=404, detail="session not found") from exc
+    except ChatProviderError as exc:
+        raise HTTPException(status_code=502, detail=str(exc)) from exc
+    except SessionStorageError as exc:
+        raise HTTPException(status_code=500, detail=str(exc)) from exc
+
+
+@router.get("/{session_id}/messages", response_model=SessionHistoryResponse)
+async def get_session_history(
+    session_id: str,
+    request: Request,
+) -> SessionHistoryResponse:
+    try:
+        return await get_chat_service(request).get_session_history(session_id)
+    except SessionNotFoundError as exc:
+        raise HTTPException(status_code=404, detail="session not found") from exc
+    except SessionStorageError as exc:
+        raise HTTPException(status_code=500, detail=str(exc)) from exc