from fastapi import APIRouter
from functools import lru_cache
import json
import asyncio

router = APIRouter(prefix='/api/v1', tags=['tariffs'])

@lru_cache(maxsize=1)
def get_tariffs_sync():
    with open('data/tariffs.json', 'r', encoding='utf-8') as f:
        return json.load(f)

@router.get('/tariffs')
async def get_tariffs():
    return await asyncio.to_thread(get_tariffs_sync)