import httpx
from typing import Optional

async def fetch_product(barcode: str) -> Optional[dict]:
    url = f"https://world.openfoodfacts.org/api/v2/product/{barcode}.json"
    headers = {"User-Agent": "Aletheia/1.0 (contato@aletheia.app)"}
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            resp = await client.get(url, headers=headers)
            if resp.status_code != 200:
                return None
            data = resp.json()
            if data.get("status") != 1:
                return None
            p = data["product"]
            return {
                "name": p.get("product_name") or p.get("product_name_pt") or "Produto desconhecido",
                "brand": p.get("brands", ""),
                "category": p.get("categories", ""),
                "ingredients_text": p.get("ingredients_text") or p.get("ingredients_text_pt") or "",
                "nutri_score": (p.get("nutriscore_grade") or "").lower(),
                "nova_group": p.get("nova_group"),
                "nutrition": p.get("nutriments", {}),
                "image_url": p.get("image_url", ""),
            }
    except Exception:
        return None