from datetime import date

import requests

CBU_URL = "https://cbu.uz/oz/arkhiv-kursov-valyut/json/{code}/{date}/"
TIMEOUT_SECONDS = 5
CURRENCY_CODES = ("USD", "EUR", "RUB")


def fetch_rates(target_date):
    """CBU.uz dan berilgan sanaga oid USD, EUR, RUB kurslarini olish.

    Tarmoq xatosi yoki notogri javob bolsa bosh dict qaytadi.
    """
    if target_date is None:
        target_date = date.today()
    date_str = target_date.strftime("%Y-%m-%d")
    rates = {}
    for code in CURRENCY_CODES:
        try:
            resp = requests.get(
                CBU_URL.format(code=code, date=date_str),
                timeout=TIMEOUT_SECONDS,
            )
            resp.raise_for_status()
            data = resp.json()
            if isinstance(data, list) and data:
                rate_value = data[0].get("Rate")
                if rate_value:
                    rates[code] = rate_value
        except (requests.RequestException, ValueError):
            continue
    return rates