"""CSI 300 (HS300) universe helpers."""
import logging

import baostock as bs
import pandas as pd

logger = logging.getLogger(__name__)

# First 30 HS300 constituents (large caps) in 'shXXXXXX' / 'szXXXXXX' format.
# Hardcoded for fast, deterministic smoke tests. Use get_hs300_stocks() for the
# live, full list — downloading daily bars for all ~300 takes roughly 10 minutes.
SYMBOLS = [
    "sh600000", "sh600009", "sh600010", "sh600028", "sh600030",
    "sh600036", "sh600048", "sh600050", "sh600104", "sh600276",
    "sh600309", "sh600519", "sh600585", "sh600887", "sh600900",
    "sh601012", "sh601166", "sh601288", "sh601318", "sh601398",
    "sh601628", "sh601668", "sh601857", "sh601888", "sh601988",
    "sz000001", "sz000002", "sz000333", "sz000651", "sz000858",
]


def get_hs300_stocks() -> pd.DataFrame:
    """Fetch the current CSI 300 constituents from baostock.

    Returns:
        DataFrame with columns ``code`` (e.g. ``sh600000``), ``name``, ``date``.
    """
    bs.login()
    try:
        rs = bs.query_hs300_stocks()
        stocks = []
        while rs.next():
            stocks.append(rs.get_row_data())
    finally:
        bs.logout()
    df = pd.DataFrame(stocks, columns=["code", "name", "date"])
    df["code"] = df["code"].str.replace(".", "", regex=False)
    return df