"""测试辅助函数。"""
from __future__ import annotations

import numpy as np
import pandas as pd


def make_ohlcv(n: int = 400, seed: int = 42) -> pd.DataFrame:
    rng = np.random.default_rng(seed)
    dates = pd.date_range("2024-01-01", periods=n, freq="5min", tz="UTC")
    rets = rng.normal(0, 0.002, size=n)
    close = 100 * np.exp(np.cumsum(rets))
    open_ = np.roll(close, 1)
    open_[0] = close[0]
    spread = np.abs(rng.normal(0, 0.0015, size=n)) * close
    high = np.maximum(open_, close) + spread
    low = np.minimum(open_, close) - spread
    volume = rng.uniform(100, 1000, size=n)
    return pd.DataFrame(
        {
            "date": dates,
            "open": open_,
            "high": high,
            "low": low,
            "close": close,
            "volume": volume,
        }
    )