"""从 OHLC DataFrame 计算指标，不触碰缠论结构对象。"""

from __future__ import annotations

from typing import Optional

import talib.abstract as ta
import pandas as pd

from .config import IndicatorConfig
from .store import IndicatorStore


def _volume_ratio(df: pd.DataFrame, window: int = 10) -> pd.Series:
    vol = df["volume"].astype(float)
    ma = vol.rolling(window=window).mean()
    ratio = vol / ma
    return ratio.fillna(1.0)


class IndicatorEngine:
    def __init__(self, config: Optional[IndicatorConfig] = None):
        self.config = config or IndicatorConfig()

    def compute(self, df: pd.DataFrame, config: Optional[IndicatorConfig] = None) -> IndicatorStore:
        cfg = config or self.config
        out = df.copy()
        fast, slow, period = cfg.macd_fast, cfg.macd_slow, cfg.macd_signal
        macd = ta.MACD(out, fastperiod=fast, slowperiod=slow, signalperiod=period)
        out["macd"] = macd["macd"]
        out["macdsignal"] = macd["macdsignal"]
        out["macdhist"] = macd["macdhist"]

        for period_n in cfg.ema_periods:
            out[f"ema{period_n}"] = ta.EMA(out, timeperiod=period_n)

        out["rsi"] = ta.RSI(out, timeperiod=cfg.rsi_period)
        out["atr"] = ta.ATR(out, timeperiod=cfg.atr_period)
        out["volume_ratio"] = _volume_ratio(out)

        bb_middle = ta.SMA(out, timeperiod=cfg.bb_middle_sma_period)
        for bb_period, nbup, nbdn, suffix in cfg.bbands:
            bb = ta.BBANDS(
                out,
                timeperiod=bb_period,
                nbdevup=nbup,
                nbdevdn=nbdn,
                matype=0,
            )
            bbp = (out["close"] - bb["lowerband"]) / (bb["upperband"] - bb["lowerband"])
            if suffix == "2633":
                out["bb2633upper"] = bb["upperband"]
                out["bb2633lower"] = bb["lowerband"]
                out["bb2633middle"] = bb["middleband"]
                out["bbp2633"] = bbp
            elif suffix == "365":
                out["bbup365"] = bb["upperband"]
                out["bblow365"] = bb["lowerband"]
                out["bbp365"] = bbp
            elif suffix == "120":
                out["bbup120"] = bb["upperband"]
                out["bblow120"] = bb["lowerband"]
                out["bbp120"] = bbp
            elif suffix == "30":
                out["bbup30"] = bb["upperband"]
                out["bblow30"] = bb["lowerband"]
                out["bbmiddle30"] = bb_middle
                out["bbp30"] = bbp
            elif suffix == "302":
                out["bbup302"] = bb["upperband"]
                out["bblow302"] = bb["lowerband"]
                out["bbp302"] = bbp

        return IndicatorStore(out)