# -*- coding: utf-8 -*-
"""
技术指标计算：MA / RSI / MACD / KDJ / 量比 / 动量 / 波动率
输入 bars：按日期升序的 [{date, open, high, low, close, volume}, ...]
"""
import math


def _sma(vals, n):
    if len(vals) < n:
        return None
    return sum(vals[-n:]) / n


def _ema(vals, n):
    if not vals:
        return None
    k = 2 / (n + 1)
    e = vals[0]
    for v in vals[1:]:
        e = v * k + e * (1 - k)
    return e


def _ema_series(vals, n):
    out = []
    if not vals:
        return out
    k = 2 / (n + 1)
    e = vals[0]
    out.append(e)
    for v in vals[1:]:
        e = v * k + e * (1 - k)
        out.append(e)
    return out


def rsi14(closes):
    """Wilder RSI(14)"""
    if len(closes) < 15:
        return 50.0
    gains, losses = [], []
    for i in range(1, len(closes)):
        chg = closes[i] - closes[i - 1]
        gains.append(max(chg, 0))
        losses.append(max(-chg, 0))
    avg_g = sum(gains[:14]) / 14
    avg_l = sum(losses[:14]) / 14
    for i in range(14, len(gains)):
        avg_g = (avg_g * 13 + gains[i]) / 14
        avg_l = (avg_l * 13 + losses[i]) / 14
    if avg_l == 0:
        return 100.0
    rs = avg_g / avg_l
    return 100 - 100 / (1 + rs)


def kdj(bars, n=9, k_smooth=3, d_smooth=3):
    """返回 (K, D, J)"""
    if len(bars) < n:
        return 50.0, 50.0, 50.0
    k, d = 50.0, 50.0
    for i in range(n - 1, len(bars)):
        window = bars[i - n + 1:i + 1]
        low_n = min(b["low"] for b in window)
        high_n = max(b["high"] for b in window)
        rsv = 0 if high_n == low_n else (bars[i]["close"] - low_n) / (high_n - low_n) * 100
        k = (k * (k_smooth - 1) + rsv) / k_smooth
        d = (d * (d_smooth - 1) + k) / d_smooth
    j = 3 * k - 2 * d
    return k, d, j


def compute_indicators(bars):
    """计算全部技术指标，返回 dict（最新值 + 序列用于画图）"""
    if not bars:
        return {}
    closes = [b["close"] for b in bars]
    last = bars[-1]
    prev = bars[-2] if len(bars) > 1 else last

    ma5 = _sma(closes, 5)
    ma10 = _sma(closes, 10)
    ma20 = _sma(closes, 20)
    ma60 = _sma(closes, 60)

    # MACD
    ema12 = _ema_series(closes, 12)
    ema26 = _ema_series(closes, 26)
    dif_series = [e12 - e26 for e12, e26 in zip(ema12, ema26)]
    dea_series = _ema_series(dif_series, 9)
    dif = dif_series[-1] if dif_series else 0
    dea = dea_series[-1] if dea_series else 0
    macd = (dif - dea) * 2

    rsi = rsi14(closes)
    k, d, j = kdj(bars)

    # 涨跌幅
    chg_1d = (last["close"] - prev["close"]) / prev["close"] * 100 if prev["close"] else 0
    chg_5d = (last["close"] - closes[-6]) / closes[-6] * 100 if len(closes) > 6 else chg_1d
    chg_10d = (last["close"] - closes[-11]) / closes[-11] * 100 if len(closes) > 11 else chg_1d
    chg_20d = (last["close"] - closes[-21]) / closes[-21] * 100 if len(closes) > 21 else chg_1d

    # 量比 = 今日量 / 前5日均量
    vol_ratio = 1.0
    if len(bars) > 6:
        avg5 = sum(b["volume"] for b in bars[-6:-1]) / 5
        if avg5 > 0:
            vol_ratio = last["volume"] / avg5

    # 20日波动率（年化近似省略，日波动）
    returns = []
    for i in range(1, len(closes)):
        if closes[i - 1]:
            returns.append((closes[i] - closes[i - 1]) / closes[i - 1])
    vol20 = (sum(r * r for r in returns[-20:]) / max(len(returns[-20:]), 1)) ** 0.5 * 100 if returns else 0

    # 区间高低（近120日）
    window = bars[-120:] if len(bars) > 120 else bars
    high52 = max(b["high"] for b in window)
    low52 = min(b["low"] for b in window)

    # 均线多头排列
    if ma5 and ma10 and ma20:
        bull = ma5 > ma10 > ma20
        partial = ma5 > ma10 or ma10 > ma20
    else:
        bull, partial = False, False

    return {
        "date": last["date"],
        "close": last["close"],
        "open": last["open"],
        "high": last["high"],
        "low": last["low"],
        "volume": last["volume"],
        "change_pct": round(chg_1d, 2),
        "chg_5d": round(chg_5d, 2),
        "chg_10d": round(chg_10d, 2),
        "chg_20d": round(chg_20d, 2),
        "ma5": round(ma5, 2) if ma5 else None,
        "ma10": round(ma10, 2) if ma10 else None,
        "ma20": round(ma20, 2) if ma20 else None,
        "ma60": round(ma60, 2) if ma60 else None,
        "rsi": round(rsi, 2),
        "kdj_k": round(k, 2),
        "kdj_d": round(d, 2),
        "kdj_j": round(j, 2),
        "dif": round(dif, 3),
        "dea": round(dea, 3),
        "macd": round(macd, 3),
        "vol_ratio": round(vol_ratio, 2),
        "volatility": round(vol20, 2),
        "high_52w": round(high52, 2),
        "low_52w": round(low52, 2),
        "trend_bull": bull,
        "trend_partial": partial,
        "bars": [
            {"date": b["date"], "open": b["open"], "high": b["high"],
             "low": b["low"], "close": b["close"], "volume": b["volume"]}
            for b in bars
        ],
    }