# -*- coding: utf-8 -*-
from numpy import average, log, nan, sqrt, zeros_like
from numpy import power as np_power
from pandas import Series
from pandas_ta._typing import DictLike, Int, IntFloat
from pandas_ta.utils import v_float, v_offset, v_pos_default, v_series



def jma(
    close: Series, length: IntFloat = None, phase: IntFloat = None,
    offset: Int = None, **kwargs: DictLike
) -> Series:
    """Jurik Moving Average Average

    This indicator, by Mark Jurik, attempts to eliminate noise. It claims
    to have extremely low lag, is very smooth and is responsive to gaps.

    Sources:
        * [mql5](https://c.mql5.com/forextsd/forum/164/jurik_1.pdf)
        * [prorealcode](https://www.prorealcode.com/prorealtime-indicators/jurik-volatility-bands/)

    Parameters:
        close (Series): ```close``` Series
        length (int): The period. Default: ```7```
        phase (float): Phase value between [-100, 100]. Default: ```0```
        offset (int): Post shift. Default: ```0```

    Other Parameters:
        fillna (value): ```pd.DataFrame.fillna(value)```

    Returns:
        (Series): 1 column
    """
    # Validate
    _length = v_pos_default(length, 7)
    close = v_series(close, _length)

    if close is None:
        return

    phase = v_float(phase, 0.0)
    offset = v_offset(offset)

    # Calculate
    jma = zeros_like(close)
    volty = zeros_like(close)
    v_sum = zeros_like(close)

    kv = det0 = det1 = ma2 = 0.0
    jma[0] = ma1 = uBand = lBand = close.iloc[0]

    # Static variables
    sum_length = 10
    length = 0.5 * (_length - 1)
    pr = 0.5 if phase < -100 else 2.5 if phase > 100 else 1.5 + phase * 0.01
    length1 = max((log(sqrt(length)) / log(2.0)) + 2.0, 0)
    pow1 = max(length1 - 2.0, 0.5)
    length2 = length1 * sqrt(length)
    bet = length2 / (length2 + 1)
    beta = 0.45 * (_length - 1) / (0.45 * (_length - 1) + 2.0)

    m = close.shape[0]
    for i in range(1, m):
        price = close.iloc[i]

        # Price volatility
        del1 = price - uBand
        del2 = price - lBand
        volty[i] = max(abs(del1), abs(del2)) if abs(del1) != abs(del2) else 0

        # Relative price volatility factor
        v_sum[i] = v_sum[i - 1] + \
            (volty[i] - volty[max(i - sum_length, 0)]) / sum_length
        avg_volty = average(v_sum[max(i - 65, 0):i + 1])
        d_volty = 0 if avg_volty == 0 else volty[i] / avg_volty
        r_volty = max(1.0, min(np_power(length1, 1 / pow1), d_volty))
        # r_volty = max(1.0, min(length1 **(1 / pow1), d_volty))

        # Jurik volatility bands
        pow2 = np_power(r_volty, pow1)
        kv = np_power(bet, sqrt(pow2))
        uBand = price if (del1 > 0) else price - (kv * del1)
        lBand = price if (del2 < 0) else price - (kv * del2)

        # Jurik Dynamic Factor
        power = np_power(r_volty, pow1)
        alpha = np_power(beta, power)

        # 1st stage - preliminary smoothing by adaptive EMA
        ma1 = (1 - alpha) * price + alpha * ma1

        # 2nd stage - one more preliminary smoothing by Kalman filter
        det0 = (1 - beta) * (price - ma1) + beta * det0
        ma2 = ma1 + pr * det0

        # 3rd stage - final smoothing by unique Jurik adaptive filter
        det1 = ((ma2 - jma[i - 1]) * (1 - alpha) * \
                (1 - alpha)) + (alpha * alpha * det1)
        jma[i] = jma[i - 1] + det1

    jma = Series(jma, index=close.index)
    jma.iloc[0:_length - 1] = nan

    # Offset
    if offset != 0:
        jma = jma.shift(offset)

    # Fill
    if "fillna" in kwargs:
        jma.fillna(kwargs["fillna"], inplace=True)

    # Name and Category
    jma.name = f"JMA_{_length}_{phase}"
    jma.category = "overlap"

    return jma