# -*- coding: utf-8 -*-
# Know Sure Thing (KST)
from typing import Any, Optional
from pandas import DataFrame, Series
from .roc import roc
from pandas_ta_classic.utils import get_drift, get_offset, verify_series


def kst(
    close: Series,
    roc1: Optional[int] = None,
    roc2: Optional[int] = None,
    roc3: Optional[int] = None,
    roc4: Optional[int] = None,
    sma1: Optional[int] = None,
    sma2: Optional[int] = None,
    sma3: Optional[int] = None,
    sma4: Optional[int] = None,
    signal: Optional[int] = None,
    drift: Optional[int] = None,
    offset: Optional[int] = None,
    **kwargs: Any,
) -> Optional[DataFrame]:
    """Indicator: 'Know Sure Thing' (KST)"""
    # Validate arguments
    roc1 = int(roc1) if roc1 and roc1 > 0 else 10
    roc2 = int(roc2) if roc2 and roc2 > 0 else 15
    roc3 = int(roc3) if roc3 and roc3 > 0 else 20
    roc4 = int(roc4) if roc4 and roc4 > 0 else 30

    sma1 = int(sma1) if sma1 and sma1 > 0 else 10
    sma2 = int(sma2) if sma2 and sma2 > 0 else 10
    sma3 = int(sma3) if sma3 and sma3 > 0 else 10
    sma4 = int(sma4) if sma4 and sma4 > 0 else 15

    signal = int(signal) if signal and signal > 0 else 9
    _length = max(roc1, roc2, roc3, roc4, sma1, sma2, sma3, sma4, signal)
    close = verify_series(close, _length)
    drift = get_drift(drift)
    offset = get_offset(offset)

    if close is None:
        return None

    # Calculate Result
    rocma1 = roc(close, roc1).rolling(sma1).mean()
    rocma2 = roc(close, roc2).rolling(sma2).mean()
    rocma3 = roc(close, roc3).rolling(sma3).mean()
    rocma4 = roc(close, roc4).rolling(sma4).mean()

    kst = 100 * (rocma1 + 2 * rocma2 + 3 * rocma3 + 4 * rocma4)
    kst_signal = kst.rolling(signal).mean()

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

    # Handle fills
    if "fillna" in kwargs:
        kst.fillna(kwargs["fillna"], inplace=True)
        kst_signal.fillna(kwargs["fillna"], inplace=True)
    if "fill_method" in kwargs:
        if "fill_method" in kwargs:

            if kwargs["fill_method"] == "ffill":

                kst.ffill(inplace=True)

            elif kwargs["fill_method"] == "bfill":

                kst.bfill(inplace=True)
        if "fill_method" in kwargs:

            if kwargs["fill_method"] == "ffill":

                kst_signal.ffill(inplace=True)

            elif kwargs["fill_method"] == "bfill":

                kst_signal.bfill(inplace=True)

    # Name and Categorize it
    kst.name = f"KST_{roc1}_{roc2}_{roc3}_{roc4}_{sma1}_{sma2}_{sma3}_{sma4}"
    kst_signal.name = f"KSTs_{signal}"
    kst.category = kst_signal.category = "momentum"

    # Prepare DataFrame to return
    data = {kst.name: kst, kst_signal.name: kst_signal}
    kstdf = DataFrame(data)
    kstdf.name = f"KST_{roc1}_{roc2}_{roc3}_{roc4}_{sma1}_{sma2}_{sma3}_{sma4}_{signal}"
    kstdf.category = "momentum"

    return kstdf


kst.__doc__ = """'Know Sure Thing' (KST)

The 'Know Sure Thing' is a momentum based oscillator and based on ROC.

Sources:
    https://www.tradingview.com/wiki/Know_Sure_Thing_(KST)
    https://www.incrediblecharts.com/indicators/kst.php

Calculation:
    Default Inputs:
        roc1=10, roc2=15, roc3=20, roc4=30,
        sma1=10, sma2=10, sma3=10, sma4=15, signal=9, drift=1
    ROC = Rate of Change
    SMA = Simple Moving Average
    rocsma1 = SMA(ROC(close, roc1), sma1)
    rocsma2 = SMA(ROC(close, roc2), sma2)
    rocsma3 = SMA(ROC(close, roc3), sma3)
    rocsma4 = SMA(ROC(close, roc4), sma4)

    KST = 100 * (rocsma1 + 2 * rocsma2 + 3 * rocsma3 + 4 * rocsma4)
    KST_Signal = SMA(KST, signal)

Args:
    close (pd.Series): Series of 'close's
    roc1 (int): ROC 1 period. Default: 10
    roc2 (int): ROC 2 period. Default: 15
    roc3 (int): ROC 3 period. Default: 20
    roc4 (int): ROC 4 period. Default: 30
    sma1 (int): SMA 1 period. Default: 10
    sma2 (int): SMA 2 period. Default: 10
    sma3 (int): SMA 3 period. Default: 10
    sma4 (int): SMA 4 period. Default: 15
    signal (int): It's period. Default: 9
    drift (int): The difference period. Default: 1
    offset (int): How many periods to offset the result. Default: 0

Kwargs:
    fillna (value, optional): pd.DataFrame.fillna(value)
    fill_method (value, optional): Type of fill method

Returns:
    pd.DataFrame: kst and kst_signal columns
"""
