# For education purposes 
# Ported to Indie from https://www.tradingview.com/script/HFGx4ote-Indicator-Weis-Wave-Volume-LazyBear/
# The author of the original indicator is @LazyBear

# This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.  
# If a copy of the MPL was not distributed with this file, you can obtain one at  
# <https://mozilla.org/MPL/2.0/>.

# indie:lang_version = 5
import math
from indie import indicator, SeriesF, MutSeriesF, param, plot, color


def rising(src: SeriesF, length: int) -> bool:
    for i in range(length):
        if not (src[i] > src[i + 1]):
            return False
    return True


def falling(src: SeriesF, length: int) -> bool:
    for i in range(length):
        if not (src[i] < src[i + 1]):
            return False
    return True


def nan_to_zero(val: float) -> float:
    return 0 if math.isnan(val) else val


@indicator('Weis Wave Volume')
@param.int('trend_detection_length', default=2, min=1, title='Trend detection length')
@param.bool('show_distribution_below_zero', default=False, title='Show Distribution Below Zero')
@plot.columns(id='#plot_0')
def Main(self, trend_detection_length, show_distribution_below_zero):
    mov = 0
    if self.close[0] > self.close[1]:
        mov = 1
    elif self.close[0] < self.close[1]:
        mov = -1

    is_trending = rising(self.close, trend_detection_length) or falling(self.close, trend_detection_length)

    wave = MutSeriesF.new(0)
    if mov != nan_to_zero(wave[1]) and is_trending:
        wave[0] = mov
    else:
        wave[0] = nan_to_zero(wave[1])

    vol = MutSeriesF.new(0)
    if wave[0] == wave[1]:
        vol[0] = nan_to_zero(vol[1]) + self.volume[0]
    else:
        vol[0] = self.volume[0]

    col = color.GREEN if wave[0] == 1 else color.RED
    res = vol[0]
    if show_distribution_below_zero:
        res = vol[0] * wave[0]

    return plot.Columns(res, color=col)