Dual Moving Average Indicators Fusion Strategy

/*backtest
start: 2023-01-01 00:00:00
end: 2023-03-23 00:00:00
period: 12h
basePeriod: 15m
exchanges: [{"eid":"Futures_Binance","currency":"BTC_USDT"}]
*/

//@version=5
////////////////////////////////////////////////////////////
//  Copyright by HPotter v1.0 14/01/2022
// This is combo strategies for get a cumulative signal. 
//
// First strategy
// This indicator plots 2/20 exponential moving average. For the Mov 
// Avg X 2/20 Indicator, the EMA bar will be painted when the Alert criteria is met.
//
// Second strategy
// The Absolute Price Oscillator displays the difference between two exponential 
// moving averages of a security's price and is expressed as an absolute value.
// How this indicator works
//    APO crossing above zero is considered bullish, while crossing below zero is bearish.
//    A positive indicator value indicates an upward movement, while negative readings 
//      signal a downward trend.
//    Divergences form when a new high or low in price is not confirmed by the Absolute Price 
//      Oscillator (APO). A bullish divergence forms when price make a lower low, but the APO 
//      forms a higher low. This indicates less downward momentum that could foreshadow a bullish 
//      reversal. A bearish divergence forms when price makes a higher high, but the APO forms a 
//      lower high. This shows less upward momentum that could foreshadow a bearish reversal.
//
// WARNING:
// - For purpose educate only
// - This script to change bars colors.
////////////////////////////////////////////////////////////
EMA20(Length) =>
    pos = 0.0
    xPrice = close
    xXA = ta.ema(xPrice, Length)
    nHH = math.max(high, high[1])
    nLL = math.min(low, low[1])
    nXS = nLL > xXA or nHH < xXA ? nLL : nHH
    iff_1 = nXS < close[1] ? 1 : nz(pos[1], 0)
    pos := nXS > close[1] ? -1 : iff_1
    pos

APO(LengthShortEMA, LengthLongEMA) =>
    pos = 0.0
    xPrice = close
    xShortEMA = ta.ema(xPrice, LengthShortEMA)
    xLongEMA = ta.ema(xPrice, LengthLongEMA)
    xAPO = xShortEMA - xLongEMA
    iff_1 = xAPO < 0 ? -1 : nz(pos[1], 0)
    pos := xAPO > 0 ? 1 : iff_1
    pos

strategy(title='Combo 2/20 EMA & Absolute Price Oscillator (APO) ', shorttitle='Combo', overlay=true)
var I1 = '●═════ 2/20 EMA ═════●'
Length = input.int(14, minval=1, group=I1)
var I2 = '●═════ Absolute Price Oscillator (APO)  ═════●'
LengthShortEMA = input.int(10, minval=1, group=I2)
LengthLongEMA = input.int(20, minval=1, group=I2)
var misc = '●═════ MISC ═════●'
reverse = input.bool(false, title='Trade reverse', group=misc)
var timePeriodHeader = '●═════ Time Start ═════●'
d = input.int(1, title='From Day', minval=1, maxval=31, group=timePeriodHeader)
m = input.int(1, title='From Month', minval=1, maxval=12, group=timePeriodHeader)
y = input.int(2005, title='From Year', minval=0, group=timePeriodHeader)

StartTrade = time > timestamp(y, m, d, 00, 00) ? true : false
posEMA20 = EMA20(Length)
prePosAPO = APO(LengthShortEMA, LengthLongEMA)
iff_1 = posEMA20 == -1 and prePosAPO == -1 and StartTrade ? -1 : 0
pos = posEMA20 == 1 and prePosAPO == 1 and StartTrade ? 1 : iff_1
iff_2 = reverse and pos == -1 ? 1 : pos
possig = reverse and pos == 1 ? -1 : iff_2
if possig == 1
    strategy.entry('Long', strategy.long)
if possig == -1
    strategy.entry('Short', strategy.short)
if possig == 0
    strategy.close_all()
barcolor(possig == -1 ? #b50404 : possig == 1 ? #079605 : #0536b3)