Ari zScore

//@version=4
study(title="Ari zScore", shorttitle="ARI-zScore", overlay=true)


src = close
periodFast = input(5, "Fast")
periodSlow = input(20, "Slow")
periodStDev = input(20, "St Dev")
zscoreMin = input(1, "z first band")
// zscoreMax = input(1.25, "z second band")
showMAGraph = input(false, "Show Bands")
showZScore = input(false, "Show zScore line")
showZScoreCross = input(true, "Show zScore cross")
showPSAR = input(false, "Show PSAR")
maFast = sma(src, periodFast)
maSlow = sma(src, periodSlow)
std = stdev(src,periodStDev)

zscore = (maFast-maSlow)/std
// if periodFast < 2
//     zscore := (src-maSlow)/std
    
// plot(zscore, color=color.green)
start = (0.02)
increment = (0.02)
maximum = 0.2
sar =sar(start, increment, maximum)
plot(showPSAR ? sar : na, "ParabolicSAR", style=plot.style_cross, color=#2962FF)


plotshape(-1.25<zscore and zscore<=-1,      style=shape.triangleup,location=location.belowbar, text="1", color=color.lime)
plotshape(-1.5<zscore and zscore<=-(1.25),  style=shape.triangleup,location=location.belowbar, text="", color=color.green)
plotshape(-1.75<zscore and zscore<=-(1.5),   style=shape.triangleup,location=location.belowbar, text="", color=color.olive)
plotshape(-2<zscore and zscore<=-(1.75),  style=shape.triangleup,location=location.belowbar, text="", color=color.teal)
plotshape(-3<zscore and zscore<=-2,         style=shape.triangleup,location=location.belowbar, text="2", color=color.teal)
plotshape(zscore<=-3,                       style=shape.triangleup,location=location.belowbar, text="3", color=color.teal)

// drawing when zScore = 0
plotshape(showZScoreCross and crossover(zscore,0), style=shape.diamond, location=location.belowbar, color=color.yellow, text="0",textcolor=color.white)


plotshape(1<=zscore and zscore<1.25,     style=shape.triangledown,location=location.abovebar, text="1", color=color.orange)
plotshape(1.25<=zscore and zscore<1.5,  style=shape.triangledown,location=location.abovebar, text="", color=color.red)
plotshape(1.5<=zscore and zscore<1.75,  style=shape.triangledown,location=location.abovebar, text="", color=color.purple)
plotshape(1.75<=zscore and zscore<2,    style=shape.triangledown,location=location.abovebar, text="", color=color.maroon)
plotshape(2<=zscore and zscore<3,       style=shape.triangledown,location=location.abovebar, text="2", color=color.maroon)
plotshape(zscore>=3,                    style=shape.triangledown,location=location.abovebar, text="3", color=color.maroon)

// plotshape(zscore<-zscoreMin, style=shape.triangleup,
//                  location=location.belowbar, color=color.lime)
// plotshape(zscore<-zscoreMax, style=shape.triangleup,
//                  location=location.belowbar, color=color.teal)
                 
// drawing top and bottom zscores
max_signalPos = highest(zscore, 20)[1] > zscore //and zscore > zscoreMax
the_signalPos = max_signalPos != max_signalPos[1] and max_signalPos == true
plotshape(the_signalPos, style=shape.square,
                 location=location.belowbar, color=color.white, text="T",textcolor=color.red)
                 
min_signalPos = lowest(zscore, 20)[1] < zscore //and zscore < -zscoreMax
the_signalNeg = min_signalPos != min_signalPos[1] and min_signalPos == true
plotshape(the_signalNeg, style=shape.square,
                 location=location.abovebar, color=color.white, text="B",textcolor=color.green)


                 
// drawing the band
plotFast = plot(showMAGraph ? maFast : na, color=color.yellow)
plotSlow = plot(showMAGraph ? maSlow : na, color=color.blue)
plot(showZScore ? zscore : na, color=color.green)

color = color.black
if zscore>0
    color := color.yellow
    if zscore>1
        color := color.orange
    if zscore>2
        color := color.red
    if zscore>3
        color := color.purple   
    if zscore>4
        color := color.fuchsia  
if zscore<0
    color := color.yellow
    if zscore<-1
        color := color.lime
    if zscore<-2
        color := color.green
    if zscore<-3
        color := color.olive
    if zscore<-4
        color := color.teal
        

fill(plot1=plotFast, plot2=plotSlow,color=color, transp=30, title="")