HalfTrend

// This Pine Script™ code is subject to the terms of the Mozilla Public License 2.0 at https://mozilla.org/MPL/2.0/
// © Flapjackcoin

//@version=5
indicator('HalfTrend', overlay=true)
amplitude = input(title='Amplitude', defval=6)
channelDeviation = input(title='Channel Deviation', defval=3)
showArrows = input(title='Show Arrows', defval=true)
showChannels = input(title='Show Channels', defval=true)
emaPeriod = input(title='EMA Period', defval=9)  // Add EMA period input

var int trend = 0
var int nextTrend = 0
var float maxLowPrice = nz(low[1], low)
var float minHighPrice = nz(high[1], high)

var float up = 0.0
var float down = 0.0
float atrHigh = 0.0
float atrLow = 0.0
float arrowUp = na
float arrowDown = na

atr2 = ta.atr(100) / 2
dev = channelDeviation * atr2

highPrice = high[math.abs(ta.highestbars(amplitude))]
lowPrice = low[math.abs(ta.lowestbars(amplitude))]
highma = ta.sma(high, amplitude)
lowma = ta.sma(low, amplitude)

emaLine = ta.ema(close, emaPeriod)  // Calculate EMA

if nextTrend == 1
    maxLowPrice := math.max(lowPrice, maxLowPrice)

    if highma < maxLowPrice and close < nz(low[1], low)
        trend := 1
        nextTrend := 0
        minHighPrice := highPrice
        minHighPrice
else
    minHighPrice := math.min(highPrice, minHighPrice)

    if lowma > minHighPrice and close > nz(high[1], high)
        trend := 0
        nextTrend := 1
        maxLowPrice := lowPrice
        maxLowPrice

if trend == 0
    if not na(trend[1]) and trend[1] != 0
        up := na(down[1]) ? down : down[1]
        arrowUp := up - atr2
        arrowUp
    else
        up := na(up[1]) ? maxLowPrice : math.max(maxLowPrice, up[1])
        up
    atrHigh := up + dev
    atrLow := up - dev
    atrLow
else
    if not na(trend[1]) and trend[1] != 1
        down := na(up[1]) ? up : up[1]
        arrowDown := down + atr2
        arrowDown
    else
        down := na(down[1]) ? minHighPrice : math.min(minHighPrice, down[1])
        down
    atrHigh := down + dev
    atrLow := down - dev
    atrLow

ht = trend == 0 ? up : down

var color buyColor = color.blue
var color sellColor = color.red

htColor = trend == 0 ? buyColor : sellColor
htPlot = plot(ht, title='HalfTrend', linewidth=2, color=htColor)

atrHighPlot = plot(showChannels ? atrHigh : na, title='ATR High', style=plot.style_circles, color=color.new(sellColor, 0))
atrLowPlot = plot(showChannels ? atrLow : na, title='ATR Low', style=plot.style_circles, color=color.new(buyColor, 0))

fill(htPlot, atrHighPlot, title='ATR High Ribbon', color=color.new(sellColor, 90))
fill(htPlot, atrLowPlot, title='ATR Low Ribbon', color=color.new(buyColor, 90))

buySignal = not na(arrowUp) and trend == 0 and trend[1] == 1
sellSignal = not na(arrowDown) and trend == 1 and trend[1] == 0

plotshape(showArrows and buySignal ? atrLow : na, title='Arrow Up', style=shape.triangleup, location=location.absolute, size=size.tiny, color=color.new(buyColor, 0))
plotshape(showArrows and sellSignal ? atrHigh : na, title='Arrow Down', style=shape.triangledown, location=location.absolute, size=size.tiny, color=color.new(sellColor, 0))

alertcondition(buySignal, title='Alert: HalfTrend Buy', message='HalfTrend Buy')
alertcondition(sellSignal, title='Alert: HalfTrend Sell', message='HalfTrend Sell')

// Hull Moving Average (HMA) Ribbon based on EMA
lengthHMA = input(9, title="HMA Length")
srcHMA = close
halfLength = (lengthHMA / 2)
ema1 = ta.ema(srcHMA, halfLength)
ema2 = ta.ema(srcHMA, lengthHMA)
diff = 2 * ema1 - ema2
hullMa = (diff)

plot(hullMa, color=color.rgb(11, 159, 144), title="HMA")
plot(emaLine, title='EMA', color=color.new(#fff200, 0))  // Plot EMA line