MACD Integration for GemHunter (Smoothed)

//@version=6
// ════════════════════════════════════════════════════════════════════════════════
//  MACD Integration for GemHunter  (Smoothed · Volume-aware · MTF · Divergence)
//  Companion oscillator for the GemHunter trend-regime indicator.
//  https://github.com/Finland93/GemHunter
//  Educational tool, not financial advice. Backtest before using.
// ════════════════════════════════════════════════════════════════════════════════
indicator(title="MACD Integration for GemHunter (Smoothed)", shorttitle="GemHunter MACD+", overlay=false)

// ── Inputs ──────────────────────────────────────────────────────────────────────
source        = input.source(close, title="Source")
fastLength    = input.int(12,  title="Fast Length",   minval=1)
slowLength    = input.int(26,  title="Slow Length",   minval=1)
signalLength  = input.int(9,   title="Signal Length", minval=1)
maType        = input.string(defval="SuperSmoother", title="MA Type", options=["EMA","DEMA","TEMA","SuperSmoother","RMA"], tooltip="Smoothing applied to the fast/slow averages. SuperSmoother (Ehlers) gives low lag with little noise; EMA reproduces the classic MACD.")
useVolume     = input.bool(true,  title="Use Volume Factor", tooltip="Scales MACD by relative volume so low-volume drift is de-emphasised. Safely ignored on instruments without volume.")
volSmaLen     = input.int(50,     title="Volume SMA Len",   minval=1)
volEmaLen     = input.int(10,     title="Volume EMA Len",   minval=1)
volCap        = input.float(1.8,  title="Volume Factor Cap (x)", minval=0.5, step=0.1, tooltip="Clamps the volume factor to [1/cap, cap] so a single spike can't dominate.")
mtfTF         = input.timeframe("", title="MTF Confirm TF (optional)", tooltip="Leave blank to disable. When set, crosses must agree with this higher timeframe's MACD.")
showHist      = input.bool(true,  title="Show Histogram")
showCross     = input.bool(true,  title="Show Cross Dots")
showDiv       = input.bool(false, title="Show Divergence (pivot-based)")
showLabel     = input.bool(true,  title="Show Trend Label")
// Extra visual smoothing (EMA passes; 0 = off)
macdSmoothLen = input.int(3, title="Extra MACD Smooth",   minval=0)
sigSmoothLen  = input.int(3, title="Extra Signal Smooth", minval=0)
histSmoothLen = input.int(2, title="Extra Hist Smooth",   minval=0)

// ── Moving-average helpers ───────────────────────────────────────────────────────
dema(src, l) => 2 * ta.ema(src, l) - ta.ema(ta.ema(src, l), l)

tema(src, l) =>
    e1 = ta.ema(src, l)
    e2 = ta.ema(e1, l)
    e3 = ta.ema(e2, l)
    3 * (e1 - e2) + e3

// Ehlers 2-pole SuperSmoother
superSmoother(src, length) =>
    PI = 3.141592653589793
    a1 = math.exp(-1.414 * PI / length)
    b1 = 2 * a1 * math.cos(1.414 * PI / length)
    c2 = b1
    c3 = -a1 * a1
    c1 = 1 - c2 - c3
    var float filt = na
    filt := na(filt[1]) ? src : c1 * (src + nz(src[1])) / 2 + c2 * nz(filt[1]) + c3 * nz(filt[2])
    filt

ma(src, l) =>
    switch maType
        "EMA"  => ta.ema(src, l)
        "DEMA" => dema(src, l)
        "TEMA" => tema(src, l)
        "RMA"  => ta.rma(src, l)
        => superSmoother(src, math.max(l, 2))

emaIf(src, l) => l > 0 ? ta.ema(src, l) : src

// ── Non-repainting HTF wrapper (confirmed values only) ───────────────────────────
htfConfirm(expr) =>
    mtfTF == "" ? expr : request.security(syminfo.tickerid, mtfTF, barstate.isconfirmed ? expr : nz(expr[1]), barmerge.gaps_off, barmerge.lookahead_off)

// ── Core MACD (smoothed + volume-normalised) ─────────────────────────────────────
fastMA  = ma(source, fastLength)
slowMA  = ma(source, slowLength)
macdRaw = fastMA - slowMA

// Volume factor with division-by-zero / no-volume guard
volSma  = ta.sma(volume, volSmaLen)
volNorm = na(volSma) or volSma == 0 ? 1.0 : volume / volSma
volFac  = useVolume ? math.min(volCap, math.max(1 / volCap, ta.ema(volNorm, volEmaLen))) : 1.0

// Build the MACD, then derive the signal from the *final* (extra-smoothed) MACD so
// the two lines stay internally consistent.
macd   = macdRaw * volFac
macd   := emaIf(macd, macdSmoothLen)
signal = ta.ema(macd, signalLength)
signal := emaIf(signal, sigSmoothLen)
hist   = macd - signal
hist   := emaIf(hist, histSmoothLen)

// ── MTF confirm series ───────────────────────────────────────────────────────────
macdHTF   = htfConfirm(macd)
signalHTF = htfConfirm(signal)

// ── Cross logic (aligned with HTF when set) ──────────────────────────────────────
bullCross = ta.crossover(macd, signal)  and (mtfTF == "" or macdHTF > signalHTF)
bearCross = ta.crossunder(macd, signal) and (mtfTF == "" or macdHTF < signalHTF)

// ── Divergence (pivot-based, optional) ───────────────────────────────────────────
left  = 5
right = 5
pl = ta.pivotlow(low, left, right)
ph = ta.pivothigh(high, left, right)
plCond = not na(pl)
phCond = not na(ph)

lastPL     = ta.valuewhen(plCond, pl, 0)
prevPL     = ta.valuewhen(plCond, pl, 1)
lastPLmacd = ta.valuewhen(plCond, macd[right], 0)
prevPLmacd = ta.valuewhen(plCond, macd[right], 1)
bullDiv = showDiv and plCond and lastPL < prevPL and lastPLmacd > prevPLmacd

lastPH     = ta.valuewhen(phCond, ph, 0)
prevPH     = ta.valuewhen(phCond, ph, 1)
lastPHmacd = ta.valuewhen(phCond, macd[right], 0)
prevPHmacd = ta.valuewhen(phCond, macd[right], 1)
bearDiv = showDiv and phCond and lastPH > prevPH and lastPHmacd < prevPHmacd

// ── Plots ────────────────────────────────────────────────────────────────────────
plot(macd,   "MACD",        color=color.new(color.purple, 0), linewidth=2)
plot(signal, "Signal Line", color=color.new(color.blue,   0), linewidth=2)

// 4-colour histogram: bright when momentum is expanding, faded when contracting
histRise = hist >= nz(hist[1])
colUp    = #26a69a
colDn    = #ef5350
histCol  = hist >= 0 ? (histRise ? colUp : color.new(colUp, 55)) : (histRise ? color.new(colDn, 55) : colDn)
plot(showHist ? hist : na, "Histogram", color=histCol, style=plot.style_columns)

plot(showCross and bullCross ? macd : na, "Cross Over",  style=plot.style_circles, color=color.new(color.green, 0), linewidth=3)
plot(showCross and bearCross ? macd : na, "Cross Under", style=plot.style_circles, color=color.new(color.red,   0), linewidth=3)
hline(0, "Zero Line", color=color.new(color.gray, 0))

plotshape(bullDiv, title="Bull Div", style=shape.triangleup,   location=location.belowbar, color=color.new(color.green, 0), size=size.tiny, text="DIV")
plotshape(bearDiv, title="Bear Div", style=shape.triangledown, location=location.abovebar, color=color.new(color.red,   0), size=size.tiny, text="DIV")

// ── Trend label (delivers the README's "Uptrend/Downtrend/Neutral" tag) ──────────
trendBull = macd > signal and macd > 0
trendBear = macd < signal and macd < 0
trendTxt  = trendBull ? "Uptrend" : trendBear ? "Downtrend" : "Neutral"
trendCol  = trendBull ? color.green : trendBear ? color.red : color.gray
mtfTxt    = mtfTF == "" ? "—" : (macdHTF > signalHTF ? "Bull" : macdHTF < signalHTF ? "Bear" : "Neutral")
mtfCol    = mtfTF == "" ? color.gray : (macdHTF > signalHTF ? color.green : macdHTF < signalHTF ? color.red : color.gray)

var table tbl = table.new(position.top_right, 2, 2, bgcolor=color.new(color.white, 88), frame_color=color.new(color.black, 75), frame_width=1)
if showLabel and barstate.islast
    table.cell(tbl, 0, 0, "MACD:", text_color=color.white, bgcolor=color.new(color.blue, 0))
    table.cell(tbl, 1, 0, trendTxt, text_color=trendCol, bgcolor=color.white)
    table.cell(tbl, 0, 1, "MTF:",  text_color=color.white, bgcolor=color.new(color.blue, 0))
    table.cell(tbl, 1, 1, mtfTxt,  text_color=mtfCol, bgcolor=color.white)

// ── Alerts (create via Alerts → Condition: GemHunter MACD+) ──────────────────────
alertcondition(bullCross, title="MACD+ ▲ Bullish Cross", message="GemHunter MACD+: bullish cross — {{ticker}} {{interval}}")
alertcondition(bearCross, title="MACD+ ▼ Bearish Cross", message="GemHunter MACD+: bearish cross — {{ticker}} {{interval}}")
alertcondition(bullDiv,   title="MACD+ • Bullish Divergence", message="GemHunter MACD+: bullish divergence — {{ticker}} {{interval}}")
alertcondition(bearDiv,   title="MACD+ • Bearish Divergence", message="GemHunter MACD+: bearish divergence — {{ticker}} {{interval}}")