// The MIT License (MIT)
// © mihakralj

//@version=6
indicator("MCNMA - McNicholl EMA", "MCNMA", overlay=true)

// ── Functions ──────────────────────────────────────────────────────────
// @function Calculates the McNicholl EMA (Zero-Lag TEMA).
//   Dennis McNicholl, "Better Bollinger Bands," Futures Magazine, October 1998.
//   MCNMA = 2*TEMA(src,N) - TEMA(TEMA(src,N),N) where
//   TEMA(x,N) = 3*EMA1 - 3*EMA2 + EMA3.
//   Six cascaded EMA stages total, each with warmup compensation.
// @param source Series to smooth
// @param period Lookback period (must be > 0)
// @returns McNicholl EMA value, valid from bar 1
export mcnma(series float source, simple int period) =>
    if period <= 0
        runtime.error("Period must be greater than 0")

    float src = nz(source)
    float alpha = 2.0 / (period + 1)
    float beta = 1.0 - alpha

    var float e1 = 0.0
    var float e2 = 0.0
    var float e3 = 0.0
    var float e4 = 0.0
    var float e5 = 0.0
    var float e6 = 0.0
    var float e_decay = 1.0
    var int n = 0

    n += 1
    e_decay *= beta
    float comp = 1.0 / (1.0 - e_decay)

    e1 += alpha * (src - e1)
    float c1 = e1 * comp

    e2 += alpha * (c1 - e2)
    float c2 = e2 * comp

    e3 += alpha * (c2 - e3)
    float c3 = e3 * comp

    float tema1 = 3.0 * c1 - 3.0 * c2 + c3

    e4 += alpha * (tema1 - e4)
    float c4 = e4 * comp

    e5 += alpha * (c4 - e5)
    float c5 = e5 * comp

    e6 += alpha * (c5 - e6)
    float c6 = e6 * comp

    float tema2 = 3.0 * c4 - 3.0 * c5 + c6

    float result = 2.0 * tema1 - tema2
    result

// ── Inputs ─────────────────────────────────────────────────────────────
int i_period = input.int(14, "Period", minval=1)
string i_source = input.source(close, "Source")

// ── Calculation ────────────────────────────────────────────────────────
float value = mcnma(i_source, i_period)

// ── Plot ───────────────────────────────────────────────────────────────
plot(value, "MCNMA", color.yellow, 2)