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

//@version=6
indicator("TRAMA: Trend Regularity Adaptive Moving Average", shorttitle="TRAMA", overlay=true)

// @function Calculates the Trend Regularity Adaptive Moving Average.
//   An adaptive EMA where the smoothing factor is derived from
//   the regularity of new highest-highs and lowest-lows over the lookback.
//   More frequent HH/LL = trending = faster adaptation; fewer = ranging = slower.
//   tc = sma(HH_or_LL_occurred ? 1 : 0, length)²
//   TRAMA = TRAMA[1] + tc * (src - TRAMA[1])
//   Squaring penalizes low trend regularity, making the MA nearly flat in ranges.
//   Source: LuxAlgo (TradingView, December 2020).
// @param src Series to smooth.
// @param length Lookback period. Must be >= 1.
// @returns The trend regularity adaptive moving average value.
trama(series float src, simple int length) =>
    float ama = 0.0
    // Detect new highest-high: sign of change in rolling highest
    float hh = math.max(math.sign(ta.change(ta.highest(length))), 0.0)
    // Detect new lowest-low: sign of negative change in rolling lowest
    float ll = math.max(math.sign(ta.change(ta.lowest(length)) * -1.0), 0.0)
    // Trend coefficient: fraction of bars with HH or LL, squared
    float tc = math.pow(ta.sma((hh != 0.0 or ll != 0.0) ? 1.0 : 0.0, length), 2)
    ama := nz(ama[1]) + tc * (src - nz(ama[1]))
    if na(ama[1])
        ama := src
    ama

// ── Inputs ──────────────────────────────────────────────
p = input.int(14, "Period", minval=1)

// ── Calculation ─────────────────────────────────────────
result = trama(close, p)

// ── Plot ────────────────────────────────────────────────
plot(result, "TRAMA", color=color.yellow, linewidth=2)