// Licensed under the Apache License, Version 2.0
// © mihakralj
//@version=6
indicator("TTM Wave (TTM_WAVE)", "TTM_WAVE", overlay=false)

//@function EMA — standard exponential moving average for MACD computation.
//@param src Source series
//@param length EMA period
//@returns EMA value
ema_calc(series float src, simple int length) =>
    float alpha = 2.0 / (length + 1)
    var float result = 0.0
    result := bar_index == 0 ? src : alpha * src + (1 - alpha) * result
    result

//@function MACD histogram — (fast_ema - slow_ema) - signal_ema(fast_ema - slow_ema)
//          This is the second derivative of momentum: acceleration of the spread.
//@param src Source series
//@param fast Fast EMA period
//@param slow Slow EMA period
//@param signal Signal EMA period (same as slow for TTM Wave)
//@returns MACD histogram value
macd_hist(series float src, simple int fast, simple int slow, simple int signal) =>
    float fast_ema = ema_calc(src, fast)
    float slow_ema = ema_calc(src, slow)
    float macd_line = fast_ema - slow_ema
    float signal_line = ema_calc(macd_line, signal)
    macd_line - signal_line

//@function TTM Wave — six parallel MACD histogram channels at Fibonacci periods.
//          Wave A (short-term):  channels 1 (8,34,34) and 2 (8,55,55)
//          Wave B (medium-term): channels 3 (8,89,89) and 4 (8,144,144)
//          Wave C (long-term):   channels 5 (8,233,233) and 6 (8,377,377)
//          All channels share fast period 8. Signal period equals slow period.
//@param src Source series (default: close)
//@returns [waveA1, waveA2, waveB1, waveB2, waveC1, waveC2]
//@reference John Carter, "Mastering the Trade" (2005, 2012)
//@optimized Six independent EMA cascades, O(1) per bar per channel
ttm_wave(series float src) =>
    float waveA1 = macd_hist(src, 8, 34,  34)
    float waveA2 = macd_hist(src, 8, 55,  55)
    float waveB1 = macd_hist(src, 8, 89,  89)
    float waveB2 = macd_hist(src, 8, 144, 144)
    float waveC1 = macd_hist(src, 8, 233, 233)
    float waveC2 = macd_hist(src, 8, 377, 377)
    [waveA1, waveA2, waveB1, waveB2, waveC1, waveC2]

// ── Inputs ──
float i_src = input.source(close, "Source")

// ── Calculation ──
[waveA1, waveA2, waveB1, waveB2, waveC1, waveC2] = ttm_wave(i_src)

// ── Plot (thinkorswim color convention) ──
// Wave A: yellow/green (short-term momentum)
plot(waveA1, "Wave A1", color=color.yellow, style=plot.style_histogram, linewidth=2)
plot(waveA2, "Wave A2", color=color.lime,   style=plot.style_histogram, linewidth=2)

// Wave B: magenta/pink (medium-term momentum)
plot(waveB1, "Wave B1", color=color.fuchsia, style=plot.style_histogram, linewidth=2)
plot(waveB2, "Wave B2", color=color.new(color.fuchsia, 40), style=plot.style_histogram, linewidth=2)

// Wave C: red/orange (long-term momentum)
plot(waveC1, "Wave C1", color=color.red,    style=plot.style_histogram, linewidth=2)
plot(waveC2, "Wave C2", color=color.orange, style=plot.style_histogram, linewidth=2)

hline(0, "Zero", color=color.gray, linestyle=hline.style_dotted)