TTM Squeeze Box

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

//@version=6
indicator("TTM Squeeze Box", shorttitle="TTM SQZ Box", overlay=true, max_boxes_count=500)

// === Inputs ===
bbLen        = input.int(20,  "BB Length",        minval=1,   group="Bollinger Bands")
bbMult       = input.float(2.0, "BB Multiplier",  minval=0.1, step=0.1, group="Bollinger Bands")
kcLen        = input.int(20,  "KC Length",        minval=1,   group="Keltner Channel")
kcMult       = input.float(1.5, "KC Multiplier",  minval=0.1, step=0.1, group="Keltner Channel")

boxColor     = input.color(color.yellow, "Box Border Color", group="Style")
boxWidth     = input.int(1, "Box Border Width",   minval=1, maxval=4, group="Style")

// === Bollinger Bands ===
basis   = ta.sma(close, bbLen)
dev     = bbMult * ta.stdev(close, bbLen)
bbUpper = basis + dev
bbLower = basis - dev

// === Keltner Channel ===
kma     = ta.sma(close, kcLen)
krange  = kcMult * ta.atr(kcLen)
kcUpper = kma + krange
kcLower = kma - krange

// === Squeeze Detection ===
// Squeeze is ON when Bollinger Bands are fully inside the Keltner Channel
squeezeOn = bbUpper < kcUpper and bbLower > kcLower

// Squeeze state transitions
squeezeStart = squeezeOn and not squeezeOn[1]   // Rising edge: squeeze just turned on
squeezeEnd   = not squeezeOn and squeezeOn[1]   // Falling edge: squeeze just turned off

// === Box State Variables ===
var box   sqBox = na   // The currently active squeeze box
var float sqHi  = na   // Highest high during current squeeze
var float sqLo  = na   // Lowest low during current squeeze

// === Box Drawing Logic ===
if squeezeStart
    // Open a new box at the start of each squeeze period
    sqHi  := high
    sqLo  := low
    sqBox := box.new(
         left         = bar_index,
         right        = bar_index,
         top          = high,
         bottom       = low,
         bgcolor      = na,           // Border only, no background fill
         border_color = boxColor,
         border_width = boxWidth
         )

else if squeezeOn and not na(sqBox)
    // Expand the box to track the full high/low range during the squeeze
    sqHi := math.max(sqHi, high)
    sqLo := math.min(sqLo, low)
    box.set_top(sqBox, sqHi)
    box.set_bottom(sqBox, sqLo)
    box.set_right(sqBox, bar_index)

// When the squeeze ends, the box is frozen in place automatically —
// no further updates occur once squeezeOn is false.
// (We do not reset sqBox to na so the last box remains visible.)