Support Line: Max Buying Volume

//version=5
indicator("Support Line: Max Buying Volume", overlay=true)

// === INPUTS ===
length = input.int(100, title="Lookback Period")
priceResolution = input.float(0.5, title="Price Bin Size") // Granularity of price levels
lineColor = input.color(color.green, title="Support Line Color")
lineWidth = input.int(2, title="Line Width")

// === BINNING UTILITY ===
get_bin(price) =>
math.round(price / priceResolution) * priceResolution

// === DATA STRUCTURES ===
var float[] priceBins = array.new_float()
var float[] buyVolumeBins = array.new_float()

// === RESET DATA IF EXCEEDED LENGTH ===
if array.size(priceBins) > length
array.clear(priceBins)
array.clear(buyVolumeBins)

// === TRACK BUYING VOLUME ===
if close > open
bin = get_bin(close)
idx = array.indexof(priceBins, bin)

if idx == -1
array.push(priceBins, bin)
array.push(buyVolumeBins, volume)
else
oldVol = array.get(buyVolumeBins, idx)
array.set(buyVolumeBins, idx, oldVol + volume)

// === FIND MAX BUYING VOLUME BIN ===
var float supportPrice = na
maxVol = 0.0

for i = 0 to array.size(priceBins) - 1
vol = array.get(buyVolumeBins, i)
if vol > maxVol
maxVol := vol
supportPrice := array.get(priceBins, i)

// === DRAW SUPPORT LINE ===
var line supportLine = na

if not na(supportPrice)
if na(supportLine)
supportLine := line.new(x1=bar_index, y1=supportPrice, x2=bar_index + 1, y2=supportPrice, color=lineColor, width=lineWidth)
else
line.set_xy1(supportLine, bar_index, supportPrice)
line.set_xy2(supportLine, bar_index + 1, supportPrice)