Auto Fibonacci Retracement

// Draw retracement levels across the latest two confirmed alternating pivots.
indicator("Auto Fibonacci Retracement", { overlay: true, maxLines: 10, maxLabels: 10, maxLineFills: 2 });

const depth = input.int("Pivot depth", 8, { min: 2, max: 50 });
const projectionBars = input.int("Projection bars", 30, { min: 1, max: 200 });
const showPrices = input.bool("Show prices", true);
const baseColor = input.color("Level color", "#22d3ee");
const goldenColor = input.color("Golden zone color", "#f59e0b");

const highs = pivothigh(high, depth, depth);
const lows = pivotlow(low, depth, depth);
const pivots = [];

function acceptPivot(kind, index, price) {
  const candidate = { kind, index, price };
  const previous = pivots[pivots.length - 1];
  if (!previous) {
    pivots.push(candidate);
    return;
  }
  if (previous.kind === kind) {
    const moreExtreme = kind === "high" ? price >= previous.price : price <= previous.price;
    if (moreExtreme) pivots[pivots.length - 1] = candidate;
    return;
  }
  pivots.push(candidate);
}

for (let confirmation = 0; confirmation < close.length; confirmation++) {
  const pivotIndex = confirmation - depth;
  if (pivotIndex < 0) continue;
  if (Number.isFinite(highs[confirmation])) acceptPivot("high", pivotIndex, highs[confirmation]);
  if (Number.isFinite(lows[confirmation])) acceptPivot("low", pivotIndex, lows[confirmation]);
}

if (pivots.length >= 2) {
  const start = pivots[pivots.length - 2];
  const finish = pivots[pivots.length - 1];
  const levels = [0, 0.236, 0.382, 0.5, 0.618, 0.786, 1];
  const lines = [];
  const right = close.length - 1 + projectionBars;
  levels.forEach((level) => {
    const price = start.price + (finish.price - start.price) * level;
    const isGoldenBoundary = level === 0.382 || level === 0.618;
    const id = line.new({
      x1: start.index,
      y1: price,
      x2: right,
      y2: price,
      xloc: "index",
      color: isGoldenBoundary ? goldenColor : baseColor,
      width: isGoldenBoundary ? 2 : 1,
      style: level === 0 || level === 1 ? "solid" : "dashed",
      extend: "right",
    });
    lines.push(id);
    label.new({
      x: right,
      y: price,
      xloc: "index",
      text: showPrices ? `${level.toFixed(3)} · ${price.toFixed(2)}` : level.toFixed(3),
      position: "right",
      color: "#0f172a",
      textColor: isGoldenBoundary ? goldenColor : baseColor,
      size: "small",
    });
  });
  linefill.new(lines[2], lines[4], { color: goldenColor, opacity: 0.12 });
}