Setting kinds

// a number field, a toggle, a menu, two handles on one slider, a text field
param.int("length", 20, { min: 2, max: 500 });
param.text("label", "Session VWAP", { max_bytes: 64 });
param.bool("show_bands", true);
param.choice("kind", ["Simple", "Exponential"], "Simple");
param.range("band_pct", [0.5, 2.0], { min: 0, max: 10 });

function onStart(): void {
  const n = i32(p_length());
  sma = new Sma(n);
  useEma = p_kind() == 1.0;
  bandsOn = pb_show_bands();
  lowPct = p_band_pct_lo();
  highPct = p_band_pct_hi();
}

// A moving average with a corner readout that says what you typed in the settings.
param.int("length", 20, { min: 1, max: 500 });
// One line of text, at most 64 bytes.
param.text("label", "Session average", { max_bytes: 64, hint: "Shown in the corner of the chart" });
// Several lines of text. The readout shows the first line.
param.text_area("notes", "Buy the dip above it.\nStand aside below it.", { max_bytes: 512 });
// A preset may set a text setting like any other.
presets({ Fast: { length: 9, label: "Fast average" }, Slow: { length: 50, label: "Slow average" } });

output("average", line, overlay, { color: "#2563eb" });
// Sized for the label's 64 bytes plus a space and a number.
string("tag", { max_bytes: 96 });
string("note", { max_bytes: 512 });
render.table("corner", { rows: 2, cols: 1, cells: ["tag", "note"], position: "top_left" });

let average = new Sma(20);
let label: string = "";
let firstNote: string = "";

// Text settings are read once, here, through pt_<name>().
function onStart(): void {
  average = new Sma(i32(p_length()));
  label = pt_label();
  firstNote = pt_notes().split("\n")[0];
}

function onBar(): void {
  const value = average.update(bar.close());
  if (isNaN(value)) return;
  out_average(value);
  sb_clear();
  sb_text(label);
  sb_text(" ");
  sb_auto(value);
  str_tag_sb();
  str_note(firstNote);
}

// int: a whole number.
param.int("length", 20, { min: 2, max: 500 });
// choice: a menu; the reader returns the picked index, 0 for Simple.
param.choice("kind", ["Simple", "Exponential"], "Simple", { label: "Average" });
// source: declares the primary input too; in_src() reads the picked field.
param.source("src", ohlcv.close);
// bool: a toggle, read as a bool.
param.bool("show_bands", true);
// range: a low..high pair on one slider.
param.range("band_pct", [0.5, 2.0], { min: 0, max: 10, step: 0.1, label: "Band width %" });
// number with a unit picker: the value and the unit's code.
param.number("offset", 0.0, { min: -100, max: 100, unit: ["price", "ticks", "%", "atr"], unit_default: "%" });
// A bounded int drawn as a slider: the ATR an atr-unit offset scales by.
param.int("atr_length", 14, { min: 2, max: 50, slider: true, label: "ATR length" });
// color: painted onto the basis line below, by name.
param.color("basis_color", "#2962ff");
// timeframe and symbol: each pins the input that names it.
param.timeframe("htf", "chart", { label: "Reference timeframe" });
input("close_htf", ohlcv.close, { interval: "@htf" });
param.symbol("pair", "BINANCE_FUTURES:ETHUSDT", { label: "Ratio against" });
input("close_pair", ohlcv.close, { symbol: "@pair" });
// list: up to four momentum lookbacks.
param.list("lookbacks", [5.0, 20.0], { max: 4 });
// time and price: both can be picked on the chart.
param.time("since", "2024-01-01 00:00", { label: "Start" });
param.price("floor", 0.0, { hint: "0 draws no floor" });
// session and multi: a window in its zone, and the weekdays it applies on.
param.session("rth", "09:30-16:00", { tz: "America/New_York", label: "Active hours" });
param.multi("days", ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"], ["Mon", "Tue", "Wed", "Thu", "Fri"]);
// The tick size, written by the chart into a hidden setting.
market.tick_size();
output("basis", line, overlay, { color: "@basis_color", width: 2 });
output("upper", line, overlay, { color: "#26a69a" });
output("lower", line, overlay, { color: "#ef5350" });
output("reference", line, overlay, { color: "#94a3b8", line_style: "dashed" });
output("floor", line, overlay, { color: "#f59e0b" });
output("momentum", line, lower, { color: "#8b5cf6" });
output("ratio", line, lower, { color: "#0ea5e9" });

let sma = new Sma(20);
let ema = new Ema(20);
let atr = new Atr(14);
let rocs: Roc[] = [];
let useEma = false;
let bandsOn = true;
let lowPct = 0.5;
let highPct = 2.0;
let offset = 0.0;
let offsetUnit = 0;
let tick = 0.0;
let since = 0.0;
let floorPrice = 0.0;
let dayMask = 0.0;
let sessionStart = 570.0;
let sessionEnd = 960.0;
let zone = 0;

// Every setting is read here, once, and kept in module state.
function onStart(): void {
  const n = i32(p_length());
  sma = new Sma(n);
  ema = new Ema(n);
  useEma = p_kind() == 1.0;
  bandsOn = pb_show_bands();
  lowPct = p_band_pct_lo();
  highPct = p_band_pct_hi();
  offset = p_offset();
  offsetUnit = i32(p_offset_unit());
  atr = new Atr(i32(p_atr_length()));
  tick = p_market_tick_size();
  since = p_since();
  floorPrice = p_floor();
  dayMask = p_days();
  sessionStart = p_rth_start();
  sessionEnd = p_rth_end();
  zone = i32(p_rth_tz());
  const lookbacks = p_lookbacks();
  rocs = [];
  for (let i = 0; i < lookbacks.length; i += 1) rocs.push(new Roc(i32(lookbacks[i])));
}

function onBar(): void {
  const t = bar.time();
  const close = in_src();
  const reference = in_close_htf();
  const pair = in_close_pair();
  const simple = sma.update(close);
  const exponential = ema.update(close);
  let basis = useEma ? exponential : simple;
  const atrValue = atr.update(bar.high(), bar.low(), close);
  // The offset in the unit the dialog picked, as a price distance.
  if (isFinite(basis)) basis += unitToPrice(offset, offsetUnit, close, tick, atrValue);
  const ratio = isFinite(pair) && pair != 0.0 ? close / pair : NaN;
  let sum = 0.0;
  let count = 0;
  for (let i = 0; i < rocs.length; i += 1) {
    const r = rocs[i].update(close);
    if (isFinite(r)) {
      sum += r;
      count += 1;
    }
  }
  const momentum = count > 0 ? sum / f64(count) : NaN;
  // 0 = Monday, from the bar's UTC day: the bit the days setting is tested by.
  const weekday = i32((Math.floor(t / 86400.0) + 3.0) % 7.0);
  const active = inSession(t, sessionStart, sessionEnd, zone) && multiHas(dayMask, weekday);
  if (!isFinite(basis) || t < since) return;
  out_basis(basis);
  // A hidden line is NaN: nothing is drawn.
  out_upper(bandsOn ? basis * (1.0 + highPct / 100.0) : NaN);
  out_lower(bandsOn ? basis * (1.0 - lowPct / 100.0) : NaN);
  out_reference(reference);
  out_floor(floorPrice > 0.0 ? floorPrice : NaN);
  // Momentum draws inside the session window only.
  out_momentum(active ? momentum : NaN);
  out_ratio(ratio);
}