RSI cross

// What the Pine front end would emit for a small RSI script (docs/scripting.md, "Pine").
//
// //@version=5
// indicator("RSI cross")
// len = input.int(14, "Length")
// r = ta.rsi(close, len)
// var int crosses = 0
// if ta.crossover(r, 30)
//     crosses += 1
// plot(r, "RSI")
// plotshape(ta.crossover(r, 30), "Up", shape.triangleup, location.bottom)
// lower = hline(30, "Oversold")
// upper = hline(70, "Overbought")
// fill(upper, lower, color=color.new(color.purple, 90))
indicator('RSI cross');

const len = input.int('Length', 14);
const chart = bars();

const rsi = ta.rsi(len);
const crossInIf = ta.crossover();
const crossInPlot = ta.crossover();
const crosses = state.bar(0);
const history = series(2);

const p0 = plot.line('RSI');
const s0 = plot.shape('Up', { shape: 'triangleUp', location: 'bottom' });
const lower = plot.level('Oversold', 30, { style: 'dashed' });
const upper = plot.level('Overbought', 70, { style: 'dashed' });
const band = plot.fill('Band', upper, lower, { color: '#9c27b01a' });

chart.onBar(() => {
  const r = rsi.update(chart.close);
  history.set(r);
  if (crossInIf.update(r, 30)) crosses.value += 1;
  p0.set(r);
  s0.set(crossInPlot.update(r, 30));
});