calculate method

@override IndicatorResult calculate(List<Candle> candles)

Pure computation function that produces an IndicatorResult from candles.

Implementation

@override
IndicatorResult calculate(List<Candle> candles) {
  final n = candles.length;
  final empty = List<double?>.filled(n, null);

  if (n < 2) {
    return _result(empty, empty, empty, empty, empty, empty, empty);
  }

  // Use the last-completed candle as the "previous session"
  final prev = candles[n - 2];
  final h = prev.high;
  final l = prev.low;
  final c = prev.close;

  final p = (h + l + c) / 3.0;
  final r1 = (2 * p) - l;
  final r2 = p + (h - l);
  final r3 = h + 2 * (p - l);
  final s1 = (2 * p) - h;
  final s2 = p - (h - l);
  final s3 = l - 2 * (h - p);

  // Flat lines across all candles
  List<double?> flat(double v) => List<double?>.filled(n, v);

  return _result(flat(p), flat(r1), flat(r2), flat(r3), flat(s1), flat(s2), flat(s3));
}