/* 454 — 옛 masshaul 단계 탐침 자리: 묶음 cross · profile 출력으로 누가토량 끝값(m3).
 * 유토곡선 판(`B05_Profile_UI_Profile_MassHaul`)과 같은 공용 계산(`computeMassHaulSeries`) · 횡단 기준.
 * `load` = 부르는 헬퍼의 TS 로더(`load("common_util", "…ts")`). */
module.exports = function finalCumulative(load, pipe, conversion) {
  const cross = pipe.output("cross");
  const samples = pipe.output("profile")?.samples ?? [];
  if (!cross) return null;
  const { computeMassHaulSeries } = load("common_util", "common_util_mass_haul.ts");
  const sections = Object.values(cross.byKey)
    .sort((a, b) => a.chainageM - b.chainageM)
    .map((e) => ({ station_id: e.key, chainage_m: e.chainageM, design: e.detail }));
  const series = computeMassHaulSeries(
    {
      length_m:
        samples[samples.length - 1]?.chainage_m ?? sections[sections.length - 1]?.chainage_m ?? 0,
      design_profiles: samples.length ? [{ samples }] : [],
    },
    sections,
    conversion,
  );
  const picked = series.find((s) => s.basis === "cross") ?? series[0];
  return picked?.result?.final_cumulative_m3 ?? null;
};