function canPreserveSpecial(parts, title, num) {
  const sequences = new Set(parts.map((part) => part.F_SEQ));
  return (
    parts.length > 0 &&
    sequences.size === parts.length &&
    parts.every((part) => Boolean(part.F_SEQ)) &&
    [
      ["F_MCOST", "F_MPRICE"],
      ["F_LCOST", "F_LPRICE"],
      ["F_ECOST", "F_EPRICE"],
    ].every(
      ([field, total]) =>
        Math.abs(parts.reduce((sum, part) => sum + num(part[field]), 0) - num(title[total])) < 1e-6,
    )
  );
}

function fixedSpecialPart(part, source, pk, num) {
  const GC = num(part.F_MCOST),
    NC = num(part.F_LCOST),
    JC = num(part.F_ECOST);
  return {
    PkID: pk,
    Index: 0,
    Code: source ? part.F_CODE1 : "",
    JdlSourceCode: part.F_CODE1,
    Name: part.F_DES,
    Size: part.F_SIZE,
    Unite: part.F_UNIT,
    LinkIndex: source?.kind || 0,
    CalcIndex: 1,
    JdlSummary: true,
    GN: num(part.F_QQTY),
    GC,
    NC,
    JC,
    SC: 0,
    TC: GC + NC + JC,
  };
}

module.exports = { canPreserveSpecial, fixedSpecialPart };