/**
 * Normalize a decimal string/number for display in a numeric `<input>`.
 *
 * Two problems this fixes:
 *  - DB decimals arrive with trailing zeros (e.g. `"10.000000"`), which show
 *    verbatim in a number input.
 *  - Client-side arithmetic on those numbers introduces binary-float artifacts
 *    (e.g. `1500.5 - 500.3 === 1000.1999999999999`).
 *
 * The value is rounded to `maxDecimals` (removing the artifacts) and stripped of
 * trailing zeros and a bare decimal point, so `"10.000000"` → `"10"` and
 * `1000.1999999999999` → `"1000.2"`. Returns `""` for null/undefined/NaN so it
 * can seed a controlled input directly.
 */
export function normalizeDecimal(
  value: string | number | null | undefined,
  maxDecimals = 6,
): string {
  if (value == null) return "";
  const n = typeof value === "number" ? value : Number(value);
  if (!Number.isFinite(n)) return "";
  // toFixed rounds away float noise and guarantees a decimal point to strip.
  return n.toFixed(maxDecimals).replace(/\.?0+$/, "");
}