export function getDecimalPlaces(value: number): number {
  if (!Number.isFinite(value)) return 0;
  const str = String(value);
  const dotIndex = str.indexOf('.');
  if (dotIndex === -1) return 0;
  const expIndex = str.indexOf('e-');
  if (expIndex !== -1) {
    const mantissaDecimals = str.substring(dotIndex + 1, expIndex).length;
    const exp = parseInt(str.substring(expIndex + 2), 10);
    return mantissaDecimals + exp;
  }
  return str.length - dotIndex - 1;
}

const MAX_DECIMAL_PLACES = 10;
const DEFAULT_FACTOR = 100000;
const DEFAULT_DECIMAL_PLACES = 5;

export function computeFactor(values: number[]): number {
  let maxDecimals = 0;
  for (const v of values) {
    const d = getDecimalPlaces(v);
    if (d > maxDecimals) maxDecimals = d;
  }
  if (maxDecimals === 0) return 1;
  if (maxDecimals > MAX_DECIMAL_PLACES) maxDecimals = MAX_DECIMAL_PLACES;
  return Math.pow(10, maxDecimals);
}

export function factoredInteger(value: number, factor: number = DEFAULT_FACTOR): number {
  return Math.round(value * factor);
}

export function toOriginal(value: number, factor: number = DEFAULT_FACTOR): number {
  if (factor === 1) return value;
  const decimalPlaces = Math.round(Math.log10(factor));
  return Number((value / factor).toFixed(decimalPlaces));
}