const DECIMAL = /^-?(?:\d+\.?\d*|\.\d*)?$/u;

export function isValidPercent(value: string): boolean {
  if (!value.trim()) return false;
  const number = Number(value);
  return Number.isFinite(number) && number >= -9999 && number <= 9999;
}

export function normalizePercentInput(nextValue: string, currentValue = ""): string {
  const value = nextValue.trim();
  return DECIMAL.test(value) ? value : currentValue;
}

export function finalizePercentInput(value: string): string {
  return value === "-" ? "0" : value;
}