export const MONEY_UNITS_PER_YUAN = 10_000;

export function formatAmount(value: number) {
  return value.toLocaleString('zh-CN', {
    minimumFractionDigits: 0,
    maximumFractionDigits: 4,
  });
}

export function formatRateAmount(value: number) {
  return value.toLocaleString('zh-CN', { minimumFractionDigits: 4, maximumFractionDigits: 4 });
}

export function formatCents(cents?: number | null) {
  return formatAmount((cents ?? 0) / MONEY_UNITS_PER_YUAN);
}

export function formatYuan(cents?: number | null) {
  return `¥${formatCents(cents)}`;
}

export function yuanToMoneyUnits(value: number | string | null | undefined) {
  const amount = typeof value === 'string' ? Number(value) : (value ?? 0);
  return Math.round(amount * MONEY_UNITS_PER_YUAN);
}

export function isValidMoneyInput(value: string, options: { allowNegative?: boolean; allowZero?: boolean } = {}) {
  const normalized = value.trim();
  const pattern = options.allowNegative ? /^-?\d+(?:\.\d{1,4})?$/ : /^\d+(?:\.\d{1,4})?$/;
  if (!pattern.test(normalized)) return false;
  return options.allowZero !== false || Number(normalized) !== 0;
}

export function moneyUnitsToYuan(value?: number | null) {
  return (value ?? 0) / MONEY_UNITS_PER_YUAN;
}