const PERSIAN_DIGITS = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹'] as const

export function toPersianDigits(value: string | number | null | undefined): string {
  if (value === null || value === undefined) return ''
  return String(value).replace(/\d/g, (digit) => PERSIAN_DIGITS[Number(digit)] ?? digit)
}

export function toEnglishDigits(value: string): string {
  return value.replace(/[۰-۹]/g, (digit) => {
    const index = PERSIAN_DIGITS.indexOf(digit as (typeof PERSIAN_DIGITS)[number])
    return index >= 0 ? String(index) : digit
  })
}

export function formatFixed(value: string | number | null | undefined, decimals = 2): string {
  const num = Number(value)
  if (!Number.isFinite(num)) return toPersianDigits(String(value ?? ''))
  return toPersianDigits(num.toFixed(decimals))
}

export function formatPercent(
  value: number,
  decimals = 2,
  options: { showSign?: boolean; suffix?: string } = {},
): string {
  const { showSign = false, suffix = '%' } = options
  const prefix = showSign && value > 0 ? '+' : value < 0 ? '-' : showSign ? '+' : ''
  return `${prefix}${formatFixed(Math.abs(value), decimals)}${suffix}`
}