import { randomBytes } from 'node:crypto'

export function encodeBase64Url(value: Buffer | Uint8Array | string): string {
  const buffer = typeof value === 'string'
    ? Buffer.from(value, 'utf8')
    : Buffer.from(value)

  return buffer
    .toString('base64')
    .replace(/\+/g, '-')
    .replace(/\//g, '_')
    .replace(/=+$/g, '')
}

export function decodeBase64Url(value: string): Buffer {
  const normalized = value
    .replace(/-/g, '+')
    .replace(/_/g, '/')

  const padding = normalized.length % 4 === 0
    ? ''
    : '='.repeat(4 - (normalized.length % 4))

  return Buffer.from(`${normalized}${padding}`, 'base64')
}

export function randomToken(length = 32): string {
  return encodeBase64Url(randomBytes(length))
}

export function toIsoString(value: Date | string | null): string | null {
  if (!value) {
    return null
  }

  if (value instanceof Date) {
    return value.toISOString()
  }

  return new Date(value).toISOString()
}