/**
 * The actual `ulid` library depends on a secure random number generator, which looks like it
 * may require a native dependency to polyfill in React Native.
 * Since this is only used as a local temporary ID, I think we can get away with a simpler
 * implementation that doesn't require any native dependencies.
 */

const ULID_CHARS = '0123456789ABCDEFGHJKMNPQRSTVWXYZ' // Crockford's Base32

function encodeBase32(value: number, length: number) {
  let result = ''
  for (let i = 0; i < length; i++) {
    result = ULID_CHARS[value % 32] + result
    value = Math.floor(value / 32)
  }
  return result
}

export function generatePlaceholderUlid({ offsetMs = 0 }: { offsetMs?: number } = {}): string {
  const timestamp = Date.now() + offsetMs // Milliseconds since epoch
  // 48 bits for timestamp (6 Base32 characters)
  const timeComponent = encodeBase32(timestamp, 10) // 48 bits = 6 bytes = 10 Base32 characters (approx, needs more precise bit shifting)

  // 80 bits for randomness (16 Base32 characters)
  let randomComponent = ''
  for (let i = 0; i < 16; i++) {
    // Generate 16 random Base32 chars
    randomComponent += ULID_CHARS[Math.floor(Math.random() * 32)]
  }

  return timeComponent + randomComponent
}