encodingUtils.ts

import base64url from 'base64url';

export const ID_MAX_LENGTH = 32;

export function isValidId(id: unknown): id is string {
  return typeof id === 'string' && id.length <= ID_MAX_LENGTH && /^[ -~]+$/.test(id);
}

export function isValidUtf8Input(input: unknown): input is string {
  if (typeof input !== 'string' || input.length !== 16) {
    return false;
  }

  try {
    const buffer = Buffer.from(input, 'utf8');
    return buffer.toString('utf8') === input;
  } catch {
    return false;
  }
}

export function isValidBase64UrlInput(input: unknown): input is string {
  return typeof input === 'string' && /^[A-Za-z0-9_-]{60,64}$/.test(input);
}

export function isValidHexInput(input: unknown): input is string {
  return typeof input === 'string' && /^[A-Fa-f0-9]{90,96}$/.test(input);
}

export function base64urlToUtf8(input: string): string {
  return base64url.toBuffer(input).toString('utf8');
}

export function utf8ToBase64url(input: string): string {
  return base64url(Buffer.from(input, 'utf8'));
}

export function hexToUtf8(input: string): string {
  return Buffer.from(input, 'hex').toString('utf8');
}

export function utf8ToHex(input: string): string {
  return Buffer.from(input, 'utf8').toString('hex');
}