/**
 * Lightweight browser-safe JWT payload decoder without external native dependencies.
 */
export function parseJwtClaims(token: string): Record<string, any> {
  if (!token || typeof token !== 'string') return {};
  try {
    const parts = token.split('.');
    if (parts.length < 2) return {};
    const base64Url = parts[1];
    const base64 = base64Url.replace(/-/g, '+').replace(/_/g, '/');
    const jsonPayload = decodeURIComponent(
      window
        .atob(base64)
        .split('')
        .map((c) => '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2))
        .join('')
    );
    return JSON.parse(jsonPayload);
  } catch (err) {
    console.debug('Failed to decode JWT claims payload:', err);
    return {};
  }
}