import md5 from 'md5'

/**
 * Returns Gravatar avatar URL for the given email, or empty string if no email.
 * Gravatar expects: trim, lowercase, then MD5 hex. Use empty string to show a placeholder (e.g. initial letter) in the UI.
 *
 * @param email - User email (optional)
 * @param size - Avatar size in pixels (default 64; navbar 32, drawer 40, profile 64–80)
 */
export function useGravatarUrl(email: string | undefined, size?: number): string {
  const normalized = email?.trim().toLowerCase()
  if (!normalized) return ''
  const hash = md5(normalized)
  const s = size ?? 64
  return `https://www.gravatar.com/avatar/${hash}?s=${s}&d=identicon`
}