/**
 * Emits <link rel="preconnect"> + <link rel="dns-prefetch"> for the media CDN
 * domain (R2_PUBLIC_URL), so the browser opens the TLS/DNS connection to the
 * media host early — before it hits the first <img>. Saves ~150–300ms on the
 * first image load.
 *
 * Reads the domain from R2_PUBLIC_URL (the same env var buildR2Storage uses),
 * so there's ONE source of truth — no per-project hardcoded domain. Renders
 * nothing when R2_PUBLIC_URL isn't set (local disk / no CDN → nothing to
 * preconnect).
 *
 * Server Component — drop it in the <head> of your locale layout:
 *
 *   import { MediaPreconnect } from '@intecion/ipal-kit/rsc'
 *   // in <head> (or top of <body> — Next hoists link tags):
 *   <MediaPreconnect />
 */
export function MediaPreconnect() {
  const publicUrl = process.env.R2_PUBLIC_URL?.replace(/\/$/, '')
  if (!publicUrl) {return null}

  // Origin only (scheme + host) — preconnect targets an origin, not a path.
  let origin: string
  try {
    origin = new URL(publicUrl).origin
  } catch {
    return null // malformed URL → skip rather than emit a broken tag
  }

  return (
    <>
      <link crossOrigin="anonymous" href={origin} rel="preconnect" />
      <link href={origin} rel="dns-prefetch" />
    </>
  )
}

export default MediaPreconnect