function configuredProxyHosts() {
  const configured = window.JC_WEB_IM_CONFIG?.mediaProxyHosts;
  const values = Array.isArray(configured)
    ? configured
    : String(configured || '').split(/[\s,]+/);
  return new Set(
    ['zhiyanim.dfpnm.cn', ...values]
      .map(value => String(value || '').trim().toLowerCase().replace(/\.$/, ''))
      .filter(Boolean)
  );
}

export function imageDisplayUrl(value) {
  const source = String(value || '').trim();
  if (!source || source.startsWith('blob:') || source.startsWith('data:')) {
    return source;
  }

  try {
    const url = new URL(source, window.location.origin);
    if (url.protocol !== 'https:' || !configuredProxyHosts().has(url.hostname.toLowerCase())) {
      return source;
    }
    const proxyUrl = new URL('/api/media_proxy.php', window.location.origin);
    proxyUrl.searchParams.set('url', url.toString());
    return proxyUrl.toString();
  } catch (error) {
    return source;
  }
}

export function videoDisplayUrl(value) {
  const source = String(value || '').trim();
  if (!source || source.startsWith('blob:') || source.startsWith('data:')) return source;
  const streamUrl = new URL('/api/media_stream.php', window.location.origin);
  streamUrl.searchParams.set('url', source);
  return streamUrl.toString();
}

export function useVideoOriginalFallback(event, value) {
  const video = event?.currentTarget;
  const source = String(value || '').trim();
  if (!video || !source || video.dataset.originalFallback === '1') return;
  video.dataset.originalFallback = '1';
  video.src = source;
  video.load();
}

export function useImageProxyFallback(event, value) {
  const image = event?.currentTarget;
  if (!image) return;
  const fallback = imageDisplayUrl(value);
  if (!fallback || fallback === value || image.dataset.proxyFallback === '1') return;
  image.dataset.proxyFallback = '1';
  image.src = fallback;
}