const MEDIA_PROXY_PATH = "/api/media/proxy";

/** 浏览器可直接加载的公开图床，无需经 MinIO 代理缓存 */
const DIRECT_MEDIA_HOSTS = [
  "images.unsplash.com",
  "unsplash.com",
  "i.pravatar.cc",
  "api.dicebear.com",
  "logo.clearbit.com",
  "avatars.githubusercontent.com",
];

function configuredMinioPublicUrl(): string {
  return (
    process.env.NEXT_PUBLIC_MINIO_PUBLIC_URL ||
    process.env.MINIO_PUBLIC_URL ||
    ""
  ).replace(/\/$/, "");
}

function isDirectMediaHost(hostname: string): boolean {
  const host = hostname.toLowerCase();
  return DIRECT_MEDIA_HOSTS.some(
    (allowed) => host === allowed || host.endsWith(`.${allowed}`)
  );
}

export function isExternalMediaUrl(value: string): boolean {
  return /^https?:\/\//i.test(value);
}

export function isMinioUrl(value: string): boolean {
  const publicUrl = configuredMinioPublicUrl();
  return Boolean(publicUrl && value.startsWith(`${publicUrl}/`));
}

export function mediaUrl(value?: string | null): string {
  const url = String(value || "").trim();
  if (!url) return "";
  if (/^(data:|blob:|#|mailto:|tel:)/i.test(url)) return url;
  if (/^file:/i.test(url)) return "";

  if (url.startsWith("/") && !url.startsWith("//")) {
    const publicUrl = configuredMinioPublicUrl();
    return publicUrl ? `${publicUrl}${url}` : url;
  }

  if (!isExternalMediaUrl(url)) return url;

  if (isMinioUrl(url)) return url;

  try {
    const parsed = new URL(url);
    if (isDirectMediaHost(parsed.hostname)) return url;
  } catch {
    return "";
  }

  return `${MEDIA_PROXY_PATH}?src=${encodeURIComponent(url)}`;
}

export function mediaUrls(values: string[]): string[] {
  return values.map(mediaUrl).filter(Boolean);
}