import "server-only";
import { getDefaultStorageConfig } from "@/lib/db/queries";
import { findImageArchiveDownloadTask } from "./image-archive-db";
import { extractImageProxySourceUrl, inferOriginalImageUrl } from "@/lib/image-url";

export async function resolveCanvasCdnDownload(urls: string[], filename: string) {
  const sources = Array.from(new Set(urls.flatMap(url => {
    const source = extractImageProxySourceUrl(url) || url;
    return [source, inferOriginalImageUrl(source) || source];
  })));
  const task = await findImageArchiveDownloadTask(sources, true);
  const asset = (task?.metadata as { downloadAsset?: { status?: string; url?: string; contentType?: string; bytes?: number } } | null)?.downloadAsset;
  if (!task) return { task, direct: null, canPrepareDirect: false };
  const config = await getDefaultStorageConfig();
  if (config?.type !== "qiniu-kodo" || !config.publicUrl || !config.isEnabled) return { task, direct: null, canPrepareDirect: false };
  const ready = asset?.status === "ready" && asset.url && asset.contentType === "image/png";
  const source = ready ? asset.url : task.targetUrl;
  if (!source) return { task, direct: null, canPrepareDirect: false };
  const url = new URL(source);
  const base = new URL(config.publicUrl);
  const origin = process.env.CANVAS_QINIU_ORIGIN_URL;
  if (origin && url.origin === new URL(origin).origin) url.host = base.host;
  if (base.protocol !== "https:" || url.origin !== base.origin
      || !(url.pathname.startsWith(base.pathname.replace(/\/$/, "") + "/"))) return { task, direct: null, canPrepareDirect: false };
  if (!ready) return { task, direct: null, canPrepareDirect: true };
  // attname is interpreted by Kodo/CDN as Content-Disposition, including Chinese
  // filenames. Keep all processing/auth parameters intact for correct cache keys.
  url.searchParams.set("attname", filename);
  return { task, direct: { delivery: "cdn", downloadUrl: url.toString(), filename, bytes: asset?.bytes || 0 }, canPrepareDirect: true };
}