import {
  DOMParser,
  Element
} from "https://deno.land/x/deno_dom/deno-dom-wasm.ts";

// https://www.nicovideo.jp/watch/sm37231246
export async function getThumUrl(url: string): Promise<string> {
  const res = await fetch(url);
  const doc = new DOMParser().parseFromString(await res.text(), "text/html");

  if (doc == null) {
    throw new Error("document not found");
  }

  const node = doc.querySelectorAll('meta[property="og:image"]')[0] as Element;
  const thumbUrl = node.getAttribute("content");
  if (thumbUrl == null) {
    throw new Error("document not found");
  }
  console.log(thumbUrl);
  return thumbUrl;
}