import { parse } from "https://deno.land/std@0.136.0/flags/mod.ts";
import {
  DOMParser,
  Element
} from "https://deno.land/x/deno_dom/deno-dom-wasm.ts";

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 title = doc.querySelectorAll('head > title')[0] as Element;
  console.log(title.textContent);
  
  const thumbUrl = node.getAttribute("content");
  if (thumbUrl == null) {
    throw new Error("document not found");
  }
  console.log(thumbUrl);
  return thumbUrl;
}

const parsedArgs = parse(Deno.args);
getThumUrl(parsedArgs.url);