E-Learning & Education

const API = "https://videodownloadapi.com/api/v1";
const headers = {
  Authorization: `Bearer ${process.env.VIDEO_API_KEY}`,
  "Content-Type": "application/json",
};

type Download = { download_id: string; status: string; title: string; download_url?: string };

async function download(url: string, options: { format?: string; quality?: string } = {}) {
  const res = await fetch(`${API}/downloads`, {
    method: "POST",
    headers,
    body: JSON.stringify({ url, ...options }),
  });
  if (res.status === 402) throw new Error("Not enough minutes");
  if (res.status === 429) throw new Error("Too many requests: retry in a few seconds");
  let item: Download = await res.json();

  // Poll until the file is ready (or failed: minutes are refunded automatically)
  while (item.status !== "ready" && item.status !== "failed") {
    await new Promise((resolve) => setTimeout(resolve, 3000));
    item = await fetch(`${API}/downloads/${item.download_id}`, { headers }).then((r) => r.json());
  }
  if (item.status === "failed") throw new Error(`Download failed: ${url}`);
  return item;
}

// Download every lesson of a course, plus an MP3 for offline listening
async function downloadCourseContent(lessons: { title: string; url: string }[]) {
  for (const lesson of lessons) {
    const video = await download(lesson.url, { format: "mp4", quality: "720p" });
    const audio = await download(lesson.url, { format: "mp3" });
    console.log(`${lesson.title}: ${video.download_url} | ${audio.download_url}`);
  }
}

downloadCourseContent([{ title: "Lesson 1", url: "https://youtube.com/watch?v=VIDEO_ID" }]);