const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function waitForHappyHorseVideo(taskId) {
  const deadline = Date.now() + 15 * 60 * 1000;
  let delayMs = 8000;

  while (Date.now() < deadline) {
    const res = await fetch(
      `${BASE_URL}/api/status?task_id=${encodeURIComponent(taskId)}`,
      { headers: { Authorization: `Bearer ${API_KEY}` } }
    );

    if (res.status === 429) {
      await sleep(Math.min(delayMs * 2, 30000));
      continue;
    }

    const payload = await res.json();
    if (!res.ok) {
      throw new Error(payload.message || `Status request failed: ${res.status}`);
    }

    const task = payload.data;
    if (task.status === "SUCCESS") {
      return task.response?.resultUrls?.[0];
    }
    if (task.status === "FAILED") {
      throw new Error(task.error_message || "Generation failed");
    }

    await sleep(delayMs);
    delayMs = Math.min(delayMs + 2000, 20000);
  }

  throw new Error("Timed out. Keep the task_id and check again later.");
}