async function grammarlyWithBackoff<T>(fn: () => Promise<T>, maxRetries = 3): Promise<T> {
  for (let i = 0; i <= maxRetries; i++) {
    try { return await fn(); }
    catch (err: any) {
      if (err.status !== 429 || i === maxRetries) throw err;
      const delay = 1000 * Math.pow(2, i) + Math.random() * 1000;
      await new Promise(r => setTimeout(r, delay));
    }
  }
  throw new Error('Unreachable');
}

import PQueue from 'p-queue';
const grammarlyQueue = new PQueue({ concurrency: 2, interval: 1000, intervalCap: 5 });

async function queuedScore(text: string, token: string) {
  return grammarlyQueue.add(() =>
    fetch('https://api.grammarly.com/ecosystem/api/v2/scores', {
      method: 'POST',
      headers: { 'Authorization': `Bearer ${token}`, 'Content-Type': 'application/json' },
      body: JSON.stringify({ text }),
    }).then(r => r.json())
  );
}