class RateLimitedSpeakClient {
  private lastRequest = 0;
  private minDelay: number;

  constructor(private client: SpeakClient, requestsPerMinute: number = 60) {
    this.minDelay = 60000 / requestsPerMinute;
  }

  private async throttle() {
    const elapsed = Date.now() - this.lastRequest;
    if (elapsed < this.minDelay) {
      await new Promise(r => setTimeout(r, this.minDelay - elapsed));
    }
    this.lastRequest = Date.now();
  }

  async assessPronunciation(config: PronunciationConfig) {
    await this.throttle();
    return this.retryOn429(() => this.client.assessPronunciation(config));
  }

  private async retryOn429<T>(fn: () => Promise<T>, maxRetries = 3): Promise<T> {
    for (let i = 0; i < maxRetries; i++) {
      try {
        return await fn();
      } catch (err: any) {
        if (err.response?.status === 429 && i < maxRetries - 1) {
          const wait = parseInt(err.response.headers['retry-after'] || String(2 ** i));
          console.log(`Rate limited. Waiting ${wait}s...`);
          await new Promise(r => setTimeout(r, wait * 1000));
          continue;
        }
        throw err;
      }
    }
    throw new Error('Max retries exceeded');
  }
}

async function batchAssess(client: RateLimitedSpeakClient, recordings: Recording[]) {
  const results = [];
  for (const rec of recordings) {
    const result = await client.assessPronunciation({
      audioPath: rec.path, targetText: rec.text, language: rec.lang,
    });
    results.push({ ...rec, score: result.score });
    console.log(`Assessed "${rec.text}": ${result.score}/100`);
  }
  return results;
}