Handle errors and retries

// batterypass.mts: npx tsx batterypass.mts
const BASE = `${process.env.BATTERYPASS_URL}/api/v1`;
const KEY = process.env.BATTERYPASS_API_KEY;
const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));

export class ApiError extends Error {
  status: number;
  problem: { code?: string; detail?: string; request_id?: string; errors?: unknown[] };
  constructor(status: number, problem: ApiError['problem']) {
    super(`${status} ${problem.code}: ${problem.detail} (request_id ${problem.request_id})`);
    this.status = status;
    this.problem = problem;
  }
}

/** Sends a request; retries 429 always, and 5xx or network errors unless the method is POST. */
export async function call<T>(method: string, path: string, body?: unknown, maxAttempts = 5): Promise<T> {
  for (let attempt = 1; ; attempt++) {
    let res: Response | undefined;
    try {
      res = await fetch(BASE + path, {
        method,
        headers: { Authorization: `Bearer ${KEY}`, 'Content-Type': 'application/json' },
        body: body === undefined ? undefined : JSON.stringify(body),
        signal: AbortSignal.timeout(30_000),
      });
    } catch (err) {
      if (method === 'POST' || attempt === maxAttempts) throw err; // network error or timeout
    }
    if (res?.ok) return (await res.json()) as T;
    const retryable = !res || res.status === 429 || (res.status >= 500 && method !== 'POST');
    if (res && (!retryable || attempt === maxAttempts)) {
      const requestId = res.headers.get('X-Request-Id') ?? undefined;
      const problem = await res.json().catch(() => ({ request_id: requestId }));
      throw new ApiError(res.status, problem);
    }
    // Retry-After (seconds) wins; otherwise exponential backoff with full jitter, at most 30 s.
    const retryAfter = Number(res?.headers.get('Retry-After'));
    await sleep(retryAfter > 0 ? retryAfter * 1000 : Math.random() * Math.min(30_000, 500 * 2 ** attempt));
  }
}

// Usage
try {
  const page = await call<{ items: { serial_number: string }[] }>('GET', '/batteries?limit=10');
  console.log(page.items.map((u) => u.serial_number));
} catch (err) {
  if (err instanceof ApiError) console.error(err.message); // log the request_id, never the key
  else throw err;
}