Retries and idempotency

type NewEvent = { type: string; occurred_on: string; description: string };
type LifecycleEvent = NewEvent & { id: string; source: string };

const base = `${process.env.BATTERYPASS_URL}/api/v1`;
const headers = {
  Authorization: `Bearer ${process.env.BATTERYPASS_API_KEY}`,
  'Content-Type': 'application/json',
};

// Looks for an event this integration already recorded (same type, day and description).
async function findEvent(batteryId: string, e: NewEvent): Promise<LifecycleEvent | undefined> {
  let cursor: string | null = null;
  do {
    const query = new URLSearchParams({ limit: '200' });
    if (cursor) query.set('cursor', cursor);
    const res = await fetch(`${base}/batteries/${batteryId}/lifecycle-events?${query}`, { headers });
    if (!res.ok) throw new Error(`listLifecycleEvents: ${res.status}`);
    const page: { items: LifecycleEvent[]; next_cursor: string | null } = await res.json();
    const hit = page.items.find(
      (x) => x.source === 'api' && x.type === e.type && x.occurred_on === e.occurred_on && x.description === e.description,
    );
    if (hit) return hit;
    // Newest first: once a page reaches older days, the event is not there.
    if (page.items.some((x) => x.occurred_on < e.occurred_on)) return undefined;
    cursor = page.next_cursor;
  } while (cursor);
  return undefined;
}

async function recordEvent(batteryId: string, e: NewEvent): Promise<LifecycleEvent> {
  for (let attempt = 1; attempt <= 3; attempt++) {
    let res: Response | undefined;
    try {
      res = await fetch(`${base}/batteries/${batteryId}/lifecycle-events`, {
        method: 'POST',
        headers,
        body: JSON.stringify(e),
        signal: AbortSignal.timeout(30_000),
      });
    } catch {
      res = undefined; // timeout or connection error
    }
    if (res?.status === 201) return res.json();
    if (res && res.status < 500) throw new Error(`createLifecycleEvent: ${res.status} ${await res.text()}`);
    // No answer or a 5xx: the event may have been recorded anyway.
    const existing = await findEvent(batteryId, e);
    if (existing) return existing;
  }
  throw new Error('createLifecycleEvent: no success after 3 attempts');
}

const event = await recordEvent('0192f0a3-1b7c-7e2a-8f45-6a9d0c3e5b12', {
  type: 'inspection',
  occurred_on: '2026-10-24',
  description: 'Service order SO-2026-0815: annual inspection',
});
console.log(event.id);