// One discovery cycle: scan → upsert → mark-absent → prune. Deps injected for
// tests. Prune only runs after a successful, non-empty scan, so a failed scan
// can never reap rows.
import { runScan } from './scan.js';
import * as devices from '../db/repos/lan_devices.js';
import { log } from '../log.js';

export async function runDeviceScanCycle({ scan = runScan, repo = devices } = {}) {
  const rows = await scan();
  if (!rows.length) {
    log.warn('device scan returned no hosts; skipping upsert/prune');
    return { seen: 0 };
  }
  await repo.upsertScan(rows);
  await repo.markAbsent(rows.map(r => r.mac));
  const pruned = await repo.prune();
  log.info({ seen: rows.length, pruned }, 'device scan cycle complete');
  return { seen: rows.length, pruned };
}