// Runs once for all items. References upstream nodes by exact name.
const sources = $('Set sources').first().json.sources;
const runs = $('Get backup_runs (last 7d)').all().map(item => item.json);
const weekAgo = new Date(Date.now() - 7 * 24 * 60 * 60 * 1000);

const results = sources.map(source => {
  const sourceRuns = runs.filter(r =>
    r.machine === source.machine &&
    r.destination === source.destination &&
    new Date(r.timestamp) >= weekAgo
  );
  const hasSuccess = sourceRuns.some(r => r.status === 'success');
  const hasAnyRun = sourceRuns.length > 0;
  const status = hasSuccess ? 'green' : hasAnyRun ? 'yellow' : 'red';
  const lastSuccess = sourceRuns
    .filter(r => r.status === 'success')
    .sort((a, b) => new Date(b.timestamp) - new Date(a.timestamp))[0] || null;
  return { ...source, status, runs: sourceRuns, lastSuccess };
});

const overallStatus = results.some(r => r.status === 'red') ? 'red'
  : results.some(r => r.status === 'yellow') ? 'yellow' : 'green';

return [{ json: { results, overallStatus } }];