// Builds subject + body from Evaluate Sources output.
// Uses an array of lines joined at the end to avoid \n escape issues in JSON storage.
const { results, overallStatus } = $input.first().json;
const icon  = { green: '✓', yellow: '⚠', red: '✗' };
const label = { green: 'Backups healthy', yellow: 'Backup warning', red: 'Backup failure' };
const weekOf = new Date().toLocaleDateString('en-US', { month: 'short', day: 'numeric' });
const subject = icon[overallStatus] + ' ' + label[overallStatus] + ' — week of ' + weekOf;

const fmt = ts => ts
  ? new Date(ts).toLocaleString('en-US', { month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' })
  : 'unknown';

const L = [];

if (overallStatus === 'green') {
  L.push('All backup sources ran successfully this week.');
  L.push('');
  results.forEach(r =>
    L.push('✓  ' + r.machine + ' / ' + r.destination +
      '  (last success: ' + fmt(r.lastSuccess && r.lastSuccess.timestamp) + ')')
  );
} else {
  const problems = results.filter(r => r.status !== 'green');
  const healthy  = results.filter(r => r.status === 'green');

  L.push(problems.length + ' source(s) need attention:');
  L.push('');

  problems.forEach(r => {
    L.push(icon[r.status] + '  ' + r.machine + ' / ' + r.destination);

    if (r.status === 'yellow') {
      L.push('   Ran this week but never succeeded.');
      r.runs.slice(0, 3).forEach(run => {
        var line = '   ' + fmt(run.timestamp) + '  [' + run.status + ']';
        if (run.log_path) line += '  log: ' + run.log_path;
        L.push(line);
        if (run.notes) L.push('   notes: ' + (run.notes || '').slice(0, 300));
      });
      L.push('');
      L.push('   Next steps:');
      L.push('   1. Check the log at the path shown above');
      L.push('   2. For Synology failures: verify LAN reachability (ssh synology) — disks need ~30s to spin up');
      L.push('   3. Re-run manually:  bash ~/.local/bin/backup.sh');
      L.push('   4. One-off skip (power outage, travel) is expected — yellow is a heads-up, not an alarm');
      L.push('');
    }

    if (r.status === 'red') {
      L.push('   No runs reported all week — silent failure.');
      if (r.lastSuccess) {
        L.push('   Last known good run: ' + fmt(r.lastSuccess.timestamp));
        if (r.lastSuccess.log_path) L.push('   Last log: ' + r.lastSuccess.log_path);
      } else {
        L.push('   No history found in the datatable.');
      }
      L.push('');
      L.push('   Next steps:');
      L.push('   1. Check systemd timer:  systemctl --user status restic-backup.timer');
      L.push('   2. Verify backup.sh calls notify_backup.rb at the end');
      L.push('   3. Check n8n Workflow 1 execution log for webhook errors');
      L.push('   4. Run manually:  bash ~/.local/bin/backup.sh');
      L.push('');
    }
  });

  if (healthy.length > 0) {
    L.push('Healthy sources:');
    healthy.forEach(r => L.push('✓  ' + r.machine + ' / ' + r.destination));
  }
}

return [{ json: { subject, body: L.join('\n') } }];