// Native diagnostic trial: archive the current observation, then one input and immediate refresh.
globalThis.recordDiagnosticTrial = async function(label) {
  if (!/^[a-z0-9-]+$/.test(label)) throw Error('Invalid evidence label');
  const s = diagnosticState;
  if (!s) throw Error('No current native observation');
  const n = String(++diagnosticSequence).padStart(3, '0');
  const meta = {atUtc:new Date().toISOString(), label, window:s.window, accessibility:s.accessibility, screenshots:[]};
  for (let i = 0; i < s.screenshots.length; i++) {
    const {url, ...info} = s.screenshots[i];
    const filename = n + '-' + label + '-' + i + '.jpg';
    await diagnosticFs.writeFile(diagnosticEvidence + '/' + filename, Buffer.from(url.split(',')[1], 'base64'), {flag:'wx'});
    meta.screenshots.push({...info, file:filename});
  }
  await diagnosticFs.writeFile(diagnosticEvidence + '/' + n + '-' + label + '.json', JSON.stringify(meta, null, 2) + '\n', {flag:'wx'});
};
globalThis.diagnosticAct = async function(kind, args, label, screenshotIndex = 0) {
  const allowed = ['click', 'scroll', 'press_key', 'type_text', 'drag'];
  if (!allowed.includes(kind)) throw Error('Unsupported trial action');
  const s = diagnosticState;
  if (!s) throw Error('Reobserve before acting');
  const input = {...args, window:s.window};
  if (['click', 'scroll', 'drag'].includes(kind)) {
    if (!s.screenshots[screenshotIndex]) throw Error('Missing observed screenshot');
    input.screenshotId = s.screenshots[screenshotIndex].id;
  }
  diagnosticState = null;
  await sky[kind](input);
  diagnosticState = await sky.get_window_state({window:s.window, include_screenshot:true, include_text:true});
  if (label) await recordDiagnosticTrial(label);
  nodeRepl.write(String(diagnosticState.accessibility?.tree || diagnosticState.accessibility?.document_text || ''));
};