export function updateStatsPanel(analysisResults = {}) {
  const statsContainer = document.getElementById('stats-summary');
  if (!statsContainer) {
    console.warn('Stats summary container missing (#stats-summary)');
    return;
  }

  if (!analysisResults || !Array.isArray(analysisResults.runs)) {
    statsContainer.textContent = 'Keine Analysedaten vorhanden.';
    return;
  }

  const totalRuns = analysisResults.runs.length;
  if (totalRuns === 0) {
    statsContainer.textContent = 'Keine Analysedaten verfügbar.';
    return;
  }

  const medianAvg = (
    analysisResults.runs.reduce((sum, r) => sum + (r.median_shift || 0), 0) / totalRuns
  ).toFixed(2);

  const varianceAvg = (
    analysisResults.runs.reduce((sum, r) => sum + (r.variance || 0), 0) / totalRuns
  ).toFixed(2);

  const migratedAvg = (
    analysisResults.runs.reduce((sum, r) => sum + (r.migrated_ratio || 0), 0) / totalRuns
  ).toFixed(2);

  const offsetAvg = (
    analysisResults.runs.reduce((sum, r) => sum + (r.offset_constant || 0), 0) / totalRuns
  ).toFixed(2);

  const strongDeviations = analysisResults.runs.filter(r => (r.variance || 0) > 1.5).length;

  const summaryHTML = `
    <h3>Analyse-Zusammenfassung</h3>
    <ul>
      <li><strong>Anzahl Durchläufe:</strong> ${totalRuns}</li>
      <li><strong>Mittlerer Median-Shift:</strong> ${medianAvg}</li>
      <li><strong>Mittlere Varianz:</strong> ${varianceAvg}</li>
      <li><strong>Durchschnittlicher WF_MIGRATED-Anteil:</strong> ${migratedAvg}</li>
      <li><strong>Mittlerer Offset-Koeffizient:</strong> ${offsetAvg}</li>
      <li><strong>Signifikante Abweichungen:</strong> ${strongDeviations}</li>
    </ul>
  `;

  statsContainer.innerHTML = summaryHTML;
}

export function setupFilterEvents() {
  const filterElements = document.querySelectorAll('[data-filter]');
  if (!filterElements.length) {
    console.warn('Keine Filterelemente mit data-filter gefunden.');
    return;
  }

  filterElements.forEach(el => {
    el.addEventListener('click', () => {
      const filter = el.getAttribute('data-filter');
      const event = new CustomEvent('filterChanged', { detail: { filter } });
      document.dispatchEvent(event);
    });
  });
}