/**
 * visualization.js
 * Verantwortlich für Rendering der Diagramme und Aktualisierung bei neuen Daten.
 * Part of experiment: resonanzband_analysis (artifact: data_visualization)
 */

/**
 * Aktualisiert die aggregierten Kennzahlen im summary-section.
 * @param {Array<Object>} data - Analyseergebnisse mit Feldern { run_id, band_center, band_width_p10_p90, max_outlier, overhead_ms }
 */
export function updateSummary(data) {
  if (!Array.isArray(data) || data.length === 0) {
    const summaryEl = document.getElementById('summary-section');
    if (summaryEl) summaryEl.textContent = 'Keine Daten verfügbar.';
    return;
  }

  const avg = (arr, key) => arr.reduce((sum, d) => sum + (d[key] ?? 0), 0) / arr.length;
  const maxOutlier = Math.max(...data.map(d => d.max_outlier ?? 0));

  const summary = {
    avgBandCenter: avg(data, 'band_center').toFixed(2),
    avgWidth: avg(data, 'band_width_p10_p90').toFixed(2),
    maxOutlier,
    avgOverhead: avg(data, 'overhead_ms').toFixed(2)
  };

  const summaryEl = document.getElementById('summary-section');
  if (!summaryEl) return;
  summaryEl.innerHTML = `
    <div class="summary__metric"><span class="summary__label">Durchschnitt Bandcenter:</span> <span class="summary__value">${summary.avgBandCenter}</span></div>
    <div class="summary__metric"><span class="summary__label">Durchschnitt Bandbreite (P10–P90):</span> <span class="summary__value">${summary.avgWidth}</span></div>
    <div class="summary__metric"><span class="summary__label">Maximaler Ausreißer:</span> <span class="summary__value">${summary.maxOutlier}</span></div>
    <div class="summary__metric"><span class="summary__label">Mittlerer Overhead (ms):</span> <span class="summary__value">${summary.avgOverhead}</span></div>
  `;
}

/**
 * Zeichnet Diagramme und Statistiken im charts-container basierend auf Analyseergebnissen.
 * @param {Array<Object>} results - Analyseergebnisse
 */
export function renderResults(results) {
  const container = document.getElementById('charts-container');
  if (!container) return;
  container.innerHTML = '';

  if (!Array.isArray(results) || results.length === 0) {
    container.textContent = 'Keine Ergebnisse gefunden.';
    updateSummary([]);
    return;
  }

  // Diagramm mit Canvas-Element zeichnen (native Lösung ohne externe Lib)
  const canvas = document.createElement('canvas');
  canvas.width = container.clientWidth;
  canvas.height = 300;
  canvas.setAttribute('role', 'img');
  canvas.setAttribute('aria-label', 'Diagramm der Resonanzband-Metriken');
  container.appendChild(canvas);

  const ctx = canvas.getContext('2d');
  const padding = 40;
  const width = canvas.width - 2 * padding;
  const height = canvas.height - 2 * padding;

  const maxBand = Math.max(...results.map(r => r.band_center + r.band_width_p10_p90));
  const minBand = Math.min(...results.map(r => r.band_center - r.band_width_p10_p90));

  const scaleY = val => height - ((val - minBand) / (maxBand - minBand)) * height + padding;
  const scaleX = (i) => padding + (i / (results.length - 1)) * width;

  // Achsen zeichnen
  ctx.strokeStyle = '#333';
  ctx.beginPath();
  ctx.moveTo(padding, padding);
  ctx.lineTo(padding, height + padding);
  ctx.lineTo(width + padding, height + padding);
  ctx.stroke();

  // Linien für Bandcenter zeichnen
  ctx.strokeStyle = '#0057b7';
  ctx.lineWidth = 2;
  ctx.beginPath();
  results.forEach((r, i) => {
    const x = scaleX(i);
    const y = scaleY(r.band_center);
    if (i === 0) ctx.moveTo(x, y);
    else ctx.lineTo(x, y);
  });
  ctx.stroke();

  // Outlier Punkte zeichnen
  ctx.fillStyle = '#b70000';
  results.forEach((r, i) => {
    const x = scaleX(i);
    const y = scaleY(r.band_center + r.max_outlier);
    ctx.beginPath();
    ctx.arc(x, y, 3, 0, Math.PI * 2);
    ctx.fill();
  });

  // Tooltips: einfache textuelle Version
  canvas.addEventListener('mousemove', e => {
    const rect = canvas.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;

    const idx = Math.round((x - padding) / width * (results.length - 1));
    const item = results[idx];
    if (!item) return;

    const tooltip = document.getElementById('chart-tooltip') ?? document.createElement('div');
    tooltip.id = 'chart-tooltip';
    tooltip.className = 'chart__tooltip';
    tooltip.style.position = 'absolute';
    tooltip.style.left = `${x + 10}px`;
    tooltip.style.top = `${y + 10}px`;
    tooltip.style.background = '#222';
    tooltip.style.color = '#fff';
    tooltip.style.padding = '4px 8px';
    tooltip.style.borderRadius = '4px';
    tooltip.style.fontSize = '0.8rem';
    tooltip.style.pointerEvents = 'none';
    tooltip.textContent = `Run ${item.run_id}: Center=${item.band_center}, Width=${item.band_width_p10_p90}, Outlier=${item.max_outlier}`;

    document.body.appendChild(tooltip);
  });

  canvas.addEventListener('mouseleave', () => {
    const tooltip = document.getElementById('chart-tooltip');
    if (tooltip) tooltip.remove();
  });

  // Zusammenfassung aktualisieren
  updateSummary(results);
}