/* UI Logic for temperature and image rendering */

/**
 * Render a temperature line chart in the #temperature-chart container.
 * @param {Array<{timestamp: string, value: number}>} temperatures
 */
export function renderChart(temperatures) {
  const container = document.querySelector('#temperature-chart');
  if (!container) return;
  container.innerHTML = '';

  const canvas = document.createElement('canvas');
  canvas.setAttribute('role', 'img');
  canvas.setAttribute('aria-label', 'Temperaturverlauf');
  canvas.width = container.clientWidth;
  canvas.height = 200;
  container.appendChild(canvas);

  const ctx = canvas.getContext('2d');
  if (!ctx || temperatures.length === 0) return;

  const values = temperatures.map(t => t.value);
  const minVal = Math.min(...values);
  const maxVal = Math.max(...values);
  const range = maxVal - minVal || 1;

  ctx.strokeStyle = '#2196f3';
  ctx.lineWidth = 2;
  ctx.beginPath();

  temperatures.forEach((t, i) => {
    const x = (i / (temperatures.length - 1)) * canvas.width;
    const y = canvas.height - ((t.value - minVal) / range) * canvas.height;
    if (i === 0) {
      ctx.moveTo(x, y);
    } else {
      ctx.lineTo(x, y);
    }
  });
  ctx.stroke();
}

/**
 * Render an interactive image gallery.
 * @param {Array<{filename: string, timestamp: string, metadata?: object}>} images
 */
export function renderGallery(images) {
  const container = document.querySelector('#image-gallery');
  if (!container) return;
  container.innerHTML = '';

  const galleryGrid = document.createElement('div');
  galleryGrid.classList.add('gallery-grid');

  images.forEach((imgData, index) => {
    const imgEl = document.createElement('div');
    imgEl.classList.add('gallery-item');
    imgEl.tabIndex = 0;
    imgEl.setAttribute('role', 'button');
    imgEl.setAttribute('aria-label', `Bild ${index + 1}`);
    imgEl.style.backgroundColor = '#e0e0e0';
    imgEl.style.display = 'flex';
    imgEl.style.alignItems = 'center';
    imgEl.style.justifyContent = 'center';
    imgEl.style.height = '100px';
    imgEl.textContent = `Bild ${index + 1}`;

    imgEl.addEventListener('click', () => openImageModal(imgData));
    imgEl.addEventListener('keypress', e => {
      if (e.key === 'Enter' || e.key === ' ') {
        openImageModal(imgData);
      }
    });

    galleryGrid.appendChild(imgEl);
  });

  container.appendChild(galleryGrid);
}

/**
 * Display a modal view for a selected image (textual substitute, no actual image).
 * @param {{filename: string, timestamp: string, metadata?: object}} imgData
 */
function openImageModal(imgData) {
  let modal = document.querySelector('#image-modal');
  if (!modal) {
    modal = document.createElement('div');
    modal.id = 'image-modal';
    modal.setAttribute('role', 'dialog');
    modal.setAttribute('aria-modal', 'true');
    modal.style.position = 'fixed';
    modal.style.top = 0;
    modal.style.left = 0;
    modal.style.right = 0;
    modal.style.bottom = 0;
    modal.style.background = 'rgba(0,0,0,0.8)';
    modal.style.color = '#fff';
    modal.style.display = 'flex';
    modal.style.alignItems = 'center';
    modal.style.justifyContent = 'center';

    const content = document.createElement('div');
    content.classList.add('modal-content');
    content.style.padding = '1rem';
    content.style.background = '#111';
    content.style.maxWidth = '90%';
    content.style.textAlign = 'center';

    const closeBtn = document.createElement('button');
    closeBtn.textContent = 'Schließen';
    closeBtn.style.marginTop = '1rem';
    closeBtn.addEventListener('click', () => {
      modal.remove();
    });

    modal.appendChild(content);
    content.appendChild(closeBtn);
    document.body.appendChild(modal);
  }

  const content = modal.querySelector('.modal-content');
  if (content) {
    content.innerHTML = `<h2>Bild: ${imgData.filename}</h2><p>Aufgenommen: ${imgData.timestamp}</p>`;
    const closeBtn = document.createElement('button');
    closeBtn.textContent = 'Schließen';
    closeBtn.style.marginTop = '1rem';
    closeBtn.addEventListener('click', () => modal.remove());
    content.appendChild(closeBtn);
  }
}

/**
 * Update summary statistics for displayed data.
 * @param {Array<{timestamp: string, value: number}>} temperatures
 * @param {Array<{filename: string, timestamp: string}>} images
 */
export function updateStats(temperatures, images) {
  const container = document.querySelector('#summary-stats');
  if (!container) return;
  container.innerHTML = '';

  const avgTemp =
    temperatures.length > 0
      ? (temperatures.reduce((sum, t) => sum + t.value, 0) / temperatures.length).toFixed(2)
      : 'N/A';

  const imgCount = images.length;

  const statsText = `Durchschnittstemperatur: ${avgTemp}°C | Bilder: ${imgCount}`;
  container.textContent = statsText;
}