/**
 * Image Gallery Web Component
 * Displays a gallery of pharmaceutical products with lightbox functionality
 */
class ImageGallery extends HTMLElement {
  constructor() {
    super();
    this.attachShadow({ mode: 'open' });
    this.images = [];
    this.currentIndex = 0;
  }

  connectedCallback() {
    // Parse images from data attribute or children
    const imagesData = this.getAttribute('data-images');
    if (imagesData) {
      try {
        this.images = JSON.parse(imagesData);
      } catch (e) {
        console.error('Failed to parse images data', e);
      }
    }

    // If no images data attribute, look for child elements
    if (this.images.length === 0) {
      this.querySelectorAll('img').forEach(img => {
        this.images.push({
          src: img.src,
          alt: img.alt,
          title: img.title || img.alt
        });
      });
    }

    this.render();
  }

  render() {
    const columns = this.getAttribute('columns') || '4';
    const gap = this.getAttribute('gap') || '4';
    const showCaptions = this.hasAttribute('show-captions');

    this.shadowRoot.innerHTML = `
      <style>
        :host {
          display: block;
          width: 100%;
        }
        
        .gallery-container {
          display: grid;
          grid-template-columns: repeat(${columns}, 1fr);
          gap: ${gap}px;
          margin: 0 auto;
        }
        
        @media (max-width: 1024px) {
          .gallery-container {
            grid-template-columns: repeat(3, 1fr);
          }
        }
        
        @media (max-width: 768px) {
          .gallery-container {
            grid-template-columns: repeat(2, 1fr);
          }
        }
        
        @media (max-width: 480px) {
          .gallery-container {
            grid-template-columns: 1fr;
          }
        }
        
        .gallery-item {
          position: relative;
          cursor: pointer;
          border-radius: 8px;
          overflow: hidden;
          transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        
        .gallery-item:hover {
          transform: translateY(-4px);
          box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }
        
        .gallery-image {
          width: 100%;
          height: 200px;
          object-fit: cover;
          display: block;
        }
        
        .image-caption {
          padding: 12px;
          background: white;
          text-align: center;
          font-size: 14px;
          color: #333;
        }
        
        /* Lightbox styles */
        .lightbox {
          display: none;
          position: fixed;
          top: 0;
          left: 0;
          width: 100%;
          height: 100%;
          background: rgba(0, 0, 0, 0.9);
          z-index: 1000;
          align-items: center;
          justify-content: center;
        }
        
        .lightbox.active {
          display: flex;
        }
        
        .lightbox-content {
          position: relative;
          max-width: 90%;
          max-height: 90%;
        }
        
        .lightbox-image {
          max-width: 100%;
          max-height: 80vh;
          object-fit: contain;
        }
        
        .lightbox-caption {
          color: white;
          text-align: center;
          padding: 15px;
          font-size: 18px;
        }
        
        .lightbox-close {
          position: absolute;
          top: 20px;
          right: 20px;
          background: none;
          border: none;
          color: white;
          font-size: 30px;
          cursor: pointer;
          z-index: 1001;
        }
        
        .lightbox-nav {
          position: absolute;
          top: 50%;
          width: 100%;
          display: flex;
          justify-content: space-between;
          transform: translateY(-50%);
          padding: 0 20px;
        }
        
        .lightbox-prev,
        .lightbox-next {
          background: rgba(255, 255, 255, 0.2);
          border: none;
          color: white;
          width: 50px;
          height: 50px;
          border-radius: 50%;
          font-size: 24px;
          cursor: pointer;
          transition: background 0.3s;
        }
        
        .lightbox-prev:hover,
        .lightbox-next:hover {
          background: rgba(255, 255, 255, 0.4);
        }
      </style>
      
      <div class="gallery-container">
        ${this.images.map((image, index) => `
          <div class="gallery-item" data-index="${index}">
            <optimized-image
              src="${image.src}"
              alt="${image.alt}"
              height="200px"
              lazy
              class="gallery-image"
            ></optimized-image>
            ${showCaptions ? `<div class="image-caption">${image.title || image.alt}</div>` : ''}
          </div>
        `).join('')}
      </div>
      
      <!-- Lightbox -->
      <div class="lightbox">
        <button class="lightbox-close">&times;</button>
        <div class="lightbox-nav">
          <button class="lightbox-prev">&#10094;</button>
          <button class="lightbox-next">&#10095;</button>
        </div>
        <div class="lightbox-content">
          <img class="lightbox-image" src="" alt="">
          <div class="lightbox-caption"></div>
        </div>
      </div>
    `;

    // Add event listeners
    this.addEventListeners();
  }

  addEventListeners() {
    const lightbox = this.shadowRoot.querySelector('.lightbox');
    const lightboxImage = this.shadowRoot.querySelector('.lightbox-image');
    const lightboxCaption = this.shadowRoot.querySelector('.lightbox-caption');
    const closeBtn = this.shadowRoot.querySelector('.lightbox-close');
    const prevBtn = this.shadowRoot.querySelector('.lightbox-prev');
    const nextBtn = this.shadowRoot.querySelector('.lightbox-next');
    const galleryItems = this.shadowRoot.querySelectorAll('.gallery-item');

    // Open lightbox on image click
    galleryItems.forEach(item => {
      item.addEventListener('click', () => {
        this.currentIndex = parseInt(item.dataset.index);
        this.updateLightbox();
        lightbox.classList.add('active');
        document.body.style.overflow = 'hidden';
      });
    });

    // Close lightbox
    closeBtn.addEventListener('click', () => {
      lightbox.classList.remove('active');
      document.body.style.overflow = 'auto';
    });

    // Lightbox navigation
    prevBtn.addEventListener('click', () => {
      this.currentIndex = (this.currentIndex - 1 + this.images.length) % this.images.length;
      this.updateLightbox();
    });

    nextBtn.addEventListener('click', () => {
      this.currentIndex = (this.currentIndex + 1) % this.images.length;
      this.updateLightbox();
    });

    // Keyboard navigation
    document.addEventListener('keydown', (e) => {
      if (!lightbox.classList.contains('active')) return;
      
      switch (e.key) {
        case 'Escape':
          lightbox.classList.remove('active');
          document.body.style.overflow = 'auto';
          break;
        case 'ArrowLeft':
          this.currentIndex = (this.currentIndex - 1 + this.images.length) % this.images.length;
          this.updateLightbox();
          break;
        case 'ArrowRight':
          this.currentIndex = (this.currentIndex + 1) % this.images.length;
          this.updateLightbox();
          break;
      }
    });

    // Close on background click
    lightbox.addEventListener('click', (e) => {
      if (e.target === lightbox) {
        lightbox.classList.remove('active');
        document.body.style.overflow = 'auto';
      }
    });
  }

  updateLightbox() {
    const lightboxImage = this.shadowRoot.querySelector('.lightbox-image');
    const lightboxCaption = this.shadowRoot.querySelector('.lightbox-caption');
    const image = this.images[this.currentIndex];
    
    lightboxImage.src = image.src;
    lightboxImage.alt = image.alt;
    lightboxCaption.textContent = image.title || image.alt;
  }
}

customElements.define('image-gallery', ImageGallery);