/**
 * Utility functions and helpers
 */
export class Utils {
  /**
   * Format file size in human readable format
   */
  static formatFileSize(bytes) {
    if (bytes === 0) return '0 B';
    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(1)) + ' ' + sizes[i];
  }

  /**
   * Handle thumbnail highlighting from URL parameters
   */
  static handleThumbnailHighlight() {
    const urlParams = new URLSearchParams(window.location.search);
    const highlightPlot = urlParams.get('highlight');
    
    if (highlightPlot) {
      // Find and highlight the thumbnail
      const gridItems = document.querySelectorAll('.grid-item');
      gridItems.forEach(item => {
        const plotName = item.querySelector('.plot-name');
        if (plotName && plotName.textContent.trim() === highlightPlot) {
          item.classList.add('highlighted');
          // Scroll to the highlighted item
          setTimeout(() => {
            item.scrollIntoView({ 
              behavior: 'smooth', 
              block: 'center' 
            });
          }, 100);
          // Remove highlight after animation
          setTimeout(() => {
            item.classList.remove('highlighted');
          }, 3000);
        }
      });
      
      // Clean up URL
      const newUrl = new URL(window.location);
      newUrl.searchParams.delete('highlight');
      window.history.replaceState({}, document.title, newUrl.toString());
    }
  }

  /**
   * Calculate approximate total size of displayed files
   */
  static async calculateApproximateSize() {
    const images = document.querySelectorAll('.grid-item img');
    let totalSize = 0;
    let loadedCount = 0;
    
    const sizeElement = document.getElementById('totalSize');
    if (!sizeElement) return;
    
    sizeElement.textContent = 'Loading...';
    
    // Estimate size based on a sample of images
    const sampleSize = Math.min(images.length, 5);
    const sampleImages = Array.from(images).slice(0, sampleSize);
    
    if (sampleImages.length === 0) {
      sizeElement.textContent = '0 KB';
      return;
    }
    
    // Calculate average size from sample
    for (const img of sampleImages) {
      try {
        const response = await fetch(img.src, { method: 'HEAD' });
        const size = parseInt(response.headers.get('content-length') || '0');
        if (size > 0) {
          totalSize += size;
          loadedCount++;
        }
      } catch (e) {
        // Fallback: estimate 100KB per image
        totalSize += 102400;
        loadedCount++;
      }
    }
    
    if (loadedCount > 0) {
      const averageSize = totalSize / loadedCount;
      const estimatedTotal = averageSize * images.length;
      sizeElement.textContent = Utils.formatFileSize(estimatedTotal);
    } else {
      sizeElement.textContent = 'Unknown';
    }
  }

  /**
   * Toggle keyboard shortcuts help display
   */
  static toggleShortcutsHelp() {
    const help = document.getElementById('shortcutsHelp');
    if (help) {
      help.style.display = help.style.display === 'block' ? 'none' : 'block';
    }
  }
}