import fs from 'fs';
import { parse, HTMLElement } from 'node-html-parser';

interface Article {
  title: string;
  link: string;
}

/**
 * Parse HTML file and return array of articles
 * @param htmlFilePath - Path to HTML file
 * @returns Array of articles with title and link
 */
function parseArticles(htmlFilePath: string): Article[] {
  try {
    // Read HTML file
    const htmlContent = fs.readFileSync(htmlFilePath, 'utf-8');
    
    // Parse HTML with node-html-parser
    const root = parse(htmlContent);
    
    // Array to store results
    const articles: Article[] = [];
    
    // Set to track unique links (avoid duplicates)
    const seenLinks = new Set<string>();
    
    // Method 1: Find all li elements with data-component-name="card"
    const cardElements = root.querySelectorAll('li[data-component-name="card"]');
    
    cardElements.forEach((element: HTMLElement) => {
      // Get title from headline text
      const titleElement = element.querySelector('.container__headline-text');
      const title = titleElement ? titleElement.text.trim() : '';
      
      // Get link from data-open-link attribute
      let link = element.getAttribute('data-open-link') || '';
      
      // If no data-open-link, try to find link in anchor tag
      if (!link) {
        const linkElement = element.querySelector('a[href]');
        link = linkElement ? linkElement.getAttribute('href') || '' : '';
      }
      
      // If link is relative path, add domain
      if (link && !link.startsWith('http')) {
        link = `https://www.cnn.com${link}`;
      }
      
      // Only add to array if both title and link exist and link is not duplicate
      if (title && link && !seenLinks.has(link)) {
        articles.push({ title, link });
        seenLinks.add(link);
      }
    });
    
    // Method 2: Also check for article links in other containers
    const allLinks = root.querySelectorAll('a.container__link');
    
    allLinks.forEach((linkElement: HTMLElement) => {
      // Get href
      let link = linkElement.getAttribute('href') || linkElement.getAttribute('data-open-link') || '';
      
      // If link is relative path, add domain
      if (link && !link.startsWith('http')) {
        link = `https://www.cnn.com${link}`;
      }
      
      // Skip if already added or empty
      if (!link || seenLinks.has(link)) return;
      
      // Try to find title in parent element
      const parentLi = linkElement.closest('li[data-component-name="card"]');
      if (parentLi) {
        const titleElement = parentLi.querySelector('.container__headline-text');
        const title = titleElement ? titleElement.text.trim() : '';
        
        if (title) {
          articles.push({ title, link });
          seenLinks.add(link);
        }
      }
    });
    
    return articles;
    
  } catch (error) {
    console.error('Error parsing HTML:', error);
    return [];
  }
}

/**
 * Main function for testing
 */
function main(): void {
  const htmlFilePath = 'source-pages/world.html';
  const articles = parseArticles(htmlFilePath);
  
  console.log(`Found ${articles.length} articles:\n`);
  
  // Print first 10 articles for demo
  articles.slice(0, 10).forEach((article, index) => {
    console.log(`${index + 1}. ${article.title}`);
    console.log(`   ${article.link}\n`);
  });
  
  console.log(`\n... and ${articles.length - 10} more articles`);
  
  // Export to JSON file
  fs.writeFileSync('data/articles.json', JSON.stringify(articles, null, 2));
  console.log('\nAll articles saved to articles.json');
}

// Run main function
main();

// Export function for use in other modules
export { parseArticles };