#!/usr/bin/env node

/**
 * Build custom highlight.js bundle by downloading and combining CDN files
 * This creates a single local file with all required languages
 * 
 * Usage:
 *   node scripts/build-highlight-bundle.js
 * 
 * This generates a bundle at public/js/highlight-bundle.min.js
 */

import fs from 'fs';
import path from 'path';
import https from 'https';
import { fileURLToPath } from 'url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

/**
 * Discover available languages by scanning content/locales directory
 * This mimics the Rust discover_available_languages() function
 */
async function discoverAvailableLanguages() {
  const localesPath = process.env.SITE_I18N_PATH ? path.join(process.env.SITE_I18N_PATH, 'locales') : path.join('site', 'i18n', 'locales');
  
  try {
    if (!fs.existsSync(localesPath)) {
      console.log(`⚠️  Locales directory not found: ${localesPath}, using fallback languages`);
      return ['en', 'es'];
    }
    
    const entries = fs.readdirSync(localesPath, { withFileTypes: true });
    const languages = entries
      .filter(entry => entry.isDirectory())
      .map(entry => entry.name)
      .filter(name => name.length === 2) // Only 2-letter language codes
      .sort();
    
    if (languages.length === 0) {
      console.log(`⚠️  No language directories found in ${localesPath}, using fallback`);
      return ['en', 'es'];
    }
    
    console.log(`🌐 Discovered languages: ${languages.join(', ')}`);
    return languages;
  } catch (error) {
    console.log(`⚠️  Error discovering languages: ${error.message}, using fallback`);
    return ['en', 'es'];
  }
}

// Languages we want to include (in addition to core languages)
const additionalLanguages = [
  'rust',
  'typescript', 
  'bash',
  'yaml',
  'dockerfile', 
  'sql',
  'python',
  'ini', // For TOML-like syntax
  'properties', // Also TOML-like syntax
  'markdown',
  'nix' // Closest grammar for Nickel (NCL) blocks tagged ```nix
];

const CDN_BASE = 'https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0';
const HIGHLIGHTJS_COPY_VERSION = '1.0.6';
const COPY_PLUGIN_BASE = `https://unpkg.com/highlightjs-copy@${HIGHLIGHTJS_COPY_VERSION}/dist`;

function downloadFile(url) {
  return new Promise((resolve, reject) => {
    https.get(url, (response) => {
      if (response.statusCode !== 200) {
        reject(new Error(`HTTP ${response.statusCode}: ${url}`));
        return;
      }
      
      let data = '';
      response.on('data', (chunk) => data += chunk);
      response.on('end', () => resolve(data));
    }).on('error', reject);
  });
}

async function buildBundle() {
  try {
    // Discover available languages first
    const availableLanguages = await discoverAvailableLanguages();
    
    // Ensure output directory exists first
    const outputDir = path.join(__dirname, '../../site/public/js');
    if (!fs.existsSync(outputDir)) {
      fs.mkdirSync(outputDir, { recursive: true });
    }
    
    // Check if bundle already exists and is recent (less than 24 hours old)
    const outputPath = path.join(outputDir, 'highlight-bundle.min.js');
    
    if (fs.existsSync(outputPath)) {
      const stats = fs.statSync(outputPath);
      const fileAge = Date.now() - stats.mtime.getTime();
      const maxAge = 24 * 60 * 60 * 1000; // 24 hours in milliseconds
      
      if (fileAge < maxAge) {
        const fileSizeKB = Math.round(stats.size / 1024);
        const ageHours = Math.round(fileAge / (60 * 60 * 1000));
        
        console.log('✅ Highlight.js bundle already exists and is recent!');
        console.log(`📁 File: ${outputPath}`);
        console.log(`📊 Size: ${fileSizeKB}KB`);
        console.log(`⏰ Age: ${ageHours}h (created: ${stats.mtime.toLocaleString()})`);
        console.log('🎯 Languages: Core JS/HTML/CSS/JSON/XML + ' + additionalLanguages.join(', '));
        console.log('💡 To force rebuild, delete the file or wait 24 hours');
        return;
      } else {
        console.log('🔄 Bundle exists but is older than 24 hours, rebuilding...');
      }
    }
    
    console.log('🔨 Building highlight.js bundle from CDN...');
    console.log(`📦 Including core + ${additionalLanguages.length} additional languages: ${additionalLanguages.join(', ')}`);
    
    // Download core highlight.js
    console.log('📥 Downloading core highlight.js...');
    const coreJs = await downloadFile(`${CDN_BASE}/highlight.min.js`);
    
    // Download highlightjs-copy plugin
    console.log('📥 Downloading highlightjs-copy plugin...');
    const copyPluginJs = await downloadFile(`${COPY_PLUGIN_BASE}/highlightjs-copy.min.js`);
    
    let bundleContent = `/*! Custom Highlight.js Bundle for Rustelo
 * Generated on ${new Date().toISOString()}
 * Core + Additional Languages: ${additionalLanguages.join(', ')}
 * Based on Highlight.js 11.9.0 from CDN
 * Includes highlightjs-copy plugin v${HIGHLIGHTJS_COPY_VERSION}
 */

// Core highlight.js
${coreJs}

// Copy button plugin
${copyPluginJs}

// Additional language definitions
(function() {
  if (typeof hljs === 'undefined') {
    console.error('Highlight.js core not available');
    return;
  }

`;

    // Download and add each language
    console.log('📝 Downloading language definitions...');
    
    for (const lang of additionalLanguages) {
      try {
        console.log(`  📥 Downloading: ${lang}`);
        const langJs = await downloadFile(`${CDN_BASE}/languages/${lang}.min.js`);
        
        // Wrap the language code to register it properly
        bundleContent += `
  // Language: ${lang}
  (function() {
    ${langJs}
  })();
`;
        console.log(`  ✅ Added: ${lang}`);
      } catch (error) {
        console.log(`  ❌ Failed to download ${lang}: ${error.message}`);
      }
    }

    // Close the bundle
    bundleContent += `
})();

// Expose available languages globally for use by other scripts
if (typeof window !== 'undefined') {
  window.__AVAILABLE_LANGUAGES = ${JSON.stringify(availableLanguages)};
} else if (typeof globalThis !== 'undefined') {
  globalThis.__AVAILABLE_LANGUAGES = ${JSON.stringify(availableLanguages)};
}

// Auto-initialize when DOM is ready
if (typeof document !== 'undefined') {
  function initializeHighlightJs() {
    if (typeof hljs !== 'undefined' && hljs.highlightAll) {
      hljs.configure({ ignoreUnescapedHTML: true });
      hljs.highlightAll();
      
      // Add copy button plugin with dynamic language detection and autohide configuration
      if (typeof CopyButtonPlugin !== 'undefined') {
        const docLang = document.documentElement.lang || 'en';
        
        // Dynamically discovered available languages from content/locales
        const AVAILABLE_LANGUAGES = ${JSON.stringify(availableLanguages)};
        
        // Build language configuration for all available languages
        const langConfig = {};
        AVAILABLE_LANGUAGES.forEach(lang => {
          langConfig[lang] = { autohide: false, lang: lang };
        });
        
        // Use detected language or fallback to first available language
        const config = langConfig[docLang] || langConfig[AVAILABLE_LANGUAGES[0]] || { autohide: false, lang: 'en' };
        hljs.addPlugin(new CopyButtonPlugin(config));
      }
    }
  }
  
  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', initializeHighlightJs);
  } else {
    // DOM already ready
    initializeHighlightJs();
  }
}
`;

    // Write the bundle (directory already created at the start)
    fs.writeFileSync(outputPath, bundleContent);
    
    // Get file size
    const stats = fs.statSync(outputPath);
    const fileSizeKB = Math.round(stats.size / 1024);
    
    console.log(`✅ Highlight.js bundle created successfully!`);
    console.log(`📁 Output: ${outputPath}`);
    console.log(`📊 Size: ${fileSizeKB}KB`);
    console.log(`🎯 Languages: Core JS/HTML/CSS/JSON/XML + ${additionalLanguages.join(', ')}`);
    console.log(`📋 Plugin: highlightjs-copy v${HIGHLIGHTJS_COPY_VERSION} (with i18n support)`);
    console.log('');
    console.log('🚀 Ready to use! The bundle includes:');
    console.log('  - Auto-initialization on DOM ready');
    console.log('  - All required languages pre-registered');
    console.log('  - Copy code buttons with language detection (en/es)');
    console.log('  - Single HTTP request instead of multiple CDN calls');
    
  } catch (error) {
    console.error('❌ Error building bundle:', error.message);
    process.exit(1);
  }
}

buildBundle();