const { MongoClient, GridFSBucket } = require('mongodb');
const fs = require('fs');
const path = require('path');

async function exportGridFS() {
  const client = new MongoClient('mongodb://localhost:27017/');
  
  try {
    await client.connect();
    const db = client.db('portfolio');
    
    const buckets = ['images', 'album_art', 'scores', 'pubs'];
    
    for (const bucketName of buckets) {
      const bucket = new GridFSBucket(db, { bucketName });
      const outputDir = path.join(__dirname, 'public', bucketName);
      
      if (!fs.existsSync(outputDir)) {
        fs.mkdirSync(outputDir, { recursive: true });
      }
      
      const cursor = bucket.find({});
      const files = await cursor.toArray();
      
      console.log(`Exporting ${files.length} files from ${bucketName}...`);
      
      const promises = files.map(file => {
        return new Promise((resolve, reject) => {
          const outputPath = path.join(outputDir, file.filename);
          const stream = bucket.openDownloadStreamByName(file.filename);
          const writeStream = fs.createWriteStream(outputPath);
          
          stream.pipe(writeStream);
          
          stream.on('end', () => {
            console.log(`  Saved: ${file.filename}`);
            resolve();
          });
          
          stream.on('error', (err) => {
            console.error(`  Error saving ${file.filename}:`, err.message);
            reject(err);
          });
        });
      });
      
      await Promise.all(promises);
      console.log(`Finished ${bucketName}`);
    }
    
    console.log('Done!');
  } finally {
    await client.close();
  }
}

exportGridFS();