Audio Upload and Extension Callbacks

const express = require('express');
const fs = require('fs');
const https = require('https');
const app = express();

app.use(express.json());

app.post('/suno-extend-callback', (req, res) => {
  const { code, msg, data } = req.body;
  
  console.log('Received Suno audio extension callback:', {
    taskId: data.task_id,
    callbackType: data.callbackType,
    status: code,
    message: msg
  });
  
  if (code === 200) {
    // Task progressed or completed successfully
    const { callbackType, task_id, data: tracks } = data;
    
    console.log(`Callback type: ${callbackType}`);
    console.log(`Number of tracks: ${tracks.length}`);
    
    switch (callbackType) {
      case 'text':
        console.log('Text generation completed, waiting for audio...');
        break;
        
      case 'first':
        console.log('First track completed, processing remaining tracks...');
        downloadTracks(tracks, task_id);
        break;
        
      case 'complete':
        console.log('All tracks completed successfully!');
        downloadTracks(tracks, task_id);
        break;
    }
    
  } else {
    // Task failed
    console.log('Suno audio extension failed:', msg);
    
    // Handle specific error types
    if (code === 400) {
      console.log('Validation error - check for copyrighted content');
    } else if (code === 408) {
      console.log('Rate limited - please wait before retrying');
    } else if (code === 413) {
      console.log('Content conflict - uploaded audio matches existing work');
    } else if (code === 501) {
      console.log('Generation failed - may need to adjust parameters');
    } else if (code === 531) {
      console.log('Server error with credit refund - safe to retry');
    }
  }
  
  // Return 200 status code to confirm callback received
  res.status(200).json({ status: 'received' });
});

// Function to download tracks
function downloadTracks(tracks, taskId) {
  tracks.forEach((track, index) => {
    const { 
      id, 
      audio_url, 
      source_audio_url,
      image_url, 
      source_image_url,
      title, 
      duration 
    } = track;
    
    console.log(`Track ${index + 1}: ${title} (${duration}s)`);
    
    // Download extended audio file
    if (audio_url) {
      downloadFile(audio_url, `suno_extended_${taskId}_${id}.mp3`)
        .then(() => console.log(`Extended audio downloaded: ${id}`))
        .catch(err => console.error(`Extended audio download failed for ${id}:`, err));
    }
    
    // Download source audio file
    if (source_audio_url) {
      downloadFile(source_audio_url, `suno_source_${taskId}_${id}.mp3`)
        .then(() => console.log(`Source audio downloaded: ${id}`))
        .catch(err => console.error(`Source audio download failed for ${id}:`, err));
    }
    
    // Download extended cover image
    if (image_url) {
      downloadFile(image_url, `suno_extended_cover_${taskId}_${id}.jpeg`)
        .then(() => console.log(`Extended cover downloaded: ${id}`))
        .catch(err => console.error(`Extended cover download failed for ${id}:`, err));
    }
    
    // Download source cover image
    if (source_image_url) {
      downloadFile(source_image_url, `suno_source_cover_${taskId}_${id}.jpeg`)
        .then(() => console.log(`Source cover downloaded: ${id}`))
        .catch(err => console.error(`Source cover download failed for ${id}:`, err));
    }
  });
}

// Helper function to download files
function downloadFile(url, filename) {
  return new Promise((resolve, reject) => {
    const file = fs.createWriteStream(filename);
    
    https.get(url, (response) => {
      if (response.statusCode === 200) {
        response.pipe(file);
        file.on('finish', () => {
          file.close();
          resolve();
        });
      } else {
        reject(new Error(`HTTP ${response.statusCode}`));
      }
    }).on('error', reject);
  });
}

app.listen(3000, () => {
  console.log('Callback server running on port 3000');
});