音乐扩展回调

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('收到 Suno 音乐扩展回调:', {
    taskId: data.task_id,
    callbackType: data.callbackType,
    status: code,
    message: msg
  });
  
  if (code === 200) {
    // 任务进展或成功完成
    const { callbackType, task_id, data: tracks } = data;
    
    console.log(`回调类型: ${callbackType}`);
    console.log(`音乐数量: ${tracks.length}`);
    
    switch (callbackType) {
      case 'text':
        console.log('文本生成完成，等待音乐扩展...');
        break;
        
      case 'first':
        console.log('第一首扩展完成，正在处理剩余音乐...');
        downloadTracks(tracks, task_id);
        break;
        
      case 'complete':
        console.log('全部音乐扩展完成！');
        downloadTracks(tracks, task_id);
        break;
    }
    
  } else {
    // 任务失败
    console.log('Suno 音乐扩展失败:', msg);
    
    // 处理特定错误类型
    if (code === 400) {
      console.log('验证错误 - 检查版权内容');
    } else if (code === 408) {
      console.log('速率限制 - 请等待后重试');
    } else if (code === 413) {
      console.log('内容冲突 - 音频与现有作品匹配');
    } else if (code === 501) {
      console.log('扩展失败 - 可能需要调整参数');
    } else if (code === 531) {
      console.log('服务器错误已退还积分 - 可安全重试');
    }
  }
  
  // 返回 200 状态码确认收到回调
  res.status(200).json({ status: 'received' });
});

// 下载音乐函数
function downloadTracks(tracks, taskId) {
  tracks.forEach((track, index) => {
    const { id, audio_url, image_url, title, duration } = track;
    
    console.log(`音乐 ${index + 1}: ${title} (${duration}秒)`);
    
    // 下载音频文件
    if (audio_url) {
      downloadFile(audio_url, `suno_extend_${taskId}_${id}.mp3`)
        .then(() => console.log(`音频下载成功: ${id}`))
        .catch(err => console.error(`音频下载失败 ${id}:`, err));
    }
    
    // 下载封面图片
    if (image_url) {
      downloadFile(image_url, `suno_extend_cover_${taskId}_${id}.jpeg`)
        .then(() => console.log(`封面下载成功: ${id}`))
        .catch(err => console.error(`封面下载失败 ${id}:`, err));
    }
  });
}

// 辅助函数：下载文件
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('回调服务器运行在端口 3000');
});