pages/api/auth/callback.js

import axios from 'axios';

export default async function handler(req, res) {
  const { code } = req.query;
  const { clientId, clientSecret, redirectUri } = req.body;

  if (!code) {
    return res.status(400).json({ error: 'No code provided' });
  }

  try {
    const response = await axios.post(
      'https://accounts.spotify.com/api/token',
      new URLSearchParams({
        grant_type: 'authorization_code',
        code: code,
        redirect_uri: redirectUri,
        client_id: clientId,
        client_secret: clientSecret,
      }),
      {
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
        },
      }
    );

    res.status(200).json(response.data);
  } catch (error) {
    console.error('Token exchange error:', error.response?.data || error.message);
    res.status(500).json({ 
      error: 'Failed to exchange token', 
      details: error.response?.data 
    });
  }
}