import { sql } from '@vercel/postgres';

export default async function handler(req, res) {
  if (req.method !== 'POST') {
    return res.status(405).json({ error: 'Method not allowed' });
  }

  const { id } = req.query;
  const { quantity } = req.body;

  try {
    // Update the card's quantity
    const result = await sql`
      UPDATE cards 
      SET quantity = ${quantity}
      WHERE id = ${id}
      RETURNING id, name, quantity
    `;

    if (result.rows.length === 0) {
      return res.status(404).json({ error: 'Card not found' });
    }

    res.status(200).json({
      success: true,
      card: result.rows[0]
    });
  } catch (error) {
    console.error('Error updating ownership:', error);
    res.status(500).json({ error: 'Failed to update ownership' });
  }
}