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

const JWT_SECRET = process.env.JWT_SECRET || 'your-secret-key-change-in-production';

export default async function handler(req, res) {
  // Set CORS headers
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');

  if (req.method === 'OPTIONS') {
    res.status(200).end();
    return;
  }

  if (req.method !== 'GET') {
    return res.status(405).json({ error: 'Method not allowed' });
  }

  // Verify authentication
  const authHeader = req.headers.authorization;
  if (!authHeader || !authHeader.startsWith('Bearer ')) {
    return res.status(401).json({ error: 'Authentication required' });
  }

  const token = authHeader.substring(7);
  try {
    jwt.verify(token, JWT_SECRET);
  } catch (error) {
    return res.status(401).json({ error: 'Invalid token' });
  }

  const { q: query } = req.query;

  if (!query || query.length < 2) {
    return res.status(400).json({ error: 'Query must be at least 2 characters' });
  }

  try {
    // Search users by email (partial match)
    const result = await sql`
      SELECT id, email, role, created_at
      FROM users 
      WHERE email ILIKE ${`%${query}%`}
      ORDER BY email
      LIMIT 10
    `;

    res.status(200).json({
      users: result.rows
    });

  } catch (error) {
    console.error('User search error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
}