import bcrypt from 'bcryptjs';
import { sql } from '@vercel/postgres';
import { generateToken } from '../auth-utils.js';

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

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

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

  try {
    const { email, password } = req.body;

    if (!email || !password) {
      return res.status(400).json({ error: 'Email and password are required' });
    }

    // Get user from database
    const result = await sql`
      SELECT id, email, password, role, created_at 
      FROM users 
      WHERE email = ${email}
    `;

    if (result.rows.length === 0) {
      return res.status(401).json({ error: 'Invalid credentials' });
    }

    const user = result.rows[0];

    // Verify password
    const isValidPassword = await bcrypt.compare(password, user.password);
    
    if (!isValidPassword) {
      return res.status(401).json({ error: 'Invalid credentials' });
    }

    // Generate JWT token
    const token = generateToken({ id: user.id, email: user.email, role: user.role });

    // Return user data (without password) and token
    const { password: _, ...userWithoutPassword } = user;
    
    res.status(200).json({
      success: true,
      user: userWithoutPassword,
      token
    });

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