<?php
require_once 'db/config.php';
session_start();

if (!isset($_SESSION['user_id'])) {
    header('Location: ' . APP_URL . 'login.php');
    exit;
}

$user_id = $_SESSION['user_id'];
$car_id = $_GET['id'] ?? 0;
$action = $_GET['action'] ?? 'add';

if ($car_id) {
    $pdo = db();
    if ($action === 'add') {
        $stmt = $pdo->prepare("INSERT IGNORE INTO favorites (user_id, car_id) VALUES (?, ?)");
        $stmt->execute([$user_id, $car_id]);
    } else {
        $stmt = $pdo->prepare("DELETE FROM favorites WHERE user_id = ? AND car_id = ?");
        $stmt->execute([$user_id, $car_id]);
    }
}

header('Location: ' . ($_SERVER['HTTP_REFERER'] ?? APP_URL . 'favorites.php'));
exit;