Get user location in PHP

CREATE TABLE users (
    id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    email VARCHAR(255) NOT NULL UNIQUE,
    password VARCHAR(255) NOT NULL,
    location JSON NULL DEFAULT NULL,
    last_location_at TIMESTAMP NULL DEFAULT NULL
);

if (isset($_SERVER['HTTP_X_FORWARDED_FOR']))
{
    $client_ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
}
else if (isset($_SERVER['HTTP_X_REAL_IP']))
{
    $client_ip = $_SERVER['HTTP_X_REAL_IP'];
}
else
{
    $client_ip = $_SERVER['REMOTE_ADDR'];
}

$user_agent = $_SERVER['HTTP_USER_AGENT'];

$timestamp = strtotime($user->last_location_at);

$current_timestamp = time();

$difference = $current_timestamp - $timestamp;

$twenty_four_hours_in_seconds = 24 * 60 * 60;

if ($difference >= $twenty_four_hours_in_seconds)
{
    $curl = curl_init();
    curl_setopt_array($curl, [
        CURLOPT_URL => "http://www.geoplugin.net/json.gp?ip=" . $client_ip,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_POST => true,
        CURLOPT_POSTFIELDS => json_encode([]),
        CURLOPT_HTTPHEADER => [
            "Content-Type: application/json"
        ]
    ]);
    $response = curl_exec($curl);

    if (curl_errno($curl))
    {
        $error = curl_error($curl);
    }
    else
    {
        $response = json_decode($response);
        if ($response->geoplugin_status == 200)
        {
            $location = [
                "city" => $response->geoplugin_city,
                "continent" => $response->geoplugin_continentName,
                "continentCode" => $response->geoplugin_continentCode,
                "country" => $response->geoplugin_countryName,
                "countryCode" => $response->geoplugin_countryCode,
                "currencyCode" => $response->geoplugin_currencyCode,
                "currencySymbol" => $response->geoplugin_currencySymbol,
                "currencyConverter" => $response->geoplugin_currencyConverter,
                "latitude" => $response->geoplugin_latitude,
                "longitude" => $response->geoplugin_longitude,
                "region" => $response->geoplugin_region,
                "ipAddress" => $response->geoplugin_request,
                "timezone" => $response->geoplugin_timezone,
                "user_agent" => $user_agent
            ];
            $location = json_encode($location);

            // UPDATE `users` SET location = '$location', last_location_at = NOW() WHERE id = 2
        }
    }
    curl_close($curl);
}