Display username, message & avatar shortcode with link to My Account page - conditional based on existing user fields

gistfile1.txt

/* DISPLAY AVATAR & USER SHORTCODE - CONDITIONAL */
function display_current_user_shortcode()
{
    global $current_user;
    $user = wp_get_current_user();
    $avatar = get_avatar($current_user->ID, 32, '', '', $args = array('class' => 'rounded-circle'));
    $custom_avatar = get_avatar('https://url-to-custom-avatar.webp');
    $first = $user->user_firstname;
    $display = $user->display_name;
    $email = $user->user_email;
    if (is_user_logged_in()) {
        if (!empty($display)) {
            return $avatar . '<a href="https://site-url.com/my-account/"' . 'class="">' . 'Welcome, ' . esc_html($display) . '!' . '</a>';
        } else {
            return $custom_avatar . '<a href="https://site-url.com/my-account/"' . 'class="">' . 'Welcome, ' . esc_html($display) . '!' . '</a>';
        }
    } elseif (is_user_logged_in()) {
        if (empty($display) && (!empty($first))) {
            return $avatar . '<a href="https://site-url.com/my-account/"' . 'class="">' . 'Welcome, ' . esc_html($first) . '!' . '</a>';
        } else {
            return $custom_avatar . '<a href="https://site-url.com/my-account/"' . 'class="">' . 'Welcome, ' . esc_html($first) . '!' . '</a>';
        }
    } elseif (is_user_logged_in()) {
        if (empty($display) && (empty($first)) && (!empty($email))) {
            return $avatar . '<a href="https://site-url.com/my-account/"' . 'class="">' . 'Welcome, ' . esc_html($email) . '!' . '</a>';
        } else {
            return $custom_avatar . '<a href="https://site-url.com/my-account/"' . 'class="">' . 'Welcome, ' . esc_html($email) . '!' . '</a>';
        }
    }
}
add_shortcode('current-user', 'display_current_user_shortcode');