Method getActiveCategoryId

public static function getActiveCategoryId()
{
    $app = Factory::getApplication();
    $option = $app->input->get('option', '', 'string');
    $view = $app->input->get('view', '', 'string');
    $catid = $app->input->get('catid', '', 'int');
    // ID in items view is category id
    $id = $app->input->get('id', '', 'int');
    $c = $app->input->get('c', '', 'string');
    // Category ID in items view - filter options (does not work with ajax)
    if ($option == 'com_phocacart' && ($view == 'items' || $view == 'category')) {
        if ((int) $id > 0) {
            return $id;
        }
    }
    if ($option == 'com_phocacart' && $view == 'item') {
        if ((int) $catid > 0) {
            return $catid;
        }
    }
    // If in filtering only one category is selected, make active the selected category in e.g. tree (not working in ajax)
    if ($option == 'com_phocacart' && $view == 'items') {
        if ($c != '') {
            $cA = explode(',', $c);
            if (isset($cA[0]) && count($cA) == 1) {
                return (int) $cA[0];
            }
        }
    }
    return 0;
}