yf_manage_shop_region_update admin module

    public function products_region_update()
    {
        $data = $this->_data();
        $form = $this->_form($data);
        return  $form;
    }

    public function _data()
    {
        $_sub_action = [
            '0' => '- not selected -',
            'add' => 'add',
            'delete' => 'delete',
            'clean' => 'clear',
        ];
        $sub_action = ($_POST['sub_action'] ?? null);
        $is_sub_action = $sub_action !== '0' && isset($_sub_action[$sub_action]);
        // -----
        $_region = _class('_shop_region', 'modules/shop/')->_get_list();
        $region = null;
        if ($sub_action == 'clean') {
            $is_region = true;
        } else {
            $region = array_values((array) ($_POST['region'] ?? null));
            $is_region = false;
            if ( ! empty($region)) {
                $region = array_combine($region, $region);
                $count = 0;
                foreach ($region as $id) {
                    if ($id === '0' || ! isset($_region[$id])) {
                        break;
                    }
                    $count++;
                }
                $count == count($region) && $is_region = true;
            }
        }
        // prepare filter
        list($_where, $_order) = _class('table2_filter', 'classes/table2/')->_filter_sql_prepare($this->_filter, $this->_filter_params);
        // compile sql
        $sql_filter = $this->_class_admin_products->_sql([
            'fields' => 'DISTINCT p.id',
            'where' => 1 . $_where,
            'order' => $_order,
        ]);
        $sql_count = $this->_class_admin_products->_sql([
            'fields' => 'COUNT(p.id)',
            'where' => 1 . $_where,
            'order' => $_order,
        ]);
        $total = (int) db()->get_one($sql_count);
        // update
        $apply = ($_POST['apply'] ?? null);
        $confirm = ($_POST['confirm'] ?? null);
        $is_action = $this->is_post && $is_sub_action && $is_region && isset($apply) ? true : false;
        $is_update = $is_action && isset($confirm) ? true : false;
        $no_confirm = $is_action && ! isset($confirm) ? true : false;
        if ($is_update) {
            // prepare data
            $sql_table_action = 'shop_product_to_region';
            $data = [];
            $sub_action_count = null;
            $ids = db()->get_2d($sql_filter);
            // ----- add regions to products
            if ($sub_action == 'add') {
                foreach ($ids as $id) {
                    foreach ($region as $r_id) {
                        $data[] = ['product_id' => $id, 'region_id' => $r_id];
                    }
                }
                db_query('START TRANSACTION');
                db()->insert_on_duplicate_key_update($sql_table_action, $data);
                $sub_action_count = db()->affected_rows();
                db_query('COMMIT');
                // ----- delete regions to products
            } elseif ($sub_action == 'delete' || $sub_action == 'clean') {
                $product_ids = array_map('intval', (array) $ids);
                $region_ids = array_map('intval', (array) $region);
                if ($product_ids && ($sub_action == 'clean' || $region_ids)) {
                    $query = db()->from($sql_table_action)->where('product_id', 'in', $product_ids);
                    if ($sub_action != 'clean') {
                        $query->where('region_id', 'in', $region_ids);
                    }
                    db_query('START TRANSACTION');
                    $query->delete();
                    $sub_action_count = db()->affected_rows();
                    db_query('COMMIT');
                }
            }
            if ($sub_action_count) {
                common()->message_success('Operation completed successfully.');
                _class('_shop_region', 'modules/shop/')->_cache_refresh();
            } else {
                common()->message_warning('This operation has already been performed.');
            }
            $sub_action = null;
            $region = null;
        }
        if ($no_confirm) {
            common()->message_warning('Confirmation required.');
        }
        // -----
        $result = [
            'total' => $total,
            '_sub_action' => $_sub_action,
                'sub_action' => $sub_action,
            '_region' => $_region,
                'region' => $region,
        ];
        return  $result;
    }

    public function _form($data)
    {
        // create form
        $link_back = './?object=manage_shop&action=products';
        $_form = form($data)
            ->row_start(['desc' => 'Total selected'])
                ->info('total')
                ->link('Back', $link_back, ['title' => 'Back to product filter', 'icon' => 'fa fa-arrow-circle-left'])
            ->row_end()
            ->select2_box([
                'desc' => 'Action',
                'name' => 'sub_action',
                'values' => $data['_sub_action'],
            ])
            ->select2_box([
                'desc' => 'Region',
                'name' => 'region',
                'multiple' => true,
                'values' => $data['_region'],
            ])
            ->row_start(['desc' => ''])
                ->submit('apply', 'Apply')
                ->check_box('confirm', false, ['desc' => 'confirmation', 'no_label' => true])
            ->row_end();
        return  $_form;
    }

    public function _init()
    {
        $this->_class_admin_products = _class('manage_shop_products', 'admin_modules/manage_shop/');
        $this->is_post = input()->is_post();
        $this->is_init = (bool) input()->get('init');
        // get filter
        $_object = input()->get('object');
        $_action = input()->get('action');
        $_action_parent = input()->get('filter');
        $_session_parent_key = $_object . '__' . $_action_parent;
        $_session_key = $_object . '__' . $_action;
        if ($this->is_init) {
            $_SESSION[$_session_key] = ($_SESSION[$_session_parent_key] ?? null);
        }
        $this->_filter = ($_SESSION[$_session_key] ?? null);
        $this->_filter_params = $this->_class_admin_products->_filter_params;
    }