<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * @package   block_tags
 * @copyright 2016 Marina Glancy
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/**
 * Specialised restore task for the tags block
 * (using execute_after_tasks for recoding of tag collection id)
 *
 * @package   block_tags
 * @copyright 2016 Marina Glancy
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class restore_tags_block_task extends restore_block_task {

    protected function define_my_settings() {
    }

    protected function define_my_steps() {
    }

    public function get_fileareas() {
        return array(); // No associated fileareas.
    }

    public function get_configdata_encoded_attributes() {
        return array(); // No special handling of configdata.
    }

    /**
     * This function, executed after all the tasks in the plan
     * have been executed, will remove tag collection reference in case block was restored into another site.
     * Also get mapping of contextid.
     */
    public function after_restore() {
        global $DB;

        // Get the blockid.
        $blockid = $this->get_blockid();

        // Extract block configdata and remove tag collection reference if this is another site. Also map contextid.
        if ($configdata = $DB->get_field('block_instances', 'configdata', array('id' => $blockid))) {
            $config = $this->decode_configdata($configdata);
            $changed = false;
            if (!empty($config->tagcoll) && $config->tagcoll > 1 && !$this->is_samesite()) {
                $config->tagcoll = 0;
                $changed = true;
            }
            if (!empty($config->ctx)) {
                if ($ctxmap = restore_dbops::get_backup_ids_record($this->get_restoreid(), 'context', $config->ctx)) {
                    $config->ctx = $ctxmap->newitemid;
                } else {
                    $config->ctx = 0;
                }
                $changed = true;
            }
            if ($changed) {
                $configdata = base64_encode(serialize($config));
                $DB->set_field('block_instances', 'configdata', $configdata, array('id' => $blockid));
            }
        }
    }

    public static function define_decode_contents() {
        return array();
    }

    public static function define_decode_rules() {
        return array();
    }
}
