MODX importer for Wordpress

<?php
///*
//Plugin Name: MODX importer
//Plugin URI: http://gho.nl/
//Description: Import newsitems from MODX.
//Version: 1.0
//Author: Wouter Groenewold
//License: GPL
//Copyright: GH+O Communicatie
//*/
//

require_once( ABSPATH . 'wp-admin/includes/plugin.php' );

function modx_import() {
    if(!class_exists( 'Redirection_Admin' ) ) {
        //Dependency check. Redirection not activated, bail.
        deactivate_plugins( plugin_basename( __FILE__ ) );
        wp_die( 'This plugin requires Redirection.' );
    }else{
        //configuration
        $servername = "";
        $table_prefix = '';
        $redirection_group = 3; //make sure this is present!
        //old server config
        $username = "";
        $password = "";
        $db = "";

        // Create connection
        $conn = new mysqli($servername, $username, $password, $db);
        $conn->set_charset('utf8mb4'); //set to extended charset so special chars get a good import.

        // Check connection
        if ($conn->connect_error) {
            die("Connection failed: " . $conn->connect_error);
        }

        $sql = "SELECT pagetitle, alias, introtext, content, publishedon FROM modx_site_content";
        $result = $conn->query($sql);

        $data = array();

        $term = get_term_by( 'slug', 'imported', 'category' );
        $term_id = $term->term_id;

        while($row = $result->fetch_assoc()) {

            $epoch = $row['publishedon'];
            $dt = new DateTime("@$epoch");
            $date = $dt->format('Y-m-d H:i:s');

            $data[] = array(
                'title'     => $row['pagetitle'],
                'content'   => $row['content'],
                'post_date' => $date,
                'post_name' => $row['alias'],
                'intro'     => $row['introtext']
            );
        }

        foreach($data as $value){
            $args = array(
                'post_date'     => $value['post_date'],
                'post_content'  => $value['content'],
                'post_status'   => 'publish',
                'post_type'     => 'nieuws',
                'post_name'     => $value['post_name'],
                'post_title'    => $value['title'],
                'tax_input' => array( 'category' => $term_id )
            );

            $postid = wp_insert_post($args);

            if($postid){
                update_field('intro', $value['intro'], $postid);
                $oldurl = '/nieuws/nieuws/' . $value['post_name'];
                $newurl = get_permalink($postid);

                global $wpdb;
                $wpdb->insert(
                    $table_prefix . '_redirection_items',
                    array(
                        //id = autoincrement
                        'url' => $oldurl,
                        //regex = default 0
                        //position = default 0
                        'last_count'    => 0,
                        'last_access'   => '0000-00-00 00:00:00',
                        'group_id'      => $redirection_group,
                        //status = default enabled
                        'action_type'   => 'url',
                        'action_code'   => 301,
                        'action_data'   => $newurl,
                        'match_type'    => 'url'
                    ),
                    array(
                        //
                        "%s",
                        //
                        //
                        "%d",
                        "%s",
                        "%d",
                        //
                        "%s",
                        "%d",
                        "%s",
                        "%s"
                    )
                );
            }else{
                echo 'Failed to import ' . $value['post_title'];
            }
        }

        $conn->close();
        deactivate_plugins( plugin_basename( __FILE__ ) );
        wp_die( 'Finished importing' );
    }
}

add_action( 'init', 'modx_import' );