Rewrite CPT permalinks (alt way)

<?php

/*
 * Plugin Name: Rewrite "Hersteller" & "Dienstleistungen" permalinks
 * Plugin URI: http://maciejbis.net
 * Description: A plugin that adjusts the functionality of this website
 * Version: 1.0
 * Author: Maciej Bis
 * Author URI: http://www.maciejbis.net
 * License: GPL2
 */

/**
 * Detect ad permalinks
 */
function bis_detect_cpt_permalinks( $query ) {
    global $wpdb, $pm_query, $wp, $wp_rewrite;

    // 1. Extract the slugs
    preg_match( '/datenrettung-([^\/]+)\/(([^\/]*)(-[^-\/]+))(?:\/|$)/Ui', $wp->request, $parts );

    if ( ! empty( $parts[2] ) ) {
        // 2A. Get all posts that have exact or similar slug extracted from URL
        $post_slug     = basename( $parts[2] );
        $post_slug_alt = basename( $parts[3] );

        $sql_query = sprintf( 'SELECT ID FROM %1$s WHERE 1=1 AND
        (
            (post_type = "dienstleistung" AND (post_name = "%2$s" OR post_name LIKE "%2$s-%%")) OR
            (post_type = "hersteller" AND (post_name = "%3$s" OR post_name LIKE "%3$s-%%"))
        )
        ', $wpdb->posts, esc_sql( $post_slug ), esc_sql( $post_slug_alt ) );
        $url_posts = $wpdb->get_col( $sql_query );

        // 2B. Get all posts that are assigned to a "ort" term extracted from URL
        $term_slug = basename( $parts[1] );

        $sql_query = sprintf( 'SELECT object_id FROM %s AS tr LEFT JOIN %s AS t ON tr.term_taxonomy_id = t.term_id WHERE t.slug = "%s"', $wpdb->term_relationships, $wpdb->terms, esc_sql( $term_slug ) );

        $ort_posts = $wpdb->get_col( $sql_query );

        // 2C. Check what posts are in both arrays (there should be only one post)
        if ( ! empty( $url_posts ) && ! empty( $ort_posts ) ) {
            $found_posts = array_intersect( $url_posts, $ort_posts );

            if ( ! empty( $found_posts ) ) {
                $post_id = (int) reset( $found_posts );
                $post    = get_post( $post_id );
            }
        }

        if ( ! empty( $post->post_name ) ) {
            $new_query = array(
                'post_type'       => $post->post_type,
                $post->post_type  => $post->post_name,
                'name'            => $post->post_name,
                'do_not_redirect' => 1,
            );
        }

        // 3. Debug the query parameters
        if ( isset( $_GET['debug_bis_query'] ) ) {
            printf( '<pre>%s</pre> <pre>%s</pre> <pre>%s</pre>', print_r( $parts, true ), print_r( $query, true ), print_r( $new_query, true ) );
            die();
        }

        // 4. Overwrite the query object & Disable canonical redirect
        if ( ! empty( $new_query ) ) {
            remove_action( 'template_redirect', 'wp_old_slug_redirect' );
            remove_action( 'template_redirect', 'redirect_canonical' );
            add_filter( 'wpml_is_redirected', '__return_false', 99, 2 );
            add_filter( 'pll_check_canonical_url', '__return_false', 99, 2 );

            $query = $new_query;
        }
    }

    return $query;
}

add_filter( 'request', 'bis_detect_cpt_permalinks', 9999 );

/**
 * Rewrite permalinks
 */
function pm_filter_cpt_permalinks( $permalink, $post ) {
    if ( empty( $post->post_type ) || $post->post_status !== 'publish' ) {
        return $permalink;
    }

    if ( in_array( $post->post_type, array( 'hersteller', 'dienstleistung' ) ) ) {
        // Get the slug of assigned 'orte' term
        $o_terms       = wp_get_object_terms( $post->ID, 'orte' );
        $o_lowest_term = ( ! is_wp_error( $o_terms ) && ! empty( $o_terms ) && is_object( $o_terms[0] ) ) ? pm_get_lowest_element( $o_terms[0], $o_terms ) : "";
        $o_slug        = ( ! empty( $o_lowest_term->slug ) ) ? $o_lowest_term->slug : '';

        // A. Hersteller (datenrettung-%orte_flat%/%hersteller%-%herstellerkategorie%)
        if ( $post->post_type == 'hersteller' ) {

            // Get the slug of assigned 'herstellerkategorie' term
            $h_terms       = wp_get_object_terms( $post->ID, 'herstellerkategorie' );
            $h_lowest_term = ( ! is_wp_error( $h_terms ) && ! empty( $h_terms ) && is_object( $h_terms[0] ) ) ? pm_get_lowest_element( $h_terms[0], $h_terms ) : "";
            $h_slug        = ( ! empty( $h_lowest_term->slug ) ) ? $h_lowest_term->slug : '';

            $new_permalink = sprintf( '%s/datenrettung-%s/%s-%s', trim( get_option( 'home' ), '/' ), $o_slug, sanitize_title( $post->post_title ), $h_slug );
        }

        // B. Datenrettung (datenrettung-%orte_flat%/%dienstleistung%)
        if ( $post->post_type == 'dienstleistung' ) {
            $new_permalink = sprintf( '%s/datenrettung-%s/%s', trim( get_option( 'home' ), '/' ), $o_slug, sanitize_title( $post->post_title ) );
        }

        $permalink = user_trailingslashit( $new_permalink );
    }

    return $permalink;
}

add_filter( 'post_type_link', 'pm_filter_cpt_permalinks', 1000, 2 );

/**
 * Get the lowest-level term
 */
function pm_get_lowest_element( $first_element, $elements ) {
    if ( ! empty( $elements ) && ! empty( $first_element ) ) {
        // Get the ID of first element
        if ( ! empty( $first_element->term_id ) ) {
            $first_element_id = $first_element->term_id;
            $parent_key       = 'parent';
        } else if ( ! empty( $first_element->ID ) ) {
            $first_element_id = $first_element->ID;
            $parent_key       = 'post_parent';
        } else if ( is_numeric( $first_element ) ) {
            $first_element_id = $first_element;
            $parent_key       = 'post_parent';
        } else {
            return false;
        }

        $children = wp_filter_object_list( $elements, array( $parent_key => $first_element_id ) );
        if ( ! empty( $children ) ) {
            // Get the first term
            $child_term    = reset( $children );
            $first_element = pm_get_lowest_element( $child_term, $elements );
        }
    }

    return $first_element;
}