WP Save CSV in Uploads

//Create the Catalogue Code File
function sp_create_catalogues() {

    $terms = get_terms( 'product_cat',
        array(
            'parent'    => 0,
            'hide_empty' => 1
        )
    );
    $count = count($terms);
    if ($count == 0) return;

    $file_options = get_option('sp_file');
    $shortname = isset( $file_options['catalogues'] ) && !is_null( $file_options['catalogues'] ) ? $file_options['catalogues'] : 'Catalogues.csv';
    $filename = SP_FILE_PATH .$shortname;

    $data = array();
    $data[] = 'Code';
    $data[] = 'Description';

    $fh = @fopen( $filename, 'w' );

    fputcsv($fh, $data);

    foreach ( $terms as $term ) {
        // Put the data into the stream
        $data = array();
        $data[] = $term->slug;
        $data[] = html_entity_decode($term->name);
        fputcsv($fh, $data);

        $children = get_terms( 'product_cat',
            array(
                'parent'    => $term->term_id,
                'hide_empty' => 1
            )
        );

        $count = count($children);
        if ($count > 0) {
            foreach ( $children as $child ) {
                $data = array();
                $data[] = $child->slug;
                $data[] = '> ' .html_entity_decode($child->name);
                fputcsv($fh, $data);
            }
        }
    }
    // Close the file
    fclose($fh);
    $currpage = site_url() .'/wp-admin/tools.php?page=export';
    wp_redirect($currpage);
    // Make sure nothing else is sent, our file is done
    exit;
}