EDD License upgrade: Extend expiration

edd-sl.php

/**
 * License upgrade: Extend expiration
 */
add_action('edd_sl_license_upgraded', function( $license_id, $args ) {

    $license = edd_software_licensing()->get_license( $license_id );

    $download_id =$license->download->id;
    $download = new EDD_SL_Download( $download_id );
    $download_exp_length = $download->get_expiration_length();
    $download_exp_length_unit = $download->get_expiration_unit();

    $exp_date = ucfirst( $license->expiration );
    $exp_date_new = strtotime('+' . $download_exp_length . ' ' . $download_exp_length_unit, $exp_date);

    $updated = update_post_meta( $license_id, '_edd_sl_expiration', $exp_date_new );

    if ( $updated ) {
        $log_id = wp_insert_post(
            array(
                'post_title'   => __( 'LOG - Expiration extended after license upgrade: +', 'edd' ) . $download_exp_length . ' ' . $download_exp_length_unit,
                'post_name'    => 'fwwp-log-license-extended-' . $license_id . '-' . md5( current_time( 'timestamp' ) ),
                'post_type'    => 'edd_license_log',
                'post_content' => json_encode( 'Expiration extended.' ),
                'post_status'  => 'publish'
            )
        );

        add_post_meta( $log_id, '_edd_sl_log_license_id', $license_id );
    }

}, 10, 2);