Mainland ID card number processing class

Including the conversion of 15-digit mainland ID number to 18-digit, ID number validity check and ID card information extraction.

use DateTime;
/**
 * ID card number processing class
 * @author WeakSun <52132522@qq.com>
*/
class Idcard {

 static private $factor = array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2),
 $verify = array(1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2),
 $info = array('status' => false, 'info' => '', 'data' => array());
 /**
 * Verify the validity of the ID number
 * @param string $idnum ID number
 * @return array
*/
 public function index($idnum = null) {
 switch (strlen($idnum)) {
 case 18:
 break;
 case 15:
 $idnum = $this->upgrade($idnum);
 break;
 default :
 return $this ->info(false, 'error', $idnum);
 }
 $info = $this->getInfo($idnum);
 $info['status'] = $this->getCode($idnum ) == strtoupper(substr($idnum, -1));
 return $info;
 }

 /**
 * Get ID card information
 * @param string $idnum ID number
 * @return array
*/
 public function getInfo($idnum) {
 $data = array(
 'id ' => $idnum,
 'city' => substr($idnum, 0, 6),
 'birthday' => substr($idnum, 6, 4) . '-' . substr($idnum, 10, 2) . '-' . substr($idnum, 10, 2),
 'sex' => substr($idnum, -2, 1) % 2 ? 'Male' : 'Female'
 );
 $datetime = new DateTime($data['birthday']);
 $data['age'] = $datetime->diff(date_create())->format('%y');
 return $this ->info(true, null, $data);
 }

 /**
 * 15-digit number upgraded to 18 digits
 * @param string $idnum
 * @return array
*/
 public function upgrade($idnum) {
 if (strlen($idnum) != 15) {
 $this ->info(true, null, $idnum);
 } else {
 $idnum = array(substr($idnum, 0, 6), 19, substr($idnum, 6));
 substr($idnum, -3) > 995 && $idnum[1] --;
 $idnum = implode('', $idnum);
 }
 return $this->info(true, null, $idnum . $this-> ;getCode($idnum));
 }

 /**
 * Get confirmation code
 * @param string $idnum ID number
 * @return string Return confirmation code if successful, false if failed
*/
 protected function getCode($idnum) {
 $code = 0;
 foreach (str_split($idnum) as $k => $ v) {
 $code += $v * static::$factor[$k];
 }
 $index = $code % 11;
 return static::$verify[$index];
 }

 protected function info($status, $msg = null, $data = null) {
 $info = static::$info;
 empty($msg) || $info['info'] = $msg;
 empty($data ) || $info['data'] = $data;
 if(is_array($status)){
 $this->info = array_merge($info, $status);
 }elseif(is_bool($status) ){
 $info['status'] = $status;
 }
 return $this->info;
 }

}