Redirect based on username

/*
 * Redirect based on username
 */
 
add_filter( 'login_redirect', 'wppbc_custom_login_redirect', 99, 3 );
function wppbc_custom_login_redirect( $redirect_to, $requested_redirect_to, $user ) {
   if( is_wp_error( $user ) ) {
      return $redirect_to;
   }
   $username = $user->user_login;
   if ( is_array( $form_args ) ) {
      switch ( $username ) {
         case 'admin':
            $redirect_to = 'http://www.website.com/page1';
            break;
         case 'username1':
            $redirect_to = 'http://www.website.com/page2';
            break;
         case 'username2':
            $redirect_to = 'http://www.website.com/page3';
            break;
         case 'username3':
            $redirect_to = 'http://www.website.com/page4';
            break;
         default:
            $redirect_to = 'http://www.website.com/default-redirect-for-other-users';
      }
   }
   return $redirect_to;
}