searchbarによるtableview検索

Question

searchbarを使用して使用してtableviewに表示されているCellの検索を行いたいです。
firebaseの情報をtableviewに反映させたのですが、この検索を行おうとしてもうまくできません。Cellにはfirebaseの中に入っている情報を表示しています。searchbarより、何らかの単語を検索した際にヒットするものを表示できるようにしたいと考えています。

import UIKit
import Firebase

class roomlist:UIViewController{
                      
    private let cellId = "cellId"
    private var rooms = [Room]()
    var gotroom = [Room]()
    private var selectedRoom : Room?
    
    
    @IBOutlet weak var roomlisttable: UITableView!
    @IBOutlet weak var roomsearch: UISearchBar!
    
    var searchroom = [String]()
    
    
    override func viewDidLoad() {
        super.viewDidLoad()

        roomlisttable.delegate = self
        roomlisttable.dataSource = self
        fechroominfofirestore()

    }

    struct PasswordData {
        var documentID: String

    }
    private func fechroominfofirestore(){

        Firestore.firestore().collection("rooms").getDocuments{(snapshots,error) in
            if error != nil{
                print("sippai")

                return

            }
           
                self.rooms = []
                snapshots?.documents.forEach { snapshot in
                    let id = snapshot.documentID
                    let dic = snapshot.data()
                    let room = Room(dic: dic)
                    
                    self.rooms.append(room)
                }
                self.roomlisttable.reloadData()

                self.rooms.forEach{(rooms) in

                }
            }

        }
    }

extension roomlist:UITableViewDelegate, UITableViewDataSource{
    
    func searchBar(_ searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int) {
    }
    //  検索バーに入力があったら呼ばれる
    func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        guard !searchText.isEmpty else {
            gotroom = rooms
            roomlisttable.reloadData()
            return
        }
        gotroom = rooms.filter({ item -> Bool in
            item.bsubname.lowercased().contains(searchText.lowercased())
        })
        roomlisttable.reloadData()
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return rooms.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = roomlisttable.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! roomlistcell
        cell.room = rooms[indexPath.row]

        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){

        print("didSelectRowAt")
        tableView.deselectRow(at: indexPath, animated: false)

        Firestore.firestore().collection("rooms").getDocuments() { (querySnapshot, err) in
            if err != nil {
            } else {
                for doc in querySnapshot!.documents {
                    let documentID = doc.documentID

                    
                    print(documentID)
                }
                }
            }
        }
    func tableView(_ tableView: UITableView, didHighlightRowAt indexPath: IndexPath) {

    }

    override func prepare(for segue : UIStoryboardSegue, sender: Any?){

      print("Will move to next view controller.")
      switch segue.identifier {
      case "RoomdetqailsViewController":
        if let RoomdetqailsViewController = segue.destination as? RoomdetqailsViewController {
          if let indexPath = self.roomlisttable.indexPathForSelectedRow {
            let room = self.rooms[indexPath.row]
            RoomdetqailsViewController.received = room
          }
        }
      default:
        break
      }
    }
}

class roomlistcell : UITableViewCell{

        var room: Room?{
            didSet{
                roomname.text = room?.bsubname
                tname.text = "(" + room!.ctln + room!.dtfn + ")"
            }
        }

    @IBOutlet weak var tname: UILabel!
    @IBOutlet weak var roomimage: UIImageView!
    @IBOutlet weak var roomname: UILabel!
        override func awakeFromNib() {
            super.awakeFromNib()
            roomimage.layer.borderWidth = 0.5
            roomimage.layer.borderColor = UIColor.bnw.cgColor
            roomimage.layer.cornerRadius = roomimage.frame.width/2
        }
        override func setSelected(_ selected: Bool, animated: Bool) {
            super.setSelected(selected, animated: animated)
        }
    }