TransactionViewModel (Updated)

import Foundation
import Firebase

class TransactionViewModel: ObservableObject {
    @Published var transactionsByRoom: [String: [Transaction]] = [:]

    private var timer: Timer?

    init() {
        fetchData()

        //this calls the data every second
        timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
            self?.fetchData()
        }
    }

    deinit {
        //closes timer
        timer?.invalidate()
    }

    func fetchData() {
        let db = Firestore.firestore()
        let transactionsCollection = db.collection("Transactions")

        transactionsCollection.getDocuments { [weak self] (querySnapshot, error) in
            guard let self = self else { return }

            if let error = error {
                print("Error getting documents: \(error)")
            } else {
                var transactionsByRoom: [String: [Transaction]] = [:]

                for document in querySnapshot!.documents {
                    let patientRequest = document["PatientRequest"] as? String ?? ""
                    let roomNumber = document["RoomNumber"] as? String ?? ""

                    // Check
                    if document["DateCompleted"] == nil {
                        let transaction = Transaction(patientRequest: patientRequest, roomNumber: roomNumber)

                        if var roomTransactions = transactionsByRoom[roomNumber] {
                            roomTransactions.append(transaction)
                            transactionsByRoom[roomNumber] = roomTransactions
                        } else {
                            transactionsByRoom[roomNumber] = [transaction]
                        }
                    }
                }

                DispatchQueue.main.async {
                    self.transactionsByRoom = transactionsByRoom
                }
            }
        }
    }

    func refreshData() {
        fetchData()
    }

    func deleteTransaction(_ transaction: Transaction, inRoom roomNumber: String) {
        if var roomTransactions = transactionsByRoom[roomNumber],
           let index = roomTransactions.firstIndex(of: transaction) {

            roomTransactions.remove(at: index)
            transactionsByRoom[roomNumber] = roomTransactions

            updateFirestoreDocument(transaction, inRoom: roomNumber)
        }
    }

    private func updateFirestoreDocument(_ transaction: Transaction, inRoom roomNumber: String) {
        let db = Firestore.firestore()
        let transactionsCollection = db.collection("Transactions")

        transactionsCollection
            .whereField("PatientRequest", isEqualTo: transaction.patientRequest)
            .whereField("RoomNumber", isEqualTo: roomNumber)
            .getDocuments { (querySnapshot, error) in
                if let error = error {
                    print("Error updating documents: \(error)")
                } else {
                    for document in querySnapshot!.documents {

                        if document.data()["DateCompleted"] == nil {
                            // Timestamp Nurse
                            let timestamp = FieldValue.serverTimestamp()
                            document.reference.updateData(["DateCompleted": timestamp])
                        }
                    }
                }
            }
    }
}