Wire BaseViewModel protocol into BaseViewController and migrate Account VM/VC to delegate-based error handling

Topical Dictionary/Controller/AccountViewController.swift

@@ -9,28 +9,31 @@
 import UIKit
 import FirebaseAuth
 
-class AccountViewController: UIViewController, AccountViewModelDelegate {
+class AccountViewController: BaseViewController, AccountViewModelDelegate {
 
     @IBOutlet weak var accountTableView: UITableView!
 
     var viewModel: AccountViewModel?
+    private let authService = AuthService.shared
 
     override func viewDidLoad() {
         super.viewDidLoad()
 
-        viewModel = AccountViewModel(delegate: self)
-
         accountTableView.dataSource = self
         accountTableView.delegate = self
 
     }
-
+
+    override func configureViewModel() {
+        viewModel = AccountViewModel(delegate: self)
+        baseViewModel = viewModel
+    }
+
     func logout() {
         let alert = UIAlertController(title: "Loging out", message: "You are currently logging out. Do you want to continue?", preferredStyle: .alert)
         alert.addAction(UIAlertAction(title: "Logout", style: .cancel, handler: { _ in
-            let auth = Auth.auth()
             do {
-                try auth.signOut()
+                try authService.signOut()
             } catch let signoutError as NSError {
                 print("Error while signing out: \(signoutError)")
             }
@@ -53,12 +56,6 @@ class AccountViewController: UIViewController, AccountViewModelDelegate {
 
     // MARK: - View Model Delegate
 
-    func didErrorOccured(_ viewModel: AccountViewModel, error: Error) {
-        let alert = UIAlertController(title: "Something Went Wrong", message: error.localizedDescription, preferredStyle: .alert)
-        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
-        present(alert, animated: true, completion: nil)
-    }
-
     func didUpdateName(_ viewModel: AccountViewModel, name: String) {
         DispatchQueue.main.async {
             self.accountTableView.reloadRows(at: [IndexPath(row: 0, section: 0)], with: .fade)

Topical Dictionary/Controller/BaseViewController.swift

@@ -0,0 +1,40 @@
+//
+//  BaseViewController.swift
+//  Topical Dictionary
+//
+//  Created by İbrahim Ethem Karalı on 2025-02-14.
+//
+
+import UIKit
+
+class BaseViewController: UIViewController, BaseViewModelDelegate {
+    var baseViewModel: BaseViewModelProtocol? {
+        didSet {
+            baseViewModel?.delegate = self
+        }
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        configureViewModel()
+        bindViewModel()
+    }
+
+    func configureViewModel() {
+        // Override in subclasses to create view model.
+    }
+
+    func bindViewModel() {
+        // Override in subclasses to bind view model outputs.
+    }
+
+    func didReceiveError(_ error: Error) {
+        presentError(error)
+    }
+
+    func presentError(_ error: Error) {
+        let alert = UIAlertController(title: "Something Went Wrong", message: error.localizedDescription, preferredStyle: .alert)
+        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
+        present(alert, animated: true, completion: nil)
+    }
+}

Topical Dictionary/Controller/DictionaryViewController.swift

@@ -10,7 +10,7 @@ import UIKit
 import FirebaseCore
 import FirebaseFirestore
 
-class DictionaryViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate, WordManagerDelegate, HeadCellDelegate, WordDetailViewDelegate, DictionaryServiceDelegate {
+class DictionaryViewController: BaseViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate, WordManagerDelegate, HeadCellDelegate, WordDetailViewDelegate, DictionaryServiceDelegate {
 
     enum sections: Int {
         case head = 0
@@ -21,6 +21,8 @@ class DictionaryViewController: UIViewController, UITableViewDelegate, UITableVi
 
     @IBOutlet var wordsTableView: UITableView!
     @IBOutlet weak var favoriteButton: UIBarButtonItem!
+
+    var viewModel: DictionaryViewModel?
 
     lazy var selectedDictionary = DictionaryModel()
     var searchedWord: WordData?
@@ -53,6 +55,11 @@ class DictionaryViewController: UIViewController, UITableViewDelegate, UITableVi
         setFavoriteImage(isFavorite, favoriteButton)
 
     }
+
+    override func configureViewModel() {
+        viewModel = DictionaryViewModel()
+        baseViewModel = viewModel
+    }
 
     private func fireBaseSettings() {
         let settings = FirestoreSettings()

Topical Dictionary/Controller/HomeViewController.swift

@@ -19,13 +19,15 @@ enum SortingType {
     case zToA
 }
 
-class HomeViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate, DictionariesManagerDelegate {
+class HomeViewController: BaseViewController, UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate, DictionariesManagerDelegate {
 
     // MARK: Implementations
     var db: Firestore!
 
     @IBOutlet var mainTableView: UITableView!
     @IBOutlet var favButton: UIBarButtonItem!
+
+    var viewModel: HomeViewModel?
 
     private var isFav = false
     private var stockRightBarItems: [UIBarButtonItem]?
@@ -68,6 +70,11 @@ class HomeViewController: UIViewController, UITableViewDelegate, UITableViewData
 
         dictionaryManager.setListener()
     }
+
+    override func configureViewModel() {
+        viewModel = HomeViewModel()
+        baseViewModel = viewModel
+    }
 
     // MARK: - Bar Button Actions
 

Topical Dictionary/Controller/LoginRegister/EmailLoginViewController.swift

@@ -7,9 +7,8 @@
 //
 
 import UIKit
-import FirebaseAuth
 
-class EmailLoginViewController: UIViewController, UITextFieldDelegate {
+class EmailLoginViewController: BaseViewController, UITextFieldDelegate {
 
     @IBOutlet weak var loginOrRegisterSegment: UISegmentedControl!
 
@@ -23,6 +22,8 @@ class EmailLoginViewController: UIViewController, UITextFieldDelegate {
     @IBOutlet weak var fullnameTextField: UITextField!
 
     @IBOutlet weak var privacyPolicy: UILabel! // add real terms and conditions
+
+    var viewModel: EmailLoginViewModel?
 
     override func viewDidLoad() {
         super.viewDidLoad()
@@ -46,6 +47,11 @@ class EmailLoginViewController: UIViewController, UITextFieldDelegate {
         privacyPolicy.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(didTapPrivacyPolicy)))
 
     }
+
+    override func configureViewModel() {
+        viewModel = EmailLoginViewModel()
+        baseViewModel = viewModel
+    }
 
     @objc func didTapPrivacyPolicy() {
         let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PrivacyViewController")
@@ -66,6 +72,12 @@ class EmailLoginViewController: UIViewController, UITextFieldDelegate {
             self.myActivityIndicator?.endActivity()
         }
     }
+
+    override func didReceiveError(_ error: Error) {
+        myActivityIndicator?.endActivity()
+        view.isUserInteractionEnabled = true
+        super.didReceiveError(error)
+    }
 
     @IBAction func loginOrRegister(_ sender: UISegmentedControl) {
         view.endEditing(true)
@@ -96,41 +108,24 @@ class EmailLoginViewController: UIViewController, UITextFieldDelegate {
         if loginOrRegisterSegment.selectedSegmentIndex == 0 {
             // Login
             view.isUserInteractionEnabled = false
-            Auth.auth().signIn(withEmail: emailTextField.text!, password: passwordTextField.text!) { (authDataResult, error) in
-                if error != nil {
-                    self.displayAlert(detail: error!.localizedDescription, title: "Something Went Wrong")
-                    self.view.isUserInteractionEnabled = true
-
-                    return
-                }
-
+            viewModel?.login(email: emailTextField.text ?? "", password: passwordTextField.text ?? "") { authDataResult in
                 if let authDataRes = authDataResult {
                     print("user signed in: UID: \(authDataRes.user.uid)")
                     print("is email verified: \(authDataRes.user.isEmailVerified)")
-                    self.myActivityIndicator?.endActivity()
                 }
+                self.myActivityIndicator?.endActivity()
                 self.view.isUserInteractionEnabled = true
             }
 
         } else {
             if let password = passwordTextField.text,
                password == confirmPasswordTextField.text,
                let email = emailTextField.text, let name = fullnameTextField.text {
-                Auth.auth().createUser(withEmail: email, password: password) { authDataResult, error in
-                    if let err = error {
-                        self.displayAlert(detail: err.localizedDescription, title: "Something Went Wrong")
-                        return
+                viewModel?.register(email: email, password: password, displayName: name) { authDataResult in
+                    if let authDataRes = authDataResult {
+                        print("user signed up: UID: \(authDataRes.user.uid)")
                     }
                     self.myActivityIndicator?.endActivity()
-                    let changeRequest = authDataResult?.user.createProfileChangeRequest()
-                    changeRequest?.displayName = name
-                    changeRequest?.commitChanges(completion: { error in
-                        if error != nil {
-                            print("Error while setting display name: \(error!.localizedDescription)")
-                        } else {
-                            print("success")
-                        }
-                    })
                 }
             } else {
                 print("Passwords doesn't match")

Topical Dictionary/Controller/LoginRegister/LoginViewController.swift

@@ -15,7 +15,7 @@ import CryptoKit
 import AuthenticationServices
 import NVActivityIndicatorView
 
-class LoginViewController: UIViewController, UIScrollViewDelegate, GIDSignInDelegate {
+class LoginViewController: BaseViewController, UIScrollViewDelegate, GIDSignInDelegate {
 
     fileprivate var currentNonce: String?
     fileprivate var myActivityIndicator: MyActivityIndicator?
@@ -29,7 +29,9 @@ class LoginViewController: UIViewController, UIScrollViewDelegate, GIDSignInDele
     @IBOutlet weak var facebookButton: UIButton!
     @IBOutlet weak var appleButton: UIButton!
     @IBOutlet weak var googleButton: UIButton!
-
+
+    var viewModel: LoginViewModel?
+
     let fbLoginManager = LoginManager()
 
     @IBOutlet weak var scrollView: UIScrollView!
@@ -56,6 +58,11 @@ class LoginViewController: UIViewController, UIScrollViewDelegate, GIDSignInDele
         GIDSignIn.sharedInstance()?.delegate = self
 
     }
+
+    override func configureViewModel() {
+        viewModel = LoginViewModel()
+        baseViewModel = viewModel
+    }
 
     // MARK: Facebook login
 

Topical Dictionary/Service/AuthService.swift

@@ -0,0 +1,76 @@
+//
+//  AuthService.swift
+//  Topical Dictionary
+//
+//  Created by İbrahim Ethem Karalı on 2025-02-14.
+//
+
+import Foundation
+import FirebaseAuth
+
+enum AuthServiceError: Error {
+    case missingUser
+}
+
+final class AuthService {
+    static let shared = AuthService()
+
+    private let auth: Auth
+
+    init(auth: Auth = .auth()) {
+        self.auth = auth
+    }
+
+    var currentUser: User? {
+        auth.currentUser
+    }
+
+    func loginMethod(for user: User?) -> AuthProvider? {
+        let providerID = user?.providerData.first?.providerID
+        switch providerID {
+        case AuthProvider.email.rawValue:
+            return AuthProvider.email
+        case AuthProvider.facebook.rawValue:
+            return AuthProvider.facebook
+        case AuthProvider.google.rawValue:
+            return AuthProvider.google
+        case AuthProvider.apple.rawValue:
+            return AuthProvider.apple
+        default:
+            return nil
+        }
+    }
+
+    func signOut() throws {
+        try auth.signOut()
+    }
+
+    func signIn(email: String, password: String, completion: @escaping (AuthDataResult?, Error?) -> Void) {
+        auth.signIn(withEmail: email, password: password, completion: completion)
+    }
+
+    func register(email: String, password: String, displayName: String, completion: @escaping (AuthDataResult?, Error?) -> Void) {
+        auth.createUser(withEmail: email, password: password) { authDataResult, error in
+            if let error = error {
+                completion(authDataResult, error)
+                return
+            }
+            guard let _ = authDataResult?.user else {
+                completion(authDataResult, AuthServiceError.missingUser)
+                return
+            }
+            self.updateDisplayName(displayName) { updateError in
+                completion(authDataResult, updateError)
+            }
+        }
+    }
+
+    func updateDisplayName(_ name: String, completion: @escaping (Error?) -> Void) {
+        guard let change = auth.currentUser?.createProfileChangeRequest() else {
+            completion(AuthServiceError.missingUser)
+            return
+        }
+        change.displayName = name
+        change.commitChanges(completion: completion)
+    }
+}