(chore): Add SignUpViewModel

Author: N3v1

ScribbleLab/App/ScribbleLabApp.swift

@@ -41,7 +41,10 @@ struct ScribbleLabApp: App {
     init() {
         /* SCRLog */
         logger = SCRLog.shared
-        SCRLog.configureShared(subsystem: "com.nhsystems.scribblelab", category: .log)
+        SCRLog.configureShared(
+            subsystem: "com.nhsystems.scribblelab",
+            category: .log
+        )
         logger.log("SCRLogStream successfully initialized")
     }
 

ScribbleLab/Core/Authentication/Models/SignInViewModel.swift

@@ -75,7 +75,7 @@ class SignInViewModel: ObservableObject {
         return !email.isEmpty && validateEmail(withEmail: email) && password.count >= 8
     }
 
-    func validateEmail(withEmail email: String) -> Bool {
+    private func validateEmail(withEmail email: String) -> Bool {
         return Validation.isValidEmail(email)
     }
 

ScribbleLab/Core/Authentication/Models/SignUpViewModel.swift

@@ -37,8 +37,13 @@ import ScribbleFoundation
 
 class SignUpViewModel: ObservableObject {
 
+    /// Published property holding the entered email.
     @Published var email: String = ""
+    
+    /// Published property holding the entered password.
     @Published var password: String = ""
+    
+    /// Published property holding the entered username.
     @Published var username: String = ""
 
     /// Published property determining if the sign-up button is enabled.
@@ -50,10 +55,79 @@ class SignUpViewModel: ObservableObject {
 
     private var cancellables = Set<AnyCancellable>()
 
+    init() {
+        setUpValidation()
+    }
+    
+    // That's the most ugliest code I've ever written - please don't blame me
+    // I'm just tired - Thank you for your understanding!
+    private func setUpValidation() {
+        Publishers.CombineLatest3($email, $password, $username)
+            .sink { [weak self] email, password, username in
+                guard let self = self else { return }
+                
+                let isInputValid = self.validateInput(
+                    email: email,
+                    password: password,
+                    username: username
+                )
+                
+                if isInputValid {
+                    Task {
+                        if let isAvailable = try? await self.checkUsernameAvailability(for: username) {
+                            DispatchQueue.main.async {
+                                self.isSignUpButtonEnabled = isAvailable
+                            }
+                        }
+                    }
+                } else {
+                    self.isSignUpButtonEnabled = false
+                }
+            }
+            .store(in: &cancellables)
+    }
 
+    private func validateInput(
+        email: String,
+        password: String,
+        username: String
+    ) -> Bool {
+        guard Validation.isValidEmail(email),
+              Validation.isStrongPassword(password),
+              !username.isEmpty
+        else {
+            return false
+        }
+        
+        return true
+    }
 
-    init() {}
+    private func checkUsernameAvailability(for username: String) async throws -> Bool {
+        // swiftlint:disable:next identifier_name
+        let db = Firestore.firestore()
+        
+        let usersRef = db.collection("users")
+        let query = usersRef.whereField("username", isEqualTo: username)
+        
+        let snapshot = try await query.getDocuments()
+        
+        return snapshot.isEmpty
+    }
 
+    func createScribbleID() async throws {
+        try await SCIDAuthService.shared.createUser(
+            email: email,
+            password: password,
+            username: username
+        )
+        
+        // Resetting published properties after user creation
+        username = ""
+        password = ""
+        email = ""
+    }
 
-    deinit {}
+    deinit {
+        cancellables.removeAll()
+    }
 }

ScribbleLab/Misc/SCIDError.swift

@@ -0,0 +1,121 @@
+//
+//  SCIDError.swift
+//  ScribbleLab
+//
+//  Copyright (c) 2024 ScribbleLabApp LLC. - All rights reserved.
+//
+//  Redistribution and use in source and binary forms, with or without
+//  modification, are permitted provided that the following conditions are met:
+//
+//  1. Redistributions of source code must retain the above copyright notice, this
+//     list of conditions and the following disclaimer.
+//
+//  2. Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//
+//  3. Neither the name of the copyright holder nor the names of its
+//     contributors may be used to endorse or promote products derived from
+//     this software without specific prior written permission.
+//
+//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+//  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+//  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+//  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+//  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+//  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+//  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+//  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+//  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import Foundation
+
+/// A comprehensive list of errors that can occur within the ScribbleLabApp identity and user services.
+///
+/// The `SCIDError` enum categorizes errors into those related to Google authentication processes, such as
+/// OAuth flows and user sign-ins, and errors encountered in user data retrieval and handling. Each error case
+/// provides contextual information and a standardized error code to support debugging and enhance error
+/// tracking throughout the app.
+///
+/// - Note: These error codes can be used in logging and alerting systems to quickly identify the
+///         error source and cause.
+internal enum SCIDError: Error {
+    
+    /// The client ID required for Google Sign-In is missing.
+    ///
+    /// This error occurs if the app is unable to retrieve the necessary client ID to initiate Google OAuth
+    /// authentication. The absence of this ID prevents the app from making the initial connection with
+    /// Google’s authentication services.
+    ///
+    /// - Error Code: `GID-E115`
+    case missingClientID
+    
+    /// Failed to present the OAuth consent sheet for Google Sign-In.
+    ///
+    /// This error is encountered when the app cannot display the OAuth consent sheet, which is
+    /// required for users to grant permissions to their Google account. This may happen due to
+    /// UI-related constraints or network issues.
+    ///
+    /// - Error Code: `GID-E110`
+    case failedOAuthSheet
+    
+    
+    /// The signed-in user or the ID token is unavailable after an attempt to sign in.
+    ///
+    /// This error is returned if the app fails to retrieve the expected user profile or ID token
+    /// following a successful OAuth flow, potentially due to session timeouts or network interruptions.
+    ///
+    /// - Error Code: `GID-E116`
+    case missingUserOrToken
+    
+    /// Google Sign-In failed due to an unknown error.
+    ///
+    /// This error generally occurs when the sign-in process does not complete successfully, either due
+    /// to connectivity issues or unhandled exceptions during authentication.
+    ///
+    /// - Error Code: `GID-E118`
+    case signInFailed
+    
+    /// The signed-in user object is unavailable after Google authentication completes.
+    ///
+    /// This error occurs when the user object is not retrievable even after a successful Google Sign-In.
+    /// It is likely related to session handling or data parsing issues during the sign-in process.
+    ///
+    /// - Error Code: `GID-E119`
+    case missingSignedInUser
+    
+    /// The user’s login attempt failed.
+    ///
+    /// This error represents a general failure in the login process. It may be caused by invalid credentials,
+    /// connectivity issues, or other authentication-related errors.
+    ///
+    /// - Error Code: `AUT-E101`
+    case logInFailed
+    
+    /// Failed to create a new user account.
+    ///
+    /// This error occurs when the app fails to establish a new user account, potentially due to server-side
+    /// issues, invalid data inputs, or connectivity problems during account creation.
+    ///
+    /// - Error Code: `AUT-E102`
+    case userCreationFailed
+    
+    /// The requested user data could not be found or was invalid.
+    ///
+    /// This error is encountered when attempting to fetch user data from the database, but the returned data
+    /// is either missing or improperly formatted. This may occur if the user’s record does not exist or if data
+    /// parsing fails.
+    ///
+    /// - Error Code: `SLUSR-E201`
+    case userDataNotFound
+    
+    /// Required user fields are missing or incomplete in the retrieved data.
+    ///
+    /// This error is thrown when essential fields such as user ID, username, or email are missing in the
+    /// retrieved user data, leading to incomplete user profiles. This may happen due to improper data
+    /// entry or issues in database management.
+    ///
+    /// - Error Code: `SLUSR-E202`
+    case missingRequiredUserFields
+}