feat: implement Auth functionality (#3)

android/app/build.gradle

@@ -22,6 +22,7 @@ if (flutterVersionName == null) {
 }
 
 apply plugin: 'com.android.application'
+apply plugin: 'com.google.gms.google-services'
 apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
@@ -35,7 +36,7 @@ android {
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.example.borderhacks"
-        minSdkVersion 16
+        minSdkVersion 21
         targetSdkVersion 30
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName

android/build.gradle

@@ -8,6 +8,7 @@ buildscript {
     dependencies {
         classpath 'com.android.tools.build:gradle:4.1.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath 'com.google.gms:google-services:4.3.10'
     }
 }
 

lib/locator.dart

@@ -1,11 +1,27 @@
+import 'package:borderhacks/services/auth_service.dart';
+import 'package:borderhacks/services/localstorage_service.dart';
+import 'package:borderhacks/viewmodels/auth_viewmodel.dart';
 import 'package:borderhacks/viewmodels/home_viewmodel.dart';
 import 'package:borderhacks/viewmodels/landing_viewmodel.dart';
 import 'package:borderhacks/viewmodels/profile_viewmodel.dart';
+import 'package:borderhacks/viewmodels/startup_viewmodel.dart';
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:firebase_auth/firebase_auth.dart';
 import 'package:get_it/get_it.dart';
 
 GetIt locator = GetIt.instance;
 
 Future<void> setupLocator() async {
+  var localStorage = await LocalStorageService.getInstance();
+  locator.registerSingleton<LocalStorageService>(localStorage);
+  var _firebaseAuth = FirebaseAuth.instance;
+  locator.registerSingleton<FirebaseAuth>(_firebaseAuth);
+  var _firebaseFirestore = FirebaseFirestore.instance;
+  locator.registerSingleton<FirebaseFirestore>(_firebaseFirestore);
+  locator.registerSingleton<FirebaseAuthService>(FirebaseAuthService());
+
+  locator.registerFactory<StartUpViewModel>(() => StartUpViewModel());
+  locator.registerFactory<AuthViewModel>(() => AuthViewModel());
   locator.registerFactory<HomeViewModel>(() => HomeViewModel());
   locator.registerFactory<LandingViewModel>(() => LandingViewModel());
   locator.registerFactory<ProfileViewmodel>(() => ProfileViewmodel());

lib/main.dart

@@ -1,22 +1,38 @@
 import 'package:borderhacks/locator.dart';
-import 'package:borderhacks/views/landing_view.dart';
+import 'package:borderhacks/ui/views/auth_view.dart';
+import 'package:borderhacks/ui/views/landing_view.dart';
+import 'package:borderhacks/ui/views/startup_view.dart';
+import 'package:firebase_core/firebase_core.dart';
 import 'package:flutter/material.dart';
+import 'package:get/get.dart';
 
 void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  await Firebase.initializeApp();
   await setupLocator();
   runApp(MyApp());
 }
 
 class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
+    return GetMaterialApp(
       debugShowCheckedModeBanner: false,
-      title: 'Flutter Demo',
-      theme: ThemeData(
-        primarySwatch: Colors.blue,
-      ),
-      home: LandingView(),
+      title: 'Admin App',
+      initialRoute: '/',
+      getPages: [
+        GetPage(name: '/', page: () => StartUpView()),
+        GetPage(
+          name: '/login',
+          page: () => const AuthView('Log in', 'Sign Up'),
+        ),
+        GetPage(
+          name: '/signup',
+          page: () => const AuthView('Sign Up', 'Log In'),
+        ),
+        GetPage(name: '/landing', page: () => LandingView()),
+      ],
+      home: StartUpView(),
     );
   }
 }

lib/services/auth_service.dart

@@ -0,0 +1,57 @@
+import 'package:borderhacks/locator.dart';
+import 'package:borderhacks/ui/constants/error_code.dart';
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:firebase_auth/firebase_auth.dart';
+
+class FirebaseAuthService {
+  final FirebaseAuth _firebaseAuth = locator<FirebaseAuth>();
+
+  User get currentUser => _firebaseAuth.currentUser!;
+
+  // Sign In with email and password
+  Future<UserCredential> signIn(String email, String password) async {
+    try {
+      return await _firebaseAuth.signInWithEmailAndPassword(
+        email: email,
+        password: password,
+      );
+    } on FirebaseAuthException catch (e) {
+      throw signInErrorCodes[e.code] ?? 'Database Error Occured!';
+    } catch (e) {
+      throw '${e.toString()} Error Occured!';
+    }
+  }
+
+  // Sign Up using email address
+  Future<UserCredential> signUp(String email, String password) async {
+    try {
+      var _user = await _firebaseAuth.createUserWithEmailAndPassword(
+        email: email,
+        password: password,
+      );
+      return _user;
+    } on FirebaseAuthException catch (e) {
+      throw signUpErrorCodes[e.code] ?? 'Firebase ${e.code} Error Occured!';
+    } catch (e) {
+      throw '${e.toString()} Error Occured!';
+    }
+  }
+
+  // Sign Out
+  Future<String> signOut() async {
+    await _firebaseAuth.signOut();
+    return 'Signed Out Successfully';
+  }
+
+  Future<String> sendResetPasswordEmail(String email) async {
+    try {
+      await _firebaseAuth.sendPasswordResetEmail(email: email);
+      return 'Email Sent Succesfully';
+    } on FirebaseException catch (e) {
+      throw passwordResetErrorCodes[e.code] ??
+          'Firebase ${e.code} Error Occured!';
+    } catch (e) {
+      throw '${e.toString()} Error Occured!';
+    }
+  }
+}

lib/services/localstorage_service.dart

@@ -0,0 +1,42 @@
+import 'package:flutter/foundation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class LocalStorageService {
+  static late LocalStorageService _instance;
+  static late SharedPreferences _preferences;
+
+  static const String authStateKey = 'is_LoggedIn';
+
+  static Future<LocalStorageService> getInstance() async {
+    _instance = LocalStorageService();
+    _preferences = await SharedPreferences.getInstance();
+    return _instance;
+  }
+
+  dynamic _getFromDisk(String key) {
+    var value = _preferences.get(key);
+    return value;
+  }
+
+  void _saveToDisk<T>(String key, T value) {
+    if (value is bool) {
+      _preferences.setBool(key, value);
+    } else if (value is double) {
+      _preferences.setDouble(key, value);
+    } else if (value is int) {
+      _preferences.setInt(key, value);
+    } else if (value is String) {
+      _preferences.setString(key, value);
+    } else if (value is List<String>) {
+      _preferences.setStringList(key, value);
+    } else {
+      debugPrint('passed value is none of the specified type');
+    }
+  }
+
+  //Getter
+  bool get isLoggedIn => _getFromDisk(authStateKey) ?? false;
+
+  //Setter
+  set isLoggedIn(bool isLoggedIn) => _saveToDisk(authStateKey, isLoggedIn);
+}

lib/ui/components/buttons/primary_button.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+
+class PrimaryButton extends StatelessWidget {
+  final VoidCallback press;
+  final String text;
+  final bool isFilled;
+
+  const PrimaryButton({
+    required this.press,
+    required this.text,
+    required this.isFilled,
+    Key? key,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialButton(
+      padding: const EdgeInsets.all(12.0),
+      color: isFilled ? Colors.blue : Colors.white,
+      minWidth: double.infinity,
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(9.0),
+        side: const BorderSide(color: Colors.blue),
+      ),
+      onPressed: press,
+      child: Text(
+        text,
+        style: TextStyle(
+          fontSize: 18,
+          color: isFilled ? Colors.white : Colors.blue,
+        ),
+      ),
+    );
+  }
+}

lib/ui/components/text_field/custom_textfield.dart

@@ -0,0 +1,62 @@
+import 'package:flutter/material.dart';
+
+class CustomTextField extends StatefulWidget {
+  final TextEditingController controller;
+  final String label;
+  final String? hint;
+  final Icon? prefix;
+  final String? Function(String?)? _validator;
+  final IconButton? _suffix;
+  final int? _maxlines;
+  final bool _isHidden;
+
+  const CustomTextField(
+      {required this.controller,
+      required this.label,
+      this.hint,
+      this.prefix,
+      IconButton? suffix,
+      bool isHidden = false,
+      int maxlines = 1,
+      Key? key,
+      String? Function(String?)? validator})
+      : _suffix = suffix,
+        _maxlines = maxlines,
+        _isHidden = isHidden,
+        _validator = validator,
+        super(key: key);
+
+  @override
+  _CustomTextFieldState createState() => _CustomTextFieldState();
+}
+
+class _CustomTextFieldState extends State<CustomTextField> {
+  @override
+  Widget build(BuildContext context) {
+    return TextFormField(
+      obscureText: widget._isHidden,
+      controller: widget.controller,
+      validator: widget._validator,
+      maxLines: widget._maxlines,
+      style: const TextStyle(fontSize: 18.0),
+      decoration: InputDecoration(
+          filled: true,
+          fillColor: Colors.grey[100],
+          focusColor: Colors.white,
+          labelText: widget.label,
+          hintText: widget.hint,
+          labelStyle: const TextStyle(
+            fontSize: 18.0,
+          ),
+          focusedBorder: const OutlineInputBorder(
+              borderRadius: BorderRadius.all(Radius.circular(10.0)),
+              borderSide: BorderSide(color: Colors.blue)),
+          border: const OutlineInputBorder(
+            borderRadius: BorderRadius.all(Radius.circular(10.0)),
+            borderSide: BorderSide(color: Colors.grey),
+          ),
+          prefixIcon: widget.prefix,
+          suffixIcon: widget._suffix),
+    );
+  }
+}

lib/ui/components/text_field/email_textfield.dart

@@ -0,0 +1,29 @@
+import 'package:borderhacks/ui/components/text_field/custom_textfield.dart';
+import 'package:flutter/material.dart';
+
+class EmailTextField extends StatelessWidget {
+  const EmailTextField(
+      {required TextEditingController emailController, Key? key})
+      : _emailController = emailController,
+        super(key: key);
+
+  final TextEditingController _emailController;
+
+  String? validateUsernameField(String? value) {
+    if (value!.isEmpty) {
+      return 'Required Field';
+    }
+    return null;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return CustomTextField(
+      controller: _emailController,
+      label: 'Username',
+      prefix: const Icon(Icons.person),
+      hint: 'Enter the Username',
+      validator: validateUsernameField,
+    );
+  }
+}

lib/ui/components/text_field/password_textfield.dart

@@ -0,0 +1,48 @@
+import 'package:borderhacks/ui/components/text_field/custom_textfield.dart';
+import 'package:flutter/material.dart';
+
+class PasswordTextField extends StatefulWidget {
+  const PasswordTextField({
+    required TextEditingController passwordController,
+    Key? key,
+  })  : _passwordController = passwordController,
+        super(key: key);
+
+  final TextEditingController _passwordController;
+
+  @override
+  _PasswordTextFieldState createState() => _PasswordTextFieldState();
+}
+
+class _PasswordTextFieldState extends State<PasswordTextField> {
+  bool _isHidden = true;
+
+  String? validatePasswordField(String? value) {
+    if (value!.isEmpty) {
+      return 'Required Field';
+    }
+    return null;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return CustomTextField(
+      controller: widget._passwordController,
+      label: 'Password',
+      prefix: const Icon(Icons.lock),
+      hint: 'Enter the Password',
+      validator: validatePasswordField,
+      isHidden: _isHidden,
+      suffix: IconButton(
+        icon: _isHidden
+            ? const Icon(Icons.visibility_off)
+            : const Icon(Icons.visibility),
+        onPressed: () {
+          setState(() {
+            _isHidden = !_isHidden;
+          });
+        },
+      ),
+    );
+  }
+}

lib/ui/constants/error_code.dart

@@ -0,0 +1,14 @@
+const signInErrorCodes = <String, String>{
+  'user-not-found': 'User not Found',
+  'wrong-password': 'Either eamil or password is wrong',
+};
+
+const signUpErrorCodes = <String, String>{
+  'weak-password': 'The password is too weak',
+  'email-already-in-use': 'An account already exists for this email',
+};
+
+const passwordResetErrorCodes = <String, String>{
+  'auth/invalid-email': 'Enter a valid email',
+  'auth/user-not-found': 'User not found',
+};