velocity-pay-flutter/lib/screens/onboarding/login/login_screen.dart

import 'dart:async';
import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:go_router/go_router.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:qpay/screens/onboarding/login/login_controller.dart';
import 'package:shared_preferences/shared_preferences.dart';

class LoginScreen extends StatefulWidget {
  const LoginScreen({super.key});

  @override
  State<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  late SharedPreferences prefs;
  final _formKey = GlobalKey<FormState>();
  bool _loading = false;

  List<String> scopes = <String>[
    'https://www.googleapis.com/auth/contacts.readonly',
  ];

  late LoginController _loginController;

  @override
  void initState() {
    super.initState();
    _loginController = LoginController(context);
  }

  Future<void> signInWithGoogle() async {
    final GoogleSignIn googleSignIn = GoogleSignIn.instance;

    unawaited(googleSignIn.initialize(serverClientId: dotenv.env['CLIENTID']));

    if (GoogleSignIn.instance.supportsAuthenticate()){

      unawaited(GoogleSignIn.instance.authenticate().then((value) async {
        print(value);

        saveUser(value);
        await _loginController.login(value.email, value.id);
        context.go('/');

        googleSignIn.authenticationEvents
            .listen(_handleAuthenticationEvent)
            .onError(_handleAuthenticationError);

      }));
    }
  }

  void saveUser(GoogleSignInAccount user) async {
    final Map<String, dynamic> data = <String, dynamic>{
      'displayName': user.displayName,
      'email': user.email,
      'id': user.id,
      'photoUrl': user.photoUrl,
    };

    prefs = await SharedPreferences.getInstance();
    if (prefs.getString("googleUser") == null) {
      prefs.setString("googleUser", jsonEncode(data));
    }
  }

  Future<void> _handleAuthenticationEvent(
      GoogleSignInAuthenticationEvent event,
      ) async {
    // #docregion CheckAuthorization
    final GoogleSignInAccount? user = // ...
    // #enddocregion CheckAuthorization
    switch (event) {
      GoogleSignInAuthenticationEventSignIn() => event.user,
      GoogleSignInAuthenticationEventSignOut() => null,
    };

    // Check for existing authorization.
    // #docregion CheckAuthorization
    final GoogleSignInClientAuthorization? authorization = await user
        ?.authorizationClient
        .authorizationForScopes(scopes);
    // #enddocregion CheckAuthorization
  }

  Future<void> _handleAuthenticationError(Object e) async {
    print(e.toString());
  }

  @override
  void dispose() {
    _loginController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SingleChildScrollView(
        child: Padding(
          padding: const EdgeInsets.all(25),
          child: Form(
            key: _formKey,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                SizedBox(height: 75),
                Text(
                  'Login',
                  style: TextStyle(
                    fontSize: 30,
                    fontWeight: FontWeight.bold,
                    color: Theme.of(context).colorScheme.primary,
                  ),
                ),
                SizedBox(height: 5),
                Text(
                  'Welcome back to Peak',
                  style: TextStyle(fontSize: 18),
                  textAlign: TextAlign.center,
                ),
                SizedBox(height: 40),
                Image.asset('assets/password.png', width: 300),
                Text(
                  'Tap on your preferred social media platform to get started',
                  style: TextStyle(fontSize: 18),
                  textAlign: TextAlign.center,
                ),
                // Username Field
                SizedBox(height: 20),
                // Forgot Password Link
                // Divider with "or" text
                Row(
                  children: [
                    Expanded(child: Divider(color: Colors.grey.shade300)),
                    Padding(
                      padding: EdgeInsets.symmetric(horizontal: 16),
                      child: Text(
                        'choose from the options below to continue',
                        style: TextStyle(
                          color: Colors.grey.shade600,
                          fontSize: 14,
                        ),
                        textAlign: TextAlign.center,
                      ),
                    ),
                    Expanded(child: Divider(color: Colors.grey.shade300)),
                  ],
                ),
                SizedBox(height: 30),
                // Social Login Buttons
                Row(
                  children: [
                    Expanded(
                      child: OutlinedButton.icon(
                        onPressed: () async {
                          await signInWithGoogle();

                        },
                        icon: Image.asset(
                          'assets/google.png',
                          width: 20,
                          height: 20,
                        ),
                        label: Text('Google', style: TextStyle(fontSize: 16)),
                        style: OutlinedButton.styleFrom(
                          padding: EdgeInsets.symmetric(vertical: 16),
                          side: BorderSide(color: Colors.grey.shade300),
                          shape: RoundedRectangleBorder(
                            borderRadius: BorderRadius.circular(12),
                          ),
                        ),
                      ),
                    ),
                  ],
                ),
                SizedBox(height: 40),
              ],
            ),
          ),
        ),
      ),
      bottomNavigationBar: SizedBox(
        height: 130,
        child: Column(
          children: [
            SizedBox(height: 5),
            TextButton(
              onPressed: () {
                context.go('/');
              },
              child: Text('Continue as guest?', style: TextStyle(fontSize: 14)),
            ),
          ],
        ),
      ),
    );
  }
}