import 'package:flutter/material.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../widgets/input_field.dart';
import 'home_screen.dart';
import 'register_screen.dart';

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

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

class _LoginScreenState extends State<LoginScreen> {
  final usernameController = TextEditingController();
  final passwordController = TextEditingController();
  bool rememberMe = false;

  final GoogleSignIn _googleSignIn = GoogleSignIn(
    clientId: 'YOUR_WEB_CLIENT_ID_HERE',
    scopes: ['email'],
  );

  @override
  void initState() {
    super.initState();
    _checkAutoLogin();
  }

  Future<void> _checkAutoLogin() async {
    final prefs = await SharedPreferences.getInstance();
    final isRemembered = prefs.getBool('rememberMe') ?? false;
    final googleUser = prefs.getString('googleUser');

    if (isRemembered) {
      final savedUsername = prefs.getString('loginUsername') ?? prefs.getString('username');
      final savedPassword = prefs.getString('password');
      if (savedUsername != null && savedPassword != null) {
        usernameController.text = savedUsername;
        passwordController.text = savedPassword;
        setState(() => rememberMe = true);
      }
    } else if (googleUser != null) {
      Navigator.pushReplacement(
        context,
        MaterialPageRoute(builder: (context) => const HomeScreen()),
      );
    }
  }

  Future<void> _saveLoginDetails(String username, String password) async {
  final prefs = await SharedPreferences.getInstance();
  await prefs.setString('loginUsername', username); // Ensures login uses latest username
  await prefs.setString('password', password);

  if (rememberMe) {
    await prefs.setBool('rememberMe', true);
  } else {
    await prefs.remove('rememberMe');
  }
}


  void login() async {
  String username = usernameController.text.trim();
  String password = passwordController.text.trim();

  final prefs = await SharedPreferences.getInstance();
  String? savedUsername = prefs.getString('loginUsername') ?? prefs.getString('username'); // Get the latest username
  String? savedPassword = prefs.getString('password'); // Get the saved password

  if (savedUsername == username && savedPassword == password) {
    await _saveLoginDetails(username, password);
    Navigator.pushReplacement(
      context,
      MaterialPageRoute(builder: (context) => const HomeScreen()),
    );
  } else {
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('Invalid username or password')),
    );
  }
}


  Future<void> googleLogin() async {
    try {
      final GoogleSignInAccount? googleUser = await _googleSignIn.signIn();
      if (googleUser != null) {
        final prefs = await SharedPreferences.getInstance();
        await prefs.setString('googleUser', googleUser.displayName ?? 'Google User');
        await prefs.setString('googleEmail', googleUser.email);

        Navigator.pushReplacement(
          context,
          MaterialPageRoute(builder: (context) => const HomeScreen()),
        );
      }
    } catch (error) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Google Sign-In Failed: $error')),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      body: Center(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Image.asset(
                'assets/logo.png',
                width: 1000,
                height: 150,
              ),
              const SizedBox(height: 40),
              InputField(
                hintText: 'Username',
                icon: Icons.person,
                controller: usernameController,
              ),
              const SizedBox(height: 16),
              InputField(
                hintText: 'Password',
                icon: Icons.lock,
                obscureText: true,
                controller: passwordController,
              ),
              const SizedBox(height: 16),

              /// Remember Me Checkbox - Centered
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Checkbox(
                    value: rememberMe,
                    onChanged: (value) {
                      setState(() {
                        rememberMe = value ?? false;
                      });
                    },
                    activeColor: Colors.grey[800],
                  ),
                  const Text(
                    'Remember Me',
                    style: TextStyle(
                      color: Colors.black87,
                      fontSize: 16,
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 24),

              /// Login Button
              ElevatedButton(
                style: ElevatedButton.styleFrom(
                  backgroundColor: Colors.grey[800],
                  foregroundColor: Colors.white,
                  minimumSize: const Size.fromHeight(50),
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8),
                  ),
                ),
                onPressed: login,
                child: const Text('Login', style: TextStyle(fontSize: 18)),
              ),
              const SizedBox(height: 16),

              /// Horizontal Line with "or"
              Row(
                children: const [
                  Expanded(
                    child: Divider(color: Colors.grey, thickness: 1),
                  ),
                  Padding(
                    padding: EdgeInsets.symmetric(horizontal: 8),
                    child: Text("or", style: TextStyle(color: Colors.grey, fontSize: 16)),
                  ),
                  Expanded(
                    child: Divider(color: Colors.grey, thickness: 1),
                  ),
                ],
              ),
              const SizedBox(height: 16),

              /// Google Sign-In Button (Styled same as Login)
              ElevatedButton.icon(
                style: ElevatedButton.styleFrom(
                  backgroundColor: Colors.grey[800], // Match Login Button
                  foregroundColor: Colors.white,
                  minimumSize: const Size.fromHeight(50),
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8),
                  ),
                ),
                onPressed: googleLogin,
                icon: const Icon(Icons.g_mobiledata, size: 30), // Google Icon
                label: const Text('Sign in with Google', style: TextStyle(fontSize: 18)),
              ),
              const SizedBox(height: 20),

              /// Register Text (Styled in Blue)
              GestureDetector(
                onTap: () {
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => const RegisterScreen()),
                  );
                },
                child: const Text(
                  "Don't have an account? Register",
                  style: TextStyle(
                    fontSize: 16,
                    fontWeight: FontWeight.w500,
                    color: Colors.grey, // Better visibility
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}