import 'package:flutter/material.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:provider/provider.dart';
import 'package:login_vault_app/auth_service.dart';
import 'package:login_vault_app/dashboard_screen.dart';
import 'package:login_vault_app/theme_provider.dart';

/// First-launch screen: register with email+password, or with Google.
class AuthScreen extends StatefulWidget {
  final AuthService auth;
  const AuthScreen({super.key, required this.auth});

  @override
  State<AuthScreen> createState() => _AuthScreenState();
}

class _AuthScreenState extends State<AuthScreen> {
  final _emailCtrl = TextEditingController();
  final _passCtrl = TextEditingController();
  bool _isLogin = true; // toggle register/login
  bool _busy = false;
  String? _error;

  void _goToDashboard(String email) {
    if (!mounted) return;
    Navigator.of(context).pushReplacement(
      MaterialPageRoute(
        builder: (_) => DashboardScreen(
          auth: widget.auth,
          theme: Provider.of<ThemeProvider>(context, listen: false),
          email: email,
        ),
      ),
    );
  }

  Future<void> _submitEmail() async {
    setState(() => _busy = true);
    final email = _emailCtrl.text.trim();
    final pass = _passCtrl.text;
    if (email.isEmpty || pass.isEmpty) {
      setState(() => _error = 'Email & password wajib diisi');
      _busy = false;
      return;
    }
    try {
      if (_isLogin) {
        final stored = await widget.auth.getAppPassword();
        final ok = await widget.auth.verifyPassword(pass);
        if (stored == null) {
          setState(() => _error = 'Belum terdaftar, silakan registrasi');
        } else if (!ok) {
          setState(() => _error = 'Password aplikasi salah');
        } else {
          _goToDashboard(email);
        }
      } else {
        await widget.auth.registerWithEmail(email, pass);
        _goToDashboard(email);
      }
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  Future<void> _signInGoogle() async {
    setState(() => _busy = true);
    try {
      final gs = GoogleSignIn(scopes: ['email']);
      final account = await gs.signIn();
      if (account?.email != null) {
        await widget.auth.registerWithGoogle(account!.email);
        _goToDashboard(account.email);
      } else {
        setState(() => _error = 'Google sign-in dibatalkan');
      }
    } catch (e) {
      setState(() => _error = 'Google sign-in gagal: ${e.toString()}');
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Login Vault')),
      body: Padding(
        padding: const EdgeInsets.all(24),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(_isLogin ? 'Masuk' : 'Daftar',
                style: Theme.of(context).textTheme.headlineSmall),
            const SizedBox(height: 16),
            TextField(
              controller: _emailCtrl,
              keyboardType: TextInputType.emailAddress,
              decoration: const InputDecoration(
                  labelText: 'Email', border: OutlineInputBorder()),
            ),
            const SizedBox(height: 12),
            TextField(
              controller: _passCtrl,
              obscureText: true,
              decoration: const InputDecoration(
                  labelText: 'Password aplikasi', border: OutlineInputBorder()),
            ),
            const SizedBox(height: 8),
            if (_error != null)
              Text(_error!, style: const TextStyle(color: Colors.red)),
            const SizedBox(height: 12),
            _busy
                ? const CircularProgressIndicator()
                : Column(
                    children: [
                      ElevatedButton(
                        onPressed: _submitEmail,
                        child: Text(_isLogin ? 'Masuk' : 'Daftar'),
                      ),
                      TextButton(
                        onPressed: () =>
                            setState(() => _isLogin = !_isLogin),
                        child: Text(_isLogin
                            ? 'Belum punya akun? Daftar'
                            : 'Sudah punya akun? Masuk'),
                      ),
                      const Divider(),
                      OutlinedButton.icon(
                        onPressed: _signInGoogle,
                        icon: const Icon(Icons.login),
                        label: const Text('Lanjut dengan Google'),
                      ),
                    ],
                  ),
          ],
        ),
      ),
    );
  }
}