import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart' show defaultTargetPlatform, kIsWeb;
import 'package:shared_preferences/shared_preferences.dart';
import '../services/api_service.dart';
import '../entities/auth_token.dart';
import 'dashboard_page.dart';

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

  @override
  State<LoginPage> createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();
  bool _loading = false;
  bool _rememberMe = false;
  String? _error;

  bool get isMobile {
    final platform = defaultTargetPlatform;
    return platform == TargetPlatform.android ||
        platform == TargetPlatform.iOS ||
        (kIsWeb && MediaQuery.of(context).size.width < 600);
  }

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

  Future<void> _checkRememberedUser() async {
    final prefs = await SharedPreferences.getInstance();
    final token = prefs.getString('token');
    if (token != null && prefs.getBool('rememberMe') == true) {
      AuthToken.instance.saveToken(token);
      if (mounted) {
        Navigator.pushReplacement(
          context,
          MaterialPageRoute(builder: (_) => const DashboardPage()),
        );
      }
    }
  }

  Future<void> _login() async {
    setState(() {
      _loading = true;
      _error = null;
    });

    try {
      final token = await ApiService.login(
        _emailController.text.trim(),
        _passwordController.text,
      );
      await AuthToken.instance.saveToken(token);
      final prefs = await SharedPreferences.getInstance();
      if (_rememberMe) {
        await prefs.setString('token', token);
        await prefs.setBool('rememberMe', true);
      } else {
        await prefs.remove('token');
        await prefs.setBool('rememberMe', false);
      }

      if (!mounted) return;
      Navigator.pushReplacement(
        context,
        MaterialPageRoute(builder: (_) => const DashboardPage()),
      );
    } catch (e) {
      setState(() {
        _error = e.toString();
        _loading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final content = Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        const Icon(Icons.eco, size: 64, color: Color(0xFF388E3C)),
        const SizedBox(height: 12),
        const Text(
          'Gestione Vigna',
          style: TextStyle(
              fontSize: 26,
              fontWeight: FontWeight.bold,
              color: Color(0xFF2E7D32)),
        ),
        const SizedBox(height: 24),
        TextField(
          controller: _emailController,
          decoration: const InputDecoration(
            labelText: 'Email o Username',
            border: OutlineInputBorder(),
            prefixIcon: Icon(Icons.person),
          ),
        ),
        const SizedBox(height: 16),
        TextField(
          controller: _passwordController,
          obscureText: true,
          decoration: const InputDecoration(
            labelText: 'Password',
            border: OutlineInputBorder(),
            prefixIcon: Icon(Icons.lock),
          ),
        ),
        const SizedBox(height: 12),
        Row(
          children: [
            Checkbox(
              value: _rememberMe,
              activeColor: const Color(0xFF43A047),
              onChanged: (value) {
                setState(() {
                  _rememberMe = value ?? false;
                });
              },
            ),
            const Text("Ricorda accesso"),
          ],
        ),
        if (_error != null)
          Text(
            _error!,
            style: const TextStyle(color: Colors.red),
          ),
        const SizedBox(height: 10),
        _loading
            ? const CircularProgressIndicator()
            : SizedBox(
                width: double.infinity,
                child: ElevatedButton.icon(
                  icon: const Icon(Icons.login),
                  style: ElevatedButton.styleFrom(
                    backgroundColor: const Color(0xFF43A047),
                    padding: const EdgeInsets.symmetric(vertical: 14),
                    shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(8)),
                  ),
                  label: const Text('Login', style: TextStyle(fontSize: 18)),
                  onPressed: _login,
                ),
              ),
      ],
    );

    return Scaffold(
      backgroundColor: Colors.white,
      body: LayoutBuilder(
        builder: (context, constraints) {
          return Center(
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(24),
              child: ConstrainedBox(
                constraints: BoxConstraints(
                  maxWidth: isMobile ? double.infinity : 400,
                ),
                child: Card(
                  elevation: isMobile ? 0 : 8,
                  shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(16)),
                  child: Padding(
                    padding: const EdgeInsets.symmetric(
                        horizontal: 24, vertical: 32),
                    child: content,
                  ),
                ),
              ),
            ),
          );
        },
      ),
    );
  }
}