import 'package:flutter/material.dart';
import '../utils/constants.dart';
import '../services/auth_service.dart';
import '../services/notification_service.dart';
import 'main_screen.dart';

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

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

class _LoginScreenState extends State<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();
  final _authService = AuthService();

  bool _isLoading = false;
  bool _obscurePassword = true;
  String? _errorMessage;

  @override
  void dispose() {
    _emailController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  Future<void> _handleLogin() async {
    if (!_formKey.currentState!.validate()) return;

    setState(() {
      _isLoading = true;
      _errorMessage = null;
    });

    try {
      final success = await _authService.login(
        _emailController.text.trim(),
        _passwordController.text,
      );

      if (success && mounted) {
        // Registra FCM token dopo login riuscito
        try {
          final fcmToken = await NotificationService().getFcmToken();
          if (fcmToken != null) {
            await _authService.saveFcmToken(fcmToken);
            print('✓ FCM token registrato dopo login');
          }
        } catch (e) {
          print('⚠️  Errore registrazione FCM token: $e');
          // Non blocchiamo il login se la registrazione token fallisce
        }

        Navigator.of(context).pushReplacement(
          MaterialPageRoute(builder: (context) => const MainScreen()),
        );
      } else {
        setState(() {
          _errorMessage = 'Email o password non corretti';
        });
      }
    } catch (e) {
      setState(() {
        _errorMessage = 'Errore durante il login';
      });
    } finally {
      if (mounted) {
        setState(() {
          _isLoading = false;
        });
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        decoration: const BoxDecoration(
          gradient: AppColors.primaryGradient,
        ),
        child: SafeArea(
          child: Center(
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(AppSizes.paddingL),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  _buildHeader(),
                  const SizedBox(height: 60),
                  _buildLoginCard(),
                  const SizedBox(height: AppSizes.paddingL),
                  _buildFooter(),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildHeader() {
    return Column(
      children: [
        Container(
          width: 120,
          height: 120,
          decoration: BoxDecoration(
            color: Colors.white,
            shape: BoxShape.circle,
            boxShadow: [
              BoxShadow(
                color: Colors.black.withOpacity(0.2),
                blurRadius: 20,
                offset: const Offset(0, 10),
              ),
            ],
          ),
          child: const Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(Icons.terrain, size: 50, color: AppColors.primary),
                SizedBox(height: 4),
                Text('ASE', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold, color: AppColors.primary)),
              ],
            ),
          ),
        ),
        const SizedBox(height: AppSizes.paddingL),
        const Text('ASE Monitor', style: TextStyle(fontSize: 32, fontWeight: FontWeight.bold, color: Colors.white)),
        const SizedBox(height: AppSizes.paddingS),
        Text('Advanced Slope Engineering', style: TextStyle(fontSize: 16, color: Colors.white.withOpacity(0.9))),
      ],
    );
  }

  Widget _buildLoginCard() {
    return Card(
      elevation: 8,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(AppSizes.radiusL)),
      child: Padding(
        padding: const EdgeInsets.all(AppSizes.paddingL),
        child: Form(
          key: _formKey,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              const Text('Accedi', style: TextStyle(fontSize: 24, fontWeight: FontWeight.bold), textAlign: TextAlign.center),
              const SizedBox(height: AppSizes.paddingL),
              TextFormField(
                controller: _emailController,
                keyboardType: TextInputType.emailAddress,
                decoration: const InputDecoration(labelText: 'Email', hintText: 'nome@azienda.it', prefixIcon: Icon(Icons.email_outlined)),
                validator: (value) {
                  if (value == null || value.isEmpty) return 'Inserisci email';
                  if (!value.contains('@')) return 'Email non valida';
                  return null;
                },
              ),
              const SizedBox(height: AppSizes.paddingM),
              TextFormField(
                controller: _passwordController,
                obscureText: _obscurePassword,
                decoration: InputDecoration(
                  labelText: 'Password',
                  prefixIcon: const Icon(Icons.lock_outline),
                  suffixIcon: IconButton(
                    icon: Icon(_obscurePassword ? Icons.visibility_outlined : Icons.visibility_off_outlined),
                    onPressed: () => setState(() => _obscurePassword = !_obscurePassword),
                  ),
                ),
                validator: (value) => (value == null || value.isEmpty) ? 'Inserisci password' : null,
                onFieldSubmitted: (_) => _handleLogin(),
              ),
              if (_errorMessage != null) ...[
                const SizedBox(height: AppSizes.paddingM),
                Container(
                  padding: const EdgeInsets.all(AppSizes.paddingM),
                  decoration: BoxDecoration(
                    color: AppColors.critical.withOpacity(0.1),
                    borderRadius: BorderRadius.circular(AppSizes.radiusS),
                  ),
                  child: Row(
                    children: [
                      const Icon(Icons.error_outline, color: AppColors.critical, size: 20),
                      const SizedBox(width: AppSizes.paddingS),
                      Expanded(child: Text(_errorMessage!, style: const TextStyle(color: AppColors.critical))),
                    ],
                  ),
                ),
              ],
              const SizedBox(height: AppSizes.paddingL),
              SizedBox(
                height: AppSizes.buttonHeight,
                child: ElevatedButton(
                  onPressed: _isLoading ? null : _handleLogin,
                  child: _isLoading
                      ? const SizedBox(width: 24, height: 24, child: CircularProgressIndicator(strokeWidth: 2, valueColor: AlwaysStoppedAnimation(Colors.white)))
                      : const Row(mainAxisAlignment: MainAxisAlignment.center, children: [Icon(Icons.login), SizedBox(width: 8), Text('Accedi')]),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildFooter() {
    return Column(
      children: [
        Text('Versione ${AppConstants.appVersion}', style: TextStyle(color: Colors.white.withOpacity(0.7), fontSize: 12)),
        const SizedBox(height: 4),
        Text('© 2025 ${AppConstants.companyName}', style: TextStyle(color: Colors.white.withOpacity(0.7), fontSize: 12), textAlign: TextAlign.center),
      ],
    );
  }
}