import 'package:chepuhagram/presentation/screens/contacts_screen.dart';
import 'package:chepuhagram/presentation/screens/account_setup_screen.dart';
import 'package:chepuhagram/presentation/screens/key_recovery_screen.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../../logic/auth_provider.dart';

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

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

class _LoginScreenState extends State<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _usernameController = TextEditingController();
  final _passwordController = TextEditingController();
  final _totpController = TextEditingController();
  bool _showTotpField = false;
  String? _errorMessage;

  @override
  Widget build(BuildContext context) {
    final authProvider = context.watch<AuthProvider>();

    return Scaffold(
      body: Center(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24.0),
          child: Form(
            key: _formKey,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                // Иконка
                Icon(
                  Icons.messenger_outline,
                  size: 80,
                  color: Theme.of(context).colorScheme.primary,
                ),
                const SizedBox(height: 16),
                Text(
                  "Чепухаграм",
                  textAlign: TextAlign.center,
                  style: TextStyle(
                    fontSize: 28,
                    fontWeight: FontWeight.bold,
                    color: Theme.of(context).colorScheme.primary,
                  ),
                ),
                const SizedBox(height: 32),

                // Поле Логин
                TextFormField(
                  controller: _usernameController,
                  decoration: InputDecoration(
                    labelText: "Логин",
                    prefixIcon: const Icon(Icons.person_outline),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                    fillColor: Theme.of(context).colorScheme.primary,
                    iconColor: Theme.of(context).colorScheme.primary,
                    hoverColor: Theme.of(context).colorScheme.primary,
                    focusColor: Theme.of(context).colorScheme.primary,
                  ),
                  validator: (value) => value!.isEmpty ? "Введите логин" : null,
                ),
                const SizedBox(height: 16),

                // Поле Пароль
                TextFormField(
                  controller: _passwordController,
                  obscureText: true,
                  decoration: InputDecoration(
                    labelText: "Пароль",
                    prefixIcon: const Icon(Icons.lock_outline),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                    fillColor: Theme.of(context).colorScheme.primary,
                    iconColor: Theme.of(context).colorScheme.primary,
                    hoverColor: Theme.of(context).colorScheme.primary,
                    focusColor: Theme.of(context).colorScheme.primary,
                  ),
                  validator: (value) =>
                      value!.length < 6 ? "Минимум 6 символов" : null,
                ),
                const SizedBox(height: 16),

                // Поле TOTP, если требуется
                if (_showTotpField)
                  TextFormField(
                    controller: _totpController,
                    decoration: InputDecoration(
                      labelText: "TOTP код",
                      prefixIcon: const Icon(Icons.security),
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(12),
                      ),
                      fillColor: Theme.of(context).colorScheme.primary,
                      iconColor: Theme.of(context).colorScheme.primary,
                      hoverColor: Theme.of(context).colorScheme.primary,
                      focusColor: Theme.of(context).colorScheme.primary,
                    ),
                    validator: (value) => value!.isEmpty ? "Введите TOTP код" : null,
                  ),
                if (_showTotpField) const SizedBox(height: 16),

                // Сообщение об ошибке
                if (_errorMessage != null)
                  Text(
                    _errorMessage!,
                    style: TextStyle(color: Theme.of(context).colorScheme.error),
                    textAlign: TextAlign.center,
                  ),
                if (_errorMessage != null) const SizedBox(height: 16),

                const SizedBox(height: 24),

                // Кнопка Входа
                ElevatedButton(
                  onPressed: authProvider.isLoading ? null : _submit,
                  style: ElevatedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(vertical: 16),
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                  ),
                  child: authProvider.isLoading
                      ? const SizedBox(
                          height: 20,
                          width: 20,
                          child: CircularProgressIndicator(strokeWidth: 2),
                        )
                      : const Text("Войти", style: TextStyle(fontSize: 16)),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  void _submit() async {
    try {
      if (!_formKey.currentState!.validate()) return;

      final authProvider = context.read<AuthProvider>();
      final success = await authProvider.login(
        _usernameController.text,
        _passwordController.text,
        totpCode: _showTotpField ? _totpController.text : null,
      );
      if (success && mounted) {
        await authProvider.initRealtime();
        
        // Определяем путь пользователя после входа
        if (authProvider.needsSetup) {
          // Путь А: Первичная настройка
          Navigator.pushReplacement(
            context,
            MaterialPageRoute(builder: (_) => const AccountSetupScreen()),
          );
        } else if (authProvider.needsKeyRecovery) {
          // Путь В: Восстановление ключей
          Navigator.pushReplacement(
            context,
            MaterialPageRoute(builder: (_) => const KeyRecoveryScreen()),
          );
        } else {
          // Путь Б: Нормальный вход
          Navigator.pushReplacement(
            context,
            MaterialPageRoute(builder: (_) => const ContactsScreen()),
          );
        }
      }
    } catch (e) {
      final error = e.toString().replaceAll('Exception: ', '');
      if (error.contains('TOTP код требуется')) {
        setState(() {
          _showTotpField = true;
          _errorMessage = error;
        });
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text(error)),
        );
      }
    }
  }

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