import 'dart:ui';
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';
import '/core/theme_manager.dart';
import 'dart:io'; // Import for File

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

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

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

  late AnimationController _animationController;
  late Animation<double> _fadeAnimation;
  late Animation<Offset> _slideAnimation;

  
  void initState() {
    super.initState();
    _animationController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 900),
    );

    _fadeAnimation =
        Tween<double>(begin: 0.0, end: 1.0).animate(CurvedAnimation(
      parent: _animationController,
      curve: Curves.easeIn,
    ));

    _slideAnimation =
        Tween<Offset>(begin: const Offset(0, 0.3), end: Offset.zero).animate(
            CurvedAnimation(
      parent: _animationController,
      curve: Curves.fastOutSlowIn,
    ));

    _animationController.forward();
  }

  
  Widget build(BuildContext context) {
    final authProvider = context.watch<AuthProvider>();
    final themeProv = context.watch<ThemeProvider>();
    final colorScheme = Theme.of(context).colorScheme;

    return Scaffold(
      body: Stack(
        children: [
          // Background Wallpaper
          if (themeProv.wallpaperPath != null)
            Container(
              decoration: BoxDecoration(
                image: DecorationImage(
                  image: FileImage(File(themeProv.wallpaperPath!)),
                  fit: BoxFit.cover,
                ),
              ),
            ),
          // Blur Overlay
          if (themeProv.wallpaperPath != null)
            BackdropFilter(
              filter: ImageFilter.blur(sigmaX: 15, sigmaY: 15),
              child: Container(
                color: Colors.black.withOpacity(0.1),
              ),
            ),

          Center(
            child: SingleChildScrollView(
              padding: const EdgeInsets.all(24.0),
              child: Form(
                key: _formKey,
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    SlideTransition(
                      position: _slideAnimation,
                      child: FadeTransition(
                        opacity: _fadeAnimation,
                        child: Column(
                          children: [
                            Icon(
                              Icons.messenger_outline,
                              size: 80,
                              color: colorScheme.primary,
                            ),
                            const SizedBox(height: 16),
                            Text(
                              "Чепухаграм",
                              textAlign: TextAlign.center,
                              style: TextStyle(
                                fontSize: 28,
                                fontWeight: FontWeight.bold,
                                color: colorScheme.primary,
                              ),
                            ),
                          ],
                        ),
                      ),
                    ),
                    const SizedBox(height: 48),

                    // Поле Логин
                    _buildTextField(
                      controller: _usernameController,
                      label: "Логин",
                      icon: Icons.person_outline,
                      validator: (value) =>
                          value!.isEmpty ? "Введите логин" : null,
                    ),
                    const SizedBox(height: 16),

                    // Поле Пароль
                    _buildTextField(
                      controller: _passwordController,
                      label: "Пароль",
                      icon: Icons.lock_outline,
                      obscureText: true,
                      validator: (value) =>
                          value!.length < 6 ? "Минимум 6 символов" : null,
                    ),
                    const SizedBox(height: 16),

                    // Поле TOTP, если требуется
                    if (_showTotpField)
                      _buildTextField(
                        controller: _totpController,
                        label: "TOTP код",
                        icon: Icons.security,
                        validator: (value) =>
                            value!.isEmpty ? "Введите TOTP код" : null,
                      ),
                    if (_showTotpField) const SizedBox(height: 16),

                    // Сообщение об ошибке
                    if (_errorMessage != null)
                      Container(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 16, vertical: 10),
                        decoration: BoxDecoration(
                          color: colorScheme.errorContainer.withOpacity(0.3),
                          borderRadius: BorderRadius.circular(12),
                        ),
                        child: Text(
                          _errorMessage!,
                          style: TextStyle(
                              color: colorScheme.onErrorContainer,
                              fontWeight: FontWeight.w500),
                          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: 18),
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(16),
                        ),
                        backgroundColor: colorScheme.primary,
                        foregroundColor: colorScheme.onPrimary,
                      ),
                      child: authProvider.isLoading
                          ? const SizedBox(
                              height: 20,
                              width: 20,
                              child:
                                  CircularProgressIndicator(strokeWidth: 2, color: Colors.white),
                            )
                          : const Text("Войти",
                              style: TextStyle(
                                  fontSize: 16, fontWeight: FontWeight.bold)),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildTextField({
    required TextEditingController controller,
    required String label,
    required IconData icon,
    bool obscureText = false,
    String? Function(String?)? validator,
  }) {
    final colorScheme = Theme.of(context).colorScheme;

    return ClipRRect(
      borderRadius: BorderRadius.circular(16),
      child: BackdropFilter(
        filter: ImageFilter.blur(sigmaX: 5, sigmaY: 5),
        child: Container(
          decoration: BoxDecoration(
            color: colorScheme.surfaceVariant.withOpacity(0.35),
            borderRadius: BorderRadius.circular(16),
            border: Border.all(
              color: colorScheme.outlineVariant.withOpacity(0.15),
              width: 1,
            ),
          ),
          child: TextFormField(
            controller: controller,
            obscureText: obscureText,
            validator: validator,
            decoration: InputDecoration(
              labelText: label,
              labelStyle: TextStyle(color: colorScheme.outline),
              prefixIcon: Icon(icon, color: colorScheme.outline),
              border: InputBorder.none,
              contentPadding:
                  const EdgeInsets.symmetric(horizontal: 20, vertical: 5),
            ),
          ),
        ),
      ),
    );
  }

  void _submit() async {
    // Сначала убираем фокус с полей, чтобы клавиатура скрылась
    FocusScope.of(context).unfocus();
    await Future.delayed(const Duration(milliseconds: 200));

    if (!_formKey.currentState!.validate()) return;

    try {
      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 (mounted) {
        setState(() {
          _errorMessage = error;
          if (error.contains('TOTP код требуется')) {
            _showTotpField = true;
          }
        });
      }
    }
  }

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