import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../core/auth/auth_provider.dart';
import '../../core/theme/app_colors.dart';

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

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

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

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

  @override
  Widget build(BuildContext context) {
    final authState = ref.watch(authProvider);

    ref.listen<AuthState>(authProvider, (previous, next) {
      if (next.status == AuthStatus.authenticated) {
        context.go('/home');
      }
      if (next.error != null) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(next.error!),
            backgroundColor: AppColors.error,
          ),
        );
      }
    });

    return Scaffold(
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24),
          child: Form(
            key: _formKey,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                const SizedBox(height: 60),
                Icon(
                  Icons.restaurant_menu,
                  size: 80,
                  color: AppColors.primary,
                ),
                const SizedBox(height: 16),
                Text(
                  'FoodAI',
                  textAlign: TextAlign.center,
                  style: Theme.of(context).textTheme.headlineLarge?.copyWith(
                        fontWeight: FontWeight.bold,
                        color: AppColors.primary,
                      ),
                ),
                const SizedBox(height: 8),
                Text(
                  'Управляйте питанием\nс помощью AI',
                  textAlign: TextAlign.center,
                  style: Theme.of(context).textTheme.bodyLarge?.copyWith(
                        color: AppColors.textSecondary,
                      ),
                ),
                const SizedBox(height: 48),
                TextFormField(
                  controller: _emailController,
                  keyboardType: TextInputType.emailAddress,
                  decoration: const InputDecoration(
                    labelText: 'Email',
                    prefixIcon: Icon(Icons.email_outlined),
                  ),
                  validator: (value) {
                    if (value == null || value.isEmpty) {
                      return 'Введите email';
                    }
                    if (!RegExp(r'^[^@]+@[^@]+\.[^@]+').hasMatch(value)) {
                      return 'Некорректный email';
                    }
                    return null;
                  },
                ),
                const SizedBox(height: 16),
                TextFormField(
                  controller: _passwordController,
                  obscureText: true,
                  decoration: const InputDecoration(
                    labelText: 'Пароль',
                    prefixIcon: Icon(Icons.lock_outlined),
                  ),
                  validator: (value) {
                    if (value == null || value.isEmpty) {
                      return 'Введите пароль';
                    }
                    if (value.length < 6) {
                      return 'Минимум 6 символов';
                    }
                    return null;
                  },
                ),
                const SizedBox(height: 24),
                ElevatedButton(
                  onPressed: authState.isLoading ? null : _signInWithEmail,
                  child: authState.isLoading
                      ? const SizedBox(
                          height: 20,
                          width: 20,
                          child: CircularProgressIndicator(strokeWidth: 2),
                        )
                      : const Text('Войти'),
                ),
                const SizedBox(height: 24),
                Row(
                  children: [
                    const Expanded(child: Divider()),
                    Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 16),
                      child: Text(
                        'или',
                        style: TextStyle(color: AppColors.textSecondary),
                      ),
                    ),
                    const Expanded(child: Divider()),
                  ],
                ),
                const SizedBox(height: 24),
                OutlinedButton.icon(
                  onPressed: authState.isLoading ? null : _signInWithGoogle,
                  icon: const Text('G',
                      style: TextStyle(
                          fontSize: 18, fontWeight: FontWeight.bold)),
                  label: const Text('Войти через Google'),
                  style: OutlinedButton.styleFrom(
                    minimumSize: const Size(double.infinity, 48),
                    shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(12)),
                  ),
                ),
                if (defaultTargetPlatform == TargetPlatform.iOS) ...[
                  const SizedBox(height: 12),
                  OutlinedButton.icon(
                    onPressed: authState.isLoading ? null : () {},
                    icon: const Icon(Icons.apple, size: 24),
                    label: const Text('Войти через Apple'),
                    style: OutlinedButton.styleFrom(
                      minimumSize: const Size(double.infinity, 48),
                      shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(12)),
                    ),
                  ),
                ],
                const SizedBox(height: 24),
                TextButton(
                  onPressed: () => context.go('/auth/register'),
                  child: const Text('Нет аккаунта? Регистрация'),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  void _signInWithEmail() {
    if (_formKey.currentState!.validate()) {
      ref.read(authProvider.notifier).signInWithEmail(
            _emailController.text.trim(),
            _passwordController.text,
          );
    }
  }

  void _signInWithGoogle() {
    ref.read(authProvider.notifier).signInWithGoogle();
  }
}