import 'dart:io';
import 'package:device_info_plus/device_info_plus.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/constants/app_theme.dart';
import '../../core/providers.dart';

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

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

class _LoginScreenState extends ConsumerState<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _serverUrlController = TextEditingController();
  final _usernameController = TextEditingController();
  final _passwordController = TextEditingController();
  final _deviceNameController = TextEditingController();
  bool _obscurePassword = true;

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

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

  Future<void> _initDeviceNameAndCachedUrl() async {
    // 1. Pre-fill cached server URL if previously entered
    final cachedUrl = await ref.read(secureStorageProvider).getServerUrl();
    if (cachedUrl != null && cachedUrl.isNotEmpty) {
      _serverUrlController.text = cachedUrl;
    }

    // 2. Auto-detect device model for friendly identification in ForkFolio settings
    String defaultName = 'Mobile App';
    try {
      final deviceInfo = DeviceInfoPlugin();
      if (Platform.isAndroid) {
        final androidInfo = await deviceInfo.androidInfo;
        defaultName = '${androidInfo.manufacturer} ${androidInfo.model}'.trim();
      } else if (Platform.isIOS) {
        final iosInfo = await deviceInfo.iosInfo;
        defaultName = iosInfo.utsname.machine;
      }
    } catch (_) {}

    _deviceNameController.text = defaultName;
  }

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

    final success = await ref.read(authProvider.notifier).login(
          serverUrl: _serverUrlController.text.trim(),
          username: _usernameController.text.trim(),
          password: _passwordController.text,
          deviceName: _deviceNameController.text.trim(),
        );

    if (!success && mounted) {
      final error = ref.read(authProvider).errorMessage ?? 'Login failed';
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(backgroundColor: AppTheme.danger, content: Text(error)),
      );
    }
  }

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

    return Scaffold(
      body: SafeArea(
        child: Center(
          child: SingleChildScrollView(
            padding: const EdgeInsets.symmetric(horizontal: 28, vertical: 24),
            child: Form(
              key: _formKey,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  // App Logo & Heading
                  Center(
                    child: Container(
                      padding: const EdgeInsets.all(18),
                      decoration: BoxDecoration(
                        color: AppTheme.primary.withOpacity(0.12),
                        shape: BoxShape.circle,
                        border: Border.all(color: AppTheme.primary.withOpacity(0.3), width: 1.5),
                      ),
                      child: const Icon(Icons.restaurant_menu_rounded, size: 48, color: AppTheme.primary),
                    ),
                  ),
                  const SizedBox(height: 20),
                  const Text(
                    'ForkFolio Mobile',
                    textAlign: TextAlign.center,
                    style: TextStyle(fontSize: 26, fontWeight: FontWeight.w800, letterSpacing: -0.5),
                  ),
                  const SizedBox(height: 6),
                  const Text(
                    'Connect your mobile chef companion',
                    textAlign: TextAlign.center,
                    style: TextStyle(fontSize: 14, color: AppTheme.textMuted),
                  ),
                  const SizedBox(height: 36),

                  // Server URL Field
                  TextFormField(
                    controller: _serverUrlController,
                    keyboardType: TextInputType.url,
                    decoration: const InputDecoration(
                      labelText: 'Server Domain (HTTPS)',
                      hintText: 'https://recipes.yourdomain.com',
                      prefixIcon: Icon(Icons.dns_rounded, size: 20),
                    ),
                    validator: (v) {
                      if (v == null || v.trim().isEmpty) return 'Server URL is required';
                      if (!v.trim().startsWith('http://') && !v.trim().startsWith('https://')) {
                        return 'Include https:// at the beginning';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 16),

                  // Username Field
                  TextFormField(
                    controller: _usernameController,
                    decoration: const InputDecoration(
                      labelText: 'Username',
                      prefixIcon: Icon(Icons.person_outline_rounded, size: 20),
                    ),
                    validator: (v) => (v == null || v.trim().isEmpty) ? 'Username is required' : null,
                  ),
                  const SizedBox(height: 16),

                  // Password Field
                  TextFormField(
                    controller: _passwordController,
                    obscureText: _obscurePassword,
                    decoration: InputDecoration(
                      labelText: 'Password',
                      prefixIcon: const Icon(Icons.lock_outline_rounded, size: 20),
                      suffixIcon: IconButton(
                        icon: Icon(_obscurePassword ? Icons.visibility_outlined : Icons.visibility_off_outlined, size: 20),
                        onPressed: () => setState(() => _obscurePassword = !_obscurePassword),
                      ),
                    ),
                    validator: (v) => (v == null || v.isEmpty) ? 'Password is required' : null,
                  ),
                  const SizedBox(height: 16),

                  // Device Name Field
                  TextFormField(
                    controller: _deviceNameController,
                    decoration: const InputDecoration(
                      labelText: 'Device Friendly Name',
                      hintText: 'e.g. Pixel 8 Pro',
                      prefixIcon: Icon(Icons.smartphone_rounded, size: 20),
                    ),
                    validator: (v) => (v == null || v.trim().isEmpty) ? 'Device name is required' : null,
                  ),
                  const SizedBox(height: 28),

                  // Submit Button
                  SizedBox(
                    height: 52,
                    child: ElevatedButton(
                      onPressed: authState.isLoading ? null : _submit,
                      child: authState.isLoading
                          ? const SizedBox(
                              width: 22,
                              height: 22,
                              child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2.5),
                            )
                          : const Text('Authorize & Link Device'),
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}