import 'dart:convert';
import 'dart:io' show Platform;

import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import 'package:workmanager/workmanager.dart';
import 'package:flutter_local_notifications/flutter_local_notifications.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:developer' as dev;

const _channelId = 'alert_channel';
const _channelName = 'Alerty';
const _channelDescription = 'Alerty z API (lodówka Ubibot)';
const String NOTIFS_ENABLED_KEY = 'NOTIFICATIONS_ENABLED';

final _notifs = FlutterLocalNotificationsPlugin();

Future<void> _ensureNotificationChannel() async {
  final android = _notifs.resolvePlatformSpecificImplementation<
      AndroidFlutterLocalNotificationsPlugin>();
  await android?.createNotificationChannel(
    const AndroidNotificationChannel(
      _channelId,
      _channelName,
      description: _channelDescription,
      importance: Importance.max,
    ),
  );
}

NotificationDetails get _alertDetails => const NotificationDetails(
  android: AndroidNotificationDetails(
    _channelId,
    _channelName,
    channelDescription: _channelDescription,
    importance: Importance.max,
    priority: Priority.high,
  ),
);

Future<http.Response?> _safeGet(String url) async {
  try {
    return await http.get(Uri.parse(url)).timeout(const Duration(seconds: 30));
  } catch (_) {
    try {
      return await http.get(Uri.parse(url)).timeout(const Duration(seconds: 30));
    } catch (e) {
      return null;
    }
  }
}

@pragma('vm:entry-point')
void callbackDispatcher() {
  WidgetsFlutterBinding.ensureInitialized();
  Workmanager().executeTask((taskName, _inputData) async {
    const initAndroid = AndroidInitializationSettings('@mipmap/ic_launcher');
    await _notifs.initialize(
      const InitializationSettings(android: initAndroid),
    );

    await _ensureNotificationChannel();

    final prefs = await SharedPreferences.getInstance();
    final notificationsEnabled = prefs.getBool(NOTIFS_ENABLED_KEY) ?? true;
    if (!notificationsEnabled) return true;

    try {
      final url = prefs.getString('APIURL') ?? '';
      final threshold = prefs.getDouble('TEMP_THRESHOLD') ?? 5.0;

      final response = await _safeGet(url);

      if (response == null) {
        throw Exception("Brak odpowiedzi z API (nawet po ponowieniu).");
      }

      if (response.statusCode == 200) {
        final data = json.decode(response.body);
        final field8 = data['channel']?['last_values'] != null
            ? json.decode(data['channel']['last_values'])['field8']
            : null;

        if (field8 != null && field8['value'] != null) {
          final double temp = field8['value'].toDouble();
          if (temp > threshold) {
            await _notifs.show(
              DateTime.now().millisecondsSinceEpoch ~/ 1000,
              '⚠️ ALERT',
              'Temperatura wzrosła powyżej progu: $temp°C > $threshold°C',
              _alertDetails,
            );
          }
        }
      } else {
        throw Exception('Błąd API: ${response.statusCode}');
      }
    } catch (e) {
      await _notifs.show(
        DateTime.now().millisecondsSinceEpoch ~/ 1000,
        'Błąd API',
        e.toString(),
        _alertDetails,
      );
    }

    return true;
  });
}

Future<void> main() async {
  dev.log('starting...', name: 'lodowka_ubibot');
  WidgetsFlutterBinding.ensureInitialized();

  final prefs = await SharedPreferences.getInstance();
  await prefs.setString(
    'APIURL',
    'https://webapi.ubibot.com/channels/107563?api_key=58045f90a943499e83ad6e945c7719e8',
  );

  const initAndroid = AndroidInitializationSettings('@mipmap/ic_launcher');
  await _notifs.initialize(const InitializationSettings(android: initAndroid));

  if (Platform.isAndroid) {
    final android = _notifs.resolvePlatformSpecificImplementation<
        AndroidFlutterLocalNotificationsPlugin>();
    final granted = await android?.requestNotificationsPermission();
    if (granted == null || !granted) {
      print('⚠️  Użytkownik odmówił POST_NOTIFICATIONS.');
    }
  }

  await _ensureNotificationChannel();

  await Workmanager().initialize(callbackDispatcher, isInDebugMode: false);
  await Workmanager().registerPeriodicTask(
    'checkApiPeriodic',
    'checkApi',
    frequency: const Duration(minutes: 15),
    existingWorkPolicy: ExistingWorkPolicy.keep,
  );

  runApp(const MyApp());
}

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

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final TextEditingController _controller = TextEditingController();
  String _field8Value = '';
  double _threshold = 5.0;
  bool _notificationsEnabled = true;

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

  Future<void> _loadSettingsAndFetch() async {
    final prefs = await SharedPreferences.getInstance();
    final url = prefs.getString('APIURL') ?? '';
    _threshold = prefs.getDouble('TEMP_THRESHOLD') ?? 5.0;
    _notificationsEnabled = prefs.getBool(NOTIFS_ENABLED_KEY) ?? true;

    _controller.text = url;
    await _fetchField8(url);
    setState(() {});
  }

  Future<void> _saveApiUrl(String text) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString("APIURL", text);
  }

  Future<void> _saveThreshold() async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setDouble("TEMP_THRESHOLD", _threshold);
  }

  Future<void> _toggleNotifications(BuildContext context, bool enabled) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(NOTIFS_ENABLED_KEY, enabled);
    setState(() => _notificationsEnabled = enabled);

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text('Powiadomienia ${enabled ? "włączone" : "wyłączone"}'),
        duration: const Duration(seconds: 2),
      ),
    );
  }

  Future<void> _fetchField8([String? customUrl]) async {
    setState(() {
      _field8Value = 'Ładowanie…';
    });

    try {
      final prefs = await SharedPreferences.getInstance();
      final url = (customUrl ?? _controller.text).trim();

      if (url.isEmpty) {
        setState(() => _field8Value = 'Brak URL.');
        return;
      }

      final response = await _safeGet(url);

      if (response == null) {
        setState(() => _field8Value = 'Brak odpowiedzi z API.');
        return;
      }

      if (response.statusCode == 200) {
        final data = json.decode(response.body);
        final field8 = data['channel']?['last_values'] != null
            ? json.decode(data['channel']['last_values'])['field8']
            : null;

        if (field8 != null && field8['value'] != null) {
          final double temp = field8['value'].toDouble();
          setState(() => _field8Value = 'Temperatura w lodówce: $temp °C');
        } else {
          setState(() => _field8Value = 'Brak danych field8.');
        }
      } else {
        setState(() => _field8Value = 'Błąd: ${response.statusCode}');
      }
    } catch (e) {
      setState(() => _field8Value = 'Wyjątek: $e');
    }
  }

  Widget _buildBody(BuildContext context) {
    return SafeArea(
      child: SingleChildScrollView(
        child: Column(
          children: [
            Padding(
              padding: const EdgeInsets.all(16.0),
              child: TextField(
                controller: _controller,
                decoration: const InputDecoration(
                  border: OutlineInputBorder(),
                  labelText: 'API URL',
                ),
                onChanged: _saveApiUrl,
              ),
            ),
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
              child: Column(
                children: [
                  const Text(
                    'Próg temperatury (°C)',
                    style: TextStyle(fontSize: 16),
                  ),
                  const SizedBox(height: 8),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      IconButton(
                        onPressed: () {
                          setState(() {
                            _threshold =
                                (_threshold - 0.1).clamp(-100.0, 100.0);
                          });
                          _saveThreshold();
                        },
                        icon: const Icon(Icons.remove),
                      ),
                      Text(
                        _threshold.toStringAsFixed(1),
                        style: const TextStyle(fontSize: 20),
                      ),
                      IconButton(
                        onPressed: () {
                          setState(() {
                            _threshold =
                                (_threshold + 0.1).clamp(-100.0, 100.0);
                          });
                          _saveThreshold();
                        },
                        icon: const Icon(Icons.add),
                      ),
                    ],
                  ),
                ],
              ),
            ),
            SwitchListTile(
              title: const Text('Powiadomienia'),
              value: _notificationsEnabled,
              onChanged: (val) => _toggleNotifications(context, val),
              secondary: Icon(
                _notificationsEnabled
                    ? Icons.notifications_active
                    : Icons.notifications_off,
              ),
            ),
            ElevatedButton(
              onPressed: () => _fetchField8(),
              child: const Text('Sprawdź teraz'),
            ),
            Padding(
              padding: const EdgeInsets.all(16.0),
              child: Text(
                _field8Value,
                style: const TextStyle(fontSize: 20),
              ),
            ),
          ],
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'API Alert App',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(useMaterial3: true),
      home: Builder(
        builder: (context) => Scaffold(
          appBar: AppBar(
            title: const Text('UbiBot - powiadomienia'),
            centerTitle: true,
            backgroundColor: Colors.blue,
          ),
          body: _buildBody(context),
        ),
      ),
    );
  }
}