import 'dart:convert';

import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;

import '../models/venue.dart';
import '../services/remote_sync_service.dart';
import '../utils/app_config.dart';

enum RegistrationStep { initial, loadingVenues, venuesLoaded, error, registering, registered }

class RegistrationViewModel extends ChangeNotifier {
  final RemoteSyncService syncService;

  RegistrationViewModel({required this.syncService});

  RegistrationStep _step = RegistrationStep.initial;
  RegistrationStep get step => _step;

  List<Venue> _venues = [];
  List<Venue> get venues => _venues;

  Venue? _selectedVenue;
  Venue? get selectedVenue => _selectedVenue;

  String? _errorMessage;
  String? get errorMessage => _errorMessage;

  void selectVenue(Venue venue) {
    _selectedVenue = venue;
    notifyListeners();
  }

  Future<void> fetchVenues() async {
    _step = RegistrationStep.loadingVenues;
    _errorMessage = null;
    notifyListeners();

    try {
      final response = await http
          .get(Uri.parse('$kRemoteServerUrl/venues/'))
          .timeout(const Duration(seconds: 15));

      if (response.statusCode == 200) {
        final List<dynamic> data = jsonDecode(response.body) as List<dynamic>;
        _venues = data
            .map((e) => Venue.fromJson(e as Map<String, dynamic>))
            .toList();
        _step = RegistrationStep.venuesLoaded;
      } else {
        _errorMessage = 'Failed to load venues (HTTP ${response.statusCode})';
        _step = RegistrationStep.error;
      }
    } catch (e) {
      debugPrint('RegistrationViewModel: fetchVenues error: $e');
      _errorMessage = e.toString();
      _step = RegistrationStep.error;
    }

    notifyListeners();
  }

  Future<bool> registerDevice({
    required String deviceName,
    required String registrationCode,
  }) async {
    final venue = _selectedVenue;
    if (venue == null) return false;

    _step = RegistrationStep.registering;
    _errorMessage = null;
    notifyListeners();

    try {
      final response = await http
          .post(
            Uri.parse('$kRemoteServerUrl/devices/register'),
            headers: {'Content-Type': 'application/json'},
            body: jsonEncode({
              'venueId': venue.id,
              'name': deviceName,
              'registrationCode': registrationCode,
            }),
          )
          .timeout(const Duration(seconds: 15));

      if (response.statusCode == 201) {
        final data = jsonDecode(response.body) as Map<String, dynamic>;
        final deviceId = data['deviceId'] as String;
        final token = data['token'] as String;

        await syncService.setCredentials(
          deviceId: deviceId,
          token: token,
          venueId: venue.id,
          serverUrl: kRemoteServerUrl,
        );

        _step = RegistrationStep.registered;
        notifyListeners();
        return true;
      } else {
        String message;
        try {
          final errorData = jsonDecode(response.body) as Map<String, dynamic>;
          message = errorData['message'] as String? ?? 'Registration failed';
        } catch (_) {
          message = 'Registration failed (HTTP ${response.statusCode})';
        }
        _errorMessage = message;
        _step = RegistrationStep.venuesLoaded;
        notifyListeners();
        return false;
      }
    } catch (e) {
      debugPrint('RegistrationViewModel: registerDevice error: $e');
      _errorMessage = e.toString();
      _step = RegistrationStep.venuesLoaded;
      notifyListeners();
      return false;
    }
  }

  Future<void> retry() async {
    await fetchVenues();
  }

  void reset() {
    _step = RegistrationStep.initial;
    _venues = [];
    _selectedVenue = null;
    _errorMessage = null;
    notifyListeners();
  }
}