import 'dart:convert';

import 'package:http/http.dart' as http;
import 'package:latlong2/latlong.dart';

import '../auth/telegram_session.dart' as telegram_auth;
import '../models/place_models.dart';

class MapflowApi {
  MapflowApi({
    http.Client? client,
    String? telegramInitData,
    String? telegramLoginData,
    String? mapflowSessionToken,
    String endpoint = const String.fromEnvironment(
      'API_BASE_URL',
      defaultValue: '/graphql',
    ),
  }) : _client = client ?? http.Client(),
       _telegramInitData = telegramInitData ?? telegram_auth.telegramInitData(),
       _telegramLoginData =
           telegramLoginData ?? telegram_auth.telegramLoginData(),
       _mapflowSessionToken =
           mapflowSessionToken ?? telegram_auth.mapflowSessionToken(),
       _endpoint = Uri.base.resolve(endpoint);

  final http.Client _client;
  final String _telegramInitData;
  final String _telegramLoginData;
  final String _mapflowSessionToken;
  final Uri _endpoint;

  bool get hasTelegramAuth =>
      _telegramInitData.isNotEmpty ||
      _telegramLoginData.isNotEmpty ||
      _mapflowSessionToken.isNotEmpty;

  Future<AppUser?> authenticateTelegram() async {
    if (!hasTelegramAuth) {
      return null;
    }

    if (_mapflowSessionToken.isNotEmpty) {
      final data = await _graphql('''
        query Me {
          me {
            id
            telegramId
            username
            firstName
            lastName
            photoUrl
            languageCode
          }
        }
      ''');
      return AppUser.fromJson(data['me'] as Map<String, dynamic>);
    }

    if (_telegramLoginData.isNotEmpty) {
      final loginData = jsonDecode(_telegramLoginData) as Map<String, dynamic>;
      final data = await _graphql(
        '''
          mutation AuthenticateTelegramLogin(
            \$input: AuthenticateTelegramLoginInput!
          ) {
            authenticateTelegramLogin(input: \$input) {
              user {
                id
                telegramId
                username
                firstName
                lastName
                photoUrl
                languageCode
              }
            }
          }
        ''',
        variables: {'input': loginData},
      );

      final payload = data['authenticateTelegramLogin'] as Map<String, dynamic>;
      final user = payload['user'] as Map<String, dynamic>;
      return AppUser.fromJson(user);
    }

    final data = await _graphql(
      '''
        mutation AuthenticateTelegram(\$input: AuthenticateTelegramInput!) {
          authenticateTelegram(input: \$input) {
            user {
              id
              telegramId
              username
              firstName
              lastName
              photoUrl
              languageCode
            }
          }
        }
      ''',
      variables: {
        'input': {'initData': _telegramInitData},
      },
    );

    final payload = data['authenticateTelegram'] as Map<String, dynamic>;
    final user = payload['user'] as Map<String, dynamic>;
    return AppUser.fromJson(user);
  }

  Future<TelegramBotLogin> startTelegramBotLogin() async {
    final data = await _graphql('''
      mutation StartTelegramBotLogin {
        startTelegramBotLogin {
          token
          botUrl
          expiresAt
        }
      }
    ''');
    return TelegramBotLogin.fromJson(
      data['startTelegramBotLogin'] as Map<String, dynamic>,
    );
  }

  Future<TelegramBotLoginStatus> fetchTelegramBotLoginStatus(
    String token,
  ) async {
    final data = await _graphql(
      '''
        query TelegramBotLoginStatus(\$token: String!) {
          telegramBotLoginStatus(token: \$token) {
            status
            sessionToken
            user {
              id
              telegramId
              username
              firstName
              lastName
              photoUrl
              languageCode
            }
          }
        }
      ''',
      variables: {'token': token},
    );
    return TelegramBotLoginStatus.fromJson(
      data['telegramBotLoginStatus'] as Map<String, dynamic>,
    );
  }

  Future<List<PlaceRecommendation>> fetchPlaces() async {
    final data = await _graphql('''
      query Places {
        places {
          id
          googlePlaceId
          name
          latitude
          longitude
          experiences {
            id
            status
            analysis
            createdAt
          }
        }
      }
    ''');

    final places = data['places'] as List<dynamic>;
    return places.map((item) {
      final place = item as Map<String, dynamic>;
      return PlaceRecommendation(
        id: place['id'] as String,
        googlePlaceId: place['googlePlaceId'] as String,
        name: place['name'] as String,
        area: '',
        photoUrls: const [],
        coordinate: LatLng(
          (place['latitude'] as num).toDouble(),
          (place['longitude'] as num).toDouble(),
        ),
        traits: _traitsFromExperiences(place['experiences'] as List<dynamic>),
      );
    }).toList();
  }

  Future<List<PlaceRecommendation>> fetchNearbyPlaces({
    required LatLng coordinate,
    required int radiusMeters,
  }) async {
    final data = await _graphql(
      '''
        query NearbyPlaces(\$input: NearbyPlacesInput!) {
          nearbyPlaces(input: \$input) {
            id
            googlePlaceId
            name
            latitude
            longitude
            experiences {
              id
              status
              analysis
              createdAt
            }
          }
        }
      ''',
      variables: {
        'input': {
          'latitude': coordinate.latitude,
          'longitude': coordinate.longitude,
          'radiusMeters': radiusMeters,
        },
      },
    );

    final places = data['nearbyPlaces'] as List<dynamic>;
    return places.map((item) {
      final place = item as Map<String, dynamic>;
      return PlaceRecommendation(
        id: place['id'] as String,
        googlePlaceId: place['googlePlaceId'] as String,
        name: place['name'] as String,
        area: '',
        photoUrls: const [],
        coordinate: LatLng(
          (place['latitude'] as num).toDouble(),
          (place['longitude'] as num).toDouble(),
        ),
        traits: _traitsFromExperiences(place['experiences'] as List<dynamic>),
      );
    }).toList();
  }

  Future<void> createVoiceExperience({
    required String googlePlaceId,
    required String googleName,
    required LatLng coordinate,
    required int durationSeconds,
    required String audioObjectKey,
  }) async {
    if (!hasTelegramAuth) {
      throw StateError('Telegram authorization is required.');
    }

    await _graphql(
      '''
        mutation CreateVoiceExperience(\$input: CreateVoiceExperienceInput!) {
          createVoiceExperience(input: \$input) {
            id
          }
        }
      ''',
      variables: {
        'input': {
          'googlePlaceId': googlePlaceId,
          'googleName': googleName,
          'latitude': coordinate.latitude,
          'longitude': coordinate.longitude,
          'durationSeconds': durationSeconds,
          'audioObjectKey': audioObjectKey,
        },
      },
    );
  }

  Future<Map<String, dynamic>> _graphql(
    String query, {
    Map<String, dynamic>? variables,
  }) async {
    final response = await _client.post(
      _endpoint,
      headers: {
        'content-type': 'application/json',
        if (_telegramInitData.isNotEmpty)
          'x-telegram-init-data': _telegramInitData,
        if (_telegramLoginData.isNotEmpty)
          'x-telegram-login-data': _telegramLoginData,
        if (_mapflowSessionToken.isNotEmpty)
          'x-mapflow-session-token': _mapflowSessionToken,
      },
      body: jsonEncode({'query': query, 'variables': variables ?? {}}),
    );

    if (response.statusCode < 200 || response.statusCode >= 300) {
      throw StateError('GraphQL request failed with ${response.statusCode}.');
    }

    final payload = jsonDecode(response.body) as Map<String, dynamic>;
    final errors = payload['errors'];
    if (errors is List && errors.isNotEmpty) {
      throw StateError(jsonEncode(errors));
    }

    return payload['data'] as Map<String, dynamic>;
  }

  Set<PlaceTrait> _traitsFromExperiences(List<dynamic> experiences) {
    final traits = <PlaceTrait>{};
    for (final item in experiences) {
      final experience = item as Map<String, dynamic>;
      final analysis = experience['analysis'];
      if (analysis is! Map<String, dynamic>) {
        continue;
      }

      final tags = analysis['tags'];
      if (tags is! List) {
        continue;
      }

      for (final tag in tags) {
        final trait = _traitByTag(tag.toString());
        if (trait != null) {
          traits.add(trait);
        }
      }
    }

    return traits;
  }

  PlaceTrait? _traitByTag(String tag) {
    final name = tag.contains(':') ? tag.split(':').last : tag;
    for (final trait in PlaceTrait.values) {
      if (trait.name == name) {
        return trait;
      }
    }
    return null;
  }
}