import 'dart:convert';
import 'dart:io';
import 'dart:math';

import 'package:args/args.dart';
import 'package:isar/isar.dart';
import 'package:mnemo_cards_common_backend/mnemo_cards_common_backend.dart';

class DBManager {
  late Isar isar;
  final Function(String message) notify;
  // Backend API URL for generating auth codes
  final String backendUrl;

  DBManager(this.notify, {this.backendUrl = 'http://localhost:8443'});

  Future<void> init(ArgResults results) async {
    final dir = results.option('isar') ?? '../mnemo_cards_backend/isar/';
    final name = 'db';

    // Try to get existing instance first
    try {
      isar = Isar.getInstance(name) ??
          await _connectWithShareModel(
            dir: dir,
            inspector: results.flag('debug'),
          );
    } catch (e) {
      // If instance exists but can't be obtained, try to close and reopen
      try {
        final existing = Isar.getInstance(name);
        if (existing != null) {
          await existing.close();
        }
      } catch (_) {
        // Ignore errors when closing
      }
      isar = await _connectWithShareModel(
        dir: dir,
        inspector: results.flag('debug'),
      );
    }

    var totalUsers = await isar.userModels.count();
    // Removed automatic notification on startup
    isar.userModels.watchLazy().listen((_) async {
      final totalUsersUpd = await isar.userModels.count();
      if (totalUsersUpd != totalUsers) {
        notify('Users: $totalUsers -> $totalUsersUpd!');
        totalUsers = totalUsersUpd;
      }
    });
  }


  /// Connect to Isar with ShareRequestModel schema included
  Future<Isar> _connectWithShareModel({
    required String dir,
    required bool inspector,
  }) async {
    await Isar.initializeIsarCore(download: true);
    return Isar.open(
      [
        CardPackModelSchema,
  GameCardModelSchema,
  UserModelSchema,
  UserSubscriptionModelSchema,
  SubscriptionPlanModelSchema,
  TokenModelSchema,
  RefreshTokenModelSchema,
  TelegramAuthCodeModelSchema,
  TestModelSchema,
  TestQuestionModelSchema,
  PaymentModelSchema,
  TaskModelSchema,
  TestStatisticsModelSchema,
  UserDataModelSchema,
  PromoCodesCampaignModelSchema,
  PromoCodeModelSchema,
  DiscountCampaignModelSchema,
  DiscountModelSchema,
  UserTaskModelSchema,
  UserTaskProgressModelSchema,
  UserTaskResultModelSchema,
  ShareRequestModelSchema,
      ],
      directory: dir,
      name: 'db',
      inspector: inspector,
    );
  }

  Future<String> info() async {
    final users = await isar.txn(() => isar.userModels.where().findAll());
    for (final user in users) {
      await user.userData.load();
    }
    return 'Users (${users.length}):\n'
        '${users.map((user) => '${user.email ?? '${user.id} ${user.name}'} ${user.userData.value?.lastTimeOnline?.toShortString() ?? ''}').join('\n')}';
  }

  Future<String> userInfo(String userId) async {
    final id = int.tryParse(userId);
    final users = await isar.txn(
      () => isar.userModels
          .filter()
          .optional(id != null, (q) => q.idEqualTo(id))
          .or()
          .emailContains(userId)
          .or()
          .nameContains(userId)
          .findAll(),
    );
    if (users.isEmpty) {
      return 'Not found';
    }
    if (users.length > 1) {
      return 'Found multiple:\n${users.map((u) => u.basicInfo).join('\n')}';
    }
    final user = users.first;
    await user.packs.load();
    await user.subscriptionModel.load();
    final sub = user.subscriptionModel.value;
    return '''
${user.basicInfo}
Tags: ${user.userData.value?.tags.join(',') ?? ''}
Packs (${user.packs.length}):
${user.packs.map((p) => '${p.id} ${p.title}').join('\n')}
Purchases: ${user.purchases.length}
Subscription ${sub == null ? '' : '(${sub.start} - ${sub.finish})'}:
${sub?.features.join(' ') ?? ''}
    '''
        .trim();
  }

  Future<List<String>> words() async {
    final packs = await isar.txn(() => isar.cardPackModels.where().findAll());
    final words = packs
        .expand((p) => p.cards.map((c) => c.original))
        .whereType<String>()
        .toList();
    return words;
  }

  /// Generate a Telegram auth code for a user
  /// Calls backend API to generate the code
  Future<String?> generateAuthCode({
    required String telegramUserId,
    String? telegramUsername,
    String? firstName,
    String? lastName,
  }) async {
    try {
      final client = HttpClient();
      try {
        final uri = Uri.parse('$backendUrl/api/v2/auth/telegram/generate-code');
        final request = await client.postUrl(uri);
        request.headers.contentType = ContentType.json;
        request.write(jsonEncode({
          'telegramUserId': telegramUserId,
          if (telegramUsername != null) 'telegramUsername': telegramUsername,
          if (firstName != null) 'firstName': firstName,
          if (lastName != null) 'lastName': lastName,
        }));

        final response = await request.close();
        final responseBody = await response.transform(utf8.decoder).join();

        if (response.statusCode != 200) {
          print('Failed to generate auth code: '
              '${response.statusCode} - $responseBody');
          return null;
        }

        final json = jsonDecode(responseBody) as Map<String, dynamic>;
        return json['code'] as String?;
      } finally {
        client.close();
      }
    } catch (e, s) {
      print('Error generating Telegram auth code: $e\n$s');
      return null;
    }
  }

  /// Claim a web-generated Telegram auth code for a user.
  /// Returns true when the backend confirmed the claim.
  Future<bool> claimWebAuthCode({
    required String code,
    required String telegramUserId,
    String? telegramUsername,
    String? firstName,
    String? lastName,
  }) async {
    try {
      final client = HttpClient();
      try {
        final uri = Uri.parse('$backendUrl/api/v2/auth/telegram/claim-code');
        final request = await client.postUrl(uri);
        request.headers.contentType = ContentType.json;
        request.write(jsonEncode({
          'code': code,
          'telegramUserId': telegramUserId,
          if (telegramUsername != null) 'telegramUsername': telegramUsername,
          if (firstName != null) 'firstName': firstName,
          if (lastName != null) 'lastName': lastName,
        }));

        final response = await request.close();
        final responseBody = await response.transform(utf8.decoder).join();

        if (response.statusCode != 200) {
          print('Failed to claim auth code: '
              '${response.statusCode} - $responseBody');
          return false;
        }

        return true;
      } finally {
        client.close();
      }
    } catch (e, s) {
      print('Error claiming Telegram auth code: $e\n$s');
      return false;
    }
  }

  /// Check if user can share today (rate limiting)
  /// Returns true if user has not exceeded daily limit
  Future<bool> canShareToday(String telegramUserId, int dailyLimit) async {
    try {
      final today = DateTime.now();
      final todayStart = DateTime(today.year, today.month, today.day);
      final todayEnd = DateTime(today.year, today.month, today.day + 1); // Start of next day

      final sharesCount = await isar.shareRequestModels
          .filter()
          .telegramUserIdEqualTo(telegramUserId)
          .requestedAtBetween(todayStart, todayEnd)
          .count();

      print('[SHARE_LIMIT] User $telegramUserId: $sharesCount shares today (limit: $dailyLimit)');
      return sharesCount < dailyLimit;
    } catch (e, s) {
      print('Error checking share limit: $e\n$s');
      return true; // Allow on error to prevent blocking users
    }
  }

  /// Record a share request for a user
  Future<void> recordShareRequest({
    required String telegramUserId,
    String? telegramUsername,
    int? sharedCardId,
  }) async {
    try {
      final request = ShareRequestModel(
        telegramUserId: telegramUserId,
        telegramUsername: telegramUsername,
        requestedAt: DateTime.now(),
        sharedCardId: sharedCardId,
      );
      await isar.shareRequestModels.put(request);
      print('[SHARE_RECORDED] User $telegramUserId shared card $sharedCardId at ${request.requestedAt}');
    } catch (e, s) {
      print('Error recording share request: $e\n$s');
    }
  }

  /// Get a random card from the database
  /// Returns null if no cards are found
  Future<GameCardModel?> getRandomCard() async {
    try {
      final cards =
          await isar.gameCardModels.where().findAll();
      if (cards.isEmpty) {
        return null;
      }
      final random = Random();
      return cards[random.nextInt(cards.length)];
    } catch (e, s) {
      print('Error getting random card: $e\n$s');
      return null;
    }
  }

  Future<void> dispose() async {
    await isar.close();
  }
}

extension on UserModel {
  String get basicInfo => '$id ${email ?? ''} $name';
}

extension on DateTime {
  String toShortString() => '$day.$month';
}