import 'package:drift/drift.dart';
import 'package:drift_postgres/drift_postgres.dart';
import 'package:injectable/injectable.dart';
import 'package:mnemo_cards_backend/database/database.dart';
import 'package:mnemo_cards_backend/repository/export.dart';
import 'package:mnemo_cards_common/mnemo_cards_common.dart';
import 'package:mnemo_cards_common_backend/mnemo_cards_common_backend.dart';

@lazySingleton
class AchievementManager {
  final AchievementRepository _achievementRepository;
  final UserRepository _userRepository;

  AchievementManager(this._achievementRepository, this._userRepository);

  /// Get all available achievements with their definitions
  List<AchievementDto> get allAchievementDefinitions =>
      AchievementDefinitions.allAchievements;

  /// Check and update achievements for a user
  Future<List<AchievementDto>> checkAndUnlockAchievements(
    String userId,
    UserDataModel userData,
  ) async {
    final unlockedAchievements = <AchievementDto>[];

    // Get existing user achievements
    final userAchievements = await getUserAchievements(userId);
    final existingIds = userAchievements.map((a) => a.id).toSet();

    // Check each achievement
    for (final achievement in AchievementDefinitions.allAchievements) {
      if (existingIds.contains(achievement.id)) continue;

      final isUnlocked = await _checkAchievementCondition(
        userId,
        userData,
        achievement,
      );
      if (isUnlocked) {
        final unlocked = await unlockAchievement(userId, achievement.id);
        if (unlocked != null) {
          unlockedAchievements.add(unlocked);
        }
      } else {
        // Update progress if applicable
        final progress = await _calculateAchievementProgress(
          userId,
          userData,
          achievement,
        );
        if (progress > 0.0) {
          await _achievementRepository.updateAchievementProgress(
            userId,
            achievement.id,
            progress,
          );
        }
      }
    }

    return unlockedAchievements;
  }

  /// Get achievements for a user
  Future<List<AchievementDto>> getUserAchievements(String userId) async {
    final userAchievements = await _achievementRepository.getUserAchievements(
      userId,
    );
    final progressMap = await _achievementRepository.getAchievementProgress(
      userId,
    );

    final achievements = <AchievementDto>[];

    for (final userAchievement in userAchievements) {
      final definition = AchievementDefinitions.getById(
        userAchievement.achievementId,
      );
      if (definition != null) {
        achievements.add(
          definition.copyWith(
            unlockedAt: userAchievement.unlockedAt.dateTime,
            progress: userAchievement.progress,
          ),
        );
      }
    }

    // Add locked achievements with progress
    for (final definition in AchievementDefinitions.allAchievements) {
      if (!achievements.any((a) => a.id == definition.id)) {
        final progress = progressMap[definition.id] ?? 0.0;
        achievements.add(definition.updateProgress(progress));
      }
    }

    return achievements;
  }

  /// Check if user has specific achievement
  Future<bool> hasAchievement(String userId, String achievementId) async {
    return await _achievementRepository.hasAchievement(userId, achievementId);
  }

  /// Unlock achievement for user
  Future<AchievementDto?> unlockAchievement(
    String userId,
    String achievementId,
  ) async {
    final definition = AchievementDefinitions.getById(achievementId);
    if (definition == null) return null;

    final companion = UserAchievementsCompanion.insert(
      userId: userId,
      achievementId: achievementId,
      unlockedAt: Value(PgDateTime(DateTime.now())),
      progress: Value(1.0),
    );

    try {
      await _achievementRepository.unlockAchievement(companion);
      return definition.unlock();
    } catch (e) {
      // Achievement might already exist, return existing
      final existing = await _achievementRepository.getUserAchievement(
        userId,
        achievementId,
      );
      return existing != null ? definition.unlock() : null;
    }
  }

  /// Get achievement progress for user
  Future<Map<String, double>> getAchievementProgress(String userId) async {
    return await _achievementRepository.getAchievementProgress(userId);
  }

  /// Check if achievement condition is met
  Future<bool> _checkAchievementCondition(
    String userId,
    UserDataModel userData,
    AchievementDto achievement,
  ) async {
    switch (achievement.type) {
      // case AchievementType.firstWordLearned:
      //   return userData.totalCards > 0;

      // case AchievementType.firstTestCompleted:
      //   return userData.totalTests > 0;

      case AchievementType.firstPackCompleted:
        final userPacks = await _userRepository.getUserPacks(userId);
        return userPacks.isNotEmpty;

      // case AchievementType.words10Learned:
      //   return userData.totalCards >= 10;

      // case AchievementType.words50Learned:
      //   return userData.totalCards >= 50;

      // case AchievementType.words100Learned:
      //   return userData.totalCards >= 100;

      // case AchievementType.words500Learned:
      //   return userData.totalCards >= 500;

      // case AchievementType.words1000Learned:
      //   return userData.totalCards >= 1000;

      case AchievementType.streak7Days:
        return userData.currentStreak >= 7;

      case AchievementType.streak30Days:
        return userData.currentStreak >= 30;

      case AchievementType.streak100Days:
        return userData.currentStreak >= 100;

      // case AchievementType.perfectTest:
      //   return userData.totalTests > 0;

      // case AchievementType.speedLearner:
      //   return userData.totalCards >= 100 && userData.totalStudyTimeMinutes < 600;

      default:
        return false;
    }
  }

  /// Calculate progress towards achievement
  Future<double> _calculateAchievementProgress(
    String userId,
    UserDataModel userData,
    AchievementDto achievement,
  ) async {
    switch (achievement.type) {
      // case AchievementType.words10Learned:
      //   return (userData.totalCards / 10.0).clamp(0.0, 1.0);

      // case AchievementType.words50Learned:
      //   return (userData.totalCards / 50.0).clamp(0.0, 1.0);

      // case AchievementType.words100Learned:
      //   return (userData.totalCards / 100.0).clamp(0.0, 1.0);

      // case AchievementType.words500Learned:
      //   return (userData.totalCards / 500.0).clamp(0.0, 1.0);

      // case AchievementType.words1000Learned:
      //   return (userData.totalCards / 1000.0).clamp(0.0, 1.0);

      default:
        return 0.0;
    }
  }
}