import 'dart:math';
import '../models/cognitive_type.dart';
import '../models/assessment_data.dart'; 

class BrainTrainingService {
  final Random _random = Random();

  /// 사용자 취약점을 분석하여 맞춤형 게임 3개를 추천합니다.
  List<BrainGameType> recommendGames(Map<CognitiveArea, int>? scores) {
    if (scores == null || scores.isEmpty) {
      // 기록이 없으면 골고루 추천 (기억, 계산, 주의)
      return [
        BrainGameType.sequence,
        BrainGameType.mathQuiz,
        BrainGameType.schulte, 
      ];
    }

    // 1. 점수 기반 취약점 분석 (점수가 높을수록 위험/취약)
    Map<CognitiveArea, double> riskRatios = {};
    Map<CognitiveArea, int> totalCountByArea = {};
    
    for (var q in rawAssessmentQuestions) {
      totalCountByArea[q.area] = (totalCountByArea[q.area] ?? 0) + 1;
    }

    scores.forEach((area, score) {
      int total = totalCountByArea[area] ?? 1;
      riskRatios[area] = score / total; 
    });

    var sortedRisks = riskRatios.entries.toList()
      ..sort((a, b) => b.value.compareTo(a.value));
    
    CognitiveArea primaryWeakness = sortedRisks[0].key;
    CognitiveArea secondaryWeakness = sortedRisks.length > 1 ? sortedRisks[1].key : primaryWeakness;

    List<BrainGameType> recommendation = [];

    // 2. 추천 리스트 생성
    // (1) 가장 취약한 영역의 게임
    recommendation.add(_getGameForArea(primaryWeakness));
    
    // (2) 두 번째 취약한 영역의 게임 (중복 방지)
    BrainGameType secondGame = _getGameForArea(secondaryWeakness);
    if (!recommendation.contains(secondGame)) {
      recommendation.add(secondGame);
    } else {
      recommendation.add(_getRandomGameExcluding(recommendation));
    }

    // (3) 랜덤 게임 (밸런스)
    recommendation.add(_getRandomGameExcluding(recommendation));

    return recommendation;
  }

  /// 영역별 게임 랜덤 선택 (2개 중 1개)
  BrainGameType _getGameForArea(CognitiveArea area) {
    switch (area) {
      case CognitiveArea.memory:
        return _random.nextBool() ? BrainGameType.sequence : BrainGameType.cardFlip;
      
      case CognitiveArea.calculation:
        return _random.nextBool() ? BrainGameType.mathQuiz : BrainGameType.sudoku;
      
      case CognitiveArea.attention:
        return _random.nextBool() ? BrainGameType.colorMatch : BrainGameType.schulte; // 슐테(숫자찾기)
      
      case CognitiveArea.perception:
        return _random.nextBool() ? BrainGameType.findDiff : BrainGameType.tracing; // 따라그리기
        
      case CognitiveArea.language:
        return _random.nextBool() ? BrainGameType.readAloud : BrainGameType.dictation; // 읽기/쓰기
    }
  }

  BrainGameType _getRandomGameExcluding(List<BrainGameType> exclude) {
    var candidates = BrainGameType.values.where((g) => !exclude.contains(g)).toList();
    if (candidates.isEmpty) return BrainGameType.sudoku;
    return candidates[_random.nextInt(candidates.length)];
  }
}