saqel/apps/student_app/lib/data/models/exam_model.dart

/// Exam, Question, and Socratic Diagnostic Models for Saqel Student App
class ExamModel {
  final int id;
  final String uuid;
  final int courseId;
  final int? lessonId;
  final String title;
  final String description;
  final String scope;
  final double passingPercentage;
  final int durationMinutes;
  final int questionsCount;
  final List<QuestionModel> questions;

  const ExamModel({
    required this.id,
    required this.uuid,
    required this.courseId,
    this.lessonId,
    required this.title,
    required this.description,
    required this.scope,
    required this.passingPercentage,
    required this.durationMinutes,
    this.questionsCount = 0,
    this.questions = const [],
  });

  factory ExamModel.fromJson(Map<String, dynamic> json) {
    var rawQuestions = json['questions'];
    List<QuestionModel> parsedQuestions = [];
    if (rawQuestions is List) {
      parsedQuestions = rawQuestions
          .map((q) => QuestionModel.fromJson(Map<String, dynamic>.from(q)))
          .toList();
    }

    return ExamModel(
      id: _toInt(json['id']),
      uuid: json['uuid']?.toString() ?? '',
      courseId: _toInt(json['course_id']),
      lessonId: json['lesson_id'] != null ? _toInt(json['lesson_id']) : null,
      title: json['title']?.toString() ?? 'امتحان تشخيصي',
      description: json['description']?.toString() ?? '',
      scope: json['scope']?.toString() ?? 'unit_exam',
      passingPercentage: _toDouble(json['passing_percentage'], 60.0),
      durationMinutes: _toInt(json['duration_minutes'], 20),
      questionsCount: _toInt(json['questions_count'], parsedQuestions.length),
      questions: parsedQuestions,
    );
  }
}

int _toInt(dynamic value, [int defaultValue = 0]) {
  if (value == null) return defaultValue;
  if (value is num) return value.toInt();
  return int.tryParse(value.toString()) ?? defaultValue;
}

double _toDouble(dynamic value, [double defaultValue = 0.0]) {
  if (value == null) return defaultValue;
  if (value is num) return value.toDouble();
  return double.tryParse(value.toString()) ?? defaultValue;
}

class QuestionModel {
  final int id;
  final String questionText;
  final String questionType;
  final int points;
  final String topicTag;
  final String? explanationText;
  final String? aiHint;
  final List<QuestionOptionModel> options;

  const QuestionModel({
    required this.id,
    required this.questionText,
    required this.questionType,
    required this.points,
    required this.topicTag,
    this.explanationText,
    this.aiHint,
    this.options = const [],
  });

  factory QuestionModel.fromJson(Map<String, dynamic> json) {
    var rawOptions = json['options'];
    List<QuestionOptionModel> parsedOptions = [];
    if (rawOptions is List) {
      parsedOptions = rawOptions
          .map((opt) => QuestionOptionModel.fromJson(Map<String, dynamic>.from(opt)))
          .toList();
    }

    return QuestionModel(
      id: _toInt(json['id']),
      questionText: json['question_text']?.toString() ?? '',
      questionType: json['question_type']?.toString() ?? 'multiple_choice',
      points: _toInt(json['points'], 10),
      topicTag: json['topic_tag']?.toString() ?? 'المفاهيم العامة',
      explanationText: json['explanation_text']?.toString(),
      aiHint: json['ai_hint']?.toString(),
      options: parsedOptions,
    );
  }
}

class QuestionOptionModel {
  final int id;
  final String optionText;
  final bool isCorrect;
  final int sequenceOrder;

  const QuestionOptionModel({
    required this.id,
    required this.optionText,
    this.isCorrect = false,
    this.sequenceOrder = 1,
  });

  factory QuestionOptionModel.fromJson(Map<String, dynamic> json) {
    return QuestionOptionModel(
      id: _toInt(json['id']),
      optionText: json['option_text']?.toString() ?? '',
      isCorrect: json['is_correct'] == 1 || json['is_correct'] == true || json['is_correct'] == '1',
      sequenceOrder: _toInt(json['sequence_order'], 1),
    );
  }
}

class ExamSubmissionResultModel {
  final int attemptId;
  final int score;
  final int totalScore;
  final double percentage;
  final bool passed;
  final int rewindSeconds;
  final String aiDiagnosticReport;
  final List<String> weakTopics;
  final double tawjihiReadinessScore;
  final List<DetailedAnswerModel> detailedAnswers;

  const ExamSubmissionResultModel({
    required this.attemptId,
    required this.score,
    required this.totalScore,
    required this.percentage,
    required this.passed,
    required this.rewindSeconds,
    required this.aiDiagnosticReport,
    required this.weakTopics,
    required this.tawjihiReadinessScore,
    this.detailedAnswers = const [],
  });

  factory ExamSubmissionResultModel.fromJson(Map<String, dynamic> json) {
    var rawTopics = json['weak_topics'];
    List<String> parsedTopics = [];
    if (rawTopics is List) {
      parsedTopics = rawTopics.map((e) => e.toString()).toList();
    }

    var rawDetails = json['detailed_answers'];
    List<DetailedAnswerModel> parsedDetails = [];
    if (rawDetails is List) {
      parsedDetails = rawDetails
          .map((d) => DetailedAnswerModel.fromJson(Map<String, dynamic>.from(d)))
          .toList();
    }

    return ExamSubmissionResultModel(
      attemptId: _toInt(json['attempt_id']),
      score: _toInt(json['score']),
      totalScore: _toInt(json['total_score'], 100),
      percentage: _toDouble(json['percentage']),
      passed: json['passed'] == true || json['passed'] == 1 || json['passed'] == '1',
      rewindSeconds: _toInt(json['rewind_seconds']),
      aiDiagnosticReport: json['ai_diagnostic_report']?.toString() ?? '',
      weakTopics: parsedTopics,
      tawjihiReadinessScore: _toDouble(json['tawjihi_readiness_score'], 50.0),
      detailedAnswers: parsedDetails,
    );
  }
}

class DetailedAnswerModel {
  final int questionId;
  final int selectedOptionId;
  final bool isCorrect;
  final int pointsAwarded;
  final String? explanation;
  final String? aiHint;

  const DetailedAnswerModel({
    required this.questionId,
    required this.selectedOptionId,
    required this.isCorrect,
    required this.pointsAwarded,
    this.explanation,
    this.aiHint,
  });

  factory DetailedAnswerModel.fromJson(Map<String, dynamic> json) {
    return DetailedAnswerModel(
      questionId: _toInt(json['question_id']),
      selectedOptionId: _toInt(json['selected_option_id']),
      isCorrect: json['is_correct'] == 1 || json['is_correct'] == true || json['is_correct'] == '1',
      pointsAwarded: _toInt(json['points_awarded']),
      explanation: json['explanation']?.toString(),
      aiHint: json['ai_hint']?.toString(),
    );
  }
}