import 'question.dart';

/// Status change for a question after an attempt.
enum QuestionStatusChange {
  improved,
  regressed,
  unchanged,
}

/// Result of a single answer in an attempt.
class AnswerResult {
  /// The question that was answered.
  final Question question;

  /// The indices of answers the user selected.
  final List<int> userAnswerIndices;

  /// Deprecated: Use [userAnswerIndices] instead. Returns the first selected answer index.
  @Deprecated('Use userAnswerIndices instead')
  int get userAnswerIndex => userAnswerIndices.isNotEmpty ? userAnswerIndices.first : -1;

  /// Whether the answer was correct.
  final bool isCorrect;

  /// The status change for this question.
  final QuestionStatusChange statusChange;

  const AnswerResult({
    required this.question,
    required this.userAnswerIndices,
    required this.isCorrect,
    required this.statusChange,
  });
}

/// Result of a completed attempt.
class AttemptResult {
  /// Total number of questions in the attempt.
  final int totalQuestions;

  /// Number of correct answers.
  final int correctCount;

  /// Percentage of correct answers.
  final double percentageCorrect;

  /// Time spent on the attempt in milliseconds.
  final int timeSpent;

  /// List of questions that were answered incorrectly.
  final List<AnswerResult> incorrectQuestions;

  /// List of all answer results.
  final List<AnswerResult> allResults;

  const AttemptResult({
    required this.totalQuestions,
    required this.correctCount,
    required this.percentageCorrect,
    required this.timeSpent,
    required this.incorrectQuestions,
    required this.allResults,
  });

  /// Creates an attempt result from answer results.
  factory AttemptResult.fromAnswers({
    required List<AnswerResult> results,
    required int timeSpent,
  }) {
    final correctCount = results.where((r) => r.isCorrect).length;
    final totalQuestions = results.length;
    final percentageCorrect = totalQuestions > 0
        ? (correctCount / totalQuestions) * 100.0
        : 0.0;
    final incorrectQuestions =
        results.where((r) => !r.isCorrect).toList();

    return AttemptResult(
      totalQuestions: totalQuestions,
      correctCount: correctCount,
      percentageCorrect: percentageCorrect,
      timeSpent: timeSpent,
      incorrectQuestions: incorrectQuestions,
      allResults: results,
    );
  }
}