import 'attempt_result.dart';

/// A historical record of a completed attempt.
class AttemptHistoryEntry {
  /// Timestamp when the attempt was completed (milliseconds since epoch).
  final int timestamp;

  /// 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;

  /// Percentage of questions in the deck that are not yet known (0-100).
  /// This represents progress - as more questions become known, this decreases.
  final double unknownPercentage;

  const AttemptHistoryEntry({
    required this.timestamp,
    required this.totalQuestions,
    required this.correctCount,
    required this.percentageCorrect,
    required this.timeSpent,
    this.unknownPercentage = 0.0,
  });

  /// Creates a history entry from an attempt result.
  factory AttemptHistoryEntry.fromAttemptResult({
    required AttemptResult result,
    required int totalQuestionsInDeck,
    required int knownCount,
    int? timestamp,
  }) {
    final unknownCount = totalQuestionsInDeck - knownCount;
    final unknownPercentage = totalQuestionsInDeck > 0
        ? (unknownCount / totalQuestionsInDeck * 100.0)
        : 0.0;
    
    return AttemptHistoryEntry(
      timestamp: timestamp ?? DateTime.now().millisecondsSinceEpoch,
      totalQuestions: result.totalQuestions,
      correctCount: result.correctCount,
      percentageCorrect: result.percentageCorrect,
      timeSpent: result.timeSpent,
      unknownPercentage: unknownPercentage,
    );
  }

  /// Creates a copy of this entry with the given fields replaced.
  AttemptHistoryEntry copyWith({
    int? timestamp,
    int? totalQuestions,
    int? correctCount,
    double? percentageCorrect,
    int? timeSpent,
    double? unknownPercentage,
  }) {
    return AttemptHistoryEntry(
      timestamp: timestamp ?? this.timestamp,
      totalQuestions: totalQuestions ?? this.totalQuestions,
      correctCount: correctCount ?? this.correctCount,
      percentageCorrect: percentageCorrect ?? this.percentageCorrect,
      timeSpent: timeSpent ?? this.timeSpent,
      unknownPercentage: unknownPercentage ?? this.unknownPercentage,
    );
  }

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is AttemptHistoryEntry &&
          runtimeType == other.runtimeType &&
          timestamp == other.timestamp &&
          totalQuestions == other.totalQuestions &&
          correctCount == other.correctCount &&
          percentageCorrect == other.percentageCorrect &&
          timeSpent == other.timeSpent &&
          unknownPercentage == other.unknownPercentage;

  @override
  int get hashCode =>
      timestamp.hashCode ^
      totalQuestions.hashCode ^
      correctCount.hashCode ^
      percentageCorrect.hashCode ^
      timeSpent.hashCode ^
      unknownPercentage.hashCode;
}