/// Represents reading progress data from a KOReader sync server
class KoreaderProgress {
  /// MD5 hash identifying the document
  final String document;

  /// Reading progress percentage (0.0 to 1.0)
  final double percentage;

  /// Position string (e.g., CFI for EPUB, page number for PDF)
  final String progress;

  /// Device name that last updated the progress
  final String device;

  /// Device identifier
  final String? deviceId;

  /// Unix timestamp (seconds) of last update
  final int? timestamp;

  const KoreaderProgress({
    required this.document,
    required this.percentage,
    required this.progress,
    required this.device,
    this.deviceId,
    this.timestamp,
  });

  /// Create from JSON response
  factory KoreaderProgress.fromJson(Map<String, dynamic> json) {
    return KoreaderProgress(
      document: json['document'] as String? ?? '',
      percentage: (json['percentage'] as num?)?.toDouble() ?? 0.0,
      progress: json['progress'] as String? ?? '',
      device: json['device'] as String? ?? '',
      deviceId: json['device_id'] as String?,
      timestamp: json['timestamp'] as int?,
    );
  }

  /// Convert to JSON for API request
  Map<String, dynamic> toJson() {
    return {
      'document': document,
      'percentage': percentage,
      'progress': progress,
      'device': device,
      if (deviceId != null) 'device_id': deviceId,
    };
  }

  /// Whether this progress has meaningful data
  bool get isEmpty => document.isEmpty;

  /// Convert timestamp to DateTime
  DateTime? get lastUpdated => timestamp != null
      ? DateTime.fromMillisecondsSinceEpoch(timestamp! * 1000)
      : null;
}