class LicenseInfo {
  final int id;
  final String type; // trial | monthly | annual | lifetime
  final bool isActive;
  final int maxDevices;
  final DateTime? expiresAt;
  final String phase; // normal | grace | readonly | locked

  const LicenseInfo({
    required this.id,
    required this.type,
    required this.isActive,
    required this.maxDevices,
    required this.phase,
    this.expiresAt,
  });

  factory LicenseInfo.fromJson(Map<String, dynamic> json) {
    return LicenseInfo(
      id: (json['id'] as num?)?.toInt() ?? 0,
      type: json['type'] as String? ?? 'trial',
      isActive: json['is_active'] as bool? ?? false,
      maxDevices: (json['max_devices'] as num?)?.toInt() ?? 3,
      expiresAt: json['expires_at'] != null
          ? DateTime.tryParse(json['expires_at'] as String)
          : null,
      phase: json['phase'] as String? ?? 'normal',
    );
  }

  String get typeLabel {
    switch (type) {
      case 'monthly':
        return '月度授权';
      case 'annual':
        return '年度授权';
      case 'lifetime':
        return '永久授权';
      default:
        return '试用版';
    }
  }

  bool get isExpired =>
      expiresAt != null && DateTime.now().isAfter(expiresAt!);

  int? get daysRemaining {
    if (expiresAt == null) return null;
    final diff = expiresAt!.difference(DateTime.now()).inDays;
    return diff < 0 ? 0 : diff;
  }

  bool get isReadOnlyPhase => phase == 'readonly' || phase == 'locked';
  bool get isLockedPhase => phase == 'locked';
  bool get needsAttention => phase == 'grace' || phase == 'readonly' || phase == 'locked';
}