class Vehicle {
  /// Hidden, immutable, generated primary key — never shown in the UI and
  /// never editable. This is what fuel entries actually reference and what
  /// sync merges on, so that [vin] itself is free to be edited without
  /// breaking those references or losing sync history.
  final String id;

  /// The vehicle's identification number. Required and must be unique
  /// among active (non-deleted) vehicles, but — unlike [id] — the user can
  /// edit it later (e.g. to fix a typo from a misread VIN scan).
  final String vin;

  /// User-chosen label, e.g. "Mom's Car" or "Red Ford F-150". Optional —
  /// when absent, screens fall back to other identifying info instead.
  final String? nickname;

  final DateTime updatedAt;

  /// Soft-delete tombstone: null means active. Deleting sets this instead
  /// of removing the row, so the deletion itself can be merged/synced like
  /// any other change (newest `updatedAt` wins) instead of silently
  /// disappearing and later being resurrected by a device that hasn't seen
  /// the deletion yet.
  final DateTime? deletedAt;

  Vehicle({
    required this.id,
    required this.vin,
    required this.updatedAt,
    this.nickname,
    this.deletedAt,
  });

  /// What screens should show as the vehicle's primary label: the nickname
  /// if one was given, otherwise the VIN itself.
  String get displayLabel {
    final trimmedNickname = nickname?.trim();
    if (trimmedNickname != null && trimmedNickname.isNotEmpty) {
      return trimmedNickname;
    }
    return vin;
  }

  /// Note: [id] is intentionally not overridable here — it's the hidden
  /// identifier, not an editable field.
  Vehicle copyWith({
    String? vin,
    String? nickname,
    bool clearNickname = false,
    DateTime? updatedAt,
    DateTime? deletedAt,
  }) {
    return Vehicle(
      id: id,
      vin: vin ?? this.vin,
      nickname: clearNickname ? null : (nickname ?? this.nickname),
      updatedAt: updatedAt ?? this.updatedAt,
      deletedAt: deletedAt ?? this.deletedAt,
    );
  }

  Map<String, Object?> toMap() => {
        'id': id,
        'vin': vin,
        'nickname': nickname,
        'updated_at': updatedAt.millisecondsSinceEpoch,
        'deleted_at': deletedAt?.millisecondsSinceEpoch,
      };

  factory Vehicle.fromMap(Map<String, Object?> map) => Vehicle(
        id: map['id'] as String,
        vin: map['vin'] as String,
        nickname: map['nickname'] as String?,
        updatedAt: DateTime.fromMillisecondsSinceEpoch(map['updated_at'] as int, isUtc: true),
        deletedAt: map['deleted_at'] != null
            ? DateTime.fromMillisecondsSinceEpoch(map['deleted_at'] as int, isUtc: true)
            : null,
      );
}