/// 用户 Domain 实体
///
/// 全局共享实体，被 auth / chat / contact 等多个 Feature 共用。
/// 纯 Dart 类，零 Flutter / 零网络 / 零 DB 依赖。
///
/// ## 数据流位置
///
/// ```
/// 服务端 JSON
///   → LoginData（Response DTO，data/remote/login_request.dart）
///     → LoginData.toEntity()
///       → ★ User ★                ← 你在这里
///         → ViewModel.state
///           → View 渲染
/// ```
class User {
  final int uid;
  final String? uuid;
  final int? lastOnline;
  final String? profilePic;
  final String? profilePicGaussian;
  final String? nickname;
  final String? contact;
  final String? countryCode;
  final String? email;
  final String? recoveryEmail;
  final String? username;
  final String? bio;
  final int? relationship;
  final String? userAlias;
  final int? channelId;
  final int? channelGroupId;
  final String? hint;

  const User({
    required this.uid,
    this.uuid,
    this.lastOnline,
    this.profilePic,
    this.profilePicGaussian,
    this.nickname,
    this.contact,
    this.countryCode,
    this.email,
    this.recoveryEmail,
    this.username,
    this.bio,
    this.relationship,
    this.userAlias,
    this.channelId,
    this.channelGroupId,
    this.hint,
  });

  User copyWith({
    int? uid,
    String? uuid,
    int? lastOnline,
    String? profilePic,
    String? profilePicGaussian,
    String? nickname,
    String? contact,
    String? countryCode,
    String? email,
    String? recoveryEmail,
    String? username,
    String? bio,
    int? relationship,
    String? userAlias,
    int? channelId,
    int? channelGroupId,
    String? hint,
  }) {
    return User(
      uid: uid ?? this.uid,
      uuid: uuid ?? this.uuid,
      lastOnline: lastOnline ?? this.lastOnline,
      profilePic: profilePic ?? this.profilePic,
      profilePicGaussian: profilePicGaussian ?? this.profilePicGaussian,
      nickname: nickname ?? this.nickname,
      contact: contact ?? this.contact,
      countryCode: countryCode ?? this.countryCode,
      email: email ?? this.email,
      recoveryEmail: recoveryEmail ?? this.recoveryEmail,
      username: username ?? this.username,
      bio: bio ?? this.bio,
      relationship: relationship ?? this.relationship,
      userAlias: userAlias ?? this.userAlias,
      channelId: channelId ?? this.channelId,
      channelGroupId: channelGroupId ?? this.channelGroupId,
      hint: hint ?? this.hint,
    );
  }
}