数据和测试案例按照架构来处理

apps/im_app/lib/domain/presentation/di/user_provider.dart

@@ -1,28 +0,0 @@
-import 'package:riverpod_annotation/riverpod_annotation.dart';
-import 'package:im_app/app/di/db_provider.dart';
-import 'package:im_app/data/repositories/user_repository_impl.dart';
-import 'package:im_app/domain/entities/user.dart';
-import 'package:im_app/domain/repositories/user_repository.dart';
-
-part 'user_provider.g.dart';
-
-// ── Repository ────────────────────────────────────────────────────────────────
-
-@riverpod
-UserRepository userRepository(Ref ref) {
-  return UserRepositoryImpl(ref.watch(storageSdkProvider));
-}
-
-// ── Multiple Users ────────────────────────────────────────────────────────────
-
-@riverpod
-Stream<List<User>> users(Ref ref, Set<int> uids) {
-  return ref.watch(userRepositoryProvider).watchUsers(uids.toList());
-}
-
-// ── All Users ─────────────────────────────────────────────────────────────────
-
-@riverpod
-Stream<List<User>> allUsers(Ref ref) {
-  return ref.watch(userRepositoryProvider).watchAllUsers();
-}

apps/im_app/lib/domain/presentation/notifiers/user_notifier.dart

@@ -1,69 +0,0 @@
-import 'package:im_app/domain/presentation/di/user_provider.dart';
-import 'package:riverpod_annotation/riverpod_annotation.dart';
-import 'package:im_app/data/local/drift/app_database.dart';
-import 'package:im_app/domain/entities/user.dart';
-import 'package:im_app/domain/repositories/user_repository.dart';
-
-part 'user_notifier.g.dart';
-
-/// 单个用户状态管理 (family — 每个 uid 独立 notifier)
-///
-/// ## 用法
-/// ```dart
-/// // 监听 — 自动重建
-/// final userAsync = ref.watch(userNotifierProvider(123));
-///
-/// // 即时读取，无需 await
-/// final user = ref.read(userNotifierProvider(123).notifier).current;
-///
-/// // 部分更新
-/// ref.read(userNotifierProvider(123).notifier).updateFields(
-///   UsersCompanion(nickname: Value('New Name')),
-/// );
-/// ```
-@riverpod
-class UserNotifier extends _$UserNotifier {
-  User? _cached;
-
-  UserRepository get _repo => ref.watch(userRepositoryProvider);
-
-  @override
-  Future<User?> build(int uid) async {
-    ref.onDispose(() => _cached = null);
-
-    // Stream starts automatically — uid is the family arg
-    _repo.watchUser(uid).listen((user) {
-      _cached = user;
-      state = AsyncData(user);
-    });
-
-    // Return initial DB value
-    return _repo.getUser(uid);
-  }
-
-  // ── 即时访问，无需 await ──────────────────────────────────────────────────
-
-  User? get current => _cached;
-
-  // ── 写入 ─────────────────────────────────────────────────────────────────
-
-  Future<void> saveUser(User user) async {
-    await _repo.saveUser(user);
-  }
-
-  Future<void> updateFields(UsersCompanion companion) async {
-    await _repo.updateFields(uid, companion); // uid from build arg
-  }
-
-  Future<void> updateUser(User user) async {
-    await _repo.saveUser(user);
-  }
-
-  // ── 删除 ─────────────────────────────────────────────────────────────────
-
-  Future<void> deleteUser() async {
-    await _repo.deleteUser(uid);
-    _cached = null;
-    state = const AsyncData(null);
-  }
-}

apps/im_app/lib/domain/usecases/insert_users_use_case.dart

@@ -0,0 +1,55 @@
+import 'package:im_app/domain/entities/user.dart';
+import 'package:im_app/domain/repositories/user_repository.dart';
+
+/// 批量插入用户用例
+///
+/// ## 职责
+/// - 封装用户插入的业务规则
+/// - 去重（uid 相同时保留最后一个）
+/// - 分批插入，避免单次写入过大
+///
+/// ## 数据流
+/// ```
+/// ViewModel
+///   → InsertUsersUseCase.execute(users)
+///     → 去重
+///     → UserRepository.saveUsers(chunk)  ← 分批写入
+///     → onProgress(completed, total)     ← 可选进度回调
+///   ← 实际插入数量
+/// ```
+class InsertUsersUseCase {
+  final UserRepository _repo;
+  static const _chunkSize = 200;
+
+  InsertUsersUseCase({required UserRepository userRepository})
+    : _repo = userRepository;
+
+  /// 批量插入用户
+  ///
+  /// [users] 要插入的用户列表
+  /// [onProgress] 可选回调，每批完成后触发
+  ///
+  /// 返回实际插入数量
+  Future<int> execute(
+    List<User> users, {
+    void Function(int completed, int total, List<User> chunk)? onProgress,
+  }) async {
+    if (users.isEmpty) return 0;
+
+    final deduped = {for (final u in users) u.uid: u}.values.toList();
+    final total = deduped.length;
+    int completed = 0;
+
+    while (completed < total) {
+      final end = (completed + _chunkSize).clamp(0, total);
+      final chunk = deduped.sublist(completed, end);
+
+      await _repo.saveUsers(chunk);
+      completed += chunk.length;
+
+      onProgress?.call(completed, total, chunk);
+    }
+
+    return completed;
+  }
+}