数据和测试案例按照架构来处理

apps/im_app/lib/app/di/user_provider.dart

@@ -1,3 +1,5 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:im_app/domain/usecases/insert_users_use_case.dart';
 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';
@@ -13,15 +15,22 @@ UserRepository userRepository(Ref ref) {
   return UserRepositoryImpl(ref.watch(storageSdkProvider));
 }
 
-// ── Multiple Users ────────────────────────────────────────────────────────────
+// ── Use Cases ─────────────────────────────────────────────────────────────────
+
+/// 批量插入用户用例 Provider
+///
+/// 封装去重 + 分批插入逻辑，ViewModel 只需传入用户列表
+final insertUsersUseCaseProvider = Provider<InsertUsersUseCase>((ref) {
+  return InsertUsersUseCase(userRepository: ref.read(userRepositoryProvider));
+});
+
+// ── Streams ───────────────────────────────────────────────────────────────────
 
 @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/app/notifiers/user_notifier.dart

@@ -1,4 +1,4 @@
-import 'package:im_app/domain/presentation/di/user_provider.dart';
+import 'package:im_app/app/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';

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;
+  }
+}

apps/im_app/lib/features/chat/presentation/chat_db_test_view_model.dart

@@ -1,8 +1,8 @@
 import 'dart:math';
 
 import 'package:flutter/material.dart';
+import 'package:im_app/app/di/user_provider.dart';
 import 'package:im_app/domain/entities/user.dart';
-import 'package:im_app/domain/presentation/di/user_provider.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
 
 part 'chat_db_test_view_model.g.dart';
@@ -101,42 +101,38 @@ class ChatDbTestViewModel extends _$ChatDbTestViewModel {
   }
 
   Future<void> _testDBInsert() async {
+    final useCase = ref.read(insertUsersUseCaseProvider);
     final repo = ref.read(userRepositoryProvider);
     const count = 10000;
-    const chunkSize = 200;
     final stopwatch = Stopwatch()..start();
+    final baseUid = DateTime.now().microsecondsSinceEpoch;
 
-    debugPrint('开始测试: $count 条，每批 $chunkSize 条');
+    debugPrint('开始测试: $count 条');
 
     final workingList = List<User>.from(state.users);
-    int completed = 0;
 
-    while (completed < count) {
-      if (!_isTesting) break;
+    final allUsers = List.generate(
+      count,
+      (i) => User(uid: baseUid + i, nickname: 'User ${_random.nextInt(9999)}'),
+    );
 
-      final chunk = List.generate(
-        min(chunkSize, count - completed),
-        (_) => User(
-          uid: _random.nextInt(999999),
-          nickname: 'User ${_random.nextInt(9999)}',
-        ),
-      );
+    await useCase.execute(
+      allUsers,
+      onProgress: (completed, total, chunk) {
+        workingList.addAll(chunk);
 
-      await repo.saveUsers(chunk);
-      completed += chunk.length;
-      workingList.addAll(chunk);
-
-      debugPrint(
-        '已完成: $completed / $count (${stopwatch.elapsedMilliseconds}ms)',
-      );
-
-      if (ref.mounted) {
-        state = state.copyWith(
-          users: List.unmodifiable(workingList),
-          currentState: '已插入 $completed / $count 条',
+        debugPrint(
+          '已完成: $completed / $total (${stopwatch.elapsedMilliseconds}ms)',
         );
-      }
-    }
+
+        if (ref.mounted && _isTesting) {
+          state = state.copyWith(
+            users: List.unmodifiable(workingList),
+            currentState: '已插入 $completed / $total 条',
+          );
+        }
+      },
+    );
 
     _isTesting = false;
     final elapsed = stopwatch.elapsedMilliseconds;

apps/im_app/lib/features/chat/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;
+  }
+}

apps/im_app/lib/features/login/presentation/login_view_model.dart

@@ -1,8 +1,8 @@
 import 'dart:convert';
 
 import 'package:flutter/services.dart';
+import 'package:im_app/app/di/user_provider.dart';
 import 'package:im_app/data/remote/login_request.dart';
-import 'package:im_app/domain/presentation/di/user_provider.dart';
 import 'package:networks_sdk/networks_sdk.dart';
 import 'package:im_app/app/di/db_provider.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';