Revert Bulk implementation

src/Core/AdminConsole/OrganizationFeatures/Collections/CollectionUtils.cs

@@ -13,8 +13,7 @@ public static class CollectionUtils
     /// <param name="organizationUserIds">The IDs for organization users who need default collections.</param>
     /// <param name="defaultCollectionName">The encrypted string to use as the default collection name.</param>
     /// <returns>A tuple containing the collections and collection users.</returns>
-    public static (IEnumerable<Collection> collections,
-        IEnumerable<CollectionUser> collectionUsers)
+    public static (ICollection<Collection> collections, ICollection<CollectionUser> collectionUsers)
         BuildDefaultUserCollections(Guid organizationId, IEnumerable<Guid> organizationUserIds,
             string defaultCollectionName)
     {

src/Infrastructure.Dapper/Repositories/CollectionRepository.cs

@@ -3,6 +3,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Text.Json;
 using Bit.Core.AdminConsole.OrganizationFeatures.Collections;
 using Bit.Core.Entities;
+using Bit.Core.Enums;
 using Bit.Core.Models.Data;
 using Bit.Core.Repositories;
 using Bit.Core.Settings;
@@ -400,8 +401,64 @@ public class CollectionRepository : Repository<Collection, Guid>, ICollectionRep
 
     public async Task CreateDefaultCollectionsBulkAsync(Guid organizationId, IEnumerable<Guid> organizationUserIds, string defaultCollectionName)
     {
-        // Use the stored procedure approach which handles filtering internally
-        await CreateDefaultCollectionsAsync(organizationId, organizationUserIds, defaultCollectionName);
+        organizationUserIds = organizationUserIds.ToList();
+        if (!organizationUserIds.Any())
+        {
+            return;
+        }
+
+        await using var connection = new SqlConnection(ConnectionString);
+        connection.Open();
+        await using var transaction = connection.BeginTransaction();
+        try
+        {
+            var orgUserIdWithDefaultCollection = await GetOrgUserIdsWithDefaultCollectionAsync(connection, transaction, organizationId);
+
+            var missingDefaultCollectionUserIds = organizationUserIds.Except(orgUserIdWithDefaultCollection);
+
+            var (collections, collectionUsers) =
+                CollectionUtils.BuildDefaultUserCollections(organizationId, missingDefaultCollectionUserIds, defaultCollectionName);
+
+            if (!collectionUsers.Any() || !collections.Any())
+            {
+                return;
+            }
+
+            await BulkResourceCreationService.CreateCollectionsAsync(connection, transaction, collections);
+            await BulkResourceCreationService.CreateCollectionsUsersAsync(connection, transaction, collectionUsers);
+
+            transaction.Commit();
+        }
+        catch
+        {
+            transaction.Rollback();
+            throw;
+        }
+    }
+
+    private async Task<HashSet<Guid>> GetOrgUserIdsWithDefaultCollectionAsync(SqlConnection connection, SqlTransaction transaction, Guid organizationId)
+    {
+        const string sql = @"
+                    SELECT
+                        ou.Id AS OrganizationUserId
+                    FROM
+                        OrganizationUser ou
+                    INNER JOIN
+                        CollectionUser cu ON cu.OrganizationUserId = ou.Id
+                    INNER JOIN
+                        Collection c ON c.Id = cu.CollectionId
+                    WHERE
+                        ou.OrganizationId = @OrganizationId
+                        AND c.Type = @CollectionType;
+                ";
+
+        var organizationUserIds = await connection.QueryAsync<Guid>(
+            sql,
+            new { OrganizationId = organizationId, CollectionType = CollectionType.DefaultUserCollection },
+            transaction: transaction
+        );
+
+        return organizationUserIds.ToHashSet();
     }
 
     public class CollectionWithGroupsAndUsers : Collection

src/Infrastructure.EntityFramework/Repositories/CollectionRepository.cs

@@ -797,8 +797,8 @@ public class CollectionRepository : Repository<Core.Entities.Collection, Collect
 
     public async Task CreateDefaultCollectionsAsync(Guid organizationId, IEnumerable<Guid> organizationUserIds, string defaultCollectionName)
     {
-        organizationUserIds = organizationUserIds.ToList();
-        if (!organizationUserIds.Any())
+        var organizationUserIdsHashSet = organizationUserIds.ToHashSet();
+        if (organizationUserIdsHashSet.Count == 0)
         {
             return;
         }
@@ -807,18 +807,15 @@ public class CollectionRepository : Repository<Core.Entities.Collection, Collect
         var dbContext = GetDatabaseContext(scope);
 
         // Query for users who already have default collections
-        var organizationUserIdsHashSet = organizationUserIds.ToHashSet();
-        var existingOrgUserIds = await dbContext.CollectionUsers
+        var existingOrgUserIds = dbContext.CollectionUsers
             .Where(cu => organizationUserIdsHashSet.Contains(cu.OrganizationUserId))
             .Where(cu => cu.Collection.Type == CollectionType.DefaultUserCollection)
             .Where(cu => cu.Collection.OrganizationId == organizationId)
-            .Select(cu => cu.OrganizationUserId)
-            .ToListAsync();
+            .Select(cu => cu.OrganizationUserId);
 
         // Filter to only users who need collections
-        var filteredOrgUserIds = organizationUserIds.Except(existingOrgUserIds).ToList();
-
-        if (!filteredOrgUserIds.Any())
+        var filteredOrgUserIds = organizationUserIdsHashSet.Except(existingOrgUserIds).ToList();
+        if (filteredOrgUserIds.Count == 0)
         {
             return;
         }

test/Infrastructure.IntegrationTest/AdminConsole/Repositories/CollectionRepository/CreateDefaultCollectionsTests.cs

@@ -6,10 +6,6 @@ namespace Bit.Infrastructure.IntegrationTest.AdminConsole.Repositories.Collectio
 
 public class CreateDefaultCollectionsTests
 {
-    /// <summary>
-    /// Test that CreateDefaultCollectionsAsync successfully creates default collections for new users
-    /// with correct permissions
-    /// </summary>
     [Theory, DatabaseData]
     public async Task CreateDefaultCollectionsAsync_CreatesDefaultCollections_Success(
         IUserRepository userRepository,
@@ -63,9 +59,6 @@ public class CreateDefaultCollectionsTests
         Assert.True(orgUser2CollectionUser.Manage);
     }
 
-    /// <summary>
-    /// Test that calling CreateDefaultCollectionsAsync multiple times does NOT create duplicates
-    /// </summary>
     [Theory, DatabaseData]
     public async Task CreateDefaultCollectionsAsync_CalledMultipleTimesForSameOrganizationUser_DoesNotCreateDuplicates(
         IUserRepository userRepository,