feat(template-folder): rename folder with sibling uniqueness check

src/ScadaLink.TemplateEngine/Services/TemplateFolderService.cs

@@ -42,4 +42,29 @@ public class TemplateFolderService
 
         return Result<TemplateFolder>.Success(folder);
     }
+
+    public async Task<Result<TemplateFolder>> RenameFolderAsync(
+        int folderId, string newName, string user,
+        CancellationToken cancellationToken = default)
+    {
+        if (string.IsNullOrWhiteSpace(newName))
+            return Result<TemplateFolder>.Failure("Folder name is required.");
+
+        var folder = await _repository.GetFolderByIdAsync(folderId, cancellationToken);
+        if (folder == null)
+            return Result<TemplateFolder>.Failure($"Folder with ID {folderId} not found.");
+
+        var all = await _repository.GetAllFoldersAsync(cancellationToken);
+        if (all.Any(f => f.Id != folderId
+                         && f.ParentFolderId == folder.ParentFolderId
+                         && string.Equals(f.Name, newName, StringComparison.OrdinalIgnoreCase)))
+            return Result<TemplateFolder>.Failure($"A folder named '{newName}' already exists at this level.");
+
+        folder.Name = newName;
+        await _repository.UpdateFolderAsync(folder, cancellationToken);
+        await _repository.SaveChangesAsync(cancellationToken);
+        await _auditService.LogAsync(user, "Update", "TemplateFolder", folder.Id.ToString(), newName, folder, cancellationToken);
+
+        return Result<TemplateFolder>.Success(folder);
+    }
 }

tests/ScadaLink.TemplateEngine.Tests/Services/TemplateFolderServiceTests.cs

@@ -67,4 +67,44 @@ public class TemplateFolderServiceTests
         Assert.True(result.IsFailure);
         Assert.Contains("not found", result.Error);
     }
+
+    [Fact]
+    public async Task RenameFolder_ValidInput_ReturnsSuccess()
+    {
+        var folder = new TemplateFolder("Old") { Id = 1, ParentFolderId = null };
+        _repoMock.Setup(r => r.GetFolderByIdAsync(1, It.IsAny<CancellationToken>())).ReturnsAsync(folder);
+        _repoMock.Setup(r => r.GetAllFoldersAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new List<TemplateFolder> { folder });
+
+        var result = await _sut.RenameFolderAsync(1, "New", "admin");
+
+        Assert.True(result.IsSuccess);
+        Assert.Equal("New", result.Value.Name);
+    }
+
+    [Fact]
+    public async Task RenameFolder_NotFound_ReturnsFailure()
+    {
+        _repoMock.Setup(r => r.GetFolderByIdAsync(99, It.IsAny<CancellationToken>()))
+            .ReturnsAsync((TemplateFolder?)null);
+
+        var result = await _sut.RenameFolderAsync(99, "New", "admin");
+
+        Assert.True(result.IsFailure);
+    }
+
+    [Fact]
+    public async Task RenameFolder_DuplicateSibling_ReturnsFailure()
+    {
+        var folder = new TemplateFolder("Old") { Id = 1, ParentFolderId = null };
+        var sibling = new TemplateFolder("Other") { Id = 2, ParentFolderId = null };
+        _repoMock.Setup(r => r.GetFolderByIdAsync(1, It.IsAny<CancellationToken>())).ReturnsAsync(folder);
+        _repoMock.Setup(r => r.GetAllFoldersAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new List<TemplateFolder> { folder, sibling });
+
+        var result = await _sut.RenameFolderAsync(1, "Other", "admin");
+
+        Assert.True(result.IsFailure);
+        Assert.Contains("already exists", result.Error);
+    }
 }