private int AddDirectory()

in Nodejs/Product/Nodejs/SharedProject/ProjectNode.cs [4753:4852]
90 lines of code
13 McCabe index (conditional complexity)

        private int AddDirectory(VSADDRESULT[] result, HierarchyNode n, string file, bool? promptOverwrite)
        {
            // need to recursively add all of the directory contents

            var targetFolder = n.FindImmediateChildByName(Path.GetFileName(file));
            if (targetFolder == null)
            {
                var fullPath = Path.Combine(GetBaseDirectoryForAddingFiles(n), Path.GetFileName(file));
                Directory.CreateDirectory(fullPath);
                var newChild = CreateFolderNode(fullPath);
                n.AddChild(newChild);
                targetFolder = newChild;
            }
            else if (targetFolder.IsNonMemberItem)
            {
                var hr = targetFolder.IncludeInProject(true);
                if (ErrorHandler.Succeeded(hr))
                {
                    OnInvalidateItems(targetFolder.Parent);
                }
                return hr;
            }
            else if (promptOverwrite == null)
            {
                var res = MessageBox.Show(
                    string.Format(
                    @"This folder already contains a folder called '{0}'.

If the files in the existing folder have the same names as files in the folder you are copying, do you want to replace the existing files?", Path.GetFileName(file)),
                    "Merge Folders",
                    MessageBoxButtons.YesNoCancel
                );

                // yes means prompt for each file
                // no means don't prompt for any of the files
                // cancel means forget what I'm doing

                switch (res)
                {
                    case DialogResult.Cancel:
                        result[0] = VSADDRESULT.ADDRESULT_Cancel;
                        return (int)OleConstants.OLECMDERR_E_CANCELED;
                    case DialogResult.No:
                        promptOverwrite = false;
                        break;
                    case DialogResult.Yes:
                        promptOverwrite = true;
                        break;
                }
            }

            var empty = Guid.Empty;

            // add the files...
            var dirFiles = Directory.GetFiles(file);
            if (dirFiles.Length > 0)
            {
                var subRes = AddItemWithSpecificInternal(
                    targetFolder.ID,
                    VSADDITEMOPERATION.VSADDITEMOP_CLONEFILE,
                    null,
                    (uint)dirFiles.Length,
                    dirFiles,
                    IntPtr.Zero,
                    0,
                    ref empty,
                    null,
                    ref empty,
                    result,
                    promptOverwrite: promptOverwrite
                );

                if (ErrorHandler.Failed(subRes))
                {
                    return subRes;
                }
            }

            // add any subdirectories...

            var subDirs = Directory.GetDirectories(file);
            if (subDirs.Length > 0)
            {
                return AddItemWithSpecificInternal(
                    targetFolder.ID,
                    VSADDITEMOPERATION.VSADDITEMOP_CLONEFILE,
                    null,
                    (uint)subDirs.Length,
                    subDirs,
                    IntPtr.Zero,
                    0,
                    ref empty,
                    null,
                    ref empty,
                    result,
                    promptOverwrite: promptOverwrite
                );
            }
            return VSConstants.S_OK;
        }