private MarkdownFile? ProcessTocItems()

in src/Elastic.Markdown/IO/Navigation/DocumentationGroup.cs [204:316]
96 lines of code
20 McCabe index (conditional complexity)

	private MarkdownFile? ProcessTocItems(
		BuildContext context,
		DocumentationGroup topLevelGroup,
		MarkdownFile? configuredIndex,
		NavigationLookups lookups,
		int depth,
		ref int fileIndex,
		out List<DocumentationGroup> groups,
		out List<MarkdownFile> files,
		out List<INavigationItem> navigationItems)
	{
		groups = [];
		navigationItems = [];
		files = [];
		var indexFile = configuredIndex;
		foreach (var (tocItem, index) in lookups.TableOfContents.Select((t, i) => (t, i)))
		{
			if (tocItem is FileReference file)
			{
				if (!lookups.FlatMappedFiles.TryGetValue(file.RelativePath, out var d))
				{
					context.EmitError(context.ConfigurationPath,
						$"The following file could not be located: {file.RelativePath} it may be excluded from the build in docset.yml");
					continue;
				}

				if (d is ExcludedFile excluded && excluded.RelativePath.EndsWith(".md"))
				{
					context.EmitError(context.ConfigurationPath, $"{excluded.RelativePath} matches exclusion glob from docset.yml yet appears in TOC");
					continue;
				}

				if (d is not MarkdownFile md)
					continue;


				md.Hidden = file.Hidden;
				var navigationIndex = Interlocked.Increment(ref fileIndex);
				md.NavigationIndex = navigationIndex;
				md.ScopeDirectory = file.TableOfContentsScope.ScopeDirectory;
				md.NavigationRoot = topLevelGroup;
				md.NavigationSource = NavigationSource;

				foreach (var extension in lookups.EnabledExtensions)
					extension.Visit(d, tocItem);

				if (file.Children.Count > 0 && d is MarkdownFile virtualIndex)
				{
					if (file.Hidden)
						context.EmitError(context.ConfigurationPath, $"The following file is hidden but has children: {file.RelativePath}");
					var group = new DocumentationGroup(virtualIndex.RelativePath,
						_treeCollector, context, lookups with
						{
							TableOfContents = file.Children
						}, NavigationSource, ref fileIndex, depth + 1, topLevelGroup, this, virtualIndex);
					groups.Add(group);
					navigationItems.Add(new GroupNavigationItem(depth, group, this));
					indexFile ??= virtualIndex;
					continue;
				}

				files.Add(md);
				if (file.RelativePath.EndsWith("index.md") && d is MarkdownFile i)
					indexFile ??= i;

				// add the page to navigation items unless it's the index file
				// the index file can either be the discovered `index.md` or the parent group's
				// explicit index page. E.g. when grouping related files together.
				// if the page is referenced as hidden in the TOC do not include it in the navigation
				if (indexFile != md && !md.Hidden)
					navigationItems.Add(new FileNavigationItem(depth, md, this));
			}
			else if (tocItem is FolderReference folder)
			{
				var children = folder.Children;
				if (children.Count == 0 && lookups.FilesGroupedByFolder.TryGetValue(folder.RelativePath, out var documentationFiles))
				{
					children =
					[
						.. documentationFiles
							.Select(d => new FileReference(folder.TableOfContentsScope, d.RelativePath, false, []))
					];
				}

				DocumentationGroup group;
				if (folder is TocReference tocReference)
				{
					var toc = new TableOfContentsTree(tocReference.Source, folder.RelativePath, _treeCollector, context, lookups with
					{
						TableOfContents = children
					}, ref fileIndex, depth + 1, topLevelGroup, this);

					group = toc;
					navigationItems.Add(new TocNavigationItem(depth, toc, tocReference.Source, this));
				}
				else
				{
					group = new DocumentationGroup(folder.RelativePath, _treeCollector, context, lookups with
					{
						TableOfContents = children
					}, NavigationSource, ref fileIndex, depth + 1, topLevelGroup, this);
					navigationItems.Add(new GroupNavigationItem(depth, group, this));
				}

				groups.Add(group);
			}
		}

		if (indexFile is not null)
			indexFile.IsIndex = true;

		return indexFile ?? files.FirstOrDefault();
	}