public static FrozenDictionary GetConfiguredSources()

in src/tooling/docs-assembler/AssembleSources.cs [160:297]
126 lines of code
22 McCabe index (conditional complexity)

	public static FrozenDictionary<Uri, TocTopLevelMapping> GetConfiguredSources(AssembleContext context)
	{
		var dictionary = new Dictionary<Uri, TocTopLevelMapping>();
		var reader = new YamlStreamReader(context.NavigationPath, context.Collector);
		var entries = new List<KeyValuePair<Uri, TocTopLevelMapping>>();
		foreach (var entry in reader.Read())
		{
			switch (entry.Key)
			{
				case "toc":
					ReadTocBlocks(entries, reader, entry.Entry, null, 0, null, null);
					break;
			}
		}
		foreach (var (source, block) in entries)
			dictionary[source] = block;
		return dictionary.ToFrozenDictionary();

		static void ReadTocBlocks(
			List<KeyValuePair<Uri, TocTopLevelMapping>> entries,
			YamlStreamReader reader,
			KeyValuePair<YamlNode, YamlNode> entry,
			string? parent,
			int depth,
			Uri? topLevelSource,
			Uri? parentSource
		)
		{
			if (entry.Key is not YamlScalarNode { Value: not null } scalarKey)
			{
				reader.EmitWarning($"key '{entry.Key}' is not string");
				return;
			}

			if (entry.Value is not YamlSequenceNode sequence)
			{
				reader.EmitWarning($"'{scalarKey.Value}' is not an array");
				return;
			}

			var i = 0;
			foreach (var tocEntry in sequence.Children.OfType<YamlMappingNode>())
			{
				ReadBlock(entries, reader, tocEntry, parent, depth, i, topLevelSource, parentSource);
				i++;
			}
		}
		static void ReadBlock(
			List<KeyValuePair<Uri, TocTopLevelMapping>> entries,
			YamlStreamReader reader,
			YamlMappingNode tocEntry,
			string? parent,
			int depth,
			int order,
			Uri? topLevelSource,
			Uri? parentSource
		)
		{
			string? repository = null;
			string? source = null;
			string? pathPrefix = null;
			foreach (var entry in tocEntry.Children)
			{
				var key = ((YamlScalarNode)entry.Key).Value;
				switch (key)
				{
					case "toc":
						source = reader.ReadString(entry);
						if (source.AsSpan().IndexOf("://") == -1)
						{
							parent = source;
							pathPrefix = source;
							source = ContentSourceMoniker.CreateString(NarrativeRepository.RepositoryName, source);
						}

						break;
					case "repo":
						repository = reader.ReadString(entry);
						break;
					case "path_prefix":
						pathPrefix = reader.ReadString(entry);
						break;
				}
			}

			if (repository is not null)
			{
				if (source is not null)
					reader.EmitError($"toc config defines 'repo' can not be combined with 'toc': {source}", tocEntry);
				pathPrefix = string.Join("/", [parent, repository]);
				source = ContentSourceMoniker.CreateString(repository, parent);
			}

			if (source is null)
				return;

			source = source.EndsWith("://") ? source : source.TrimEnd('/') + "/";
			if (!Uri.TryCreate(source, UriKind.Absolute, out var sourceUri))
			{
				reader.EmitError($"Source toc entry is not a valid uri: {source}", tocEntry);
				return;
			}

			var sourcePrefix = $"{sourceUri.Host}/{sourceUri.AbsolutePath.TrimStart('/')}";
			if (string.IsNullOrEmpty(pathPrefix))
				reader.EmitError($"Path prefix is not defined for: {source}, falling back to {sourcePrefix} which may be incorrect", tocEntry);

			pathPrefix ??= sourcePrefix;
			topLevelSource ??= sourceUri;
			parentSource ??= sourceUri;

			var tocTopLevelMapping = new TocTopLevelMapping
			{
				Source = sourceUri,
				SourcePathPrefix = pathPrefix,
				TopLevelSource = topLevelSource,
				ParentSource = parentSource
			};
			entries.Add(new KeyValuePair<Uri, TocTopLevelMapping>(sourceUri, tocTopLevelMapping));

			foreach (var entry in tocEntry.Children)
			{
				var key = ((YamlScalarNode)entry.Key).Value;
				switch (key)
				{
					case "children":
						if (source is null && pathPrefix is null)
						{
							reader.EmitWarning("toc entry has no toc or path_prefix defined");
							continue;
						}

						ReadTocBlocks(entries, reader, entry, parent, depth + 1, topLevelSource, tocTopLevelMapping.Source);
						break;
				}
			}
		}
	}