Use global navigation to compute prev/next

src/Elastic.Markdown/DocumentationGenerator.cs

@@ -46,7 +46,8 @@ public DocumentationGenerator(
 		IDocumentationFileOutputProvider? documentationFileOutputProvider = null,
 		IDocumentationFileExporter? documentationExporter = null,
 		IConversionCollector? conversionCollector = null,
-		IHistoryMapper? historyMapper = null
+		IHistoryMapper? historyMapper = null,
+		IPositionalNavigation? positionalNavigation = null
 	)
 	{
 		_documentationFileOutputProvider = documentationFileOutputProvider;
@@ -57,7 +58,7 @@ public DocumentationGenerator(
 		DocumentationSet = docSet;
 		Context = docSet.Build;
 		Resolver = docSet.LinkResolver;
-		HtmlWriter = new HtmlWriter(DocumentationSet, _writeFileSystem, new DescriptionGenerator(), navigationHtmlWriter, historyMapper);
+		HtmlWriter = new HtmlWriter(DocumentationSet, _writeFileSystem, new DescriptionGenerator(), navigationHtmlWriter, historyMapper, positionalNavigation);
 		_documentationFileExporter =
 			documentationExporter
 			?? docSet.Build.Configuration.EnabledExtensions.FirstOrDefault(e => e.FileExporter != null)?.FileExporter

src/Elastic.Markdown/IO/DocumentationSet.cs

@@ -24,6 +24,12 @@ public interface INavigationLookups
 	FrozenDictionary<string, DocumentationFile[]> FilesGroupedByFolder { get; }
 }
 
+public interface IPositionalNavigation
+{
+	MarkdownFile? GetPrevious(MarkdownFile current);
+	MarkdownFile? GetNext(MarkdownFile current);
+}
+
 public record NavigationLookups : INavigationLookups
 {
 	public required FrozenDictionary<string, DocumentationFile> FlatMappedFiles { get; init; }
@@ -33,7 +39,7 @@ public record NavigationLookups : INavigationLookups
 	//public required FrozenDictionary<Uri, TableOfContentsReference> IndexedTableOfContents { get; init; }
 }
 
-public class DocumentationSet : INavigationLookups
+public class DocumentationSet : INavigationLookups, IPositionalNavigation
 {
 	public BuildContext Build { get; }
 	public string Name { get; }

src/Elastic.Markdown/IO/MarkdownFile.cs

@@ -144,7 +144,7 @@ public string Url
 		}
 	}
 
-	public int NavigationIndex { get; internal set; } = -1;
+	public int NavigationIndex { get; set; } = -1;
 
 	public string? GroupId { get; set; }
 

src/Elastic.Markdown/Slices/HtmlWriter.cs

@@ -68,12 +68,16 @@ public class HtmlWriter(
 	IFileSystem writeFileSystem,
 	IDescriptionGenerator descriptionGenerator,
 	INavigationHtmlWriter? navigationHtmlWriter = null,
-	IHistoryMapper? historyMapper = null)
+	IHistoryMapper? historyMapper = null,
+	IPositionalNavigation? positionalNavigation = null
+)
 {
 	private DocumentationSet DocumentationSet { get; } = documentationSet;
 	public INavigationHtmlWriter NavigationHtmlWriter { get; } = navigationHtmlWriter ?? new IsolatedBuildNavigationHtmlWriter(documentationSet);
 	private StaticFileContentHashProvider StaticFileContentHashProvider { get; } = new(new EmbeddedOrPhysicalFileProvider(documentationSet.Build));
 	private IHistoryMapper HistoryMapper { get; } = historyMapper ?? new BypassHistoryMapper();
+	private IPositionalNavigation PositionalNavigation { get; } = positionalNavigation ?? documentationSet;
+
 	public async Task<string> RenderLayout(MarkdownFile markdown, Cancel ctx = default)
 	{
 		var document = await markdown.ParseFullAsync(ctx);
@@ -87,8 +91,8 @@ private async Task<string> RenderLayout(MarkdownFile markdown, MarkdownDocument
 
 		var navigationHtml = await NavigationHtmlWriter.RenderNavigation(markdown.NavigationRoot, markdown.NavigationSource, ctx);
 
-		var previous = DocumentationSet.GetPrevious(markdown);
-		var next = DocumentationSet.GetNext(markdown);
+		var previous = PositionalNavigation.GetPrevious(markdown);
+		var next = PositionalNavigation.GetNext(markdown);
 
 		var remote = DocumentationSet.Build.Git.RepositoryName;
 		var branch = DocumentationSet.Build.Git.Branch;

src/docs-assembler/Building/AssemblerBuilder.cs

@@ -13,10 +13,10 @@ namespace Documentation.Assembler.Building;
 public class AssemblerBuilder(
 	ILoggerFactory logger,
 	AssembleContext context,
+	GlobalNavigation navigation,
 	GlobalNavigationHtmlWriter writer,
 	GlobalNavigationPathProvider pathProvider,
-	IHistoryMapper? historyMapper
-)
+	IHistoryMapper? historyMapper)
 {
 	private GlobalNavigationHtmlWriter HtmlWriter { get; } = writer;
 
@@ -58,7 +58,13 @@ public async Task BuildAllAsync(FrozenDictionary<string, AssemblerDocumentationS
 
 	private async Task BuildAsync(AssemblerDocumentationSet set, Cancel ctx)
 	{
-		var generator = new DocumentationGenerator(set.DocumentationSet, logger, HtmlWriter, pathProvider, historyMapper: HistoryMapper);
+		var generator = new DocumentationGenerator(
+			set.DocumentationSet,
+			logger, HtmlWriter,
+			pathProvider,
+			historyMapper: HistoryMapper,
+			positionalNavigation: navigation
+		);
 		await generator.GenerateAll(ctx);
 	}
 

src/docs-assembler/Cli/RepositoryCommands.cs

@@ -117,7 +117,7 @@ public async Task<int> BuildAll(
 
 		var historyMapper = new PageHistoryMapper(assembleSources.HistoryMappings);
 
-		var builder = new AssemblerBuilder(logger, assembleContext, htmlWriter, pathProvider, historyMapper);
+		var builder = new AssemblerBuilder(logger, assembleContext, navigation, htmlWriter, pathProvider, historyMapper);
 		await builder.BuildAllAsync(assembleSources.AssembleSets, ctx);
 
 		var sitemapBuilder = new SitemapBuilder(navigation.NavigationItems, assembleContext.WriteFileSystem, assembleContext.OutputDirectory);

src/docs-assembler/Navigation/GlobalNavigation.cs

@@ -9,7 +9,7 @@
 
 namespace Documentation.Assembler.Navigation;
 
-public record GlobalNavigation
+public record GlobalNavigation : IPositionalNavigation
 {
 	private readonly AssembleSources _assembleSources;
 	private readonly GlobalNavigationFile _navigationFile;
@@ -25,8 +25,40 @@ public GlobalNavigation(AssembleSources assembleSources, GlobalNavigationFile na
 		_assembleSources = assembleSources;
 		_navigationFile = navigationFile;
 		NavigationItems = BuildNavigation(navigationFile.TableOfContents, 0);
+		var navigationIndex = 0;
+		var markdownFiles = new HashSet<MarkdownFile>();
+		UpdateNavigationIndex(markdownFiles, NavigationItems, ref navigationIndex);
 		TopLevelItems = NavigationItems.OfType<TocNavigationItem>().ToList();
 		NavigationLookup = TopLevelItems.ToDictionary(kv => kv.Source, kv => kv);
+		var grouped = markdownFiles.GroupBy(f => f.NavigationIndex).ToList();
+		var files = grouped
+			.Select(g => g.First())
+			.ToList();
+
+		MarkdownFiles = files.Where(f => f.NavigationIndex > -1).ToDictionary(i => i.NavigationIndex, i => i).ToFrozenDictionary();
+	}
+
+	public FrozenDictionary<int, MarkdownFile> MarkdownFiles { get; set; }
+
+	private static void UpdateNavigationIndex(HashSet<MarkdownFile> markdownFiles, IReadOnlyCollection<INavigationItem> navigationItems, ref int navigationIndex)
+	{
+		foreach (var item in navigationItems)
+		{
+			switch (item)
+			{
+				case FileNavigationItem fileNavigationItem:
+					var fileIndex = Interlocked.Increment(ref navigationIndex);
+					fileNavigationItem.File.NavigationIndex = fileIndex;
+					_ = markdownFiles.Add(fileNavigationItem.File);
+					break;
+				case GroupNavigationItem { Group.Index: not null } groupNavigationItem:
+					var index = Interlocked.Increment(ref navigationIndex);
+					groupNavigationItem.Group.Index.NavigationIndex = index;
+					_ = markdownFiles.Add(groupNavigationItem.Group.Index);
+					UpdateNavigationIndex(markdownFiles, groupNavigationItem.Group.NavigationItems, ref navigationIndex);
+					break;
+			}
+		}
 	}
 
 	private IReadOnlyCollection<INavigationItem> BuildNavigation(IReadOnlyCollection<TocReference> node, int depth)
@@ -46,8 +78,8 @@ private IReadOnlyCollection<INavigationItem> BuildNavigation(IReadOnlyCollection
 					continue;
 				}
 
-				// TODO passing DocumentationSet to TableOfContentsTree constructr is temporary
-				// We only build this fallback in order to aid with bootstrapping the navigaton
+				// TODO passing DocumentationSet to TableOfContentsTree constructor is temporary
+				// We only build this fallback in order to aid with bootstrapping the navigation
 				if (!_assembleSources.TreeCollector.TryGetTableOfContentsTree(topLevel.TopLevelSource, out tree))
 				{
 					_navigationFile.EmitError(
@@ -86,13 +118,14 @@ private IReadOnlyCollection<INavigationItem> BuildNavigation(IReadOnlyCollection
 
 			var cleanNavigationItems = new List<INavigationItem>();
 			var seenSources = new HashSet<Uri>();
-			foreach (var allNavigationItem in allNavigationItems)
+			foreach (var item in allNavigationItems)
 			{
-				if (allNavigationItem is not TocNavigationItem tocNav)
+				if (item is not TocNavigationItem tocNav)
 				{
-					cleanNavigationItems.Add(allNavigationItem);
+					cleanNavigationItems.Add(item);
 					continue;
 				}
+
 				if (seenSources.Contains(tocNav.Source))
 					continue;
 
@@ -103,20 +136,47 @@ private IReadOnlyCollection<INavigationItem> BuildNavigation(IReadOnlyCollection
 					continue;
 
 				_ = seenSources.Add(tocNav.Source);
-				cleanNavigationItems.Add(allNavigationItem);
+				cleanNavigationItems.Add(item);
 			}
 
 			tree.NavigationItems = cleanNavigationItems.ToArray();
 			var navigationItem = new TocNavigationItem(i, depth, tree, toc.Source);
-			if (toc.Source == new Uri("docs-content://reference"))
-			{
-			}
-
-
 			list.Add(navigationItem);
 			i++;
 		}
 
 		return list.ToArray().AsReadOnly();
 	}
+
+	public MarkdownFile? GetPrevious(MarkdownFile current)
+	{
+		var index = current.NavigationIndex;
+		do
+		{
+			var previous = MarkdownFiles.GetValueOrDefault(index - 1);
+			if (previous is null)
+				return null;
+			if (!previous.Hidden)
+				return previous;
+			index--;
+		} while (index >= 0);
+
+		return null;
+	}
+
+	public MarkdownFile? GetNext(MarkdownFile current)
+	{
+		var index = current.NavigationIndex;
+		do
+		{
+			var previous = MarkdownFiles.GetValueOrDefault(index + 1);
+			if (previous is null)
+				return null;
+			if (!previous.Hidden)
+				return previous;
+			index++;
+		} while (index <= MarkdownFiles.Count);
+
+		return null;
+	}
 }