feat: PDF builder using Chromium

Directory.Build.props

@@ -13,8 +13,9 @@
     <!--
       Suppress warnings similar to the following:
           warning NU1507: There are 2 package sources defined in your configuration.
+          warning CS0436: IgnoresAccessChecksTo redefinition due to InternalsVisibleTo
      -->
-    <NoWarn>$(NoWarn);NU1507</NoWarn>
+    <NoWarn>$(NoWarn);NU1507;CS0436</NoWarn>
   </PropertyGroup>
 
   <PropertyGroup>

Directory.Packages.props

@@ -22,11 +22,13 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.VisualBasic" Version="4.7.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.Common" Version="4.7.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="4.7.0" />
+    <PackageVersion Include="Microsoft.Playwright" Version="1.37.1" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="1.1.1" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageVersion Include="OneOf" Version="3.0.263" />
     <PackageVersion Include="OneOf.SourceGenerator" Version="3.0.263" />
     <PackageVersion Include="PdfPig" Version="0.1.8" />
+    <PackageVersion Include="Spectre.Console" Version="0.47.0" />
     <PackageVersion Include="Spectre.Console.Cli" Version="0.47.0" />
     <PackageVersion Include="Stubble.Core" Version="1.10.8" />
     <PackageVersion Include="System.Collections.Immutable" Version="7.0.0" />
@@ -38,7 +40,6 @@
     <PackageVersion Include="FluentAssertions" Version="6.12.0" />
     <PackageVersion Include="Magick.NET-Q16-AnyCPU" Version="13.4.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.7.1" />
-    <PackageVersion Include="Microsoft.Playwright" Version="1.37.1" />
     <PackageVersion Include="NuGet.Frameworks" Version="6.8.0-rc.122" Condition="'$(TargetFramework)' != 'net8.0'" />
     <PackageVersion Include="NuGet.Frameworks" Version="6.8.0-rc.122" Condition="'$(TargetFramework)' == 'net8.0'" />
     <PackageVersion Include="Verify.DiffPlex" Version="2.2.1" />

src/Docfx.App/Docfx.App.csproj

@@ -13,6 +13,17 @@
     <InternalsVisibleTo Include="docfx" />
     <InternalsVisibleTo Include="docfx.Tests" />
   </ItemGroup>
+
+  <ItemGroup>
+    <InternalsAssemblyName Include="UglyToad.PdfPig" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="IgnoresAccessChecksToGenerator" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.Playwright" />
+    <PackageReference Include="PdfPig" />
+    <PackageReference Include="Spectre.Console" />
+  </ItemGroup>
 
   <ItemGroup>
     <FrameworkReference Include="Microsoft.AspNetCore.App" />

src/Docfx.App/PdfBuilder.cs

@@ -0,0 +1,209 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#nullable enable
+
+using System.Net.Http.Json;
+using System.Reflection;
+using System.Security.Cryptography;
+using System.Text;
+using Microsoft.Playwright;
+using Spectre.Console;
+
+using UglyToad.PdfPig;
+using UglyToad.PdfPig.Actions;
+using UglyToad.PdfPig.Outline;
+using UglyToad.PdfPig.Outline.Destinations;
+using UglyToad.PdfPig.Writer;
+
+namespace Docfx.Pdf;
+
+static class PdfBuilder
+{
+    class Outline
+    {
+        public string name { get; init; } = "";
+
+        public string? href { get; init; }
+
+        public Outline[]? items { get; init; }
+    }
+
+    public static async Task CreatePdf(Uri outlineUrl, CancellationToken cancellationToken = default)
+    {
+        using var http = new HttpClient();
+
+        var outline = await AnsiConsole.Status().StartAsync(
+            $"Downloading {outlineUrl}...",
+            c => http.GetFromJsonAsync<Outline>(outlineUrl, cancellationToken));
+
+        if (outline is null)
+            return;
+
+        AnsiConsole.Status().Start(
+            "Installing Chromium...",
+            c => Program.Main(new[] { "install", "chromium" }));
+
+        using var playwright = await Playwright.CreateAsync();
+        var browser = await playwright.Chromium.LaunchAsync();
+
+        var tempDirectory = Path.Combine(Path.GetTempPath(), ".docfx", "pdf", "pages");
+        Directory.CreateDirectory(tempDirectory);
+
+        var pages = GetPages(outline).ToArray();
+        if (pages.Length == 0)
+        {
+            // TODO: Warn
+            return;
+        }
+
+        var pagesByNode = pages.ToDictionary(p => p.node);
+        var pagesByUrl = new Dictionary<Uri, List<(Outline node, NamedDestinations namedDests)>>();
+        var pageNumbers = new Dictionary<Outline, int>();
+        var nextPageNumbers = new Dictionary<Outline, int>();
+        var nextPageNumber = 1;
+        var margin = "0.4in";
+
+        await AnsiConsole.Progress().Columns(new SpinnerColumn(), new TaskDescriptionColumn { Alignment = Justify.Left }).StartAsync(async c =>
+        {
+            await Parallel.ForEachAsync(pages, async (item, CancellationToken) =>
+            {
+                var task = c.AddTask(item.url.ToString());
+                var page = await browser.NewPageAsync();
+                await page.GotoAsync(item.url.ToString());
+                var bytes = await page.PdfAsync(new() { Margin = new() { Bottom = margin, Top = margin, Left = margin, Right = margin } });
+                File.WriteAllBytes(item.path, bytes);
+                task.Value = task.MaxValue;
+            });
+        });
+
+        AnsiConsole.Status().Start("Creating PDF...", _ => MergePdf());
+
+        IEnumerable<(string path, Uri url, Outline node)> GetPages(Outline outline)
+        {
+            if (!string.IsNullOrEmpty(outline.href))
+            {
+                var url = new Uri(outlineUrl, outline.href);
+                if (url.Host == outlineUrl.Host)
+                {
+                    var id = Convert.ToHexString(SHA256.Create().ComputeHash(Encoding.UTF8.GetBytes(url.ToString())));
+                    yield return (Path.Combine(tempDirectory, $"{id}.pdf"), url, outline);
+                }
+            }
+
+            if (outline.items != null)
+                foreach (var item in outline.items)
+                    foreach (var url in GetPages(item))
+                        yield return url;
+        }
+
+        void MergePdf()
+        {
+            using var output = File.Create("output.pdf");
+            using var builder = new PdfDocumentBuilder(output);
+
+            builder.DocumentInformation = new()
+            {
+                Title = "",
+                Producer = $"docfx ({typeof(PdfBuilder).Assembly.GetCustomAttribute<AssemblyVersionAttribute>()?.Version})",
+            };
+
+            // Calculate page number
+            var pageNumber = 1;
+            foreach (var (path, url, node) in pages)
+            {
+                using var document = PdfDocument.Open(path);
+
+                var key = CleanUrl(url);
+                if (!pagesByUrl.TryGetValue(key, out var dests))
+                    pagesByUrl[key] = dests = new();
+                dests.Add((node, document.Structure.Catalog.NamedDestinations));
+
+                pageNumbers[node] = pageNumber;
+                pageNumber += document.NumberOfPages;
+                nextPageNumbers[node] = pageNumber;
+            }
+
+            // Copy pages
+            foreach (var (path, url, node) in pages)
+            {
+                using var document = PdfDocument.Open(path);
+                for (var i = 1; i <= document.NumberOfPages; i++)
+                    builder.AddPage(document, i, CopyLink);
+            }
+
+            builder.Bookmarks = new(CreateBookmarks(outline.items).ToArray());
+        }
+
+        PdfAction CopyLink(PdfAction action)
+        {
+            return action switch
+            {
+                GoToAction link => new GoToAction(new(link.Destination.PageNumber, link.Destination.Type, link.Destination.Coordinates)),
+                UriAction url => HandleUriAction(url),
+                _ => action,
+            };
+
+            PdfAction HandleUriAction(UriAction url)
+            {
+                if (!Uri.TryCreate(url.Uri, UriKind.Absolute, out var uri) || !pagesByUrl.TryGetValue(CleanUrl(uri), out var pages))
+                    return url;
+
+                if (!string.IsNullOrEmpty(uri.Fragment) && uri.Fragment.Length > 1)
+                {
+                    var name = uri.Fragment.Substring(1);
+                    foreach (var (node, namedDests) in pages)
+                    {
+                        if (namedDests.TryGet(name, out var dest))
+                        {
+                            AnsiConsole.MarkupLine($"[green]Resolve succeed: {name}[/]");
+                            return new GoToAction(new(1, dest.Type, dest.Coordinates));
+                        }
+                    }
+
+                    AnsiConsole.MarkupLine($"[yellow]Failed to resolve named dest: {name}[/]");
+                }
+
+                return new GoToAction(new(pageNumbers[pages[0].node], ExplicitDestinationType.FitHorizontally, ExplicitDestinationCoordinates.Empty));
+            }
+        }
+
+        static Uri CleanUrl(Uri url)
+        {
+            return new UriBuilder(url) { Query = null, Fragment = null }.Uri;
+        }
+
+        IEnumerable<BookmarkNode> CreateBookmarks(Outline[]? items, int level = 0)
+        {
+            if (items is null)
+                yield break;
+
+            foreach (var item in items)
+            {
+                if (string.IsNullOrEmpty(item.href))
+                {
+                    yield return new DocumentBookmarkNode(
+                        item.name, level,
+                        new(nextPageNumber, ExplicitDestinationType.FitHorizontally, ExplicitDestinationCoordinates.Empty),
+                        CreateBookmarks(item.items, level + 1).ToArray());
+                    continue;
+                }
+
+                if (!pagesByNode.TryGetValue(item, out var page))
+                {
+                    yield return new UriBookmarkNode(
+                        item.name, level,
+                        new Uri(outlineUrl, item.href).ToString(),
+                        CreateBookmarks(item.items, level + 1).ToArray());
+                    continue;
+                }
+
+                nextPageNumber = nextPageNumbers[item];
+                yield return new DocumentBookmarkNode(
+                    item.name, level,
+                    new(pageNumbers[item], ExplicitDestinationType.FitHorizontally, ExplicitDestinationCoordinates.Empty),
+                    CreateBookmarks(item.items, level + 1).ToArray());
+            }
+        }
+    }
+}

src/docfx/Properties/launchSettings.json

@@ -26,6 +26,14 @@
       "environmentVariables": {
       }
     },
+    // Run `docfx pdf` command and launch browser.
+    "docfx pdf": {
+      "commandName": "Project",
+      "commandLineArgs": "pdf ../../samples/seed/docfx.json",
+      "workingDirectory": ".",
+      "environmentVariables": {
+      }
+    },
     // Run `docfx` command.
     "docfx": {
       "commandName": "Project",

templates/modern/src/dotnet.scss

@@ -104,6 +104,12 @@ body[data-yaml-mime="ManagedReference"] article, body[data-yaml-mime="ApiPage"]
     font-size: 1.2rem;
   }
 
+  @media print {
+    .header-action {
+      display: none;
+    }
+  }
+
   td.term {
     font-weight: 600;
   }

test/docfx.Snapshot.Tests/SamplesTest.cs

@@ -52,7 +52,7 @@ private static readonly (int width, int height, string theme, bool fullPage)[] s
 
     static SamplesTest()
     {
-        Microsoft.Playwright.Program.Main(new[] { "install" });
+        Microsoft.Playwright.Program.Main(new[] { "install", "chromium" });
         Process.Start("dotnet", $"build \"{s_samplesDir}/seed/dotnet/assembly/BuildFromAssembly.csproj\"").WaitForExit();
     }