From 2c4c1b9a7a45d527a876474af4c692bdeec1b502 Mon Sep 17 00:00:00 2001
From: Caen De Silva <caen@desilva.se>
Date: Tue, 19 Apr 2022 21:50:40 +0200
Subject: [PATCH] Add the table of contents generation

---
 src/Actions/GeneratesTableOfContents.php | 53 ++++++++++++++++++++++++
 src/Models/DocumentationPage.php         |  9 ++++
 src/Models/HasTableOfContents.php        | 20 +++++++++
 3 files changed, 82 insertions(+)
 create mode 100644 src/Actions/GeneratesTableOfContents.php
 create mode 100644 src/Models/HasTableOfContents.php

diff --git a/src/Actions/GeneratesTableOfContents.php b/src/Actions/GeneratesTableOfContents.php
new file mode 100644
index 00000000..98ea5235
--- /dev/null
+++ b/src/Actions/GeneratesTableOfContents.php
@@ -0,0 +1,53 @@
+<?php
+
+namespace Hyde\Framework\Actions;
+
+use League\CommonMark\Environment\Environment;
+use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
+use League\CommonMark\Extension\HeadingPermalink\HeadingPermalinkExtension;
+use League\CommonMark\Extension\TableOfContents\TableOfContentsExtension;
+use League\CommonMark\MarkdownConverter;
+
+/**
+ * Generates a table of contents for the Markdown document.
+ * @see \Tests\Feature\Actions\GeneratesTableOfContentsTest
+ */
+class GeneratesTableOfContents implements ActionContract
+{
+    protected string $markdown;
+
+    public function __construct(string $markdown)
+    {
+        $this->markdown = $markdown;
+    }
+
+    public static int $minHeadingLevel = 2;
+    public static int $maxHeadingLevel = 4;
+
+    public function execute(): string
+    {
+        $config = [
+            'table_of_contents' => [
+                'html_class' => 'table-of-contents',
+                'position' => 'top',
+                'style' => 'bullet',
+                'min_heading_level' => static::$minHeadingLevel,
+                'max_heading_level' => static::$maxHeadingLevel,
+                'normalize' => 'relative',
+            ],
+            'heading_permalink' => [
+                'fragment_prefix' => '',
+            ],
+        ];
+
+        $environment = new Environment($config);
+        $environment->addExtension(new CommonMarkCoreExtension());
+        $environment->addExtension(new HeadingPermalinkExtension());
+        $environment->addExtension(new TableOfContentsExtension());
+
+        $converter = new MarkdownConverter($environment);
+        $html = $converter->convert("[[END_TOC]]\n" . $this->markdown)->getContent();
+
+        return substr($html, 0, strpos($html, '[[END_TOC]]') - 9);
+    }
+}
diff --git a/src/Models/DocumentationPage.php b/src/Models/DocumentationPage.php
index 76c20a6b..61905b45 100644
--- a/src/Models/DocumentationPage.php
+++ b/src/Models/DocumentationPage.php
@@ -6,6 +6,15 @@
 
 class DocumentationPage extends MarkdownDocument
 {
+    use HasTableOfContents;
+
     public static string $sourceDirectory = '_docs';
     public static string $parserClass = DocumentationPageParser::class;
+
+    public function __construct(array $matter, string $body, string $title = '', string $slug = '')
+    {
+        parent::__construct($matter, $body, $title, $slug);
+
+        $this->constructTableOfContents();
+    }
 }
diff --git a/src/Models/HasTableOfContents.php b/src/Models/HasTableOfContents.php
new file mode 100644
index 00000000..7c2bc3da
--- /dev/null
+++ b/src/Models/HasTableOfContents.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Hyde\Framework\Models;
+
+use Hyde\Framework\Actions\GeneratesTableOfContents;
+
+/**
+ * Trait HasTableOfContents.
+ *
+ * @see \Tests\Unit\HasTableOfContentsTest
+ */
+trait HasTableOfContents
+{
+    public string $tableOfContents;
+
+    public function constructTableOfContents(): void
+    {
+        $this->tableOfContents = (new GeneratesTableOfContents($this->body))->execute();
+    }
+}
\ No newline at end of file