From b21323e9e24c8dfbd32c7f7e2f9031a390fac771 Mon Sep 17 00:00:00 2001
From: Brent Roose <brent.roose@gmail.com>
Date: Fri, 15 Mar 2024 11:15:36 +0100
Subject: [PATCH] Commonmark

---
 HighlightCodeBlockRendererTest.php            | 31 +++++++++++++++
 README.md                                     | 28 ++++++++++++-
 composer.json                                 |  4 +-
 src/CommonMark/HighlightCodeBlockRenderer.php | 39 +++++++++++++++++++
 4 files changed, 100 insertions(+), 2 deletions(-)
 create mode 100644 HighlightCodeBlockRendererTest.php
 create mode 100644 src/CommonMark/HighlightCodeBlockRenderer.php

diff --git a/HighlightCodeBlockRendererTest.php b/HighlightCodeBlockRendererTest.php
new file mode 100644
index 0000000..fd66501
--- /dev/null
+++ b/HighlightCodeBlockRendererTest.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Tempest\Highlight\CommonMark;
+
+use League\CommonMark\Environment\Environment;
+use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
+use League\CommonMark\Extension\CommonMark\Node\Block\FencedCode;
+use League\CommonMark\Extension\FrontMatter\FrontMatterExtension;
+use League\CommonMark\MarkdownConverter;
+use PHPUnit\Framework\TestCase;
+
+class HighlightCodeBlockRendererTest extends TestCase
+{
+    public function test_commonmark(): void
+    {
+        $environment = new Environment();
+
+        $environment
+            ->addExtension(new CommonMarkCoreExtension())
+            ->addExtension(new FrontMatterExtension())
+            ->addRenderer(FencedCode::class, new \Tempest\Highlight\CommonMark\HighlightCodeBlockRenderer());
+
+        $markdown = new MarkdownConverter($environment);
+        
+        $parsed = $markdown->convert("```php
+        class Foo {}
+        ```");
+
+        $this->assertStringContainsString('hl-keyword', $parsed->getContent());
+    }
+}
diff --git a/README.md b/README.md
index a1f849e..8a079ca 100644
--- a/README.md
+++ b/README.md
@@ -50,4 +50,30 @@ Or you can build your own with just a couple of classes:
 }
 ```
 
-You should style your any pre tags yourself.
\ No newline at end of file
+You should style your any pre tags yourself.
+
+## CommonMark integration
+
+If you're using `league/commonmark`, you can add highlight support to codeblocks like so:
+
+```php
+use League\CommonMark\Environment\Environment;
+use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
+use League\CommonMark\Extension\CommonMark\Node\Block\FencedCode;
+use League\CommonMark\MarkdownConverter;
+use Tempest\Highlight\CommonMark\HighlightCodeBlockRenderer;
+
+$environment = new Environment();
+
+$environment
+    ->addExtension(new CommonMarkCoreExtension())
+    ->addRenderer(FencedCode::class, new HighlightCodeBlockRenderer());
+
+$markdown = new MarkdownConverter($environment);
+```
+
+Keep in mind that you need to manually install `league/commonmark`:
+
+```php
+composer require league/commonmark;
+```
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 71ec92e..8945841 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,9 @@
     "require-dev": {
         "phpunit/phpunit": "^11.0",
         "phpstan/phpstan": "^1.10.0",
-        "friendsofphp/php-cs-fixer": "^3.21"
+        "friendsofphp/php-cs-fixer": "^3.21",
+        "league/commonmark": "^2.4",
+        "larapack/dd": "^1.1"
     },
     "scripts": {
         "phpunit": "vendor/bin/phpunit --display-warnings --display-skipped --display-deprecations --display-errors --display-notices",
diff --git a/src/CommonMark/HighlightCodeBlockRenderer.php b/src/CommonMark/HighlightCodeBlockRenderer.php
new file mode 100644
index 0000000..4f11e64
--- /dev/null
+++ b/src/CommonMark/HighlightCodeBlockRenderer.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Tempest\Highlight\CommonMark;
+
+use InvalidArgumentException;
+use League\CommonMark\Extension\CommonMark\Node\Block\FencedCode;
+use League\CommonMark\Extension\CommonMark\Renderer\Block\FencedCodeRenderer as BaseFencedCodeRenderer;
+use League\CommonMark\Node\Node;
+use League\CommonMark\Renderer\ChildNodeRendererInterface;
+use League\CommonMark\Renderer\NodeRendererInterface;
+use Tempest\Highlight\Highlighter;
+
+class HighlightCodeBlockRenderer implements NodeRendererInterface
+{
+    public function render(Node $node, ChildNodeRendererInterface $childRenderer)
+    {
+        if (! $node instanceof FencedCode) {
+            throw new InvalidArgumentException('Block must be instance of ' . FencedCode::class);
+        }
+
+        $renderer = new BaseFencedCodeRenderer();
+
+        $language = $node->getInfoWords()[0] ?? 'txt';
+
+        $highlight = new Highlighter();
+
+        /** @var \League\CommonMark\Util\HtmlElement $codeBlock */
+        $codeBlock = $renderer->render($node, $childRenderer);
+
+        /** @var string $codeText */
+        $codeText = $codeBlock->getContents(false)->getContents();
+
+        $codeBlock->setContents($highlight->parse($codeText, $language));
+
+        $codeBlock->setContents($codeBlock->getContents());
+
+        return $codeBlock;
+    }
+}