1 files changed, 166 insertions, 0 deletions
diff --git a/vendor/league/commonmark/src/Extension/TableOfContents/TableOfContentsBuilder.php b/vendor/league/commonmark/src/Extension/TableOfContents/TableOfContentsBuilder.php
new file mode 100644
index 0000000000..05d8be9d57
--- /dev/null
+++ b/vendor/league/commonmark/src/Extension/TableOfContents/TableOfContentsBuilder.php
@@ -0,0 +1,166 @@
+<?php
+
+/*
+ * This file is part of the league/commonmark package.
+ *
+ * (c) Colin O'Dell <colinodell@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace League\CommonMark\Extension\TableOfContents;
+
+use League\CommonMark\Block\Element\Document;
+use League\CommonMark\Block\Element\Heading;
+use League\CommonMark\Block\Element\ListBlock;
+use League\CommonMark\Block\Element\ListData;
+use League\CommonMark\Block\Element\ListItem;
+use League\CommonMark\Block\Element\Paragraph;
+use League\CommonMark\Event\DocumentParsedEvent;
+use League\CommonMark\Exception\InvalidOptionException;
+use League\CommonMark\Extension\HeadingPermalink\HeadingPermalink;
+use League\CommonMark\Extension\TableOfContents\Normalizer\AsIsNormalizerStrategy;
+use League\CommonMark\Extension\TableOfContents\Normalizer\FlatNormalizerStrategy;
+use League\CommonMark\Extension\TableOfContents\Normalizer\NormalizerStrategyInterface;
+use League\CommonMark\Extension\TableOfContents\Normalizer\RelativeNormalizerStrategy;
+use League\CommonMark\Inline\Element\Link;
+use League\CommonMark\Util\ConfigurationAwareInterface;
+use League\CommonMark\Util\ConfigurationInterface;
+
+final class TableOfContentsBuilder implements ConfigurationAwareInterface
+{
+    public const STYLE_BULLET = ListBlock::TYPE_BULLET;
+    public const STYLE_ORDERED = ListBlock::TYPE_ORDERED;
+
+    public const NORMALIZE_DISABLED = 'as-is';
+    public const NORMALIZE_RELATIVE = 'relative';
+    public const NORMALIZE_FLAT = 'flat';
+
+    public const POSITION_TOP = 'top';
+    public const POSITION_BEFORE_HEADINGS = 'before-headings';
+
+    /** @var ConfigurationInterface */
+    private $config;
+
+    public function onDocumentParsed(DocumentParsedEvent $event): void
+    {
+        $document = $event->getDocument();
+        $toc = $this->createToc();
+
+        $normalizer = $this->getNormalizer($toc);
+        [$min, $max] = $this->getMinAndMaxHeadingLevels();
+
+        $firstHeading = null;
+
+        foreach ($this->getHeadingLinks($document) as $headingLink) {
+            $heading = $headingLink->parent();
+            // Make sure this is actually tied to a heading
+            if (!$heading instanceof Heading) {
+                continue;
+            }
+
+            // Skip any headings outside the configured min/max levels
+            if ($heading->getLevel() < $min || $heading->getLevel() > $max) {
+                continue;
+            }
+
+            // Keep track of the first heading we see - we might need this later
+            $firstHeading = $firstHeading ?? $heading;
+
+            // Create the new link
+            $link = new Link('#' . $headingLink->getSlug(), $heading->getStringContent());
+            $paragraph = new Paragraph();
+            $paragraph->appendChild($link);
+
+            $listItem = new ListItem($toc->getListData());
+            $listItem->appendChild($paragraph);
+
+            // Add it to the correct place
+            $normalizer->addItem($heading->getLevel(), $listItem);
+        }
+
+        // Don't add the TOC if no headings were present
+        if (!$toc->hasChildren() || $firstHeading === null) {
+            return;
+        }
+
+        // Add the TOC to the Document
+        $position = $this->config->get('table_of_contents/position', self::POSITION_TOP);
+        if ($position === self::POSITION_TOP) {
+            $document->prependChild($toc);
+        } elseif ($position === self::POSITION_BEFORE_HEADINGS) {
+            $firstHeading->insertBefore($toc);
+        } else {
+            throw new InvalidOptionException(\sprintf('Invalid config option "%s" for "table_of_contents/position"', $position));
+        }
+    }
+
+    private function createToc(): TableOfContents
+    {
+        $listData = new ListData();
+
+        $style = $this->config->get('table_of_contents/style', self::STYLE_BULLET);
+        if ($style === self::STYLE_BULLET) {
+            $listData->type = ListBlock::TYPE_BULLET;
+        } elseif ($style === self::STYLE_ORDERED) {
+            $listData->type = ListBlock::TYPE_ORDERED;
+        } else {
+            throw new InvalidOptionException(\sprintf('Invalid config option "%s" for "table_of_contents/style"', $style));
+        }
+
+        $toc = new TableOfContents($listData);
+
+        $class = $this->config->get('table_of_contents/html_class', 'table-of-contents');
+        if (!empty($class)) {
+            $toc->data['attributes']['class'] = $class;
+        }
+
+        return $toc;
+    }
+
+    /**
+     * @return array<int>
+     */
+    private function getMinAndMaxHeadingLevels(): array
+    {
+        return [
+            (int) $this->config->get('table_of_contents/min_heading_level', 1),
+            (int) $this->config->get('table_of_contents/max_heading_level', 6),
+        ];
+    }
+
+    /**
+     * @param Document $document
+     *
+     * @return iterable<HeadingPermalink>
+     */
+    private function getHeadingLinks(Document $document)
+    {
+        $walker = $document->walker();
+        while ($event = $walker->next()) {
+            if ($event->isEntering() && ($node = $event->getNode()) instanceof HeadingPermalink) {
+                yield $node;
+            }
+        }
+    }
+
+    private function getNormalizer(TableOfContents $toc): NormalizerStrategyInterface
+    {
+        $strategy = $this->config->get('table_of_contents/normalize', self::NORMALIZE_RELATIVE);
+        if ($strategy === self::NORMALIZE_DISABLED) {
+            return new AsIsNormalizerStrategy($toc);
+        } elseif ($strategy === self::NORMALIZE_RELATIVE) {
+            return new RelativeNormalizerStrategy($toc);
+        } elseif ($strategy === self::NORMALIZE_FLAT) {
+            return new FlatNormalizerStrategy($toc);
+        }
+
+        throw new InvalidOptionException(\sprintf('Invalid config option "%s" for "table_of_contents/normalize"', $strategy));
+    }
+
+    public function setConfiguration(ConfigurationInterface $config)
+    {
+        $this->config = $config;
+    }
+}