Work in progress, display emojis

app/Services/Parser/Extensions/Emoji.php

@@ -0,0 +1,29 @@
+<?php
+namespace Coyote\Services\Parser\Extensions;
+
+use League\CommonMark\Node\Block\AbstractBlock;
+
+class Emoji extends AbstractBlock
+{
+    private static ?array $resourceFile = null;
+
+    public string $code;
+    public string $unified;
+    public string $name;
+
+    public function __construct(string $code)
+    {
+        parent::__construct();
+        $this->code = $code;
+
+        if (self::$resourceFile === null) {
+            self::$resourceFile = \json_decode(\file_get_contents(__DIR__ . DIRECTORY_SEPARATOR . 'emoji.json'), true);
+        }
+        $resourceFile = self::$resourceFile;
+
+        $emoji = $resourceFile['emoticons'][$code];
+
+        $this->unified = $emoji['unified'];
+        $this->name = $emoji['name'];
+    }
+}

app/Services/Parser/Extensions/EmojiParser.php

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+<?php
+namespace Coyote\Services\Parser\Extensions;
+
+use League\CommonMark\Parser\Cursor;
+use League\CommonMark\Parser\Inline\InlineParserInterface;
+use League\CommonMark\Parser\Inline\InlineParserMatch;
+use League\CommonMark\Parser\InlineParserContext;
+
+class EmojiParser implements InlineParserInterface
+{
+    public function getMatchDefinition(): InlineParserMatch
+    {
+        return InlineParserMatch::join(
+            InlineParserMatch::string(':'),
+            InlineParserMatch::regex('\w+'),
+            InlineParserMatch::string(':'));
+    }
+
+    public function parse(InlineParserContext $inlineContext): bool
+    {
+        $cursor = $inlineContext->getCursor();
+        $previous = $cursor->peek(-1);
+        if ($previous === null || $previous === ' ') {
+            return $this->appendEmoji($cursor, $inlineContext);
+        }
+        return false;
+    }
+
+    private function appendEmoji(Cursor $cursor, InlineParserContext $context): bool
+    {
+        $previousState = $cursor->saveState();
+        $emoji = $cursor->match('/^:[\w+-]+:/i');
+        if ($emoji === null) {
+            $cursor->restoreState($previousState);
+            return false;
+        }
+        $emoji = \subStr($emoji, 1, -1);
+        if (\array_key_exists($emoji, Emojis::$codes)) {
+            $container = $context->getContainer();
+            $container->appendChild(new Emoji($emoji));
+            return true;
+        }
+        $cursor->restoreState($previousState);
+        return false;
+    }
+}

app/Services/Parser/Extensions/EmojiRenderer.php

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+<?php
+namespace Coyote\Services\Parser\Extensions;
+
+use League\CommonMark\Node\Node;
+use League\CommonMark\Renderer\ChildNodeRendererInterface;
+use League\CommonMark\Renderer\NodeRendererInterface;
+use League\CommonMark\Util\HtmlElement;
+
+class EmojiRenderer implements NodeRendererInterface
+{
+    public function render(Node $node, ChildNodeRendererInterface $childRenderer): HtmlElement
+    {
+        if ($node instanceof Emoji) {
+            return $this->renderEmoji($node);
+        }
+        throw new \LogicException('Failed to parse markdown emoticons');
+    }
+
+    private function renderEmoji(Emoji $emoji): HtmlElement
+    {
+        return new HtmlElement('img', [
+            'class' => 'img-smile',
+            'src'   => $this->cdnUrl($emoji),
+            'alt'   => ":$emoji->code:, $emoji->name",
+        ]);
+    }
+
+    private function cdnUrl(Emoji $emoji): string
+    {
+        return "https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/svg/$emoji->unified.svg";
+    }
+}