From 5b2892b215669996802593f0e77d836d17f18b35 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nu=C5=A1a=20Puk=C5=A1i=C4=8D?= <nusa.puksic@dhimahi.com>
Date: Mon, 9 Dec 2024 19:53:21 +0100
Subject: [PATCH] Converting MD into HTML, setting up article view

---
 src/Controller/ArticleController.php          |  62 +++++++
 src/Util/Bech32/Bech32Decoder.php             | 154 ++++++++++++++++++
 src/Util/CommonMark/Converter.php             |  74 +++++++++
 .../NostrEventRenderer.php                    |  36 ++++
 .../NostrSchemeExtension/NostrMentionLink.php |  29 ++++
 .../NostrMentionParser.php                    |  50 ++++++
 .../NostrMentionRenderer.php                  |  34 ++++
 .../NostrRawNpubParser.php                    |  42 +++++
 .../NostrSchemeExtension/NostrSchemeData.php  |  56 +++++++
 .../NostrSchemeExtension.php                  |  27 +++
 .../NostrSchemeParser.php                     | 102 ++++++++++++
 templates/pages/article.html.twig             |  45 +++++
 12 files changed, 711 insertions(+)
 create mode 100644 src/Controller/ArticleController.php
 create mode 100644 src/Util/Bech32/Bech32Decoder.php
 create mode 100644 src/Util/CommonMark/Converter.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrEventRenderer.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrMentionLink.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrMentionParser.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrMentionRenderer.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrRawNpubParser.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrSchemeData.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrSchemeExtension.php
 create mode 100644 src/Util/CommonMark/NostrSchemeExtension/NostrSchemeParser.php
 create mode 100644 templates/pages/article.html.twig

diff --git a/src/Controller/ArticleController.php b/src/Controller/ArticleController.php
new file mode 100644
index 0000000..b753339
--- /dev/null
+++ b/src/Controller/ArticleController.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace App\Controller;
+
+use App\Entity\Article;
+use App\Entity\User;
+use App\Util\CommonMark\Converter;
+use Doctrine\ORM\EntityManagerInterface;
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Cache\InvalidArgumentException;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+
+class ArticleController  extends AbstractController
+{
+    /**
+     * @throws InvalidArgumentException
+     */
+    #[Route('/article/d/{slug}', name: 'article-slug')]
+    public function article(EntityManagerInterface $entityManager, CacheItemPoolInterface $articlesCache,
+                            Converter $converter, $slug): Response
+    {
+        $article = null;
+        // check if an item with same eventId already exists in the db
+        $repository = $entityManager->getRepository(Article::class);
+        $articles = $repository->findBy(['slug' => $slug]);
+        $revisions = count($repository->findBy(['slug' => $slug]));
+
+        if ($revisions > 1) {
+            // sort articles by created at date
+            usort($articles, function ($a, $b) {
+                return $b->getCreatedAt() <=> $a->getCreatedAt();
+            });
+            // get the last article
+            $article = end($articles);
+        } else {
+            $article = $articles[0];
+        }
+
+        if (!$article) {
+            throw $this->createNotFoundException('The article does not exist');
+        }
+
+        $cacheKey = 'article_' . $article->getId();
+        $cacheItem = $articlesCache->getItem($cacheKey);
+        if (!$cacheItem->isHit()) {
+            $cacheItem->set($converter->convertToHtml($article->getContent()));
+            $articlesCache->save($cacheItem);
+        }
+
+        // find user by npub
+        $author = $entityManager->getRepository(User::class)->findOneBy(['npub' => $article->getPubkey()]);
+
+        return $this->render('Pages/article.html.twig', [
+            'article' => $article,
+            'author' => $author,
+            'content' => $cacheItem->get()
+        ]);
+    }
+
+}
diff --git a/src/Util/Bech32/Bech32Decoder.php b/src/Util/Bech32/Bech32Decoder.php
new file mode 100644
index 0000000..7205633
--- /dev/null
+++ b/src/Util/Bech32/Bech32Decoder.php
@@ -0,0 +1,154 @@
+<?php
+
+namespace App\Util\Bech32;
+
+use Exception;
+
+class Bech32Decoder
+{
+    // Function to decode Bech32 without character length restriction
+    /**
+     * @throws Exception
+     */
+    public function decodeBech32(string $bech32): array
+    {
+        $charset = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';
+
+        // Find the separator (1)
+        $pos = strrpos($bech32, '1');
+        if ($pos === false) {
+            throw new Exception('Invalid Bech32 string');
+        }
+
+        // Extract human-readable part (HRP)
+        $hrp = substr($bech32, 0, $pos);
+
+        // Extract data part
+        $data_part = substr($bech32, $pos + 1);
+        $data = [];
+        for ($i = 0; $i < strlen($data_part); $i++) {
+            $data[] = strpos($charset, $data_part[$i]);
+            if ($data[$i] === false) {
+                throw new Exception('Invalid character in Bech32 string');
+            }
+        }
+
+        return [$hrp, $data];
+    }
+
+    // Function to convert 5-bit data to 8-bit data
+    public function convertBits(array $data, int $fromBits, int $toBits, bool $pad = true): array
+    {
+        $acc = 0;
+        $bits = 0;
+        $ret = [];
+        $maxv = (1 << $toBits) - 1;
+        $max_acc = (1 << ($fromBits + $toBits - 1)) - 1;
+
+        foreach ($data as $value) {
+            if ($value < 0 || $value >> $fromBits) {
+                throw new Exception('Invalid value in data');
+            }
+            $acc = (($acc << $fromBits) | $value) & $max_acc;
+            $bits += $fromBits;
+            while ($bits >= $toBits) {
+                $bits -= $toBits;
+                $ret[] = ($acc >> $bits) & $maxv;
+            }
+        }
+
+        if ($pad) {
+            if ($bits > 0) {
+                $ret[] = ($acc << ($toBits - $bits)) & $maxv;
+            }
+        } else if ($bits >= $fromBits || (($acc << ($toBits - $bits)) & $maxv)) {
+            throw new Exception('Invalid padding');
+        }
+
+        return $ret;
+    }
+
+    // Public method to decode a Nostr Bech32 string and return hex
+    public function decodeNostrBech32ToHex(string $bech32): string
+    {
+        list($hrp, $data) = $this->decodeBech32($bech32);
+
+        // Convert 5-bit data back to 8-bit data
+        $decodedData = $this->convertBits($data, 5, 8, false);
+
+        // Return the decoded data as a hex string
+        return bin2hex(pack('C*', ...$decodedData));
+    }
+
+    // Public method to decode a Nostr Bech32 string and return the binary data
+
+    /**
+     * @throws Exception
+     */
+    public function decodeNostrBech32ToBinary(string $bech32): array
+    {
+        list($hrp, $data) = $this->decodeBech32($bech32);
+
+        // Convert 5-bit data to 8-bit data
+        $decodedData = $this->convertBits($data, 5, 8);
+
+        return [$hrp, $decodedData];
+    }
+
+    // Public method to parse the binary data into TLV format
+    public function parseTLV(array $binaryData): array
+    {
+        $parsedTLVs = [];
+        $offset = 0;
+
+        while ($offset < count($binaryData)) {
+            if ($offset + 1 >= count($binaryData)) {
+                throw new Exception("Incomplete TLV data");
+            }
+
+            // Read the Type (T) and Length (L)
+            $type = $binaryData[$offset];
+            $length = $binaryData[$offset + 1];
+            $offset += 2;
+
+            // Ensure we have enough data for the value
+            if ($offset + $length > count($binaryData)) {
+                break;
+            } else {
+                // Extract the Value (V)
+                $value = array_slice($binaryData, $offset, $length);
+            }
+
+            $offset += $length;
+
+            // Add the TLV to the parsed array
+            $parsedTLVs[] = [
+                'type' => $type,
+                'length' => $length,
+                'value' => $value,
+            ];
+        }
+
+        return $parsedTLVs;
+    }
+
+    // Decode and parse a Bech32 string
+
+    /**
+     * @throws Exception
+     */
+    public function decodeAndParseNostrBech32(string $bech32): array
+    {
+        // Step 1: Decode Bech32 to binary data
+        list($hrp, $binaryData) = $this->decodeNostrBech32ToBinary($bech32);
+
+        if ($hrp == 'npub') {
+            return [$hrp, $binaryData];
+        }
+
+        // Step 2: Parse the binary data into TLV format
+        $tlvData = $this->parseTLV($binaryData);
+
+        return [$hrp, $tlvData];
+    }
+}
diff --git a/src/Util/CommonMark/Converter.php b/src/Util/CommonMark/Converter.php
new file mode 100644
index 0000000..e6e5e93
--- /dev/null
+++ b/src/Util/CommonMark/Converter.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace App\Util\CommonMark;
+
+use App\Util\Bech32\Bech32Decoder;
+use App\Util\CommonMark\NostrSchemeExtension\NostrSchemeExtension;
+use League\CommonMark\Environment\Environment;
+use League\CommonMark\Exception\CommonMarkException;
+use League\CommonMark\Extension\Autolink\AutolinkExtension;
+use League\CommonMark\Extension\CommonMark\CommonMarkCoreExtension;
+use League\CommonMark\Extension\Footnote\FootnoteExtension;
+use League\CommonMark\Extension\HeadingPermalink\HeadingPermalinkExtension;
+use League\CommonMark\Extension\SmartPunct\SmartPunctExtension;
+use League\CommonMark\Extension\Strikethrough\StrikethroughExtension;
+use League\CommonMark\Extension\Table\TableExtension;
+use League\CommonMark\Extension\TableOfContents\TableOfContentsExtension;
+use League\CommonMark\MarkdownConverter;
+
+class Converter
+{
+    public function __construct(private readonly Bech32Decoder $bech32Decoder)
+    {
+    }
+
+    /**
+     * @throws CommonMarkException
+     */
+    public function convertToHTML(string $markdown): string
+    {
+        // Check if the article has more than three headings
+        // Match all headings (from level 1 to 6)
+        preg_match_all('/^#+\s.*$/m', $markdown, $matches);
+        $headingsCount = count($matches[0]);
+
+
+        // Configure the Environment with all the CommonMark parsers/renderers
+        $config = [
+            'table_of_contents' => [
+                'min_heading_level' => 1,
+                'max_heading_level' => 2,
+            ],
+            'heading_permalink' => [
+                'symbol' => '§',
+            ],
+            'autolink' => [
+                'allowed_protocols' => ['https'], // defaults to ['https', 'http', 'ftp']
+                'default_protocol' => 'https', // defaults to 'http'
+            ],
+        ];
+        $environment = new Environment($config);
+        // Add the extensions
+        $environment->addExtension(new CommonMarkCoreExtension());
+        $environment->addExtension(new FootnoteExtension());
+        $environment->addExtension(new TableExtension());
+        $environment->addExtension(new StrikethroughExtension());
+        // create a custom extension, that handles nostr mentions
+        $environment->addExtension(new NostrSchemeExtension($this->bech32Decoder));
+        $environment->addExtension(new SmartPunctExtension());
+        $environment->addExtension(new AutolinkExtension());
+        if ($headingsCount > 3) {
+            $environment->addExtension(new HeadingPermalinkExtension());
+            $environment->addExtension(new TableOfContentsExtension());
+        }
+
+        // Instantiate the converter engine and start converting some Markdown!
+        $converter = new MarkdownConverter($environment);
+        $content = html_entity_decode($markdown);
+
+        dump($content);
+
+        return $converter->convert($content);
+    }
+
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrEventRenderer.php b/src/Util/CommonMark/NostrSchemeExtension/NostrEventRenderer.php
new file mode 100644
index 0000000..9e6f804
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrEventRenderer.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use League\CommonMark\Node\Node;
+use League\CommonMark\Renderer\ChildNodeRendererInterface;
+use League\CommonMark\Renderer\NodeRendererInterface;
+use League\CommonMark\Util\HtmlElement;
+
+class NostrEventRenderer implements NodeRendererInterface
+{
+
+    public function render(Node $node, ChildNodeRendererInterface $childRenderer)
+    {
+        if (!($node instanceof NostrSchemeData)) {
+            throw new \InvalidArgumentException('Incompatible inline node type: ' . get_class($node));
+        }
+
+        if ($node->getType() === 'nevent') {
+            // Construct the local link URL from the special part
+            $url = '/e/' .  $node->getSpecial();
+        } else if ($node->getType() === 'naddr') {
+            dump($node);
+            // Construct the local link URL from the special part
+            $url = '/' .  $node->getSpecial();
+        }
+
+        if (isset($url)) {
+            // Create the anchor element
+            return new HtmlElement('a', ['href' => $url], '@' . $node->getSpecial());
+        }
+
+        return false;
+
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrMentionLink.php b/src/Util/CommonMark/NostrSchemeExtension/NostrMentionLink.php
new file mode 100644
index 0000000..5d205b3
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrMentionLink.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use League\CommonMark\Node\Inline\AbstractInline;
+
+class NostrMentionLink extends AbstractInline
+{
+    private ?string $label;
+    private string $npub;
+
+    public function __construct(?string $label, string $npubPart)
+    {
+        parent::__construct();
+
+        $this->label = $label;
+        $this->npub = $npubPart;
+    }
+
+    public function getLabel(): ?string
+    {
+        return $this->label;
+    }
+
+    public function getNpub(): string
+    {
+        return $this->npub;
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrMentionParser.php b/src/Util/CommonMark/NostrSchemeExtension/NostrMentionParser.php
new file mode 100644
index 0000000..694f1da
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrMentionParser.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use League\CommonMark\Parser\Inline\InlineParserInterface;
+use League\CommonMark\Parser\Inline\InlineParserMatch;
+use League\CommonMark\Parser\InlineParserContext;
+use swentel\nostr\Key\Key;
+
+/**
+ * Class NostrMentionParser
+ * Looks for links that look like Markdown links in the format `[label](url)`,
+ * but have npub1XXXX instead of a URL
+ * @package App\Util\CommonMark
+ */
+class NostrMentionParser implements InlineParserInterface
+{
+
+    public function getMatchDefinition(): InlineParserMatch
+    {
+        // Define a match for a markdown link-like structure with "npub" links
+        return InlineParserMatch::regex('\[([^\]]+)\]\(npub1[0-9a-zA-Z]+\)');
+    }
+
+    public function parse(InlineParserContext $inlineContext): bool
+    {
+        $cursor = $inlineContext->getCursor();
+        // Get the match and extract relevant parts
+        $matches = $inlineContext->getMatches();
+
+        // The entire match is like "[label](npubXXXX)", now we need to extract "label" and "npubXXXX"
+        $fullMatch = $matches[0];  // Full matched string like "[label](npubXXXX)"
+        $label = $matches[1];      // This is the text between the square brackets: "label"
+
+        // Extract "npub" part from fullMatch
+        $npubLink = substr($fullMatch, strpos($fullMatch, 'npub1'), -1);  // e.g., "npubXXXX"
+        $npubPart = substr($npubLink, 5);  // Extract the part after "npub1", i.e., "XXXX"
+
+        $key = new Key();
+        $hex = $key->convertToHex($npubLink);
+
+        // Create a new inline node for the custom link
+        $inlineContext->getContainer()->appendChild(new NostrMentionLink($label, $hex));
+
+        // Advance the cursor to consume the matched part (important!)
+        $cursor->advanceBy(strlen($fullMatch));
+
+        return true;
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrMentionRenderer.php b/src/Util/CommonMark/NostrSchemeExtension/NostrMentionRenderer.php
new file mode 100644
index 0000000..74f03fb
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrMentionRenderer.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use League\CommonMark\Node\Node;
+use League\CommonMark\Renderer\ChildNodeRendererInterface;
+use League\CommonMark\Renderer\NodeRendererInterface;
+use League\CommonMark\Util\HtmlElement;
+
+class NostrMentionRenderer implements NodeRendererInterface
+{
+
+    public function render(Node $node, ChildNodeRendererInterface $childRenderer): HtmlElement
+    {
+        if (!($node instanceof NostrMentionLink)) {
+            throw new \InvalidArgumentException('Incompatible inline node type: ' . get_class($node));
+        }
+
+        $label = $node->getLabel() ?? $this->labelFromKey($node->getNpub());
+
+        // Construct the local link URL from the npub part
+        $url = '/p/' .  $node->getNpub();
+
+        // Create the anchor element
+        return new HtmlElement('a', ['href' => $url], '@' . $label);
+    }
+
+    private function labelFromKey($npub): string
+    {
+        $start = substr($npub, 0, 5); // First 5 characters
+        $end = substr($npub, -5);       // Last 5 characters
+        return $start . '...' . $end;              // Concatenate with ellipsis
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrRawNpubParser.php b/src/Util/CommonMark/NostrSchemeExtension/NostrRawNpubParser.php
new file mode 100644
index 0000000..03a71cd
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrRawNpubParser.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use League\CommonMark\Parser\Inline\InlineParserInterface;
+use League\CommonMark\Parser\Inline\InlineParserMatch;
+use League\CommonMark\Parser\InlineParserContext;
+use swentel\nostr\Key\Key;
+
+/**
+ * Class NostrRawNpubParser
+ * Looks for raw nostr mentions formatted as npub1XXXX
+ */
+class NostrRawNpubParser implements InlineParserInterface
+{
+
+    public function __construct()
+    {
+    }
+
+    public function getMatchDefinition(): InlineParserMatch
+    {
+        return InlineParserMatch::regex('npub1[0-9a-zA-Z]+');
+    }
+
+    public function parse(InlineParserContext $inlineContext): bool
+    {
+        $cursor = $inlineContext->getCursor();
+        // Get the match and extract relevant parts
+        $fullMatch = $inlineContext->getFullMatch();
+        $key = new Key();
+        $hex = $key->convertToHex($fullMatch);
+
+        // Create a new inline node for the custom link
+        $inlineContext->getContainer()->appendChild(new NostrMentionLink(null, $hex));
+
+        // Advance the cursor to consume the matched part (important!)
+        $cursor->advanceBy(strlen($fullMatch));
+
+        return true;
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeData.php b/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeData.php
new file mode 100644
index 0000000..3408d0e
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeData.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use League\CommonMark\Node\Inline\AbstractInline;
+
+/**
+ * Class NostrSchemeData
+ * NIP-19 bech32-encoded entities
+ *
+ * @package App\Util\CommonMark
+ */
+class NostrSchemeData  extends AbstractInline
+{
+    private $type;
+    private $special;
+    private $relays;
+    private $author;
+    private $kind;
+
+    public function __construct($type, $special, $relays, $author, $kind)
+    {
+        parent::__construct();
+
+        $this->type = $type;
+        $this->special = $special;
+        $this->relays = $relays;
+        $this->author = $author;
+        $this->kind = $kind;
+    }
+
+    public function getType()
+    {
+        return $this->type;
+    }
+
+    public function getSpecial()
+    {
+        return $this->special;
+    }
+
+    public function getRelays()
+    {
+        return $this->relays;
+    }
+
+    public function getAuthor()
+    {
+        return $this->author;
+    }
+
+    public function getKind()
+    {
+        return $this->kind;
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeExtension.php b/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeExtension.php
new file mode 100644
index 0000000..9fe4548
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeExtension.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use App\Util\Bech32\Bech32Decoder;
+use League\CommonMark\Environment\EnvironmentBuilderInterface;
+use League\CommonMark\Extension\ExtensionInterface;
+
+class NostrSchemeExtension  implements ExtensionInterface
+{
+
+    public function __construct(private readonly Bech32Decoder $bech32Decoder)
+    {
+    }
+
+    public function register(EnvironmentBuilderInterface $environment): void
+    {
+        $environment
+            ->addInlineParser(new NostrMentionParser(), 200)
+            ->addInlineParser(new NostrSchemeParser($this->bech32Decoder), 199)
+            ->addInlineParser(new NostrRawNpubParser(), 198)
+
+            ->addRenderer(NostrSchemeData::class, new NostrEventRenderer(), 2)
+            ->addRenderer(NostrMentionLink::class, new NostrMentionRenderer(), 1)
+        ;
+    }
+}
diff --git a/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeParser.php b/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeParser.php
new file mode 100644
index 0000000..8d9b3b2
--- /dev/null
+++ b/src/Util/CommonMark/NostrSchemeExtension/NostrSchemeParser.php
@@ -0,0 +1,102 @@
+<?php
+
+namespace App\Util\CommonMark\NostrSchemeExtension;
+
+use App\Util\Bech32\Bech32Decoder;
+use League\CommonMark\Parser\Inline\InlineParserInterface;
+use League\CommonMark\Parser\Inline\InlineParserMatch;
+use League\CommonMark\Parser\InlineParserContext;
+use function BitWasp\Bech32\convertBits;
+use function BitWasp\Bech32\decode;
+
+
+class NostrSchemeParser  implements InlineParserInterface
+{
+
+    public function __construct(private Bech32Decoder $bech32Decoder)
+    {
+    }
+
+    public function getMatchDefinition(): InlineParserMatch
+    {
+        return InlineParserMatch::regex('nostr:[0-9a-zA-Z]+');
+    }
+
+    public function parse(InlineParserContext $inlineContext): bool
+    {
+        $cursor = $inlineContext->getCursor();
+        // Get the match and extract relevant parts
+        $fullMatch = $inlineContext->getFullMatch();
+        // The match is a Bech32 encoded string
+        // decode it to get the parts
+        $bechEncoded = substr($fullMatch, 6);  // Extract the part after "nostr:", i.e., "XXXX"
+        dump($bechEncoded);
+
+        try {
+            list($hrp, $tlv) = $this->bech32Decoder->decodeAndParseNostrBech32($bechEncoded);
+            dump($hrp);
+            dump($tlv);
+            switch ($hrp) {
+                case 'npub':
+                    $str = '';
+                    list($hrp, $data) = decode($bechEncoded);
+                    $bytes = convertBits($data, count($data), 5, 8, false);
+                    foreach ($bytes as $item) {
+                        $str .= str_pad(dechex($item), 2, '0', STR_PAD_LEFT);
+                    }
+                    $npubPart = $str;
+                    $inlineContext->getContainer()->appendChild(new NostrMentionLink(null, $npubPart));
+                    break;
+                case 'nprofile':
+                    $type = 0; // npub
+                    foreach ($tlv as $item) {
+                        if ($item['type'] === $type) {
+                            // from array of integers to string
+                            $str = '';
+                            foreach ($item['value'] as $byte) {
+                                $str .= str_pad(dechex($byte), 2, '0', STR_PAD_LEFT);
+                            }
+                            $npubPart = $str;
+                            break;
+                        }
+                    }
+                    if (isset($npubPart)) {
+                        $inlineContext->getContainer()->appendChild(new NostrMentionLink(null, $npubPart));
+                    }
+                    break;
+                case 'nevent':
+                    foreach ($tlv as $item) {
+                        // event id
+                        if ($item['type'] === 0) {
+                            $eventId = implode('', array_map(fn($byte) => sprintf('%02x', $byte), $item['value']));
+                            break;
+                        }
+                        // relays
+                        if ($item['type'] === 1) {
+                            $relays[] = implode('', array_map('chr', $item['value']));
+                        }
+                    }
+                    dump($relays ?? null);
+                    // TODO also potentially contains relays, author, and kind
+                    $inlineContext->getContainer()->appendChild(new NostrSchemeData('nevent', $eventId, $relays ?? null, null, null));
+                    break;
+                case 'naddr':
+                    $inlineContext->getContainer()->appendChild(new NostrSchemeData('naddr', $bechEncoded, null, null, null));
+                    break;
+                case 'nrelay':
+                    // deprecated
+                default:
+                    return false;
+            }
+
+        } catch (\Exception $e) {
+            dump($e->getMessage());
+            return false;
+        }
+
+        // Advance the cursor to consume the matched part (important!)
+        $cursor->advanceBy(strlen($fullMatch));
+
+        return true;
+    }
+}
diff --git a/templates/pages/article.html.twig b/templates/pages/article.html.twig
new file mode 100644
index 0000000..83ed74a
--- /dev/null
+++ b/templates/pages/article.html.twig
@@ -0,0 +1,45 @@
+{% extends 'base.html.twig' %}
+
+{% block body %}
+    <div class="card">
+        <div class="card-header">
+            <h1 class="card-title">{{ article.title }}</h1>
+        </div>
+        {% if author %}
+            <div class="byline">
+                <span>
+                    {{ 'text.byline'|trans }} <a href="{{ path('author', {'npub': author.npub}) }}">
+                        <twig:NameOrNpub  displayName="{{ author.displayName }}" name="{{ author.name }}" npub="{{ author.npub }}" />
+                    </a>
+                </span>
+                <span>
+                    <small><twig:ux:icon name="heroicons:pencil" class="icon" /> {{ article.createdAt|date('F j, Y') }}</small><br>
+                    {% if article.publishedAt is not null %}<small>{{ article.publishedAt|date('F j, Y') }}</small>{% endif %}
+                </span>
+            </div>
+        {% endif %}
+    </div>
+    <div class="card-body">
+        <div class="lede">
+            {{ article.summary }}
+        </div>
+
+        {% if article.image %}
+            <div class="article__image">
+                <img src="{{ article.image }}" alt="{{ article.title }}">
+            </div>
+        {% endif %}
+
+        <div class="article-main">
+            {{ content|raw }}
+        </div>
+
+        <hr class="divider" />
+        <div class="tags">
+            {% for tag in article.topics %}
+                <span class="tag">{{ tag }}</span>
+            {% endfor %}
+        </div>
+
+    </div>
+{% endblock %}