First draft

src/OAI/Verb/ListMetadataFormats.php

@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\OAI\Verb;
+
+use App\OAI\OaiBase;
+use App\OAI\OaiError;
+use AC\DB\Connection;
+use Symfony\Component\Serializer\Encoder\XmlEncoder;
+use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
+use Symfony\Component\Serializer\Serializer;
+
+/**
+ * Represents a ListMetadataFormats response
+ */
+final class ListMetadataFormats
+{
+    public function __construct(
+        private Serializer $serializer = new Serializer(),
+    )
+    {
+        $this->serializer = new Serializer(
+            [new ObjectNormalizer()],
+            [new XmlEncoder()]
+        );
+    }
+    /**
+     * Returns the XML response
+     */
+    public function response(): string
+    {
+        $formats = $this->getValidFormats();
+
+        $content = $this->serializer->encode(
+            ['metadataFormat' => [...$formats]],
+            'xml',
+            [
+                'xml_format_output' => true,
+                'xml_root_node_name' => 'ListMetadataFormats',
+                // Don't include the XML declaration, handled by OaiBase
+                'encoder_ignored_node_types' => [
+                    \XML_PI_NODE, 
+                ],
+            ]
+        );
+
+        return OaiBase::create($content, 'ListMetadataFormats');
+    }
+    /**
+     * @return array<int,array<string,mixed>>
+     */
+    private function getValidFormats(): array
+    {
+        $dbConn = Connection::new();
+        $queryBuilder = $dbConn->createQueryBuilder();
+
+        $formats = $queryBuilder->select(
+            'prefix as metadataPrefix',
+            'schemaLoc as schema',
+            'namespace as metadataNamespace',
+            )
+            ->from('metadata_formats')
+            ->fetchAllAssociative();
+
+        return $formats;
+    }
+}