refactor: message object properties

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

shared/lib/Mail/Object/MessagePart.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: Sebastian Krupinski <krupinski01@gmail.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace KTXF\Mail\Object;
+
+/**
+ * Shared Message Part implementation matching the frontend JSON shape.
+ */
+class MessagePart extends MessagePartMutableAbstract {
+
+    public static function fromArray(array $data): self {
+        $part = new self();
+        $part->data = $data;
+
+        if (isset($part->data[MessagePartInterface::PROPERTY_SUB_PARTS]) && is_array($part->data[MessagePartInterface::PROPERTY_SUB_PARTS])) {
+            foreach ($part->data[MessagePartInterface::PROPERTY_SUB_PARTS] as $entry) {
+                if (is_object($entry)) {
+                    $entry = get_object_vars($entry);
+                }
+
+                if (is_array($entry)) {
+                    $part->parts[] = self::fromArray($entry);
+                }
+            }
+
+            unset($part->data[MessagePartInterface::PROPERTY_SUB_PARTS]);
+        }
+
+        return $part;
+    }
+}