feat: Reader beginning

src/Domain/Reader/Application/QueryHandler/GetChapterContextHandler.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Domain\Reader\Application\QueryHandler;
+
+use App\Domain\Reader\Application\Query\GetChapterContext;
+use App\Domain\Reader\Application\Response\ChapterContextResponse;
+use App\Domain\Reader\Domain\Contract\Repository\ChapterRepositoryInterface;
+use App\Domain\Reader\Domain\ValueObject\ChapterId;
+
+final readonly class GetChapterContextHandler
+{
+    public function __construct(
+        private ChapterRepositoryInterface $chapterRepository
+    ) {
+    }
+
+    public function handle(GetChapterContext $query): ChapterContextResponse
+    {
+        $chapterId = new ChapterId($query->getChapterId());
+
+        $context = $this->chapterRepository->getChapterContext($chapterId);
+
+        return new ChapterContextResponse(
+            $query->getChapterId(),
+            $context->getChapterTitle(),
+            $context->getNumber(),
+            $context->getTotalPages(),
+            $context->getPreviousChapterId()?->getValue(),
+            $context->getNextChapterId()?->getValue(),
+        );
+    }
+}