first impl for index action

src/Bundle/ChillMainBundle/Serializer/Normalizer/CollectionNormalizer.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Chill\MainBundle\Serializer\Normalizer;
+
+use Chill\MainBundle\Serializer\Model\Collection;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Symfony\Component\Serializer\Normalizer\NormalizerAwareInterface;
+use Symfony\Component\Serializer\Normalizer\NormalizerAwareTrait;
+
+class CollectionNormalizer implements NormalizerInterface, NormalizerAwareInterface
+{
+    use NormalizerAwareTrait; 
+
+    public function supportsNormalization($data, string $format = null): bool
+    {
+        return $data instanceof Collection;
+    }
+
+    public function normalize($collection, string $format = null, array $context = [])
+    {
+        /** @var $collection Collection */
+        /** @var $collection Chill\MainBundle\Pagination\PaginatorInterface */ 
+        $paginator = $collection->getPaginator();
+
+        $data['count'] = $paginator->getTotalItems();
+        $data['first'] = $paginator->getCurrentPageFirstItemNumber();
+        $data['items_per_page'] = $paginator->getItemsPerPage();
+        $data['next']  = $paginator->hasNextPage() ? 
+            $paginator->getNextPage()->generateUrl() : null;
+        $data['previous'] = $paginator->hasPreviousPage() ?
+            $paginator->getPreviousPage()->generateUrl() : null;
+
+        // normalize results
+        $data['results'] = $this->normalizer->normalize($collection->getItems(),
+            $format, $context);
+
+        return $data;
+    }
+}