added database driven system configurations with admin screen (#647)

src/Repository/ConfigurationRepository.php

@@ -0,0 +1,66 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Repository;
+
+use App\Configuration\ConfigLoaderInterface;
+use App\Entity\Configuration;
+use App\Form\Model\SystemConfiguration;
+use Doctrine\ORM\ORMException;
+use Doctrine\ORM\Query;
+
+class ConfigurationRepository extends AbstractRepository implements ConfigLoaderInterface
+{
+    /**
+     * @param string $prefix
+     * @return Configuration[]
+     */
+    public function getConfiguration(?string $prefix = null): array
+    {
+        if (null === $prefix) {
+            return $this->findAll();
+        }
+
+        $qb = $this->createQueryBuilder('c');
+        $qb
+            ->select('c')
+            ->where($qb->expr()->like('c.name', ':prefix'))
+            ->setParameter(':prefix', $prefix . '%');
+
+        return $qb->getQuery()->getResult(Query::HYDRATE_OBJECT);
+    }
+
+    public function saveSystemConfiguration(SystemConfiguration $model)
+    {
+        $em = $this->getEntityManager();
+        $em->beginTransaction();
+
+        try {
+            foreach ($model->getConfiguration() as $configuration) {
+                $entity = $this->findOneBy(['name' => $configuration->getName()]);
+                $value = $configuration->getValue();
+
+                if (null === $entity) {
+                    $entity = new Configuration();
+                    $entity->setName($configuration->getName());
+                }
+
+                $entity->setValue($value);
+
+                $em->persist($entity);
+            }
+
+            $em->flush();
+            $em->commit();
+        } catch (ORMException $ex) {
+            $em->rollback();
+            throw $ex;
+        }
+    }
+}