Add endpoint for subscriber statistics

[MAILPOET-3069]

lib/Subscribers/Statistics/SubscriberStatisticsRepository.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace MailPoet\Subscribers\Statistics;
+
+use MailPoet\Doctrine\Repository;
+use MailPoet\Entities\StatisticsClickEntity;
+use MailPoet\Entities\StatisticsNewsletterEntity;
+use MailPoet\Entities\StatisticsOpenEntity;
+use MailPoet\Entities\SubscriberEntity;
+
+/**
+ * @extends Repository<SubscriberEntity>
+ */
+class SubscriberStatisticsRepository extends Repository {
+  protected function getEntityClassName() {
+    return SubscriberEntity::class;
+  }
+
+  public function getStatistics(SubscriberEntity $subscriber) {
+    return new SubscriberStatistics(
+      $this->getStatisticsClickCount($subscriber),
+      $this->getStatisticsOpenCount($subscriber),
+      $this->getTotalSentCount($subscriber)
+    );
+  }
+
+  private function getStatisticsClickCount(SubscriberEntity $subscriber): int {
+    return $this->getStatisticsCount(StatisticsClickEntity::class, $subscriber);
+  }
+
+  private function getStatisticsOpenCount(SubscriberEntity $subscriber): int {
+    return $this->getStatisticsCount(StatisticsOpenEntity::class, $subscriber);
+  }
+
+  private function getTotalSentCount(SubscriberEntity $subscriber): int {
+    return $this->getStatisticsCount(StatisticsNewsletterEntity::class, $subscriber);
+  }
+
+  private function getStatisticsCount($entityName, SubscriberEntity $subscriber): int {
+    return (int)$this->entityManager->createQueryBuilder()
+      ->select('COUNT(DISTINCT stats.newsletter) as cnt')
+      ->from($entityName, 'stats')
+      ->where('stats.subscriber = :subscriber')
+      ->setParameter('subscriber', $subscriber)
+      ->getQuery()
+      ->getSingleScalarResult();
+  }
+}