Add endpoint for subscriber statistics

[MAILPOET-3069]

lib/Subscribers/Statistics/SubscriberStatistics.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace MailPoet\Subscribers\Statistics;
+
+class SubscriberStatistics {
+
+  /** @var int */
+  private $clickCount;
+
+  /** @var int */
+  private $openCount;
+
+  /** @var int */
+  private $totalSentCount;
+
+  public function __construct($clickCount, $openCount, $totalSentCount) {
+    $this->clickCount = $clickCount;
+    $this->openCount = $openCount;
+    $this->totalSentCount = $totalSentCount;
+  }
+
+  /**
+   * @return int
+   */
+  public function getClickCount(): int {
+    return $this->clickCount;
+  }
+
+  /**
+   * @return int
+   */
+  public function getOpenCount(): int {
+    return $this->openCount;
+  }
+
+  /**
+   * @return int
+   */
+  public function getTotalSentCount(): int {
+    return $this->totalSentCount;
+  }
+}