Move dynamic segments from Premium plugin

[MAILPOET-2382]

lib/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinder.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace MailPoet\Premium\DynamicSegments\FreePluginConnectors;
+
+use MailPoet\Models\Segment;
+use MailPoet\Models\Subscriber;
+use MailPoet\Premium\DynamicSegments\Persistence\Loading\SingleSegmentLoader;
+use MailPoet\Premium\DynamicSegments\Persistence\Loading\SubscribersIds;
+use MailPoet\Premium\Models\DynamicSegment;
+
+class SendingNewslettersSubscribersFinder {
+
+  /** @var SingleSegmentLoader */
+  private $single_segment_loader;
+
+  /** @var \MailPoet\Premium\DynamicSegments\Persistence\Loading\SubscribersIds */
+  private $subscribers_ids_loader;
+
+  public function __construct(SingleSegmentLoader $single_segment_loader, SubscribersIds $subscribers_ids_loader) {
+    $this->single_segment_loader = $single_segment_loader;
+    $this->subscribers_ids_loader = $subscribers_ids_loader;
+  }
+
+  /**
+   * @param Segment $segment
+   * @param int[] $subscribers_to_process_ids
+   *
+   * @return Subscriber[]
+   */
+  function findSubscribersInSegment(Segment $segment, array $subscribers_to_process_ids) {
+    if ($segment->type !== DynamicSegment::TYPE_DYNAMIC) return [];
+    $dynamic_segment = $this->single_segment_loader->load($segment->id);
+    return $this->subscribers_ids_loader->load($dynamic_segment, $subscribers_to_process_ids);
+  }
+
+  /**
+   * @param Segment $segment
+   *
+   * @return array
+   */
+  function getSubscriberIdsInSegment(Segment $segment) {
+    if ($segment->type !== DynamicSegment::TYPE_DYNAMIC) return [];
+    $dynamic_segment = $this->single_segment_loader->load($segment->id);
+    $result = $this->subscribers_ids_loader->load($dynamic_segment);
+    return $this->createResultArray($result);
+  }
+
+  private function createResultArray($subscribers) {
+    $result = [];
+    foreach ($subscribers as $subscriber) {
+      $result[] = $subscriber->asArray();
+    }
+    return $result;
+  }
+
+}