Use Doctrine model in LinkTokens service

[MAILPOET-3269]

lib/Subscribers/LinkTokens.php

@@ -1,37 +1,37 @@
-<?php
+<?php declare(strict_types=1);
 
 namespace MailPoet\Subscribers;
 
-use MailPoet\Models\Subscriber;
-use MailPoetVendor\Idiorm\ORM;
+use MailPoet\Entities\SubscriberEntity;
 
 class LinkTokens {
-  const OBSOLETE_LINK_TOKEN_LENGTH = 6;
-  const LINK_TOKEN_LENGTH = 32;
+  private const OBSOLETE_LINK_TOKEN_LENGTH = 6;
 
-  public function getToken(Subscriber $subscriber) {
-    if ($subscriber->linkToken === null) {
-      $subscriber->linkToken = $this->generateToken($subscriber->email);
-      // `$subscriber->save()` fails if the subscriber has subscriptions, segments or custom fields
-      ORM::rawExecute(sprintf('UPDATE %s SET link_token = ? WHERE email = ?', Subscriber::$_table), [$subscriber->linkToken, $subscriber->email]);
-    }
-    return $subscriber->linkToken;
+  /** @var SubscribersRepository */
+  private $subscribersRepository;
+
+  public function __construct(SubscribersRepository $subscribersRepository) {
+    $this->subscribersRepository = $subscribersRepository;
   }
 
-  public function verifyToken(Subscriber $subscriber, $token) {
+  public function getToken(SubscriberEntity $subscriber): string {
+    if ($subscriber->getLinkToken() === null) {
+      $subscriber->setLinkToken($this->generateToken($subscriber->getEmail()));
+      $this->subscribersRepository->flush();
+    }
+    return (string)$subscriber->getLinkToken();
+  }
+
+  public function verifyToken(SubscriberEntity $subscriber, string $token) {
     $databaseToken = $this->getToken($subscriber);
     $requestToken = substr($token, 0, strlen($databaseToken));
-    return call_user_func(
-      'hash_equals',
-      $databaseToken,
-      $requestToken
-    );
+    return hash_equals($databaseToken, $requestToken);
   }
 
   /**
    * Only for backward compatibility for old tokens
    */
-  private function generateToken($email = null, $length = self::OBSOLETE_LINK_TOKEN_LENGTH) {
+  private function generateToken(?string $email, int $length = self::OBSOLETE_LINK_TOKEN_LENGTH): ?string {
     if ($email !== null) {
       $authKey = '';
       if (defined('AUTH_KEY')) {
@@ -39,6 +39,6 @@ class LinkTokens {
       }
       return substr(md5($authKey . $email), 0, $length);
     }
-    return false;
+    return null;
   }
 }