Refactor Mailchimp import to API v3

[MAILPOET-3404]

lib/Subscribers/ImportExport/Import/MailChimpDataMapper.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace MailPoet\Subscribers\ImportExport\Import;
+
+class MailChimpDataMapper {
+  public function getMembersHeader(): array {
+    return [
+      'email_address',
+      'status',
+      'first_name',
+      'last_name',
+      'address',
+      'phone',
+      'birthday',
+      'ip_signup',
+      'timestamp_signup',
+      'ip_opt',
+      'timestamp_opt',
+      'member_rating',
+      'last_changed',
+      'language',
+      'vip',
+      'email_client',
+      'latitude',
+      'longitude',
+      'gmtoff',
+      'dstoff',
+      'country_code',
+      'timezone',
+      'source',
+    ];
+  }
+
+  public function mapMember(array $member): array {
+    return [
+      $member['email_address'],
+      $member['status'],
+      $member['merge_fields']['FNAME'] ?? '',
+      $member['merge_fields']['LNAME'] ?? '',
+      is_array($member['merge_fields']['ADDRESS']) ? implode(' ', $member['merge_fields']['ADDRESS'] ?? []) : $member['merge_fields']['ADDRESS'],
+      $member['merge_fields']['PHONE'] ?? '',
+      $member['merge_fields']['BIRTHDAY'] ?? '',
+      $member['ip_signup'],
+      $member['timestamp_signup'],
+      $member['ip_opt'],
+      $member['timestamp_opt'],
+      $member['member_rating'],
+      $member['last_changed'],
+      $member['language'],
+      $member['vip'],
+      $member['email_client'],
+      $member['location']['latitude'] ?? '',
+      $member['location']['longitude'] ?? '',
+      $member['location']['gmtoff'] ?? '',
+      $member['location']['dstoff'] ?? '',
+      $member['location']['country_code'] ?? '',
+      $member['location']['timezone'] ?? '',
+      $member['source'],
+    ];
+  }
+}