Adds version support to public API

lib/API/Endpoints/v1/Services.php

@@ -0,0 +1,67 @@
+<?php
+namespace MailPoet\API\Endpoints\v1;
+
+use Carbon\Carbon;
+use MailPoet\API\Endpoint as APIEndpoint;
+use MailPoet\API\Error as APIError;
+use MailPoet\Services\Bridge;
+
+if(!defined('ABSPATH')) exit;
+
+class Services extends APIEndpoint {
+  public $bridge;
+
+  function __construct() {
+    $this->bridge = new Bridge();
+  }
+
+  function verifyMailPoetKey($data = array()) {
+    $key = isset($data['key']) ? trim($data['key']) : null;
+
+    if(!$key) {
+      return $this->badRequest(array(
+        APIError::BAD_REQUEST  => __('Please specify a key.', 'mailpoet')
+      ));
+    }
+
+    try {
+      $result = $this->bridge->checkKey($key);
+    } catch(\Exception $e) {
+      return $this->errorResponse(array(
+        $e->getCode() => $e->getMessage()
+      ));
+    }
+
+    $state = !empty($result['state']) ? $result['state'] : null;
+
+    $success_message = null;
+    if($state == Bridge::MAILPOET_KEY_VALID) {
+      $success_message = __('Your MailPoet API key is valid!', 'mailpoet');
+    } elseif($state == Bridge::MAILPOET_KEY_EXPIRING) {
+      $success_message = sprintf(
+        __('Your MailPoet key expires on %s!', 'mailpoet'),
+        Carbon::createFromTimestamp(strtotime($result['data']['expire_at']))
+          ->format('Y-m-d')
+      );
+    }
+
+    if($success_message) {
+      return $this->successResponse(array('message' => $success_message));
+    }
+
+    switch($state) {
+      case Bridge::MAILPOET_KEY_INVALID:
+        $error = __('Your MailPoet key is invalid!', 'mailpoet');
+        break;
+      default:
+        $code = !empty($result['code']) ? $result['code'] : Bridge::CHECK_ERROR_UNKNOWN;
+        $error = sprintf(
+          __('Error validating API key, please try again later (code: %s)', 'mailpoet'),
+          $code
+        );
+        break;
+    }
+
+    return $this->errorResponse(array(APIError::BAD_REQUEST => $error));
+  }
+}