Fix new resource rate limit issue

lib/CurlRequest.php

@@ -9,6 +9,7 @@
 
 
 use PHPShopify\Exception\CurlException;
+use PHPShopify\Exception\ResourceRateLimitException;
 
 /*
 |--------------------------------------------------------------------------
@@ -47,6 +48,7 @@ protected static function init($url, $httpHeaders = array())
         //Return the transfer as a string
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
 
+        curl_setopt($ch, CURLOPT_HEADER, true);
         curl_setopt($ch, CURLOPT_USERAGENT, 'PHPClassic/PHPShopify');
 
         $headers = array();
@@ -143,23 +145,32 @@ public static function delete($url, $httpHeaders = array())
     protected static function processRequest($ch)
     {
         # Check for 429 leaky bucket error
-        while(1) {
-             $output = curl_exec($ch);
-             self::$lastHttpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
-             if(self::$lastHttpCode != 429) {
-                break; 
-             } 
-             usleep(500000);
+        while (1) {
+            $output   = curl_exec($ch);
+            $response = new CurlResponse($output);
+
+            self::$lastHttpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+            if (self::$lastHttpCode != 429) {
+                break;
+            }
+
+            $limitHeader = explode('/', $response->getHeader('X-Shopify-Shop-Api-Call-Limit'), 2);
+
+            if (isset($limitHeader[1]) && $limitHeader[0] < $limitHeader[1]) {
+                throw new ResourceRateLimitException($response->getBody());
+            }
+
+            usleep(500000);
         }
-    
+
         if (curl_errno($ch)) {
             throw new Exception\CurlException(curl_errno($ch) . ' : ' . curl_error($ch));
         }
 
         // close curl resource to free up system resources
         curl_close($ch);
 
-        return $output;
+        return $response->getBody();
     }
 
 }

lib/CurlResponse.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace PHPShopify;
+
+class CurlResponse
+{
+    /** @var array */
+    private $headers = [];
+    /** @var string */
+    private $body;
+
+    public function __construct($response)
+    {
+        $this->parse($response);
+    }
+
+    /**
+     * @param string $response
+     */
+    private function parse($response)
+    {
+        $response = \explode("\r\n\r\n", $response);
+        if (\count($response) > 1) {
+            // We want the last two parts
+            $response = \array_slice($response, -2, 2);
+            list($headers, $body) = $response;
+            foreach (\explode("\r\n", $headers) as $header) {
+                $pair = \explode(': ', $header, 2);
+                if (isset($pair[1])) {
+                    $this->headers[$pair[0]] = $pair[1];
+                }
+            }
+        } else {
+            $body = $response[0];
+        }
+
+        $this->body = $body;
+    }
+
+    /**
+     * @return array
+     */
+    public function getHeaders()
+    {
+        return $this->headers;
+    }
+
+    /**
+     * @param string $key
+     *
+     * @return string
+     */
+    public function getHeader($key)
+    {
+        return isset($this->headers[$key]) ? $this->headers[$key] : null;
+    }
+
+    /**
+     * @return string
+     */
+    public function getBody()
+    {
+        return $this->body;
+    }
+
+    public function __toString()
+    {
+        $body = $this->getBody();
+        $body = $body ? : '';
+
+        return $body;
+    }
+}

lib/Exception/ResourceRateLimitException.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace PHPShopify\Exception;
+
+class ResourceRateLimitException extends ApiException
+{
+
+}