add cookie parser plugin

composer.json

@@ -4,7 +4,8 @@
     "minimum-stability": "dev",
     "require": {
         "krizon/php-ga-measurement-protocol": "0.1.*",
-        "guzzle/guzzle": "~3.7"
+        "guzzle/guzzle": "~3.7",
+        "waarneembemiddeling/php-google-analytics-cookie-parser": "0.1.*"
     },
     "require-dev": {
         "phpunit/phpunit": ">=3.7.28",

src/Moriony/Google/Analytics/MeasurementProtocol/Plugin/GoogleAnalyticsCookieParser.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Moriony\Google\Analytics\MeasurementProtocol\Plugin;
+
+use Krizon\Google\Analytics\MeasurementProtocol\MeasurementProtocolClient;
+use Moriony\Google\Analytics\MeasurementProtocol\Hit\HitInterface;
+use Wb\GoogleAnalyticsCookieParser\GoogleAnalyticsCookieParser as Parser;
+
+class GoogleAnalyticsCookieParser implements PluginInterface
+{
+    const DEFAULT_COOKIE_NAME = '_ga';
+
+    protected $cookieName;
+
+    public function __construct($cookieName = self::DEFAULT_COOKIE_NAME)
+    {
+        $this->cookieName = $cookieName;
+    }
+
+    /**
+     * @param MeasurementProtocolClient $client
+     */
+    public function register($client)
+    {
+        $client->getEventDispatcher()->addListener('command.before_prepare', function ($e) {
+            if (!array_key_exists($this->cookieName, $_COOKIE)) {
+                return;
+            }
+            $parser = new Parser();
+            $data = $parser->parse($_COOKIE[$this->cookieName]);
+
+            /** @var \Guzzle\Service\Command\OperationCommand $command */
+            $command = $e['command'];
+            if (!$command->hasKey(HitInterface::FIELD_CUSTOMER_ID)) {
+                $command->set(HitInterface::FIELD_CUSTOMER_ID, $data->getClientId());
+            }
+        });
+    }
+}

tests/Moriony/Google/Analytics/MeasurementProtocol/Plugin/GoogleAnalyticsCookieParserTest.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Moriony\Google\Analytics\MeasurementProtocol\Plugin;
+
+use Guzzle\Tests\GuzzleTestCase;
+use Krizon\Google\Analytics\MeasurementProtocol\MeasurementProtocolClient;
+use Guzzle\Service\Command\OperationCommand;
+use Guzzle\Common\Event;
+
+class GoogleAnalyticsCookieParserTest extends GuzzleTestCase
+{
+    public function setUp()
+    {
+        $_COOKIE = array();
+    }
+
+    public function testSuccessfulCustomerIdSet()
+    {
+        $_COOKIE['_ga'] = 'GA1.2.230657868.1384941727';
+        $command = new OperationCommand();
+        $this->dispatchCommand($command);
+        $this->assertSame('230657868', $command->get('cid'));
+    }
+
+    public function testNotExistedCookieParsing()
+    {
+        $command = new OperationCommand();
+        $this->dispatchCommand($command);
+        $this->assertSame(null, $command->get('cid'));
+    }
+
+    protected function dispatchCommand(OperationCommand $command)
+    {
+        $client = MeasurementProtocolClient::factory();
+        $plugin = new GoogleAnalyticsCookieParser();
+        $event = new Event(array('command' => $command));
+        $plugin->register($client);
+        $client->getEventDispatcher()->dispatch('command.before_prepare', $event);
+    }
+}