A Google Shortener API wrapper

UrlShortenerService.php

<?php
/**
 * Supports URL shortening, expanding and analytics retrieval of a given period type.
 */

/*
 * Installation (Symfony):
 * =======================
 * # services.yml
 * services:
 *     # ...
 *     acme.url_shortener:
 *       class: Acme\AcmeBundle\Service\UrlShortenerService
 *       calls: [ [setDependencies, [%google.url_shortener_api.url%, %google.url_shortener_api.key%]] ]
 * 
 * # parameters.yml
 * # ...
 * parameters:
 *     google.url_shortener_api.key: "XXX"
 *     google.url_shortener_api.url: "https://www.googleapis.com/urlshortener/v1/url"
 */

namespace Acme\AcmeBundle\Service;

class UrlShortenerService
{
    const ANALYTICS_PERIOD_TWO_HOURS = "twoHours";
    const ANALYTICS_PERIOD_DAY = "day";
    const ANALYTICS_PERIOD_WEEK = "week";
    const ANALYTICS_PERIOD_MONTH = "month";
    const ANALYTICS_PERIOD_EVER = "allTime";

    private $apiUrl;
    private $apiKey;

    /**
     * Used by the dependency injection container to inject the dependencies of the service.
     * 
     * @param string $apiUrl
     * @param string $apiKey
     */
    public function setDependencies($apiUrl, $apiKey)
    {
        $this->apiUrl = $apiUrl;
        $this->apiKey = $apiKey;
    }

    /**
     * Issues an HTTP GET request and returns the response.
     * 
     * @param array $data
     * @return array
     * @throws \Exception
     */
    private function get($data = array())
    {
        $data = \array_merge($data, array("key" => $this->apiKey));

        $url = $this->apiUrl . "?" . \http_build_query($data);

        $curlClient = \curl_init();
        \curl_setopt_array($curlClient, array(
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_CONNECTTIMEOUT => 10
        ));

        $responseJson = \curl_exec($curlClient);
        \curl_close($curlClient);

        $response = \json_decode($responseJson, true);

        if (isset($response["error"])) {
            $errorMessages = $this->getErrorMessages($response);

            throw new \Exception(\implode(" ", $errorMessages));
        }

        return $response;
    }

    /**
     * Issues an HTTP POST request and returns the response.
     * 
     * @param array $data
     * @return array
     * @throws \Exception
     */
    private function post($data)
    {
        $url = $this->apiUrl . "?key=" . $this->apiKey;

        $dataJson = \json_encode($data);

        $curlClient = \curl_init();
        \curl_setopt_array($curlClient, array(
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => 1,
            CURLOPT_POST => 1,
            CURLOPT_POSTFIELDS => $dataJson,
            CURLOPT_HTTPHEADER => array(
                "Content-Type: application/json",
                "Content-Length: " . \strlen($dataJson)
            )
        ));

        $responseJson = \curl_exec($curlClient);
        \curl_close($curlClient);

        $response = \json_decode($responseJson, true);

        if (isset($response["error"])) {
            $errorMessages = $this->getErrorMessages($response);

            throw new \Exception(\implode(" ", $errorMessages));
        }

        return $response;
    }

    /**
     * Returns the shortened URL of a given long URL.
     * 
     * @param array $url
     * @return string
     * @throws \Exception
     */
    public function shorten($url)
    {        
        $response = $this->post(array("longUrl" => $url));

        if (!isset($response["id"])) {
            throw new \Exception("Malformed response");
        }

        return $response["id"];
    }

    /**
     * Returns the long URL of the given shortened URL.
     * 
     * @param string $url
     * @return string
     * @throws \Exception
     */
    public function expand($url)
    {
        $response = $this->get(array("shortUrl" => $url));

        if ("MALWARE" === $response["status"]) {
            throw new \Exception("Full URL seems fishy.");
        } elseif ("REMOVED" === $response["status"]) {
            throw new \Exception("Shortened URL has been removed.");
        } elseif (!isset($response["longUrl"])) {
            throw new \Exception("Malformed response");
        }

        return $response["longUrl"];
    }

    /**
     * Returns the analytics of a shortened URL for a requested period segment.
     * 
     * @param string $url
     * @param string $period
     * @return array
     * @throws \Exception
     */
    public function getAnalytics($url, $period = self::ANALYTICS_PERIOD_EVER)
    {
        $response = $this->get(array("shortUrl" => $url, "projection" => "FULL"));

        if (!isset($response["analytics"][$period])) {
            throw new \Exception("Malformed response");
        }

        return $response["analytics"][$period];
    }

    /**
     * Returns the error messages contained in a response.
     * 
     * @param array $response
     * @return array
     */
    private function getErrorMessages($response)
    {
        $messages = array();

        foreach ($response["error"]["errors"] as $error) {
            $messages[] = $error["message"];
        }

        return $messages;
    }
}