<?php

/**

  * HTTP Client library

  *

  * PHP version 5.2

  *

  * @author    Matt Bernier <dx@sendgrid.com>

  * @author    Elmer Thomas <dx@sendgrid.com>

  * @copyright 2016 SendGrid

  * @license   https://opensource.org/licenses/MIT The MIT License

  * @version   GIT: <git_id>

  * @link      http://packagist.org/packages/sendgrid/php-http-client

  */

namespace SendGrid;



/**

  * Holds the response from an API call.

  */

class Response

{

    /**

      * Setup the response data

      *

      * @param int   $status_code      the status code.

      * @param array $response_body    the response body as an array.

      * @param array $response_headers an array of response headers.

      */

    function __construct($status_code = null, $response_body = null, $response_headers = null)

    {

        $this->_status_code = $status_code;

        $this->_body = $response_body;

        $this->_headers = $response_headers;

    }



    /**

    * The status code

    *

    * @return integer

    */

    public function statusCode()

    {

        return $this->_status_code;

    }



    /**

    * The response body

    *

    * @return array

    */

    public function body()

    {

        return $this->_body;

    }



    /**

    * The response headers

    *

    * @return array

    */

    public function headers()

    {

        return $this->_headers;

    }

}



/**

  * Quickly and easily access any REST or REST-like API.

  */

class Client

{



    public

      $host,

      $request_headers,

      $version,

      $url_path,

      $methods;



    /**

      * Initialize the client

      *

      * @param string $host            the base url (e.g. https://api.sendgrid.com)

      * @param array  $request_headers global request headers

      * @param string $version         api version (configurable)

      * @param array  $url_path        holds the segments of the url path

      */

    function __construct($host, $request_headers = null, $version = null, $url_path = null)

    {

        $this->host = $host;

        $this->request_headers = ($request_headers ? $request_headers : []);

        $this->version = $version;

        $this->url_path = ($url_path ? $url_path : []);

        // These are the supported HTTP verbs

        $this->methods = ['delete', 'get', 'patch', 'post', 'put'];

    }



    /**

      * Make a new Client object

      *

      * @param string $name name of the url segment

      *

      * @return Client object

      */

    private function _buildClient($name = null)

    {

        if(isset($name)) {

            array_push($this->url_path, $name);

        }

        $url_path = $this->url_path;

        $this->url_path = [];

        return new Client($this->host, $this->request_headers, $this->version, $url_path);

    }



    /**

      * Subclass this function for your own needs.

      *  Or just pass the version as part of the URL

      *  (e.g. client._('/v3'))

      *

      * @param string $url URI portion of the full URL being requested

      *

      * @return string

    */

    private function _buildVersionedUrl($url)

    {

        return sprintf("%s%s%s", $this->host, $this->version, $url);

    }



    /**

      * Build the final URL to be passed

      *

      * @param array $query_params an array of all the query parameters

      *

      * @return string

      */

    private function _buildUrl($query_params = null)

    {

        $url = '/'.implode('/', $this->url_path);

        if (isset($query_params)) {

            $url_values = http_build_query($query_params);

            $url = sprintf('%s?%s', $url, $url_values);

        }

        if (isset($this->version)) {

            $url = $this->_buildVersionedUrl($url);

        } else {

            $url = sprintf('%s%s', $this->host, $url);;

        }

        return $url;

    }



    /**

      * Make the API call and return the response. This is separated into

      * it's own function, so we can mock it easily for testing.

      *

      * @param array  $method          the HTTP verb

      * @param string $url             the final url to call

      * @param array  $request_body    request body

      * @param array  $request_headers any additional request headers

      *

      * @return Response object

      */

    public function makeRequest($method, $url, $request_body = null, $request_headers = null)

    {

        $curl = curl_init($url);

        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

        curl_setopt($curl, CURLOPT_HEADER, 1);

        curl_setopt($curl, CURLOPT_CUSTOMREQUEST, strtoupper($method));

        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);

        if(isset($request_headers)) {

            $this->request_headers = array_merge($this->request_headers, $request_headers);

        }

        if(isset($request_body)) {

            $request_body = json_encode($request_body);

            curl_setopt($curl, CURLOPT_POSTFIELDS, $request_body);

            $content_length = array('Content-Length: ' . strlen($request_body));

            $content_type = array('Content-Type: application/json');

            $this->request_headers = array_merge($this->request_headers, $content_type);

        }

        curl_setopt($curl, CURLOPT_HTTPHEADER, $this->request_headers);

        $curl_response = curl_exec($curl);

        $header_size = curl_getinfo($curl, CURLINFO_HEADER_SIZE);

        $status_code = curl_getinfo($curl, CURLINFO_HTTP_CODE);

        $response_body = substr($curl_response, $header_size);

        $response_header = substr($curl_response, 0, $header_size);



        curl_close($curl);



        return new Response($status_code, $response_body, $response_header);

    }



    /**

      * Add variable values to the url.

      * (e.g. /your/api/{variable_value}/call)

      * Another example: if you have a PHP reserved word, such as and,

      * in your url, you must use this method.

      *

      * @param string $name name of the url segment

      *

      * @return Client object

      */

    public function _($name = null)

    {

        return $this->_buildClient($name);

    }



    /**

      * Dynamically add method calls to the url, then call a method.

      * (e.g. client.name.name.method())

      *

      * @param string $name name of the dynamic method call or HTTP verb

      * @param array  $args parameters passed with the method call

      *

      * @return Client or Response object

      */

    public function __call($name, $args)

    {

        if($name == 'version') {

            $this->version = $args[0];

            return $this->_();

        }



        if (in_array($name, $this->methods)) {

            $query_params = ((count($args) >= 2) ? $args[1] : null);

            $url = $this->_buildUrl($query_params);

            $request_body = ($args ? $args[0] : null);

            $request_headers = ((count($args) == 3) ? $args[2] : null);

            return $this->makeRequest($name, $url, $request_body, $request_headers);

        }



        return $this->_($name);

    }

}

?>

