How to include simple-rest library in WordPress

[amskape]

Dear pals,
I need to implement the REST service which explain in Simple-rest.
I create a file with name xyz.php with code

    <?php
    if(isset($_POST['type']) && (isset($_POST['id']))) {
        $type = $_POST['type']?$_POST['type']:"undefined";
        $id = $_POST['id']?$_POST['id']:"undefined";
 
        //echo "val is :".$type." id is ".$id;
    } else {
    $type = "table";
    $id = 2;
    }
    ?>
    <?php require_once("wp-load.php");?>
    <?php //get_header();
     wp_head();
    ?>
 
    <?php
    if($type=="chart" && $id!="undefined") {
        $kk_chart = get_html_4_chart(intval($id));
        echo $kk_chart;
    }
    if($type=="table" && $id!="undefined") {
        $kk_table = get_html_4_table(intval($id));
        echo $kk_table;
    }
        wp_footer();
    ?>

in root folder work fine . But i need to make it in a controller method. So I create a folder named "services" in root of WP and create a controller with name "chart" and write code as

    include_once("../wp-load.php");
    wp_head();
    wp_footer(); 
 
    class Controllers_Chart extends RestController {
        public function get() {
            //$this->response = array('TestResponse' => 'I am GET response. Variables sent are - ' . http_build_query($this->request['params']));
            //$this->responseStatus = 200;
            $kk_chart = get_html_4_chart(2);
            return $kk_chart;
 
        }
    }

I just include the relevant get() method only . But I got some unexpected error like
Warning: include(Translation/Entry.php): failed to open stream: No such file or directory in C:\wamp\www\wp-oscar\services\index.php on line 22
Warning: include(): Failed opening 'Translation/Entry.php' for inclusion (include_path='C:\wamp\www\wp-oscar\services;.;C:\php\pear') in C:\wamp\www\wp-oscar\services\index.php on line 22

alot of warning like this and a Fatal error as
Fatal error: Call to a member function set_filenames() on a non-object in C:\wamp\www\wp-oscar\wp-content\plugins\wp-business-intelligence-lite\functions\functions.php on line 174

please advise me a method to call WordPress Business Intelligence intelligence as a REST service .

Waiting your reply

Thanks,
Anes