How to include simple-rest library in WordPress

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