<?php
namespace Dnolbon\Wordpress\Translates;

class BingAccessTokenAuthentication
{
    /*
         * Get the access token.
         *
         * @param string $grantType    Grant type.
         * @param string $scopeUrl     Application Scope URL.
         * @param string $clientID     Application client ID.
         * @param string $clientSecret Application client ID.
         * @param string $authUrl      Oauth Url.
         *
         * @return string.
         */
    public function getTokens($grantType, $scopeUrl, $clientID, $clientSecret, $authUrl)
    {
        try {
            //Initialize the Curl Session.
            $ch = curl_init();
            //Create the request Array.
            $paramArr = array(
                'grant_type' => $grantType,
                'scope' => $scopeUrl,
                'client_id' => $clientID,
                'client_secret' => $clientSecret
            );
            //Create an Http Query.//
            $paramArr = http_build_query($paramArr);
            //Set the Curl URL.
            curl_setopt($ch, CURLOPT_URL, $authUrl);
            //Set HTTP POST Request.
            curl_setopt($ch, CURLOPT_POST, true);
            //Set data to POST in HTTP "POST" Operation.
            curl_setopt($ch, CURLOPT_POSTFIELDS, $paramArr);
            //CURLOPT_RETURNTRANSFER- true to return the transfer as a string of the return value of curl_exec().
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            //CURLOPT_SSL_VERIFYPEER- Set FALSE to stop cURL from verifying the peer's certificate.
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            //Execute the  cURL session.
            $strResponse = curl_exec($ch);
            //Get the Error Code returned by Curl.
            $curlErrno = curl_errno($ch);
            if ($curlErrno) {
                $curlError = curl_error($ch);
                throw new \Exception($curlError);
            }
            //Close the Curl Session.
            curl_close($ch);
            //Decode the returned JSON string.
            $objResponse = json_decode($strResponse);
            if (isset($objResponse->error)) {
                throw new \Exception($objResponse->error_description);
            }
            return $objResponse->access_token;
        } catch (\Exception $e) {
            echo "Exception-" . $e->getMessage();
        }
        return '';
    }
}