Fetch access token from beefree api

beefree.js

/**
 * NodeJS beefree.io integration
 */

const https = require('https');
const querystring = require('querystring');

/**
 * Fetch access token from beefree api
 */
function auth(client_id, client_secret, callback) {

    // encode credentials to query string
    let credentials = querystring.stringify({
        grant_type: 'password',
        client_id: client_id,
        client_secret: client_secret
    });

    // define beefree connection endpoint
    let options = {
        hostname: 'auth.getbee.io',
        method: 'POST',
        path: '/apiauth',
        headers: {
            'Content-Type': 'application/x-www-form-urlencoded',
            'Content-Length': Buffer.byteLength(credentials)
        }
    };

    // create the http request object
    let request = https.request(options, (response) => {

        // expect the status code to be 200, else is error
        if(response.statusCode != 200){
            return callback(new Error(`unexpected http status code: ${response.statusCode}`));
        }

        let buffer = [];
        response.setEncoding('utf8');

        // on data recived add data to the buffer
        response.on('data', (data) => {
            buffer.push(data);
        });

        // on all data recived parse response body
        response.on('end', () => {
            let data = JSON.parse(buffer.join(''));
            return callback(null, data);
        });
    });

    // listen on error events
    request.on('error', (err) => {
        return callback(err, null);
    });

    // send data
    request.write(credentials);

    // end client side request
    request.end();
}

module.exports = {
    auth: auth
};