var http = require('http');
var qs = require('querystring');
// var OAuth = require('oauth'), OAuth2 = OAuth.OAuth2;
var OAuth2 = require('../lib/oauth2.js').OAuth2;

var clientID = '';
var clientSecret = '';
var oauth2 = new OAuth2(clientID,
                        clientSecret,
                        'https://github.com/', 
                        'login/oauth/authorize',
                        'login/oauth/access_token',
                        null); /** Custom headers */

http.createServer(function (req, res) {
    var p = req.url.split('/');
    pLen = p.length;
    
    /**
     * Authorised url as per github docs:
     * https://developer.github.com/v3/oauth/#redirect-users-to-request-github-access
     * 
     * getAuthorizedUrl: https://github.com/ciaranj/node-oauth/blob/master/lib/oauth2.js#L148
     * Adding params to authorize url with fields as mentioned in github docs
     *
     */
    var authURL = oauth2.getAuthorizeUrl({
        redirect_uri: 'http://localhost:8080/code',
        scope: ['repo', 'user'],
        state: 'some random string to protect against cross-site request forgery attacks'
    });


    /**
     * Creating an anchor with authURL as href and sending as response
     */
    var body = '<a href="' + authURL + '"> Get Code </a>';
    if (pLen === 2 && p[1] === '') {
        res.writeHead(200, {
            'Content-Length': body.length,
            'Content-Type': 'text/html' });
        res.end(body);
    } else if (pLen === 2 && p[1].indexOf('code') === 0) {

        /** Github sends auth code so that access_token can be obtained */
        var qsObj = {};
        
        /** To obtain and parse code='...' from code?code='...' */
        qsObj = qs.parse(p[1].split('?')[1]); 

        /** Obtaining access_token */
        oauth2.getOAuthAccessToken(
            qsObj.code,
            {'redirect_uri': 'http://localhost:8080/code/'},
            function (e, access_token, refresh_token, results){
                if (e) {
                    console.log(e);
                    res.end(e);
                } else if (results.error) {
                    console.log(results);
                    res.end(JSON.stringify(results));
                }
                else {
                    console.log('Obtained access_token: ', access_token);
                    res.end( access_token);
                }
        });

    } else {
        // Unhandled url
    }

}).listen(8080);