Quick & Dirty nodejs app to get Fitbit second by second heart rate data

fitbithr.js

//For info about this gist, see my blog entry https://virtualdatacave.com/2016/09/fitbit-hr-data-raw/

//For API see https://dev.fitbit.com/docs/heart-rate/#get-heart-rate-intraday-time-series

var dateFormat = require('dateformat');

// initialize the express application
var express = require("express"),
    app = express();

// initialize the Fitbit API client
var FitbitApiClient = require("fitbit-node"),
    client = new FitbitApiClient("YOUR_SECRET", "YOUR_KEY");

// redirect the user to the Fitbit authorization page
app.get("/hr", function (req, res) {
    // request access to the user's activity, heartrate, location, nutrion, profile, settings, sleep, social, and weight scopes
    res.redirect(client.getAuthorizeUrl('activity heartrate location nutrition profile settings sleep social weight', 'http://YOURSERVER:8083/callback'));
});

// handle the callback from the Fitbit authorization flow
app.get("/callback", function (req, res) {
        var menu = "<p><a href='/gethr?code=" + req.query.code + "'>Get HR for Today</a>" +
                   "<p><a href='/gethr?code=" + req.query.code + "&day=yyyy-MM-dd'>Get HR for Specific Day (Must Manually Update URL)</a>";
        res.send(menu);
});

app.get("/gethr", function (req, res) {
        var specificday = req.query.day;
        var code      = req.query.code;

    // exchange the authorization code we just received for an access token
    client.getAccessToken(code, 'http://YOURSERVER:8083/callback').then(function (result) {
        // log the access token
//      console.log("Got access token: " + result.access_token);
        // use the access token to fetch the user's profile information
        if(specificday) {
                client.get("/activities/heart/date/" + specificday + "/" + specificday + "/1sec/time/00:00/23:59.json", result.access_token).then(function (results) {
                var csv = "<pre>date,time,HR";
                for(var bit in results[0]['activities-heart-intraday']['dataset']) {
                        csv = csv + "\r\n" + specificday + "," + results[0]['activities-heart-intraday']['dataset'][bit]['time'] + ',' + results[0]['activities-heart-intraday']['dataset'][bit]['value'];
                }
                res.send(csv);
               });

        } else {

        client.get("/activities/heart/date/today/1d/1sec/time/00:00/23:59.json", result.access_token).then(function (results) {
                //Now get the heart rate data
                var csv = "<pre>date,time,HR";
                var datebit = dateFormat( (new Date()), 'yyyy-mm-dd' );
                for(var bit in results[0]['activities-heart-intraday']['dataset']) {
                        csv = csv + "\r\n" + datebit + "," + results[0]['activities-heart-intraday']['dataset'][bit]['time'] + ',' + results[0]['activities-heart-intraday']['dataset'][bit]['value'];
                }
            res.send(csv);
        });

        }
    }).catch(function (error) {
        res.send(error);
    });
});



// launch the server
app.listen(8083);