const botauth = require("botauth");
const DropboxOAuth2Strategy = require("passport-dropbox-oauth2").Strategy;

...

 // Initialize with the strategies we want to use
var auth = new botauth.BotAuthenticator(server, bot, {
	secret : "something secret",
	baseUrl : "https://" + WEBSITE_HOSTNAME }
);

// Configure the Dropbox authentication provider using the passport-dropbox strategy
auth.provider("dropbox",
	function(options) {
		return new DropboxOAuth2Strategy(
			{
    				clientID : DROPBOX_APP_ID,
    				clientSecret : DROPBOX_APP_SECRET,
					callbackURL : options.callbackURL
			},
			function(accessToken, refreshToken, profile, done) {
				profile.accessToken = accessToken;
				profile.refreshToken = refreshToken;
				done(null, profile);
			}
		);
	}
);

bot.dialog('/dropbox', [].concat(
	auth.authenticate("dropbox"), //use authenticate as a waterfall step
	function(session, results) {
		// this waterfall step will only be reached if authentication succeeded

		var user = auth.profile(session, "dropbox");
		session.endDialog("Welcome " + user.displayName);
	}
));