Catch Me Up - Your No Pics Instagram Fix

'use strict';
const https = require('https');
//NOTE the latest aws-sdk must be bundled as Rekognition is not part of the default image at the time of writing
const AWS = require('aws-sdk');
const stream = require('stream').Transform;
const rekognition = new AWS.rekognition();
//TODO Expand the list of celebs
const celebs = {
    'Selen Gomez': 'selenagomez',
    'Taylor Swift': 'taylorswift',
    'Ariana Grande': 'arianagrande'
};

let getLabels = function (image) {
    return new Promise(function (resolve, reject) {
        var params = {
            Image: {
                Bytes: image.read()
            },
            MaxLabels: 1
        };
        rekognition.detectLabels(params, function (err, data) {
            if (err) {
                reject(err);
            }
            else {
                resolve(data.Labels);
            }
        });
    });
};

let getImage = function (url) {
    return new Promise(function (resolve, reject) {
        var req = https.request(url, (res) => {
            let data = new stream();
            res.on('data', (d) => {
                data.push(d);
            });
            res.on('end', () => {
                getLabels(data).then((labels) => {
                    resolve(labels);
                });
            })
        });
        req.end();
        req.on('error', (e) => {
            reject(error);
        });
    });
};

exports.handler = (event, context, callback) => {
    let person = event.request.intent.slots.Name.value;
    let id = celebs[person];
    https.get(`https://www.instagram.com/${id}/media/`, (res) => {
        let data = '';
        res.on('data', (d) => {
            data += d;
        });
        res.on('end', () => {
            let items = JSON.parse(data).items;
            let promises = [];
            let counter = 0;
            for (let item of items) {
                counter++;
                let url = item.images.standard_resolution.url;
                promises.push(getImage(url));
            }
            Promise.all(promises).then((labels) => {
                labels = [].concat.apply([], labels);
                //TODO replace, this is hacky
                let t = {};
                for (let label of labels) {
                    if (t[label.Name]) {
                        t[label.Name] = t[label.Name] + 1
                    } else {
                        t[label.Name] = 0
                    }
                }
                let speak = '';
                for (let name in t) {
                    speak += `${name} and `
                }
                speak = speak.substr(0, speak.lastIndexOf('and '));
                const handlers = {
                    'LaunchRequest': function () {
                        this.emit(':tell', 'Hello');
                    },
                    'GetName': function () {
                        //TODO replace with pauses and language library
                        this.emit(':tell', `${person} has been snapping pictures that contain ${speak}`);
                    },
                    'AMAZON.CancelIntent': function () {
                        this.emit(':tell', 'Cancelled');
                    },
                    'AMAZON.StopIntent': function () {
                        this.emit(':tell', 'Stopping');
                    },
                    'SessionEndedRequest': function () {
                        this.emit(':tell', 'Goodbye');
                    }
                };
                const Alexa = require('alexa-sdk');
                const alexa = Alexa.handler(event, context);
                alexa.registerHandlers(handlers);
                alexa.execute();
            })
        })
    }).on('error', (e) => {
        callback(e);
    });
};