carbon/api/handlers/unsplash.js

require('isomorphic-fetch')
const { default: Unsplash, toJson } = require('unsplash-js')

const WALLPAPER_COLLECTION_ID = 136026

const client = new Unsplash({
  applicationId: process.env.UNSPLASH_ACCESS_KEY,
  secret: process.env.UNSPLASH_SECRET_KEY,
  callbackUrl: process.env.UNSPLASH_CALLBACK_URL
})

const parseImageResult = img => ({
  id: img.id,
  photographer: {
    name: img.user.name,
    profile_url: img.user.links.html
  },
  url: img.urls.small
})

const getRandomImages = () =>
  client.photos
    .getRandomPhoto({
      collections: [WALLPAPER_COLLECTION_ID],
      count: 20
    })
    .then(toJson)
    .then(imgs => imgs.map(parseImageResult))

const downloadImage = imageId =>
  client.photos
    .getPhoto(imageId)
    .then(toJson)
    .then(client.photos.downloadPhoto)
    .then(toJson)

module.exports = {
  randomImages: (req, res) => getRandomImages().then(imgs => res.json(imgs)),
  downloadImage: (req, res) => downloadImage(req.params.imageId).then(url => res.json(url))
}