MarcoWorms

const seed = 1234
const shuffledDeck = shuffle(seed, deck)

MarcoWorms

const { pipe, sortBy, prop, pluck } = require('ramda')

const shuffle = (seed, deck) => {
  const routine = pipe(
    deck => deck.map((card, index) => ({
      rank: seededRandom(seed + index),
      card,
    })),
    sortBy(prop('rank')),
    pluck('card')

MarcoWorms

const seededRandom = seed => Math.abs(Math.sin(seed))

MarcoWorms

// http://ramdajs.com/docs/#pipe
const { pipe, curry } = require('ramda')

const addToTop = curry((card, deck) => [card, ...deck])

const addToBottom = curry((card, deck) => [...deck, card])

const addBoth = pipe(
  addToTop({ name: 'Ice Wall', damage: 3, cost: 1 }),
  addToBottom({ name: 'Earth Strike', damage: 6, cost: 3 })

MarcoWorms

const { head } = require('ramda')
const drawFromTop = draw(head)
const { card, newDeck } = drawFromTop(deck)

MarcoWorms

const draw = curry((cardPicker, deck) => {
  const card = cardPicker(deck)
  const newDeck = without(card, deck)
  return { card, newDeck }
})

MarcoWorms

const randomElement = array =>
  array[Math.floor(Math.random() * array.length)]

draw(randomElement, deck)

MarcoWorms

const last = array => array[array.length - 1]
const { card, newDeck } = draw(last, deck)

MarcoWorms

const head = array => array[0]
const { card, newDeck } = draw(head, deck)

MarcoWorms

const draw = (cardPicker, deck) => {
  // 1. We want to know what card we drew
  const card = cardPicker(deck)
  // 2. We want the new deck without the drawn card
  const newDeck = without(card, deck)
  return { card, newDeck }
}