Mage Night Dummy Deck Simulation

dummySim.js

"use strict";

const { randomInt } = require("crypto");

const log = false;

for (let i = 1; i <= 10; i++) {
  console.log(`Running round: ${i}`);
  runRound(i, 10000000);
}

function runRound(roundNumber, numRuns) {
  const results = { 1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0, 9: 0 };
  for (let n = 0; n < numRuns; n++) {
    results[simulateRound(roundNumber)]++;
  }

  const percentages = Object.keys(results).reduce(
    (a, v) => ({ ...a, [v]: (results[v] / numRuns) * 100 }),
    {}
  );
  console.log(Object.values(percentages).join(", "));
}

function simulateRound(roundNumber) {
  const crystals = {
    red: 2,
    white: 1,
    blue: 0,
    green: 0,
  };

  const deck = generateDummyDeck();

  // Add additional crystals and cards depending on the round number
  for (let i = 0; i < roundNumber - 1; i++) {
    crystals[getRandomColor()]++;
    deck.push(getRandomColor());
  }

  let turn = 1;
  while (deck.length > 0) {
    turn++;
    const cardsDrawn = draw(deck, 3);
    const additionalCardsDrawn = draw(
      deck,
      crystals[cardsDrawn[cardsDrawn.length - 1]]
    );
    log &&
      console.log(
        `Cards Drawn: ${cardsDrawn
          .join(", ")
          .padEnd(20)} Additional Cards Drawn: ${additionalCardsDrawn.join(
          ", "
        )}`
      );
  }
  log && console.log("End of Turn.");
  log && console.log("Turns: ", turn);
  return turn;
}

function getRandomColor() {
  return ["red", "white", "blue", "green"][randomInt(4)];
}

function draw(deck, n) {
  const cardsDrawn = [];

  if (deck.length > 0) {
    for (let i = 0; i < n; i++) {
      cardsDrawn.push(deck.pop());
      if (deck.length === 0) break;
    }
  }
  return cardsDrawn;
}

// Generate dummy deck of 16 cards, 4 of each color
function generateDummyDeck() {
  const deck = [];

  ["green", "white", "red", "blue"].forEach((color) => {
    for (let i = 0; i < 4; i++) {
      deck.push(color);
    }
  });

  return shuffle(deck);
}

// Fisher-Yates Shuffle
function shuffle(array) {
  let currentIndex = array.length;
  let randomIndex;

  // While there remain elements to shuffle.
  while (currentIndex != 0) {
    // Pick a remaining element.
    randomIndex = randomInt(currentIndex);
    currentIndex--;

    // And swap it with the current element.
    [array[currentIndex], array[randomIndex]] = [
      array[randomIndex],
      array[currentIndex],
    ];
  }

  return array;
}