script.js

// global constants
const cluePauseTime = 333; //how long to pause in between clues
const nextClueWaitTime = 1000; //how long to wait before playing sequence

//Global Variables
var pattern = [];
var progress = 0; 
var gamePlaying = false;
var tonePlaying = false;
var volume = 0.5;  // must be between 0.0 and 1.0
var guessCounter = 0;
var clueHoldTime = 1000; //how long to hold each clue's light/sound
var numMistakes;

function getPattern() {
  var new_pattern = [];
  for (var i = 0; i < 8; i++) {
    new_pattern.push(Math.floor(Math.random() * (6 - 1) + 1));
  }
  return new_pattern;
}

function startGame() {
  //initialize game variables
  progress = 0;
  pattern = getPattern();
  gamePlaying = true;
  numMistakes = 0;
  // swap the Start and Stop buttons
  document.getElementById("startBtn").classList.add("hidden");
  document.getElementById("stopBtn").classList.remove("hidden");
  playClueSequence();
}

function stopGame(){
  //initialize game variables
  gamePlaying = false;
  clueHoldTime = 1000;
  // swap the Start and Stop buttons
  document.getElementById("startBtn").classList.remove("hidden");
  document.getElementById("stopBtn").classList.add("hidden");
}

function lightButton(btn){
  document.getElementById("button"+btn).classList.add("lit")
}

function clearButton(btn){
  document.getElementById("button"+btn).classList.remove("lit")
}

function playSingleClue(btn) {
  if(gamePlaying) {
    lightButton(btn);
    playTone(btn,clueHoldTime);
    setTimeout(clearButton,clueHoldTime,btn);
  }
}

// Sound Synthesis Functions
const freqMap = {
  1: 261.0, // c
  2: 293.0, // d
  3: 440.0, // a
  4: 493.0, // b
  5: 329.0, // e
  6: 349.0 // f
}

function playTone(btn,len){ 
  o.frequency.value = freqMap[btn]
  g.gain.setTargetAtTime(volume,context.currentTime + 0.05,0.025)
  context.resume()
  tonePlaying = true
  setTimeout(function(){
    stopTone()
  },len)
}

function startTone(btn){
  if(!tonePlaying){
    context.resume()
    o.frequency.value = freqMap[btn]
    g.gain.setTargetAtTime(volume,context.currentTime + 0.05,0.025)
    context.resume()
    tonePlaying = true
  }
}

function stopTone(){
  g.gain.setTargetAtTime(0,context.currentTime + 0.05,0.025)
  tonePlaying = false
}

function playClueSequence(){
  context.resume()
  let delay = nextClueWaitTime; //set delay to initial wait time
  clueHoldTime -= 120;
  guessCounter = 0;
  for(let i = 0; i <= progress; i++) { // for each clue that is revealed so far
    console.log("play single clue: " + pattern[i] + " in " + delay + "ms")
    setTimeout(playSingleClue,delay,pattern[i]) // set a timeout to play that clue
    delay += clueHoldTime;
    delay += cluePauseTime;
  }
}

function guess(btn) {
  console.log("user guessed: " + btn);
  if(!gamePlaying) {
    return;
  }
  if (btn == pattern[guessCounter]) {
    if (progress != guessCounter) {
      guessCounter += 1;
    } else if (progress == pattern.length - 1) {
      winGame();
    }
    else {
      progress += 1;
      playClueSequence();
    }
  } else {
    numMistakes += 1;
    if (numMistakes >= 3) {
     loseGame(); 
    }
  }
}


function loseGame() {
  stopGame();
  alert("Game Over. You lost.");
}

function winGame() {
  stopGame();
  alert("Congratulations, you won!");
}

// Page Initialization
// Init Sound Synthesizer
var AudioContext = window.AudioContext || window.webkitAudioContext 
var context = new AudioContext()
var o = context.createOscillator()
var g = context.createGain()
g.connect(context.destination)
g.gain.setValueAtTime(0,context.currentTime)
o.connect(g)
o.start(0)