var started = false;
var showControls = false;

var colorWords = ["red", "orange", "yellow", "green", "blue", "purple", "white"];
var hypnoWords = ["sleep", "relax", "fall", "deeper", "trance"];
var colors = ["red", "orange", "yellow", "green", "blue", "purple", "white"];
var wordEl = document.getElementById("word");

function randomChoice(a) {
    return a[Math.floor(Math.random()*a.length)];
}

var hypnoFrequency = 0;
var hypnoIncrements = 10;
function changeWord() {
    var wordList = (Math.random()*hypnoIncrements < hypnoFrequency) ? hypnoWords : colorWords;
    var newWord;
    do {
	newWord = randomChoice(wordList);
    } while (newWord === wordEl.innerText);

    var newColor;
    do {
	newColor = randomChoice(colors);
    } while (newColor === wordEl.style.color);

    wordEl.innerText = newWord;
    wordEl.style.color = newColor;
}

window.onclick = function () {
    if (!started) {
        started = true;
        document.getElementById("controls").style.display = "none";
        changeWord();
        setInterval(changeWord, 1000);
        setInterval(function() { if (hypnoFrequency < hypnoIncrements) { hypnoFrequency++; } }, 5000);
    } else {
        document.getElementById("controls").style.display = showControls ? "none" : "block";
        showControls = !showControls;
    }
}