<div class="app">
  <h1>Sudoku Training</h1>
  <div class="game">
    <div class="message">
      <p>
        Time:
        <span class="time">00:00</span>
      </p>
      <p class="round">1/5</p>
      <p>
        Score:
        <span class="score">100</span>
      </p>
    </div>
    <div class="digits">
      <span>1</span>
      <span>2</span>
      <span>3</span>
      <span>4</span>
      <span>5</span>
      <span>6</span>
      <span>7</span>
      <span>8</span>
      <span>9</span>
    </div>
  </div>
  <div class="select-level">
    <div class="levels">
      <input type="radio" name="level" id="easy" value="easy" checked="checked">
      <label for="easy">Easy</label>

      <input type="radio" name="level" id="normal" value="normal">
      <label for="normal">Normal</label>

      <input type="radio" name="level" id="hard" value="hard">
      <label for="hard">Hard</label>
    </div>
    <div class="play">Play</div>
  </div>
  <div class="game-over">
    <h2>Game Over</h2>
    <p>
      Time:
      <span class="final-time">00:00</span>
    </p>
    <p>
      Score:
      <span class="final-score">3000</span>
    </p>
    <div class="again">Play Again</div>
  </div>
</div>

body {
    margin: 0;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: silver;
    overflow: hidden;
}

.app {
    width: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-between;
    user-select: none;
    position: relative;
}

h1 {
    margin: 0;
    color: sienna;
}

.game {
    transition: 0.3s;
}

.game.stop {
    filter: blur(10px);
}

.game .message {
    width: inherit;
    display: flex;
    justify-content: space-between;
    font-size: 1.2em;
    font-family: sans-serif;
}

.game .message span {
    font-weight: bold;
}

.game .digits {
    box-sizing: border-box;
    width: 300px;
    height: 300px;
    padding: 10px;
    border: 10px solid sienna;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-gap: 10px;
}

.game .digits span {
    box-sizing: border-box;
    width: 80px;
    height: 80px;
    background-color: blanchedalmond;
    font-size: 30px;
    font-family: sans-serif;
    text-align: center;
    line-height: 2.5em;
    color: sienna;
    position: relative;
}

.game .digits span.wrong {
    border: 2px solid crimson;
}

.game .digits span.correct {
    background-color: chocolate;
    color: gold;
}

.select-level,
.game-over {
    box-sizing: border-box;
    width: 240px;
    height: 240px;
    border: 10px solid rgba(160, 82, 45, 0.8);
    border-radius: 50%;
    box-shadow: 
        0 0 0 0.3em rgba(255, 235, 205, 0.8),
        0 0 1em 0.5em rgba(160, 82, 45, 0.8);
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: sans-serif;
    position: absolute;
    bottom: 40px;
    visibility: hidden;
    z-index: 2;
}

.select-level .levels {
    margin-top: 60px;
    width: 190px;
    display: flex;
    justify-content: space-between;
    position: relative;
}

.select-level input[type=radio] {
    position: absolute;
    visibility: hidden;
}

.select-level label {
    width: 56px;
    height: 56px;
    background-color: rgba(160, 82, 45, 0.8);
    border-radius: 50%;
    color: blanchedalmond;
    text-align: center;
    line-height: 56px;
    cursor: pointer;
}

.select-level input[type=radio]:checked + label {
    background-color: sienna;
}

.select-level .play,
.game-over .again {
    width: 120px;
    height: 30px;
    background-color: sienna;
    color: blanchedalmond;
    text-align: center;
    line-height: 30px;
    border-radius: 30px;
    text-transform: uppercase;
    cursor: pointer;
}

.select-level .play {
    margin-top: 30px;
    font-size: 20px;
    letter-spacing: 2px;
}

.select-level .play:hover,
.game-over .again:hover {
    background-color: saddlebrown;
}

.select-level .play:active,
.game-over .again:active {
    transform: translate(2px, 2px);
}

.game-over h2 {
    margin-top: 40px;
    color: sienna;
}

.game-over p {
    margin: 3px;
    font-size: 20px;
    color: sienna;
}

.game-over .again {
    margin-top: 10px;
}

const ALL_DIGITS = ['1','2','3','4','5','6','7','8','9']
const ANSWER_COUNT = {EASY: 1, NORMAL: 2, HARD: 3}
const ROUND_COUNT = 3
const SCORE_RULE = {CORRECT: 100, WRONG: -10}

const $ = (selector) => document.querySelectorAll(selector)
const dom = {
    game: $('.game')[0],
    digits: Array.from($('.game .digits span')),
    time: $('.game .time')[0],
    round: $('.game .round')[0],
    score: $('.game .score')[0],
    selectLevel: $('.select-level')[0],
    level: () => {return $('input[type=radio]:checked')[0]},
    play: $('.select-level .play')[0],
    gameOver: $('.game-over')[0],
    again: $('.game-over .again')[0],
    finalTime: $('.game-over .final-time')[0],
    finalScore: $('.game-over .final-score')[0],
}

const render = {
    initDigits: (texts) => {
        allTexts = texts.concat(_.fill(Array(ALL_DIGITS.length - texts.length), ''))
        _.shuffle(dom.digits).forEach((digit, i) => {
            digit.innerText = allTexts[i]
            digit.className = ''
        })
    },
    updateDigitStatus: (text, isAnswer) => {
        if (isAnswer) {
            let digit = _.find(dom.digits, x => (x.innerText == ''))
            digit.innerText = text
            digit.className = 'correct'
        }
        else {
            _.find(dom.digits, x => (x.innerText == text)).className = 'wrong'
        }
    },
    updateTime: (value) => {
        dom.time.innerText = value
    },
    updateScore: (value) => {
        dom.score.innerText = value.toString()
    },
    updateRound: (value) => {
        dom.round.innerText = [
            value.toString(),
            '/',
            ROUND_COUNT.toString(),
        ].join('')
    },
    updateFinal: () => {
        dom.finalTime.innerText = dom.time.innerText
        dom.finalScore.innerText = dom.score.innerText
    },
}

const animation = {
    digitsFrameOut: () => {
        return new Promise(resolve => {
            new TimelineMax()
                .staggerTo(dom.digits, 0, {rotation: 0})
                .staggerTo(dom.digits, 1, {rotation: 360, scale: 0, delay: 0.5})
                .timeScale(2)
                .eventCallback('onComplete', resolve)
        })
    },
    digitsFrameIn: () => {
        return new Promise(resolve => {
            new TimelineMax()
                .staggerTo(dom.digits, 0, {rotation: 0})
                .staggerTo(dom.digits, 1, {rotation: 360, scale: 1}, 0.1)
                .timeScale(2)
                .eventCallback('onComplete', resolve)
        })
    },
    showUI: (element) => {
        dom.game.classList.add('stop')
        return new Promise(resolve => {
            new TimelineMax()
                .to(element, 0, {visibility: 'visible', x: 0})
                .from(element, 1, {y: '-300px', ease: Elastic.easeOut.config(1, 0.3)})
                .timeScale(1)
                .eventCallback('onComplete', resolve)
        })
    },
    hideUI: (element) => {
        dom.game.classList.remove('stop')
        return new Promise(resolve => {
            new TimelineMax()
                .to(element, 1, {x: '300px', ease: Power4.easeIn})
                .to(element, 0, {visibility: 'hidden'})
                .timeScale(2)
                .eventCallback('onComplete', resolve)
        })
    },
}

let answerCount, digits, round, score, timer, canPress

window.onload = init

function init() {
    dom.play.addEventListener('click', startGame)
    dom.again.addEventListener('click', playAgain)
    window.addEventListener('keyup', pressKey)

    newGame()
}

async function newGame() {
    round = 0
    score = 0
    timer = new Timer(render.updateTime)
    canPress = false

    await animation.showUI(dom.selectLevel)
}

async function startGame() {
    render.updateRound(1)
    render.updateScore(0)
    render.updateTime('00:00')

    await animation.hideUI(dom.selectLevel)

    answerCount = ANSWER_COUNT[dom.level().value.toUpperCase()]
    newRound()
    timer.start()
    canPress = true
}

async function newRound() {
    await animation.digitsFrameOut()

    digits = _.shuffle(ALL_DIGITS).map((x, i) => {
        return {
            text: x,
            isAnwser: (i < answerCount),
            isPressed: false
        }
    })
    render.initDigits(_.filter(digits, x => !x.isAnwser).map(x => x.text))

    await animation.digitsFrameIn()

    round++
    render.updateRound(round)
}

async function gameOver() {
    canPress = false
    timer.stop()
    render.updateFinal()
    
    await animation.showUI(dom.gameOver)
}

async function playAgain() {
    await animation.hideUI(dom.gameOver)

    newGame()
}

function pressKey(e) {
    if (!canPress) return;
    if (!ALL_DIGITS.includes(e.key)) return;

    let digit = _.find(digits, x => (x.text == e.key))
    if (digit.isPressed) return;

    digit.isPressed = true
    render.updateDigitStatus(digit.text, digit.isAnwser)

    score += digit.isAnwser ? SCORE_RULE.CORRECT : SCORE_RULE.WRONG
    render.updateScore(score)

    let hasPressedAllAnswerDigits = (_.filter(digits, (x) => (x.isAnwser && x.isPressed)).length == answerCount)
    if (!hasPressedAllAnswerDigits) return;
    
    let hasPlayedAllRounds = (round == ROUND_COUNT)
    if (hasPlayedAllRounds) {
        gameOver()
    } else {
        newRound()
    }
}

function Timer(render) {
    this.render = render
    this.t = {}
    this.time = {
        minute: 0,
        second: 0,
    }
    this.tickTock = () => {
        this.time.second++;
        if (this.time.second == 60) {
            this.time.minute++
            this.time.second = 0
        }

        this.render([
            this.time.minute.toString().padStart(2, '0'),
            ':',
            this.time.second.toString().padStart(2, '0'),
        ].join(''))
    }
    this.start = () => {
        this.t = setInterval(this.tickTock, 1000)
    }
    this.stop = () => {
        clearInterval(this.t)
    }
}