script.js

let gameBoard, movesEl, timeEl, bestScoreEl, messageEl;
let firstCard, secondCard, lockBoard, moves, matchedPairs, timer, seconds;
let sounds = {};

document.addEventListener("DOMContentLoaded", () => {
  gameBoard = document.getElementById("game-board");
  movesEl = document.getElementById("moves");
  timeEl = document.getElementById("time");
  bestScoreEl = document.getElementById("best-score");
  messageEl = document.getElementById("message");

  // Load sounds
  sounds.flip = new Audio("sounds/flip.mp3");
  sounds.match = new Audio("sounds/match.mp3");
  sounds.wrong = new Audio("sounds/wrong.mp3");
  sounds.win = new Audio("sounds/win.mp3");

  loadBestScore();
});

function startGame() {
  clearInterval(timer);
  moves = 0;
  matchedPairs = 0;
  seconds = 0;
  firstCard = null;
  secondCard = null;
  lockBoard = false;
  movesEl.textContent = moves;
  timeEl.textContent = seconds;
  messageEl.textContent = "";

  let difficulty = document.getElementById("difficulty").value;
  let rows, cols, pairs;

  if (difficulty === "easy") { rows = 4; cols = 4; pairs = 8; }
  if (difficulty === "medium") { rows = 4; cols = 5; pairs = 10; }
  if (difficulty === "hard") { rows = 6; cols = 6; pairs = 18; }

  gameBoard.style.gridTemplateColumns = `repeat(${cols}, 80px)`;

  const emojis = ["😀","🎉","🚀","🐱","🍕","⚽","🎧","🌈","🔥","💡","🎂","✈️","📚","💻","🦋","🍫","🥇","🧩"];
  let cards = emojis.slice(0, pairs);
  cards = [...cards, ...cards]; // duplicate
  cards.sort(() => 0.5 - Math.random()); // shuffle

  gameBoard.innerHTML = "";
  cards.forEach((emoji) => {
    const card = document.createElement("div");
    card.classList.add("card");
    card.dataset.emoji = emoji;
    card.innerHTML = "❓";
    card.addEventListener("click", flipCard);
    gameBoard.appendChild(card);
  });

  timer = setInterval(() => {
    seconds++;
    timeEl.textContent = seconds;
  }, 1000);
}

function flipCard() {
  if (lockBoard || this.classList.contains("flipped") || this.classList.contains("matched")) return;

  sounds.flip.play();
  this.classList.add("flipped");
  this.innerHTML = this.dataset.emoji;

  if (!firstCard) {
    firstCard = this;
    return;
  }

  secondCard = this;
  moves++;
  movesEl.textContent = moves;

  checkMatch();
}

function checkMatch() {
  if (firstCard.dataset.emoji === secondCard.dataset.emoji) {
    sounds.match.play();
    firstCard.classList.add("matched");
    secondCard.classList.add("matched");
    matchedPairs++;
    resetTurn();
    if (matchedPairs === gameBoard.children.length / 2) {
      endGame();
    }
  } else {
    lockBoard = true;
    sounds.wrong.play();
    setTimeout(() => {
      firstCard.classList.remove("flipped");
      secondCard.classList.remove("flipped");
      firstCard.innerHTML = "❓";
      secondCard.innerHTML = "❓";
      resetTurn();
    }, 1000);
  }
}

function resetTurn() {
  [firstCard, secondCard, lockBoard] = [null, null, false];
}

function endGame() {
  clearInterval(timer);
  sounds.win.play();
  messageEl.textContent = `🎉 You won in ${seconds}s and ${moves} moves!`;

  // Save best score
  let best = JSON.parse(localStorage.getItem("bestScore")) || {time: Infinity, moves: Infinity};
  if (seconds < best.time || (seconds === best.time && moves < best.moves)) {
    localStorage.setItem("bestScore", JSON.stringify({time: seconds, moves: moves}));
    loadBestScore();
  }
}

function loadBestScore() {
  let best = JSON.parse(localStorage.getItem("bestScore"));
  if (best) {
    bestScoreEl.textContent = `${best.time}s, ${best.moves} moves`;
  } else {
    bestScoreEl.textContent = "--";
  }
}