class MemoryGame {
    constructor() {
        this.symbols = ['🍎', '🍊', '🍋', '🍇', '🍓', '🍒', '🥝', '🍑'];
        this.cards = [];
        this.flippedCards = [];
        this.matchedPairs = 0;
        this.moves = 0;
        this.timer = null;
        this.seconds = 0;
        this.isLocked = false;
        this.gameStarted = false;

        this.boardEl = document.getElementById('game-board');
        this.movesEl = document.getElementById('moves');
        this.timerEl = document.getElementById('timer');
        this.pairsEl = document.getElementById('pairs');
        this.winModal = document.getElementById('win-modal');
        this.finalMovesEl = document.getElementById('final-moves');
        this.finalTimeEl = document.getElementById('final-time');
        
        document.getElementById('restart-btn').addEventListener('click', () => this.init());
        document.getElementById('play-again-btn').addEventListener('click', () => {
            this.winModal.style.display = 'none';
            this.init();
        });

        this.init();
    }

    init() {
        // 重置状态
        this.cards = [];
        this.flippedCards = [];
        this.matchedPairs = 0;
        this.moves = 0;
        this.seconds = 0;
        this.isLocked = false;
        this.gameStarted = false;

        // 清除计时器
        if (this.timer) {
            clearInterval(this.timer);
            this.timer = null;
        }

        // 更新UI
        this.movesEl.textContent = '0';
        this.timerEl.textContent = '0:00';
        this.pairsEl.textContent = '0/8';

        // 生成卡牌
        this.generateCards();
        this.renderBoard();
    }

    generateCards() {
        // 创建配对卡牌
        const cardPairs = [...this.symbols, ...this.symbols];
        // 洗牌 (Fisher-Yates shuffle)
        for (let i = cardPairs.length - 1; i > 0; i--) {
            const j = Math.floor(Math.random() * (i + 1));
            [cardPairs[i], cardPairs[j]] = [cardPairs[j], cardPairs[i]];
        }
        this.cards = cardPairs.map((symbol, index) => ({
            id: index,
            symbol: symbol,
            isFlipped: false,
            isMatched: false
        }));
    }

    renderBoard() {
        this.boardEl.innerHTML = '';
        this.cards.forEach(card => {
            const cardEl = document.createElement('div');
            cardEl.className = 'card';
            cardEl.dataset.id = card.id;
            cardEl.innerHTML = `
                <div class="card-face card-back"></div>
                <div class="card-face card-front">${card.symbol}</div>
            `;
            cardEl.addEventListener('click', () => this.flipCard(card.id));
            this.boardEl.appendChild(cardEl);
        });
    }

    flipCard(id) {
        const card = this.cards[id];
        const cardEl = this.boardEl.querySelector(`[data-id="${id}"]`);

        // 防止重复点击或锁定状态
        if (this.isLocked || card.isFlipped || card.isMatched) return;

        // 开始计时
        if (!this.gameStarted) {
            this.gameStarted = true;
            this.startTimer();
        }

        // 翻牌
        card.isFlipped = true;
        cardEl.classList.add('flipped');
        this.flippedCards.push(card);

        // 检查是否翻了两张
        if (this.flippedCards.length === 2) {
            this.moves++;
            this.movesEl.textContent = this.moves;
            this.checkMatch();
        }
    }

    checkMatch() {
        const [card1, card2] = this.flippedCards;
        
        if (card1.symbol === card2.symbol) {
            // 配对成功
            this.matchSuccess(card1, card2);
        } else {
            // 配对失败
            this.matchFail(card1, card2);
        }
    }

    matchSuccess(card1, card2) {
        card1.isMatched = true;
        card2.isMatched = true;
        this.matchedPairs++;
        this.pairsEl.textContent = `${this.matchedPairs}/8`;

        const cardEl1 = this.boardEl.querySelector(`[data-id="${card1.id}"]`);
        const cardEl2 = this.boardEl.querySelector(`[data-id="${card2.id}"]`);

        // 延迟消除动画
        setTimeout(() => {
            cardEl1.classList.add('matched');
            cardEl2.classList.add('matched');
        }, 500);

        this.flippedCards = [];

        // 检查胜利
        if (this.matchedPairs === 8) {
            this.win();
        }
    }

    matchFail(card1, card2) {
        this.isLocked = true;

        // 延迟翻回
        setTimeout(() => {
            card1.isFlipped = false;
            card2.isFlipped = false;

            const cardEl1 = this.boardEl.querySelector(`[data-id="${card1.id}"]`);
            const cardEl2 = this.boardEl.querySelector(`[data-id="${card2.id}"]`);
            cardEl1.classList.remove('flipped');
            cardEl2.classList.remove('flipped');

            this.flippedCards = [];
            this.isLocked = false;
        }, 1000);
    }

    startTimer() {
        this.timer = setInterval(() => {
            this.seconds++;
            const mins = Math.floor(this.seconds / 60);
            const secs = this.seconds % 60;
            this.timerEl.textContent = `${mins}:${secs.toString().padStart(2, '0')}`;
        }, 1000);
    }

    win() {
        clearInterval(this.timer);
        
        const mins = Math.floor(this.seconds / 60);
        const secs = this.seconds % 60;
        const timeStr = `${mins}:${secs.toString().padStart(2, '0')}`;

        this.finalMovesEl.textContent = this.moves;
        this.finalTimeEl.textContent = timeStr;

        setTimeout(() => {
            this.winModal.style.display = 'flex';
        }, 800);
    }
}

// 启动游戏
new MemoryGame();