// ==== 音声管理 ====
let soundEnabled = false;
let titleBgm, bgm, sfxPut, sfxMatch, sfxGameover, sfxRotate, sfxWin, sfxDamage;
let isPlayingGame = false;

function createAudio(src) { const a = new Audio(src); a.preload = 'auto'; return a; }

function ensureAudioCreated() {
    if (!bgm) {
        titleBgm = createAudio('static/title.mp3'); titleBgm.loop = true;
        bgm = createAudio('static/bgm.mp3'); bgm.loop = true;
        sfxPut = createAudio('static/put.mp3');
        sfxMatch = createAudio('static/match.mp3');
        sfxGameover = createAudio('static/gameover.mp3');
        sfxRotate = createAudio('static/rotate.mp3');
        sfxWin = createAudio('static/win.mp3');
        sfxDamage = createAudio('static/damage.mp3');
    }
}

function playSfx(audio, vol = 1.0) {
    if (!soundEnabled || !audio) return;
    const c = audio.cloneNode(); c.volume = vol; c.play().catch(() => { });
}

function bgmControl(state) {
    if (!soundEnabled || !titleBgm || !bgm) return;
    titleBgm.pause(); bgm.pause();
    if (state === 'title') { titleBgm.currentTime = 0; titleBgm.volume = 0.4; titleBgm.play().catch(() => { }); }
    else if (state === 'game') { bgm.currentTime = 0; bgm.volume = 0.4; bgm.play().catch(() => { }); }
}

document.getElementById('sound-toggle').addEventListener('click', () => {
    ensureAudioCreated();
    soundEnabled = !soundEnabled;
    document.getElementById('sound-toggle').textContent = soundEnabled ? '🔊' : '🔇';
    if (soundEnabled) {
        if (isPlayingGame && (!p1 || !p1.isGameOver)) bgmControl('game');
        else if (!isPlayingGame) bgmControl('title');
    } else {
        bgmControl('stop');
    }
});

// ==== ゲーム設定 ====
const COLS = 8, ROWS = 8, COLORS = 4, MIN_MATCH = 3;
const tileImages = ['static/tile1.png', 'static/tile2.png', 'static/tile3.png', 'static/tile4.png', 'static/tile5.png'];
const tileImg = (i) => { const img = document.createElement('img'); img.src = tileImages[i]; img.draggable = false; return img; };
const sleep = ms => new Promise(r => setTimeout(r, ms));

let p1, p2;
let gameMode = '1p'; // '1p', 'vs-real', 'vs-turn'
let currentTurn = 1; // 1: Player, 2: AI (ターン制用)
let isDemoActive = true;

class QuadGame {
    constructor(rootEl, isAI, isDemo = false) {
        this.root = rootEl; this.isAI = isAI; this.isDemo = isDemo;
        this.boardEl = rootEl.querySelector('.board');
        this.handEl = rootEl.querySelector('.hand-area');
        this.scoreEl = rootEl.querySelector('.score-display');
        this.msgEl = rootEl.querySelector('.message-pop');
        this.garbageUi = rootEl.querySelector('.garbage-ui');
        this.garbageBar = rootEl.querySelector('.garbage-bar');
        this.garbageText = rootEl.querySelector('.garbage-text');

        this.board = []; this.hand = [];
        this.score = 0; this.combo = 0;
        this.isProcessing = false; this.isGameOver = false; this.aiFetching = false;
        this.opponent = null;

        this.pendingGarbage = 0;
        this.garbageTimerMax = 6000;
        this.garbageTimer = 0;

        this.dragging = null; this.dragEl = null; this.ghostCells = [];
    }

    init() {
        this.board = Array.from({ length: ROWS }, () => Array(COLS).fill(-1));
        this.hand = [this.genPiece(), this.genPiece(), this.genPiece()];
        this.score = 0; this.combo = 0; this.pendingGarbage = 0;
        this.isGameOver = false; this.isProcessing = false;

        this.boardEl.innerHTML = '';
        for (let i = 0; i < 64; i++) {
            const c = document.createElement('div'); c.className = 'cell';
            this.boardEl.appendChild(c);
        }
        this.updateHandUI();
        if (this.scoreEl) this.scoreEl.textContent = '0';
        if (this.garbageUi) this.garbageUi.style.display = 'none';
    }

    genPiece() {
        let p;
        while (true) {
            p = [[Math.floor(Math.random() * COLORS), Math.floor(Math.random() * COLORS)],
            [Math.floor(Math.random() * COLORS), Math.floor(Math.random() * COLORS)]];
            if (!this.hasMatchSync(p)) return p;
        }
    }

    hasMatchSync(p) {
        for (let col = 0; col < COLORS; col++) {
            let count = 0;
            for (let r = 0; r < 2; r++) for (let c = 0; c < 2; c++) if (p[r][c] === col) count++;
            if (count >= 3) return true;
        }
        return false;
    }

    getCellEl(r, c) { return this.boardEl.children[r * COLS + c]; }

    renderBoard() {
        for (let r = 0; r < ROWS; r++) for (let c = 0; c < COLS; c++) {
            const cell = this.getCellEl(r, c);
            const ex = cell.querySelector('.block'); if (ex) ex.remove();
            if (this.board[r][c] >= 0) {
                const blk = document.createElement('div'); blk.className = 'block';
                blk.appendChild(tileImg(this.board[r][c]));
                cell.appendChild(blk);
            }
        }
    }

    updateHandUI() {
        this.handEl.innerHTML = '';
        this.hand.forEach((p, idx) => {
            const el = document.createElement('div');
            el.className = 'hand-piece' + (!this.isAI ? ' interactive' : '');
            if (!p) { el.style.visibility = 'hidden'; this.handEl.appendChild(el); return; }

            [[0, 0], [0, 1], [1, 0], [1, 1]].forEach(([r, c]) => {
                const w = document.createElement('div'); w.className = 'hand-cell-wrapper';
                const cl = document.createElement('div'); cl.className = 'hand-cell';
                cl.style.left = '0'; cl.style.top = '0';
                cl.appendChild(tileImg(p[r][c])); w.appendChild(cl); el.appendChild(w);
            });

            if (!this.isAI) {
                el.addEventListener('mousedown', e => this.onHandDown(e, idx));
                el.addEventListener('touchstart', e => this.onHandDown(e, idx), { passive: false });
            }
            this.handEl.appendChild(el);
        });
        this.checkValidMoves();
    }

    rotateCW(idx) {
        const p = this.hand[idx];
        this.hand[idx] = [[p[1][0], p[0][0]], [p[1][1], p[0][1]]];
    }

    async animateRotation(idx) {
        if (!this.isDemo) playSfx(sfxRotate, 0.4);
        this.rotateCW(idx);
        this.updateHandUI();
    }

    canPlace(piece, sr, sc) {
        if (!piece) return false;
        for (let r = 0; r < 2; r++) for (let c = 0; c < 2; c++) {
            const br = sr + r, bc = sc + c;
            if (br < 0 || br >= ROWS || bc < 0 || bc >= COLS || this.board[br][bc] >= 0) return false;
        }
        return true;
    }

    checkValidMoves() {
        if (this.isGameOver) return;
        let any = false;
        const els = this.handEl.querySelectorAll('.hand-piece');

        // ターン制での自分以外のターンの場合はすべて無効化
        const isMyTurn = (gameMode !== 'vs-turn') || (this.isAI ? currentTurn === 2 : currentTurn === 1);

        this.hand.forEach((p, i) => {
            if (!p) return;
            let ok = false;
            if (isMyTurn) {
                for (let r = 0; r < 7; r++) for (let c = 0; c < 7; c++) if (this.canPlace(p, r, c)) ok = true;
            }
            if (ok) any = true;
            if (els[i]) els[i].classList.toggle('disabled', !ok);
        });

        // 置ける手がない（本当に盤面が埋まっているか手札がない）場合のゲームオーバー判定
        let trueAny = false;
        this.hand.forEach(p => {
            if (!p) return;
            for (let r = 0; r < 7; r++) for (let c = 0; c < 7; c++) if (this.canPlace(p, r, c)) trueAny = true;
        });

        if (!trueAny && this.hand.some(p => p !== null) && !this.isProcessing) {
            this.triggerGameOver();
        }
    }

    onHandDown(e, idx) {
        if (this.isProcessing || this.isGameOver || this.isDemo) return;
        if (gameMode === 'vs-turn' && currentTurn !== 1) return; // 自分のターン以外操作不可

        const t = e.touches ? e.touches[0] : e;
        let startX = t.clientX, startY = t.clientY, moved = false;

        const onMove = ev => {
            const tt = ev.touches ? ev.touches[0] : ev;
            if (!moved && Math.hypot(tt.clientX - startX, tt.clientY - startY) > 8) {
                moved = true;
                this.boardRect = this.boardEl.getBoundingClientRect();
                this.cellSize = this.boardRect.width / COLS;
                this.beginDrag(idx, tt.clientX, tt.clientY);
            }
            if (moved) this.moveDrag(tt.clientX, tt.clientY);
        };

        const onUp = ev => {
            document.removeEventListener('mousemove', onMove); document.removeEventListener('mouseup', onUp);
            document.removeEventListener('touchmove', onMove); document.removeEventListener('touchend', onUp);
            if (!moved) { this.animateRotation(idx); }
            else { const tt = ev.changedTouches ? ev.changedTouches[0] : ev; this.finishDrag(tt.clientX, tt.clientY); }
        };

        document.addEventListener('mousemove', onMove); document.addEventListener('mouseup', onUp);
        document.addEventListener('touchmove', onMove, { passive: false }); document.addEventListener('touchend', onUp);
    }

    beginDrag(idx, x, y) {
        this.dragging = { idx, piece: this.hand[idx] };
        this.dragEl = document.createElement('div'); this.dragEl.className = 'dragging-piece';
        for (let r = 0; r < 2; r++) for (let c = 0; c < 2; c++) {
            const cl = document.createElement('div'); cl.className = 'drag-cell'; cl.appendChild(tileImg(this.hand[idx][r][c])); this.dragEl.appendChild(cl);
        }
        document.body.appendChild(this.dragEl);
        this.handEl.children[idx].style.opacity = '0.3';
        this.moveDrag(x, y);
    }

    moveDrag(x, y) {
        if (!this.dragEl) return;
        this.dragEl.style.left = (x - 45) + 'px'; this.dragEl.style.top = (y - 45) + 'px';
        const relX = x - this.boardRect.left, relY = y - this.boardRect.top;
        const c = Math.round(relX / this.cellSize - 1), r = Math.round(relY / this.cellSize - 1);

        this.ghostCells.forEach(el => { el.classList.remove('highlight'); const g = el.querySelector('.ghost'); if (g) g.remove(); });
        this.ghostCells = [];
        if (this.canPlace(this.dragging.piece, r, c)) {
            for (let ir = 0; ir < 2; ir++) for (let ic = 0; ic < 2; ic++) {
                const el = this.getCellEl(r + ir, c + ic); el.classList.add('highlight');
                const g = document.createElement('div'); g.className = 'ghost'; g.appendChild(tileImg(this.dragging.piece[ir][ic]));
                el.appendChild(g); this.ghostCells.push(el);
            }
        }
    }

    finishDrag(x, y) {
        const relX = x - this.boardRect.left, relY = y - this.boardRect.top;
        const c = Math.round(relX / this.cellSize - 1), r = Math.round(relY / this.cellSize - 1);
        if (this.canPlace(this.dragging.piece, r, c)) {
            this.placePiece(this.dragging.idx, r, c);
        } else {
            this.handEl.children[this.dragging.idx].style.opacity = '1';
        }
        this.ghostCells.forEach(el => { el.classList.remove('highlight'); const g = el.querySelector('.ghost'); if (g) g.remove(); });
        this.ghostCells = [];
        if (this.dragEl) { this.dragEl.remove(); this.dragEl = null; }
        this.dragging = null;
    }

    placePiece(idx, r, c) {
        if (!this.isDemo) playSfx(sfxPut, 0.6);
        const p = this.hand[idx];
        for (let ir = 0; ir < 2; ir++) for (let ic = 0; ic < 2; ic++) this.board[r + ir][c + ic] = p[ir][ic];
        this.hand[idx] = this.genPiece();
        this.combo = 0; this.isProcessing = true;
        this.renderBoard(); this.updateHandUI();
        setTimeout(() => this.processMatches(), 150);
    }

    processMatches() {
        const vis = Array.from({ length: ROWS }, () => Array(COLS).fill(false));
        const toRemove = new Set();

        for (let r = 0; r < ROWS; r++) for (let c = 0; c < COLS; c++) {
            if (this.board[r][c] >= 0 && this.board[r][c] <= 3 && !vis[r][c]) {
                const color = this.board[r][c], grp = [], q = [[r, c]]; vis[r][c] = true;
                while (q.length > 0) {
                    const [cr, cc] = q.shift(); grp.push([cr, cc]);
                    [[-1, 0], [1, 0], [0, -1], [0, 1]].forEach(([dr, dc]) => {
                        const nr = cr + dr, nc = cc + dc;
                        if (nr >= 0 && nr < ROWS && nc >= 0 && nc < COLS && !vis[nr][nc] && this.board[nr][nc] === color) {
                            vis[nr][nc] = true; q.push([nr, nc]);
                        }
                    });
                }
                if (grp.length >= MIN_MATCH) grp.forEach(([gr, gc]) => toRemove.add(`${gr},${gc}`));
            }
        }

        if (toRemove.size > 0) {
            if (!this.isDemo) playSfx(sfxMatch, 0.7);
            this.combo++;
            const garbageSet = new Set();
            toRemove.forEach(k => {
                const [r, c] = k.split(',').map(Number);
                [[-1, 0], [1, 0], [0, -1], [0, 1]].forEach(([dr, dc]) => {
                    const nr = r + dr, nc = c + dc;
                    if (nr >= 0 && nr < ROWS && nc >= 0 && nc < COLS && this.board[nr][nc] === 4) garbageSet.add(`${nr},${nc}`);
                });
            });
            garbageSet.forEach(k => toRemove.add(k));

            const count = toRemove.size;
            this.score += count * 10 * this.combo;
            if (this.scoreEl) this.scoreEl.textContent = this.score;
            this.showPop(`${count} BLOCKS!` + (this.combo > 1 ? `<br>${this.combo} COMBO!` : ''));

            if (this.opponent && (this.combo >= 2 || count >= 4)) {
                const atk = Math.max(1, count - 3) + (this.combo - 1) * 2;
                this.sendGarbage(atk);
            }

            toRemove.forEach(k => {
                const [r, c] = k.split(',').map(Number);
                const el = this.getCellEl(r, c).querySelector('.block');
                if (el) el.classList.add('clearing');
            });

            setTimeout(() => {
                toRemove.forEach(k => { const [r, c] = k.split(',').map(Number); this.board[r][c] = -1; });
                this.renderBoard();
                setTimeout(() => this.processMatches(), 200);
            }, 400);

        } else {
            this.isProcessing = false;
            this.checkValidMoves();

            // 処理終了後のアクション
            if (gameMode === 'vs-turn' && !this.isGameOver) {
                // ターン切り替え
                switchTurn();
            } else if (this.isAI && !this.isGameOver && gameMode !== 'vs-turn') {
                // リアルタイムAIの連続操作
                setTimeout(() => requestAI(this), 300);
            }
        }
    }

    showPop(txt) {
        if (!this.msgEl) return;
        this.msgEl.innerHTML = txt;
        this.msgEl.style.transition = 'none'; this.msgEl.style.opacity = '1'; this.msgEl.style.transform = 'translate(-50%,-50%) scale(0.5)';
        requestAnimationFrame(() => {
            this.msgEl.style.transition = 'transform 0.3s cubic-bezier(0.175,0.885,0.32,1.275), opacity 0.5s';
            this.msgEl.style.transform = 'translate(-50%,-50%) scale(1)';
            setTimeout(() => this.msgEl.style.opacity = '0', 800);
        });
    }

    sendGarbage(amount) {
        if (this.pendingGarbage > 0) {
            if (this.pendingGarbage >= amount) { this.pendingGarbage -= amount; amount = 0; }
            else { amount -= this.pendingGarbage; this.pendingGarbage = 0; }
            this.garbageTimer = this.garbageTimerMax;
            this.updateGarbageUI();
        }

        if (amount > 0 && this.opponent) {
            if (gameMode === 'vs-turn') {
                // ターン制の場合は即時落下させるために相手側に保留させずそのまま落とす
                this.opponent.receiveGarbageInstant(amount);
            } else {
                this.opponent.receiveGarbage(amount);
            }
        }
    }

    receiveGarbage(amount) {
        this.pendingGarbage += amount;
        this.garbageTimer = this.garbageTimerMax;
        this.updateGarbageUI();
    }

    receiveGarbageInstant(amount) {
        this.pendingGarbage += amount;
        this.dropGarbage();
    }

    updateGarbageUI() {
        if (!this.garbageUi) return;
        if (gameMode === 'vs-turn') { this.garbageUi.style.display = 'none'; return; } // ターン制はUI不要

        if (this.pendingGarbage > 0) {
            this.garbageUi.style.display = 'block';
            this.garbageText.textContent = `+${this.pendingGarbage}`;
            this.garbageBar.style.transform = `scaleX(${Math.max(0, this.garbageTimer / this.garbageTimerMax)})`;
        } else {
            this.garbageUi.style.display = 'none';
        }
    }

    tick(dt) {
        if (this.isGameOver || this.isProcessing || gameMode === 'vs-turn') return;
        if (this.pendingGarbage > 0) {
            this.garbageTimer -= dt;
            this.updateGarbageUI();
            if (this.garbageTimer <= 0) {
                this.dropGarbage();
            }
        }
    }

    dropGarbage() {
        if (!this.isDemo) playSfx(sfxDamage, 0.8);
        let empty = [];
        for (let r = 0; r < ROWS; r++) for (let c = 0; c < COLS; c++) if (this.board[r][c] === -1) empty.push({ r, c });
        for (let i = empty.length - 1; i > 0; i--) {
            const j = Math.floor(Math.random() * (i + 1));
            [empty[i], empty[j]] = [empty[j], empty[i]];
        }
        const drop = Math.min(this.pendingGarbage, empty.length);
        for (let i = 0; i < drop; i++) this.board[empty[i].r][empty[i].c] = 4;

        this.pendingGarbage -= drop;
        if (this.pendingGarbage < 0) this.pendingGarbage = 0;
        this.updateGarbageUI();
        this.renderBoard();
        this.checkValidMoves();
    }

    triggerGameOver() {
        this.isGameOver = true;
        if (this.isDemo) {
            setTimeout(() => {
                if (!isPlayingGame && isDemoActive) {
                    this.init();
                    requestAI(this);
                }
            }, 2000);
            return;
        }
        checkGlobalGameOver();
    }
}

// ==== グローバル制御 ====
let lastTime = 0;
let demoGame = null;

window.onload = () => {
    demoGame = new QuadGame(document.getElementById('demo-area'), true, true);
    demoGame.init();
    requestAI(demoGame); // デモ用AI起動
};

document.getElementById('btn-1p').onclick = () => startGame('1p');
document.getElementById('btn-vs-real').onclick = () => startGame('vs-real');
document.getElementById('btn-vs-turn').onclick = () => startGame('vs-turn');

function startGame(mode) {
    isDemoActive = false;
    isPlayingGame = true;
    gameMode = mode;
    currentTurn = 1;

    ensureAudioCreated();
    bgmControl('game');

    document.getElementById('title-screen').classList.add('hidden');
    document.getElementById('main-wrapper').classList.add('show');

    p1 = new QuadGame(document.getElementById('p1-area'), false);
    p1.init();

    const indicator = document.getElementById('turn-indicator');

    if (mode === 'vs-real' || mode === 'vs-turn') {
        document.getElementById('p2-area').style.display = 'flex';
        p2 = new QuadGame(document.getElementById('p2-area'), true);
        p2.init();
        p1.opponent = p2; p2.opponent = p1;

        if (mode === 'vs-turn') {
            indicator.style.display = 'block';
            updateTurnUI();
        } else {
            indicator.style.display = 'none';
            setTimeout(() => requestAI(p2), 1000);
        }
    } else {
        document.getElementById('p2-area').style.display = 'none';
        indicator.style.display = 'none';
    }

    lastTime = performance.now();
    requestAnimationFrame(gameLoop);
}

function gameLoop(time) {
    const dt = time - lastTime; lastTime = time;
    if (p1 && !p1.isGameOver) p1.tick(dt);
    if (p2 && !p2.isGameOver) p2.tick(dt);
    requestAnimationFrame(gameLoop);
}

function switchTurn() {
    if (p1.isGameOver || p2.isGameOver) return;
    currentTurn = currentTurn === 1 ? 2 : 1;
    updateTurnUI();

    // それぞれの手札の活性/非活性を更新
    p1.checkValidMoves();
    p2.checkValidMoves();

    if (currentTurn === 2) {
        setTimeout(() => requestAI(p2), 800); // ターン交代のゆとり
    }
}

function updateTurnUI() {
    const ind = document.getElementById('turn-indicator');
    const p1a = document.getElementById('p1-area');
    const p2a = document.getElementById('p2-area');

    if (currentTurn === 1) {
        ind.textContent = "PLAYER'S TURN";
        ind.style.color = "#4d96ff";
        p1a.classList.remove('waiting');
        p2a.classList.add('waiting');
    } else {
        ind.textContent = "AI'S TURN";
        ind.style.color = "#ff6b6b";
        p1a.classList.add('waiting');
        p2a.classList.remove('waiting');
    }
}

function checkGlobalGameOver() {
    if (gameMode !== '1p') {
        if (p1.isGameOver || p2.isGameOver) {
            bgmControl('stop');
            if (p1.isGameOver) {
                document.getElementById('result-title').textContent = "YOU LOSE...";
                document.getElementById('result-title').style.color = "#ff6b6b";
                playSfx(sfxGameover, 0.8);
            } else {
                document.getElementById('result-title').textContent = "YOU WIN!!";
                document.getElementById('result-title').style.color = "#6bcb77";
                playSfx(sfxWin, 0.8);
            }
            document.getElementById('game-over-overlay').classList.add('show');
        }
    } else {
        if (p1.isGameOver) {
            bgmControl('stop');
            playSfx(sfxGameover, 0.8);
            document.getElementById('game-over-overlay').classList.add('show');
        }
    }
}

async function requestAI(gameObj) {
    if (gameObj.isGameOver || gameObj.isProcessing || gameObj.aiFetching) return;
    if (!gameObj.hand.some(p => p !== null)) return;
    if (gameObj.isDemo && !isDemoActive) return;

    // 難易度（温度）設定
    // 0: デモ用(最強)、 25: ターン制(少し手加減)、 35: リアルタイム(隙を見せる)
    let temp = 0.0;
    if (!gameObj.isDemo) {
        temp = gameMode === 'vs-turn' ? 20.0 : 35.0;
    }

    gameObj.aiFetching = true;
    try {
        const res = await fetch('/api/ai_move', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({
                board: gameObj.board,
                hand: gameObj.hand,
                temperature: temp
            })
        });
        const move = await res.json();
        gameObj.aiFetching = false;

        if (gameObj.isDemo && !isDemoActive) return;

        if (move && move.piece_idx !== undefined && !gameObj.isGameOver && !gameObj.isProcessing) {

            // 人間らしい遅延の設定
            // リアルタイム対戦の場合、思考にわざと時間をかける
            let thinkTime = gameObj.isDemo ? 300 : (gameMode === 'vs-real' ? 1200 + Math.random() * 800 : 600);
            await sleep(thinkTime);

            if (gameObj.isGameOver || gameObj.isProcessing || (gameObj.isDemo && !isDemoActive)) return;

            for (let i = 0; i < move.rotations; i++) {
                gameObj.animateRotation(move.piece_idx);
                await sleep(gameObj.isDemo ? 100 : 250); // 回転のディレイ
            }

            if (gameObj.canPlace(gameObj.hand[move.piece_idx], move.r, move.c)) {
                gameObj.placePiece(move.piece_idx, move.r, move.c);
            }
        }
    } catch (e) {
        gameObj.aiFetching = false;
        setTimeout(() => { if (!gameObj.isGameOver && !gameObj.isProcessing && (!gameObj.isDemo || isDemoActive)) requestAI(gameObj); }, 2000);
    }
}