async function loadAssets() {
    playerSprite.src = "assets/player.png";
    if (gameConfig.backgrounds && gameConfig.backgrounds.length > 0) {
        const bgName = gameConfig.backgrounds[0];
        if (!bgName.startsWith("#")) bgSprite.src = "assets/" + bgName;
    }
    const promises = gameConfig.obstacles.map(def => {
        return new Promise((resolve) => {
            if (!def.image) { resolve(); return; }
            const img = new Image(); img.src = "assets/" + def.image;
            img.onload = () => { sprites[def.id] = img; resolve(); };
            img.onerror = () => { resolve(); };
        });
    });
    if (bgSprite.src) {
        promises.push(new Promise(r => { bgSprite.onload = r; bgSprite.onerror = r; }));
    }
    await Promise.all(promises);
}

window.startGameClick = async function() {
    if (!isLoaded) return;
    startScreen.style.display = 'none';
    document.body.classList.add('game-active'); // Handy Rotate Check
    try {
        const sRes = await fetch('/api/start', {method:'POST'});
        const sData = await sRes.json();
        sessionID = sData.sessionId;
        rng = new PseudoRNG(sData.seed);
        isGameRunning = true;
        resize();
    } catch(e) { location.reload(); }
};

function gameOver(reason) {
    if (isGameOver) return;
    isGameOver = true;
    const finalScoreVal = Math.floor(score / 10);
    const currentHighscore = localStorage.getItem('escape_highscore') || 0;
    if (finalScoreVal > currentHighscore) localStorage.setItem('escape_highscore', finalScoreVal);
    gameOverScreen.style.display = 'flex';
    document.getElementById('finalScore').innerText = finalScoreVal;
    loadLeaderboard();
    drawGame();
}

function gameLoop(timestamp) {
    requestAnimationFrame(gameLoop);

    if (!isLoaded || !isGameRunning || isGameOver) {
        lastTime = timestamp;
        return;
    }

    if (!lastTime) lastTime = timestamp;
    const deltaTime = timestamp - lastTime;
    lastTime = timestamp;

    if (deltaTime > 1000) {
        accumulator = 0;
        return;
    }

    accumulator += deltaTime;

    while (accumulator >= MS_PER_TICK) {
        updateGameLogic();
        currentTick++;
        score++;

        if (currentTick - lastSentTick >= CHUNK_SIZE) sendChunk();

        accumulator -= MS_PER_TICK;
    }

    const scoreEl = document.getElementById('score');
    if (scoreEl) scoreEl.innerText = Math.floor(score / 10);

    drawGame();
}

async function initGame() {
    try {
        const cRes = await fetch('/api/config'); gameConfig = await cRes.json();
        await loadAssets();
        await loadStartScreenLeaderboard();
        isLoaded = true;
        if(loadingText) loadingText.style.display = 'none'; if(startBtn) startBtn.style.display = 'inline-block';
        const savedHighscore = localStorage.getItem('escape_highscore') || 0;
        const hsEl = document.getElementById('localHighscore'); if(hsEl) hsEl.innerText = savedHighscore;
        requestAnimationFrame(gameLoop);
    } catch(e) { if(loadingText) loadingText.innerText = "Fehler!"; }
}

initGame();