async function sendChunk() {
    const ticksToSend = currentTick - lastSentTick;
    if (ticksToSend <= 0) return;


    const snapshotobstacles = JSON.parse(JSON.stringify(obstacles));

    const payload = {
        sessionId: sessionID,
        inputs: [...inputLog],
        totalTicks: ticksToSend
    };

    inputLog = [];
    lastSentTick = currentTick;

    try {
        const res = await fetch('/api/validate', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify(payload)
        });

        const data = await res.json();

        // Update für visuelles Debugging
        if (data.serverObs) {
            serverObstacles = data.serverObs;

            // --- NEU: DEBUG MODUS VERGLEICH ---
            if (typeof DEBUG_SYNC !== 'undefined' && DEBUG_SYNC) {
                compareState(snapshotobstacles, data.serverObs);
            }
            // ----------------------------------
        }

        if (data.status === "dead") {
            console.error("💀 SERVER KILL", data);
            gameOver("Vom Server gestoppt");
        } else {
            const sScore = data.verifiedScore;
            // Score Korrektur
            if (Math.abs(score - sScore) > 200) {
                console.warn(`⚠️ SCORE DRIFT: Client=${score} Server=${sScore}`);
                score = sScore;
            }
        }

    } catch (e) {
        console.error("Netzwerkfehler:", e);
    }
}

window.submitScore = async function() {
    const nameInput = document.getElementById('playerNameInput');
    const name = nameInput.value;
    const btn = document.getElementById('submitBtn');

    if (!name) return alert("Namen eingeben!");
    btn.disabled = true;

    try {
        const res = await fetch('/api/submit-name', {
            method: 'POST',
            headers: {'Content-Type': 'application/json'},
            body: JSON.stringify({ sessionId: sessionID, name: name })
        });
        const data = await res.json();

        let myClaims = JSON.parse(localStorage.getItem('escape_claims') || '[]');
        myClaims.push({
            name: name, score: Math.floor(score / 10), code: data.claimCode,
            date: new Date().toLocaleString('de-DE'), sessionId: sessionID
        });
        localStorage.setItem('escape_claims', JSON.stringify(myClaims));

        document.getElementById('inputSection').style.display = 'none';
        loadLeaderboard();
    } catch (e) {}
};

async function loadLeaderboard() {
    const res = await fetch(`/api/leaderboard?sessionId=${sessionID}`);
    const entries = await res.json();
    let html = "<h3>BESTENLISTE</h3>";
    entries.forEach(e => {
        const color = e.isMe ? "yellow" : "white";
        html += `<div style="display:flex; justify-content:space-between; color:${color}; margin-bottom:5px;">
                    <span>#${e.rank} ${e.name}</span><span>${Math.floor(e.score/10)}</span></div>`;
    });
    document.getElementById('leaderboard').innerHTML = html;
}

async function loadStartScreenLeaderboard() {
    try {
        const listEl = document.getElementById('startLeaderboardList');
        if (!listEl) return;
        const res = await fetch('/api/leaderboard');
        const entries = await res.json();
        if (entries.length === 0) { listEl.innerHTML = "<div style='padding:20px'>Noch keine Scores.</div>"; return; }
        let html = "";
        entries.forEach(e => {
            let icon = "#" + e.rank;
            if (e.rank === 1) icon = "🥇"; if (e.rank === 2) icon = "🥈"; if (e.rank === 3) icon = "🥉";
            html += `<div class="hof-entry"><span><span class="hof-rank">${icon}</span> ${e.name}</span><span class="hof-score">${Math.floor(e.score / 10)}</span></div>`;
        });
        listEl.innerHTML = html;
    } catch (e) {}
}

function compareState(clientObs, serverObs) {
    // 1. Anzahl prüfen
    if (clientObs.length !== serverObs.length) {
        console.error(`🚨 ANZAHL MISMATCH! Client: ${clientObs.length}, Server: ${serverObs.length}`);
    }

    const report = [];
    const maxLen = Math.max(clientObs.length, serverObs.length);
    let hasMajorDrift = false;

    for (let i = 0; i < maxLen; i++) {
        const cli = clientObs[i];
        const srv = serverObs[i];

        let drift = 0;
        let status = "✅ OK";

        // Client Objekt vorbereiten
        let cID = "---";
        let cX = 0;
        if (cli) {
            cID = cli.def.id; // Struktur beachten: cli.def.id
            cX = cli.x;
        }

        // Server Objekt vorbereiten
        let sID = "---";
        let sX = 0;
        if (srv) {
            sID = srv.id; // Struktur vom Server: srv.id
            sX = srv.x;
        }

        // Vergleich
        if (cli && srv) {
            // IDs unterschiedlich? (z.B. Tisch vs Lehrer)
            if (cID !== sID) {
                status = "❌ ID ERROR";
                hasMajorDrift = true;
            } else {
                drift = cX - sX;
                if (Math.abs(drift) > SYNC_TOLERANCE) {
                    status = "⚠️ DRIFT";
                    hasMajorDrift = true;
                }
            }
        } else {
            status = "❌ MISSING";
            hasMajorDrift = true;
        }

        // In Tabelle eintragen
        report.push({
            Index: i,
            Status: status,
            "C-ID": cID,
            "S-ID": sID,
            "C-Pos": cX.toFixed(1),
            "S-Pos": sX.toFixed(1),
            "Drift (px)": drift.toFixed(2)
        });
    }

    // Nur loggen, wenn Fehler da sind oder alle 5 Sekunden (Tick 300)
    if (hasMajorDrift || currentTick % 300 === 0) {
        if (hasMajorDrift) console.warn("--- SYNC PROBLEME GEFUNDEN ---");
        else console.log("--- Sync Check (Routine) ---");

        console.table(report); // Das erstellt eine super lesbare Tabelle im Browser
    }
}