// --- Globals & Config ---
const CONFIG = {
    viewportPadding: 200,
    nodeWidth: 200,
    nodeHeight: 50,
    indentWidth: 60,
    rowHeight: 80
};

let currentTab = 'visualizer';
let sourceLines = [];
let allNodes = [];
let isTicking = false;

// --- Konva Setup ---
const stage = new Konva.Stage({
    container: 'container',
    width: window.innerWidth - 400, // Adjust for sidebar width
    height: window.innerHeight,
    draggable: true
});

const layer = new Konva.Layer();
stage.add(layer);

// --- UI Logic: Tabs ---
function switchTab(tabId) {
    document.querySelectorAll('.tab-pane').forEach(el => el.classList.remove('active'));
    document.getElementById(`tab-${tabId}`).classList.add('active');
    
    document.querySelectorAll('.nav-item').forEach(el => el.classList.remove('active'));
    // Find the button that triggered this or match by ID if needed
    const btn = document.querySelector(`button[onclick="switchTab('${tabId}')"]`);
    if(btn) btn.classList.add('active');
    
    currentTab = tabId;
    
    if (tabId === 'dataset') {
        loadDatasetTable();
    }
}

// --- UI Logic: Status ---
function setStatus(msg, state) {
    const el = document.getElementById('statusIndicator');
    el.innerText = msg;
    el.className = ''; 
    if(state === 'ready') el.classList.add('status-ready');
    if(state === 'working') el.classList.add('status-working');
    if(state === 'success') el.classList.add('status-success');
    if(state === 'error') el.classList.add('status-error');
}

// --- Core: Culling & Rendering Optimization ---
function updateVisibleNodes() {
    isTicking = false;
    
    const scale = stage.scaleX();
    const stageX = stage.x();
    const stageY = stage.y();

    const viewX = -(stageX / scale) - CONFIG.viewportPadding;
    const viewY = -(stageY / scale) - CONFIG.viewportPadding;
    const viewW = (stage.width() / scale) + (CONFIG.viewportPadding * 2);
    const viewH = (stage.height() / scale) + (CONFIG.viewportPadding * 2);

    const viewRight = viewX + viewW;
    const viewBottom = viewY + viewH;

    let nodesChanged = false;

    for (let i = 0; i < allNodes.length; i++) {
        const node = allNodes[i];
        const isVisible = (
            node.x < viewRight && 
            node.x + CONFIG.nodeWidth > viewX && 
            node.y < viewBottom && 
            node.y + CONFIG.nodeHeight > viewY
        );

        if (node.visible !== isVisible) {
            node.group.visible(isVisible);
            node.visible = isVisible;
            nodesChanged = true;
        }
    }

    if (nodesChanged) {
        layer.batchDraw();
    }
}

function requestUpdate() {
    if (!isTicking) {
        requestAnimationFrame(updateVisibleNodes);
        isTicking = true;
    }
}

// --- Canvas Interactions ---
stage.on('dragmove', requestUpdate);

stage.on('wheel', (e) => {
    e.evt.preventDefault();
    const oldScale = stage.scaleX();
    const pointer = stage.getPointerPosition();
    const scaleBy = 1.05;
    const newScale = e.evt.deltaY > 0 ? oldScale / scaleBy : oldScale * scaleBy;
    
    stage.scale({ x: newScale, y: newScale });
    
    const newPos = {
        x: pointer.x - (pointer.x - stage.x()) / oldScale * newScale,
        y: pointer.y - (pointer.y - stage.y()) / oldScale * newScale
    };
    stage.position(newPos);
    requestUpdate();
});

window.addEventListener('resize', () => {
    stage.width(window.innerWidth - 400);
    stage.height(window.innerHeight);
    requestUpdate();
});

// --- API: Visualizer ---
function visualize() {
    const code = document.getElementById('codeInput').value;
    setStatus('Parsing...', 'working');
    
    fetch('/parse', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ code: code })
    })
    .then(res => res.json())
    .then(data => {
        if(data.error) {
            alert(data.error);
            setStatus('Error', 'error');
        } else {
            drawGraph(data, code);
            setStatus(`Rendered ${data.nodes.length} nodes`, 'ready');
        }
    })
    .catch(err => setStatus('Network Error', 'error'));
}

function drawGraph(data, fullSourceCode) {
    layer.destroyChildren();
    allNodes = [];
    sourceLines = fullSourceCode.split('\n');

    const nodeMap = {};
    const colors = {
        'function': '#a29bfe', 'class': '#e84393', 'if': '#fab1a0',
        'for': '#fdcb6e', 'while': '#fdcb6e', 'return': '#55efc4',
        'assigned_variable': '#74b9ff', 'import': '#b2bec3', 'try': '#ff7675'
    };

    // Draw Nodes
    data.nodes.forEach((node, index) => {
        const x = 100 + (node.lvl * CONFIG.indentWidth);
        const y = 50 + (index * CONFIG.rowHeight);

        const group = new Konva.Group({ 
            x: x, 
            y: y,
            listening: true 
        });

        const rect = new Konva.Rect({
            width: CONFIG.nodeWidth, 
            height: CONFIG.nodeHeight,
            fill: '#2d3436',
            stroke: colors[node.type] || '#636e72',
            strokeWidth: 2, 
            cornerRadius: 8,
            shadowColor: 'black', 
            shadowBlur: 10, 
            shadowOpacity: 0.3,
            hitStrokeWidth: 0
        });

        const text = new Konva.Text({
            x: 10, y: 10,
            text: node.lbl,
            fontSize: 14, fontFamily: 'JetBrains Mono', fill: '#fff',
            width: 180, ellipsis: true,
            listening: false 
        });

        const vecText = new Konva.Text({
            x: 10, y: 32,
            text: `V:[${node.vec[0]}, ${node.vec[2]}...]`,
            fontSize: 10, fontFamily: 'JetBrains Mono', fill: '#636e72',
            listening: false
        });

        group.add(rect);
        group.add(text);
        group.add(vecText);
        
        // Interaction
        group.on('click', () => {
            const start = node.loc[0] - 1;
            const end = node.loc[1];
            const snippet = sourceLines.slice(start, end).join('\n');
            console.log(snippet); // Optional: log to console
            // Could add a toast or modal to show snippet here
        });

        group.on('mouseover', () => { 
            document.body.style.cursor = 'pointer'; 
            rect.fill('#353b48'); 
            layer.batchDraw(); 
        });
        
        group.on('mouseout', () => { 
            document.body.style.cursor = 'default'; 
            rect.fill('#2d3436'); 
            layer.batchDraw(); 
        });

        layer.add(group);
        
        nodeMap[node.id] = { x, y };
        allNodes.push({ group, x, y, visible: true });
    });

    // Draw Connections
    data.connections.forEach(conn => {
        const f = nodeMap[conn.f];
        const t = nodeMap[conn.t];
        if (f && t) {
            const line = new Konva.Line({
                points: [f.x+20, f.y+50, f.x+20, t.y-10, t.x+20, t.y-10, t.x+20, t.y],
                stroke: '#636e72', 
                strokeWidth: 2, 
                tension: 0.2, 
                opacity: 0.5,
                listening: false 
            });
            layer.add(line);
            line.moveToBottom();
        }
    });

    layer.batchDraw();
    stage.x(50);
    stage.y(50);
    requestUpdate();
}

// --- API: Dataset ---
function addToDataset() {
    const code = document.getElementById('codeInput').value;
    setStatus('Saving...', 'working');
    
    fetch('/dataset/add', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ code: code })
    })
    .then(res => res.json())
    .then(data => {
        if(data.status === 'success') {
            setStatus('Saved to Dataset!', 'success');
        } else {
            alert(data.message);
            setStatus('Save Failed', 'error');
        }
    })
    .catch(() => setStatus('Network Error', 'error'));
}

function loadDatasetTable() {
    const tbody = document.getElementById('datasetTableBody');
    tbody.innerHTML = '<tr><td colspan="4">Loading...</td></tr>';
    
    fetch('/dataset/list')
    .then(res => res.json())
    .then(entries => {
        tbody.innerHTML = '';
        if(entries.length === 0) {
            tbody.innerHTML = '<tr><td colspan="4" style="text-align:center; opacity:0.5">Dataset is empty</td></tr>';
            return;
        }
        
        entries.forEach(entry => {
            const row = `
                <tr>
                    <td class="mono">${entry.id.split('_')[1]}</td>
                    <td>${new Date(entry.timestamp).toLocaleTimeString()}</td>
                    <td><span class="badge">${entry.node_count} nodes</span></td>
                    <td class="mono-dim">${entry.snippet}</td>
                </tr>
            `;
            tbody.innerHTML += row;
        });
    });
}

// --- API: Hugging Face Upload ---
function openUploadModal() {
    document.getElementById('uploadModal').classList.remove('hidden');
}

function closeUploadModal() {
    document.getElementById('uploadModal').classList.add('hidden');
}

function performUpload() {
    const token = document.getElementById('hfToken').value;
    const repo = document.getElementById('hfRepo').value;
    
    if(!token || !repo) return alert("Please fill in both fields");
    
    const btn = document.querySelector('#uploadModal .btn-primary');
    const originalText = btn.innerText;
    btn.innerText = "Pushing...";
    btn.disabled = true;
    
    fetch('/dataset/upload_hf', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ token: token, repo_id: repo })
    })
    .then(res => res.json())
    .then(data => {
        btn.innerText = originalText;
        btn.disabled = false;
        if(data.status === 'success') {
            closeUploadModal();
            alert(data.message);
        } else {
            alert("Error: " + data.message);
        }
    })
    .catch(err => {
        btn.innerText = originalText;
        btn.disabled = false;
        alert("Network Error");
    });
}