let currentMetric = 'cpu';
let clusterData = null;

const formatBytes = (bytes) => {
    if (bytes === 0) return '0 B';
    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
};

const formatCpu = (millicores) => {
    if (millicores === 0) return '0 m';
    return `${millicores} m`;
};

document.getElementById('btn-cpu').addEventListener('click', (e) => {
    document.getElementById('btn-cpu').classList.add('active');
    document.getElementById('btn-mem').classList.remove('active');
    currentMetric = 'cpu';
    if (clusterData) renderChart(clusterData);
});

document.getElementById('btn-mem').addEventListener('click', (e) => {
    document.getElementById('btn-mem').classList.add('active');
    document.getElementById('btn-cpu').classList.remove('active');
    currentMetric = 'memory';
    if (clusterData) renderChart(clusterData);
});

async function fetchData() {
    try {
        const response = await fetch('/api/cluster-data');
        if (!response.ok) throw new Error('Failed to fetch data');
        clusterData = await response.json();
        
        document.getElementById('loading').classList.add('hidden');
        renderChart(clusterData);
    } catch (error) {
        console.error(error);
        document.getElementById('loading').innerHTML = `<p style="color: #ef4444;">Error loading data: ${error.message}</p>`;
    }
}

function renderChart(data) {
    const container = document.getElementById('chart-container');
    const width = container.clientWidth;
    const height = container.clientHeight;
    
    // Clear previous
    d3.select('#chart-container').selectAll('*').remove();
    
    const svg = d3.select('#chart-container')
        .append('svg')
        .attr('width', width)
        .attr('height', height)
        .style('font-family', 'Inter, sans-serif');

    // Create hierarchy
    const root = d3.hierarchy(data)
        .sum(d => {
            if (d.type === 'node') return 0;
            return d[currentMetric] || 0;
        })
        .sort((a, b) => b.value - a.value);

    // Create Treemap
    d3.treemap()
        .size([width, height])
        .paddingTop(28)
        .paddingRight(8)
        .paddingInner(4)
        .paddingBottom(8)
        .paddingLeft(8)
        .round(true)(root);

    // Get nodes and pods
    const nodes = root.descendants().filter(d => d.depth === 1); // Nodes
    const pods = root.leaves(); // Pods and Unused

    // Color scale for pods
    const getColor = (d) => {
        if (d.data.type === 'unused') return 'var(--color-unused)';
        if (d.data.status === 'Running') return 'var(--color-running)';
        if (d.data.status === 'Pending') return 'var(--color-pending)';
        return 'var(--color-failed)';
    };

    // Draw Node Groups
    const nodeGroups = svg.selectAll('.node-group')
        .data(nodes)
        .enter()
        .append('g')
        .attr('class', 'node-group')
        .attr('transform', d => `translate(${d.x0},${d.y0})`);

    // Node Background
    nodeGroups.append('rect')
        .attr('class', 'node-rect')
        .attr('width', d => Math.max(0, d.x1 - d.x0))
        .attr('height', d => Math.max(0, d.y1 - d.y0));

    // Node Label
    nodeGroups.append('text')
        .attr('class', 'node-label')
        .attr('x', 8)
        .attr('y', 20)
        .text(d => d.data.name);

    // Draw Pods
    const podGroups = svg.selectAll('.pod-group')
        .data(pods)
        .enter()
        .append('g')
        .attr('class', 'pod-group')
        .attr('transform', d => `translate(${d.x0},${d.y0})`);

    // Pod Rect
    podGroups.append('rect')
        .attr('class', 'pod-rect')
        .attr('width', d => Math.max(0, d.x1 - d.x0))
        .attr('height', d => Math.max(0, d.y1 - d.y0))
        .attr('fill', d => getColor(d))
        .on('mousemove', function(event, d) {
            const tooltip = document.getElementById('tooltip');
            tooltip.classList.remove('hidden');
            
            // Boundary detection for tooltip
            const tWidth = 240;
            let left = event.pageX + 15;
            let top = event.pageY + 15;
            
            if (left + tWidth > window.innerWidth) {
                left = event.pageX - tWidth - 15;
            }
            
            tooltip.style.left = left + 'px';
            tooltip.style.top = top + 'px';
            
            let val = currentMetric === 'cpu' ? formatCpu(d.data[`${currentMetric}_raw`]) : formatBytes(d.data[`${currentMetric}_raw`]);
            
            if (d.data.type === 'unused') {
                tooltip.innerHTML = `
                    <div class="tooltip-title">Available Capacity</div>
                    <div class="tooltip-row">
                        <span class="tooltip-label">${currentMetric.toUpperCase()}:</span>
                        <span class="tooltip-value">${val}</span>
                    </div>
                `;
            } else {
                tooltip.innerHTML = `
                    <div class="tooltip-title">${d.data.name}</div>
                    <div class="tooltip-row">
                        <span class="tooltip-label">Namespace:</span>
                        <span class="tooltip-value">${d.data.namespace}</span>
                    </div>
                    <div class="tooltip-row">
                        <span class="tooltip-label">Status:</span>
                        <span class="tooltip-value">${d.data.status}</span>
                    </div>
                    <div class="tooltip-row">
                        <span class="tooltip-label">${currentMetric.toUpperCase()}:</span>
                        <span class="tooltip-value">${val}</span>
                    </div>
                `;
            }
        })
        .on('mouseout', function() {
            document.getElementById('tooltip').classList.add('hidden');
        });

    // Pod Label (only if there is space)
    podGroups.append('text')
        .attr('class', 'pod-label')
        .attr('x', 4)
        .attr('y', 14)
        .text(d => {
            if (d.data.type === 'unused') return '';
            const width = d.x1 - d.x0;
            const height = d.y1 - d.y0;
            if (width > 60 && height > 20) {
                let txt = d.data.name;
                if (txt.length * 5 > width) {
                    return txt.substring(0, Math.floor(width/5) - 2) + '..';
                }
                return txt;
            }
            return '';
        });
}

// Handle resize
window.addEventListener('resize', () => {
    if (clusterData) {
        renderChart(clusterData);
    }
});

// Initial fetch
fetchData();
// Poll every 30 seconds
setInterval(fetchData, 30000);