// Graph Data - Reconstructed Structure
const graphData = {
    nodes: [
        { id: "About", group: 1 },
        { id: "Notes", group: 2 },
        { id: "Projects", group: 2 },
        { id: "Audio", group: 2 },
        { id: "Visual", group: 3 }
    ],
    links: [
        { source: "About", target: "Notes" },
        { source: "About", target: "Projects" },
        { source: "About", target: "Audio" },
        { source: "About", target: "Visual" }  
    ],
};

// Setup Canvas
const container = document.getElementById('graph-container');
let width = container.clientWidth;
let height = container.clientHeight;

// Clear any existing SVG to prevent duplicates on reload
d3.select("#graph-container").selectAll("*").remove();

const svg = d3.select("#graph-container")
    .append("svg")
    .attr("width", "100%")
    .attr("height", "100%")
    .attr("viewBox", [0, 0, width, height])
    .call(d3.zoom().on("zoom", (event) => {
        g.attr("transform", event.transform);
    }));

const g = svg.append("g");

// Simulation Setup
const simulation = d3.forceSimulation(graphData.nodes)
    .force("link", d3.forceLink(graphData.links).id(d => d.id).distance(150))
    .force("charge", d3.forceManyBody().strength(-400))
    .force("center", d3.forceCenter(width / 2, height / 2))
    .force("collide", d3.forceCollide().radius(30));

// Render Links
const link = g.append("g")
    .attr("class", "links")
    .selectAll("line")
    .data(graphData.links)
    .join("line")
    .attr("stroke-width", 2)
    // CSS variables are handled by style.css targeting 'line'
    // but we can add specific classes if needed
    .attr("class", "graph-link");

// Render Nodes
const node = g.append("g")
    .attr("class", "nodes")
    .selectAll("g")
    .data(graphData.nodes)
    .join("g")
    .call(d3.drag()
        .on("start", dragstarted)
        .on("drag", dragged)
        .on("end", dragended));

// Node Circles
node.append("circle")
    .attr("r", 8)
    .attr("class", "graph-node");

// Node Labels
node.append("text")
    .attr("x", 12)
    .attr("y", "0.31em")
    .text(d => d.id)
    .attr("class", "graph-text")
    .clone(true).lower()
    .attr("fill", "none")
    .attr("stroke", "var(--bg-primary)")
    .attr("stroke-width", 3);

// Simulation Tick
simulation.on("tick", () => {
    link
        .attr("x1", d => d.source.x)
        .attr("y1", d => d.source.y)
        .attr("x2", d => d.target.x)
        .attr("y2", d => d.target.y);

    node
        .attr("transform", d => `translate(${d.x},${d.y})`);
});

// Drag Interaction Functions
function dragstarted(event, d) {
    if (!event.active) simulation.alphaTarget(0.3).restart();
    d.fx = d.x;
    d.fy = d.y;
}

function dragged(event, d) {
    d.fx = event.x;
    d.fy = event.y;
}

function dragended(event, d) {
    if (!event.active) simulation.alphaTarget(0);
    d.fx = null;
    d.fy = null;
}

// Handle Window Resize
window.addEventListener('resize', () => {
    width = container.clientWidth;
    height = container.clientHeight;
    
    simulation.force("center", d3.forceCenter(width / 2, height / 2));
    simulation.alpha(0.3).restart();
});

// Populate Sidebar (Optional integration)
const nodeList = document.getElementById('node-list');
if (nodeList) {
    nodeList.innerHTML = ''; // Clear existing
    graphData.nodes.forEach(node => {
        const item = document.createElement('div');
        item.style.padding = '0.5rem';
        item.style.cursor = 'pointer';
        item.style.borderBottom = '1px solid var(--border-color)';
        item.textContent = node.id;
        item.addEventListener('click', () => {
            // Optional: Zoom to node
            console.log('Focus on:', node.id);
        });
        nodeList.appendChild(item);
    });
}