var r = 960,

    format = d3.format(",d"),

    fill = d3.scale.category20c();

var bubble = d3.layout.pack()

    .sort(null)

    .size([r, r]);

var vis = d3.select("#chart").append("svg:svg")

    .attr("width", r)

    .attr("height", r)

    .attr("class", "bubble");

d3.json("../data/flare.json", function(json) {

  var node = vis.selectAll("g.node")

      .data(bubble.nodes(classes(json))

      .filter(function(d) { return !d.children; }))

    .enter().append("svg:g")

      .attr("class", "node")

      .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });

  node.append("svg:title")

      .text(function(d) { return d.className + ": " + format(d.value); });

  node.append("svg:circle")

      .attr("r", function(d) { return d.r; })

      .style("fill", function(d) { return fill(d.packageName); });

  node.append("svg:text")

      .attr("text-anchor", "middle")

      .attr("dy", ".3em")

      .text(function(d) { return d.className.substring(0, d.r / 3); });

});

// Returns a flattened hierarchy containing all leaf nodes under the root.

function classes(root) {

  var classes = [];

  function recurse(name, node) {

    if (node.children) node.children.forEach(function(child) { recurse(node.name, child); });

    else classes.push({packageName: name, className: node.name, value: node.size});

  }

  recurse(null, root);

  return {children: classes};

}