var width = 960,
    height = 600,
    radius = Math.min(width, height) / 2,
    colorOpacity = 0.7;

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height)
  .append("g")
    .attr("transform", "translate(" + width / 2 + "," + height / 1.95 + ") scale(1.00)")
    .call(d3.behavior.zoom().scaleExtent([1, 12]).on("zoom", zoom))
  .append("g");

function zoom() {
  svg.attr("transform", "translate(" + d3.event.translate + ")scale(" + d3.event.scale + ")");
}

var partition = d3.layout.partition()
    .size([2 * Math.PI, radius * radius])
    .value(function(d) { return d.size; });

var arc = d3.svg.arc()
    .startAngle(function(d) { return d.x; })
    .endAngle(function(d) { return d.x + d.dx; })
    .innerRadius(function(d) { return Math.sqrt(d.y); })
    .outerRadius(function(d) { return Math.sqrt(d.y + d.dy); });

var text = svg.append("text")
            .attr("x", 0)
            .attr("y", 0)
            .attr("dy", "0.35em");

thousand_sep_format = d3.format(',');

d3.json("http://wafi.iit.cnr.it/webvis/tmp/foursquareCategories.json", function(error, root) {
  
  getSize(root);
  
  root = {"name": root.name, "size": root.size, "children": [root]};
  
  function getSize(d) {
    if (!d.hasOwnProperty("children")) {
      d.size = 1;
      return 1;
    } else {
      var sum = 0;
      
      d.children.forEach(function(c) {
        sum += getSize(c);
      });
      
      d.size = sum;
      return d.size;
    }
    
    return d;
  }
  
  var path = svg.datum(root).selectAll("path")
      .data(partition.nodes)
    .enter().append("path")
      .attr("display", function(d) { return d.depth ? null : "none"; }) // hide inner ring
      .attr("d", arc)
      .style("stroke", "#fff")
      .style("fill", function(d) { return "#43943E"; })
      .style("opacity", colorOpacity)
      .on("mouseover", mouseover)
      .on("mouseout", mouseout);
  
  function mouseover(d) {
    console.log(d.size);
    var percentage = (100 * d.size / root.size).toPrecision(3);
    text.html("<tspan style='font-size: 30px' x=0 dy='-20'>" + thousand_sep_format(d.size) + "</tspan><tspan style='font-size: 15px' x=0 dy='25'>" + d.name + "</tspan><tspan style='font-size: 30px' x=0 dy='35'>" + percentage + "%</tspan>");
    
    d3.selectAll("path")
      .filter(function(d1) { return d === d1; })
      .style("opacity", 0.5);
  }
  
  function mouseout(d) {
    text.html("");
    
    d3.selectAll("path")
      .filter(function(d1) { return d === d1; })
      .style("opacity", colorOpacity);
  }
});

d3.select(self.frameElement).style("height", height + "px");