/* polar layout
*/


(function() {
  var RADIUS, arc_generator, color, csv, data, height, max, polar, polar_data, polar_layout, radius_scale, svg, width;

  polar = function() {
    var angle, self;

    angle = null;
    self = function(data) {
      angle = 2 * Math.PI / data.length;
      data.forEach(function(d, i) {
        return d.angle = data.length > 2 ? i * angle : (i - 0.25) * angle;
      });
      return data;
    };
    self.angle = function() {
      return angle;
    };
    return self;
  };

  /* ---
  */


  csv = 'category,value\none,323\ntwo,534\nthree,230\nfour,180\nfive,190';

  data = d3.csv.parse(csv);

  data.forEach(function(d) {
    return d.value = +d.value;
  });

  max = d3.max(data, function(d) {
    return d.value;
  });

  width = 960;

  height = 500;

  RADIUS = Math.min(width, height) / 2 - 40;

  polar_layout = polar();

  polar_data = polar_layout(data);

  console.log(polar_data);

  svg = d3.select("body").append("svg").attr("width", width).attr("height", height).append("g").attr({
    transform: "translate(" + (width / 2) + ", " + (height / 2) + ")"
  });

  color = d3.scale.ordinal().range(["#1b9e77", "#d95f02", "#7570b3", "#e7298a", "#66a61e", "#e6ab02", "#a6761d", "#666666"]);

  radius_scale = d3.scale.sqrt().domain([0, max]).range([0, RADIUS]);

  arc_generator = d3.svg.arc().innerRadius(0).outerRadius(function(d) {
    return radius_scale(d.value);
  }).startAngle(function(d) {
    return d.angle - polar_layout.angle() / 2;
  }).endAngle(function(d) {
    return d.angle + polar_layout.angle() / 2;
  });

  svg.selectAll('.arc').data(polar_data).enter().append('path').attr({
    "class": 'arc',
    d: arc_generator,
    fill: function(d, i) {
      return color(i);
    }
  });

}).call(this);