var preterm = function(selector){

var width = 960,
    height = 500,
		color = d3.scaleLinear()
 .range(["#fff5eb","#fee6ce","#fdd0a2","#fdae6b","#fd8d3c","#f16913","#d94801","#a63603","#7f2704"])
	.domain([0.08,0.09,0.1,0.11,0.12,0.13]);
var svg = d3.select(selector).append("svg")
    .attr("width", width)
    .attr("height", height);

  d3.queue()
    .defer(d3.tsv, "birthsState.txt")
    .defer(d3.json, "us.json")
    .await(ready);

  function ready(error, preterm, us) {
  if (error) return console.warn(error);
  console.log(preterm);
  console.log(us);
  console.log(topojson.feature(us, us.objects.states).features);
  pretermByState = {};
  preterm.forEach(function(d) {
    d["pretermRate"] = +d["pretermRate"];
    pretermByState[+d["State Code"]] = d;
  });
  var path = d3.geoPath()
    .projection(d3.geoAlbersUsa());
  var subset = topojson.feature(us, us.objects.states).features.filter(function(d) {
    return d.id in pretermByState;
  });
  svg.append("g")
      .attr("class", "states")
    .selectAll("path")
      .data(subset)
    .enter().append("path")
      .attr("d", path)
      .style("fill", function(d) { 
        return color(pretermByState[d.id]["pretermRate"])
        })

  svg.append("path")
      .datum(topojson.mesh(us, us.objects.states, function(a, b) { return a.id !== b.id; }))
      .attr("class", "states")
      .attr("d", path);
svg.append("text")
    .style("font-weight", "bold")
    .attr("x", width - 195)
    .attr("y", height - 158)
    .text("% born <37 weeks");

  var legend = svg.selectAll(".legend")
    .data(color.domain())
    .enter().append("g")
    .attr("transform", function(d,i) {
      return "translate(" + (width-185) + "," + (height - 150 + 16 * i) + ")";
    })
    .on("click", function(min,i) {
      console.log(min,i);

    });

  legend.append("rect")
    .attr("width", 12)
    .attr("height", 12)
    .style("fill", function(d) {
      return color(d);
    });

  legend.append("text")
    .attr("x", 16)
    .attr("y", 7)
    .attr("alignment-baseline", "middle")
    .style("font-size", "12px")
    .text(function(d) {
      return (d*100).toFixed(0)+"%";
    });
  
  }
}