var SRC_FILE = "split-votes-all.json",
  units = "votes",
  sankey_iterations = 0,
  vote_threshold=1000;//100000

// set the dimensions and margins of the graph
var margin = {top: 10, right: 10, bottom: 10, left: 10},
    width = 600 - margin.left - margin.right,
    height = 900 - margin.top - margin.bottom;

// format variables
var formatNumber = d3.format(",.0f"),    // zero decimal places
    format = function(d) { return formatNumber(d) + " " + units; }

function label(s) {
  return s.substring(1, s.length)
}

function color(k) {
    vals = {
      'ACT New Zealand':'#fdb92d',
      'National Party':'#2e95b6',
      'New Zealand First Party':'#3d3f43',
      'The Opportunities Party (TOP)':'#2A2E71',
      'Other':'#cdcdcd',// '#426B6A',
      'Māori Party':'#7d584a',
      'MANA':'#000',
      'Labour Party':'#f15c4c',
      'Green Party':'#61bf84',
      'Party Vote Only':'#fff'
    }
    return vals[label(k)]
}

// append the svg object to the body of the page
var svg = d3.select("#chart").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform",
          "translate(" + margin.left + "," + margin.top + ")");

// Set the sankey diagram properties
var sankey = d3.sankey()
    .nodeWidth(36)
    .nodePadding(40)
    .size([width, height]);

var path = sankey.link();


d3.json(SRC_FILE, function(error, graph) {
  //console.log(graph)
    sankey
        .nodes(graph.nodes)
        .links(graph.links)
        //.layout(0);// no iterations to arrange
        .layout(sankey_iterations);

  // add in the links
    var link = svg.append("g").selectAll(".link")
        .data(graph.links)
      .enter().append("path")
        .attr("class", "link")
        .attr("d", path)
        .style("stroke-width", function(d) { return Math.max(1, d.dy); })
        .style("fill", "none")
        .style("stroke-opacity", function(d) {
            if (d.value < vote_threshold) {return 0}
            return 0.42;
        })
        //.style("stroke", "#000")
        .style("stroke", function(d) {
          //console.log(d)
            //return 'steelblue'
            return color(d.target.name)
            //return d.color = color(d.group.replace(/ .*/, ""));
  		      //return d.color = color(d.name.replace(/ .*/, ""));
        })
        .sort(function(a, b) { return b.dy - a.dy; });

  // add the link titles
    link.append("title")
          .text(function(d) {
      		return d.source.name + " → " +
                  d.target.name + "\n" + format(d.value); });

  // add in the nodes
    var node = svg.append("g").selectAll(".node")
        .data(graph.nodes)
      .enter().append("g")
        .attr("class", "node")
        .attr("font-family", "sans-serif")
        .attr("font-size", 10)
        .attr("transform", function(d) {
  		  return "translate(" + d.x + "," + d.y + ")"; })
        .call(d3.drag()
          .subject(function(d) {
            return d;
          })
          .on("start", function() {
            this.parentNode.appendChild(this);
          })
          .on("drag", dragmove));

  // add the rectangles for the nodes
    node.append("rect")
        .attr("height", function(d) { return d.dy; })
        .attr("width", sankey.nodeWidth())
        .style("fill", function(d) {
            //return 'steelblue'
            return color(d.name)
            //return d.color = color(d.group.replace(/ .*/, ""));
  		      //return d.color = color(d.name.replace(/ .*/, ""));
        })
        .style("stroke", function(d) {
          return d3.rgb(color(d.name)).darker(1);
        })
        .append("title")
        .text(function(d) {
  		  return label(d.name) + "\n" + format(d.value); });

  // add in the title for the nodes
    node.append("text")
        .attr("x", -6)
        .attr("y", function(d) { return d.dy / 2; })
        .attr("dy", ".35em")
        .attr("text-anchor", "end")
        .attr("transform", null)
        .text(function(d) { return label(d.name); })
      .filter(function(d) { return d.x < width / 2; })
        .attr("x", 6 + sankey.nodeWidth())
        .attr("text-anchor", "start");

  // the function for moving the nodes
    function dragmove(d) {
      d3.select(this)
        .attr("transform",
              "translate("
                 + d.x + ","
                 + (d.y = Math.max(
                    0, Math.min(height - d.dy, d3.event.y))
                   ) + ")");
      sankey.relayout();
      link.attr("d", path);
    }
  });