var BIN_PREFIX_LENGTH = 48, // Shift to /48 units
  COLOR_PROP = 'ratio128s';

var colorScale = d3.scaleLinear()
  .clamp(false)
  .range(['darkblue', 'red']);

d3.json('./_data_20150317_v6_aggregate_counts.json', function(prefixes) {

  var hostsData = Object.keys(prefixes).map(function(pref) {
    var prefix = new Ip.Prefix(pref),
      num64s = Math.pow(2, 64 - prefix.cidr);

    prefix = shiftPrefix(prefix, BIN_PREFIX_LENGTH - 128);

    return {
      start: prefix.firstIp().toNum(),
      length: Math.max(1, Math.pow(2, 128 - prefix.cidr)),
      name: pref,
      cnt64s: prefixes[pref]['64_count'],
      cnt128s: prefixes[pref].addr_count,
      ratio64s: prefixes[pref]['64_count'] / num64s,
      ratio128s: prefixes[pref].addr_count / num64s
    };
  }).sort(function(a, b) {
    return d3.descending(a.length, b.length);
  });

  // Set scale domain
  colorScale.domain([
    0,
    // use 99th percentile to remove outliars
    d3.quantile(hostsData.map(function(d) { return d[COLOR_PROP]; }).sort(), 0.99)
  ]);

  // Get the IANA IPv6 unicast data
  d3.csv('./iana-ipv6-unicast.csv', function (unicastData) {

    var ianaData = unicastData.map(function(row) {
      var prefix = new Ip.Prefix(row.Prefix);
      prefix = shiftPrefix(prefix, BIN_PREFIX_LENGTH - 128);

      return {
        start: prefix.firstIp().toNum(),
        length: Math.max(1, Math.pow(2, 128 - prefix.cidr)),
        name: row.Designation
      };
    }).filter(function(prefix) {
      // Remove reserved placeholders
      return prefix.name !== 'IANA';
    });

    // Combine IANA and hosts data
    var hilbertData = ianaData.concat(hostsData);

    // Render Hilbert
    HilbertChart()
      .width(window.innerHeight - 270)
      .hilbertOrder(BIN_PREFIX_LENGTH / 2)
      .data(hilbertData)
      .showValTooltip(false)
      .valFormatter(ipFormatter)
      .rangeTooltipContent(d => `<b>${d.name}</b>: ${prefixFormatter(d)}`)
      .rangeColor(rangeColor)
      (document.getElementById("ipv6-chart"))
      .focusOn(
        // Zoom in on Global Unicast area
        shiftIp(new Ip.Addr('2000::'), BIN_PREFIX_LENGTH - 128).toNum(),
        Math.pow(2, (BIN_PREFIX_LENGTH - 4))
      );

    // Render color legend
    d3.select('#color-legend').append('svg')
      .attr('width', '500px')
      .attr('height', '60px')
      .call(d3.legendColor()
        .labelFormat('.1e')
        .orient('horizontal')
        .shapeWidth(48)
        .cells(10)
        .title('# Hosts per /64')
        .scale(colorScale)
    )
    .select('.legendTitle')
      // Push title downwards
      .attr('y', 10);

  });
});

//

function rangeColor(d) {
  if (!d.hasOwnProperty(COLOR_PROP)) {
    return '#EEEEF9';
  }
  return colorScale(d[COLOR_PROP]);
}

function ipFormatter(num) {
  return shiftIp(new Ip.Addr(num), 128 - BIN_PREFIX_LENGTH).toString();
}

function prefixFormatter(d) {
  if (!d.hasOwnProperty('cnt128s')) {
    // Not a host block, show IP range
    var ipRange = new Ip.Range(d.start, d.start + d.length - 1),
      prefixes = ipRange.toPrefixes();

    return shiftPrefix(prefixes[0], 128 - BIN_PREFIX_LENGTH).toString();
  }

  // Host block
  return [
    '<br/>', d.cnt64s, '<i>/64s</i>',
    '<br/>', d.cnt128s, '<i>/128s</i>'
  ].join(' ');
}

// bits: positive shifts up, negative shifts down
function shiftIp(ip, bits) {
  var bin = ip.toBin();
  if (bits < 0) {
    bin = bin.slice(0, bin.length + bits);
    if (!bin.length) bin = '0';
  } else {
    for (;bits;bits--) { bin += '0'; }
  }

  return new Ip.Addr(parseInt(bin, 2));
}

function shiftPrefix(pref, bits) {
  return new Ip.Prefix(shiftIp(pref.firstIp(), bits), pref.cidr - bits);
}