/* eslint-disable no-param-reassign */
import d3 from 'd3';

require('./directed_force.css');

/* Modified from http://bl.ocks.org/d3noob/5141278 */
const directedForceVis = function (slice, json) {
  const div = d3.select(slice.selector);
  const width = slice.width();
  const height = slice.height();
  const fd = slice.formData;
  const linkLength = fd.link_length || 200;
  const charge = fd.charge || -500;

  const links = json.data;
  const nodes = {};
  // Compute the distinct nodes from the links.
  links.forEach(function (link) {
    link.source = nodes[link.source] || (nodes[link.source] = {
      name: link.source,
    });
    link.target = nodes[link.target] || (nodes[link.target] = {
      name: link.target,
    });
    link.value = Number(link.value);

    const targetName = link.target.name;
    const sourceName = link.source.name;

    if (nodes[targetName].total === undefined) {
      nodes[targetName].total = link.value;
    }
    if (nodes[sourceName].total === undefined) {
      nodes[sourceName].total = 0;
    }
    if (nodes[targetName].max === undefined) {
      nodes[targetName].max = 0;
    }
    if (link.value > nodes[targetName].max) {
      nodes[targetName].max = link.value;
    }
    if (nodes[targetName].min === undefined) {
      nodes[targetName].min = 0;
    }
    if (link.value > nodes[targetName].min) {
      nodes[targetName].min = link.value;
    }

    nodes[targetName].total += link.value;
  });

  /* eslint-disable no-use-before-define */
  // add the curvy lines
  function tick() {
    path.attr('d', function (d) {
      const dx = d.target.x - d.source.x;
      const dy = d.target.y - d.source.y;
      const dr = Math.sqrt((dx * dx) + (dy * dy));
      return (
        'M' +
        d.source.x + ',' +
        d.source.y + 'A' +
        dr + ',' + dr + ' 0 0,1 ' +
        d.target.x + ',' +
        d.target.y
      );
    });

    node.attr('transform', function (d) {
      return 'translate(' + d.x + ',' + d.y + ')';
    });
  }
  /* eslint-enable no-use-before-define */

  const force = d3.layout.force()
  .nodes(d3.values(nodes))
  .links(links)
  .size([width, height])
  .linkDistance(linkLength)
  .charge(charge)
  .on('tick', tick)
  .start();

  div.selectAll('*').remove();
  const svg = div.append('svg')
  .attr('width', width)
  .attr('height', height);

  // build the arrow.
  svg.append('svg:defs').selectAll('marker')
  .data(['end']) // Different link/path types can be defined here
  .enter()
  .append('svg:marker') // This section adds in the arrows
  .attr('id', String)
  .attr('viewBox', '0 -5 10 10')
  .attr('refX', 15)
  .attr('refY', -1.5)
  .attr('markerWidth', 6)
  .attr('markerHeight', 6)
  .attr('orient', 'auto')
  .append('svg:path')
  .attr('d', 'M0,-5L10,0L0,5');

  const edgeScale = d3.scale.linear()
  .range([0.1, 0.5]);
  // add the links and the arrows
  const path = svg.append('svg:g').selectAll('path')
  .data(force.links())
  .enter()
  .append('svg:path')
  .attr('class', 'link')
  .style('opacity', function (d) {
    return edgeScale(d.value / d.target.max);
  })
  .attr('marker-end', 'url(#end)');

  // define the nodes
  const node = svg.selectAll('.node')
  .data(force.nodes())
  .enter()
  .append('g')
  .attr('class', 'node')
  .on('mouseenter', function () {
    d3.select(this)
    .select('circle')
    .transition()
    .style('stroke-width', 5);

    d3.select(this)
    .select('text')
    .transition()
    .style('font-size', 25);
  })
  .on('mouseleave', function () {
    d3.select(this)
    .select('circle')
    .transition()
    .style('stroke-width', 1.5);
    d3.select(this)
    .select('text')
    .transition()
    .style('font-size', 12);
  })
  .call(force.drag);

  // add the nodes
  const ext = d3.extent(d3.values(nodes), function (d) {
    return Math.sqrt(d.total);
  });
  const circleScale = d3.scale.linear()
  .domain(ext)
  .range([3, 30]);

  node.append('circle')
  .attr('r', function (d) {
    return circleScale(Math.sqrt(d.total));
  });

  // add the text
  node.append('text')
  .attr('x', 6)
  .attr('dy', '.35em')
  .text(function (d) {
    return d.name;
  });
};

module.exports = directedForceVis;