text: import d3 from 'd3';
  import _ from 'lodash';
  import $ from 'jquery';
  import { PieContainsAllZeros, ContainerTooSmall } from 'ui/errors';
  import { VislibVisualizationsChartProvider } from './_chart';
  
  export function VislibVisualizationsPieChartProvider(Private) {
  
    const Chart = Private(VislibVisualizationsChartProvider);
  
    const defaults = {
      isDonut: false,
      showTooltip: true,
      color: undefined,
      fillColor: undefined
    };
    /**
     * Pie Chart Visualization
     *
     * @class PieChart
     * @constructor
     * @extends Chart
     * @param handler {Object} Reference to the Handler Class Constructor
     * @param el {HTMLElement} HTML element to which the chart will be appended
     * @param chartData {Object} Elasticsearch query results for this specific chart
     */
    class PieChart extends Chart {
      constructor(handler, chartEl, chartData) {
        super(handler, chartEl, chartData);
  
        const charts = this.handler.data.getVisData();
        this._validatePieData(charts);
  
        this._attr = _.defaults(handler.visConfig.get('chart', {}), defaults);
      }
  
  
      /**
       * Checks whether pie slices have all zero values.
       * If so, an error is thrown.
       */
      _validatePieData(charts) {
        const isAllZeros = charts.every(function (chart) {
          return chart.slices.children.length === 0;
        });
  
        if (isAllZeros) {
          throw new PieContainsAllZeros();
        }
      }
  
      /**
       * Adds Events to SVG paths
       *
       * @method addPathEvents
       * @param element {D3.Selection} Reference to SVG path
       * @returns {D3.Selection} SVG path with event listeners attached
       */
      addPathEvents(element) {
        const events = this.events;
  
        return element
        .call(events.addHoverEvent())
        .call(events.addMouseoutEvent())
        .call(events.addClickEvent());
      }
  
      convertToPercentage(slices) {
        (function assignPercentages(slices) {
          if (slices.sumOfChildren != null) return;
  
          const parent = slices;
          const children = parent.children;
          const parentPercent = parent.percentOfParent;
  
          const sum = parent.sumOfChildren = Math.abs(children.reduce(function (sum, child) {
            return sum + Math.abs(child.size);
          }, 0));
  
          children.forEach(function (child) {
            child.percentOfGroup = Math.abs(child.size) / sum;
            child.percentOfParent = child.percentOfGroup;
  
            if (parentPercent != null) {
              child.percentOfParent *= parentPercent;
            }
  
            if (child.children) {
              assignPercentages(child);
            }
          });
        }(slices));
      }
  
      /**
       * Adds pie paths to SVG
       *
       * @method addPath
       * @param width {Number} Width of SVG
       * @param height {Number} Height of SVG
       * @param svg {HTMLElement} Chart SVG
       * @param slices {Object} Chart data
       * @returns {D3.Selection} SVG with paths attached
       */
      addPath(width, height, svg, slices) {
        const self = this;
        const marginFactor = 0.95;
        const isDonut = self._attr.isDonut;
        const radius = (Math.min(width, height) / 2) * marginFactor;
        const color = self.handler.data.getPieColorFunc();
        const tooltip = self.tooltip;
        const isTooltip = self._attr.addTooltip;
  
        const partition = d3.layout.partition()
        .sort(null)
        .value(function (d) {
          return d.percentOfParent * 100;
        });
        const x = d3.scale.linear()
        .range([0, 2 * Math.PI]);
        const y = d3.scale.sqrt()
        .range([0, radius]);
        const arc = d3.svg.arc()
        .startAngle(function (d) {
          return Math.max(0, Math.min(2 * Math.PI, x(d.x)));
        })
        .endAngle(function (d) {
          if (d.dx < 1e-8) return x(d.x);
          return Math.max(0, Math.min(2 * Math.PI, x(d.x + d.dx)));
        })
        .innerRadius(function (d) {
          // option for a single layer, i.e pie chart
          if (d.depth === 1 && !isDonut) {
            // return no inner radius
            return 0;
          }
  
          return Math.max(0, y(d.y));
        })
        .outerRadius(function (d) {
          return Math.max(0, y(d.y + d.dy));
        });
  
        const path = svg
        .datum(slices)
        .selectAll('path')
        .data(partition.nodes)
        .enter()
        .append('path')
        .attr('d', arc)
        .attr('class', function (d) {
          if (d.depth === 0) {
            return;
          }
          return 'slice';
        })
        .call(self._addIdentifier, 'name')
        .style('fill', function (d) {
          if (d.depth === 0) {
            return 'none';
          }
          return color(d.name);
        });
  
        if (isTooltip) {
          path.call(tooltip.render());
        }
  
        return path;
      }
  
      _validateContainerSize(width, height) {
        const minWidth = 20;
        const minHeight = 20;
  
        if (width <= minWidth || height <= minHeight) {
          throw new ContainerTooSmall();
        }
      }
  
      /**
       * Renders d3 visualization
       *
       * @method draw
       * @returns {Function} Creates the pie chart
       */
      draw() {
        const self = this;
  
        return function (selection) {
          selection.each(function (data) {
            const slices = data.slices;
            const div = d3.select(this);
            const width = $(this).width();
            const height = $(this).height();
  
            if (!slices.children.length) return;
  
            self.convertToPercentage(slices);
            self._validateContainerSize(width, height);
  
            const svg = div.append('svg')
            .attr('width', width)
            .attr('height', height)
            .append('g')
            .attr('transform', 'translate(' + width / 2 + ',' + height / 2 + ')');
  
            const path = self.addPath(width, height, svg, slices);
            self.addPathEvents(path);
  
            self.events.emit('rendered', {
              chart: data
            });
  
            return svg;
          });
        };
      }
    }
  
    return PieChart;
  }
  