/*
title: Circle Packing with d3
category: custom
titleCN: Circle Packing with d3
difficulty: 11
*/

$.when(
  $.get(ROOT_PATH + '/data/asset/data/option-view.json'),
  $.getScript(
    'https://fastly.jsdelivr.net/npm/d3-hierarchy@2.0.0/dist/d3-hierarchy.min.js'
  )
).done(function (res) {
  run(res[0]);
});

function run(rawData) {
  const dataWrap = prepareData(rawData);
  initChart(dataWrap.seriesData, dataWrap.maxDepth);
}

function prepareData(rawData) {
  const seriesData = [];
  let maxDepth = 0;

  function convert(source, basePath, depth) {
    if (source == null) {
      return;
    }
    if (maxDepth > 5) {
      return;
    }
    maxDepth = Math.max(depth, maxDepth);

    seriesData.push({
      id: basePath,
      value: source.$count,
      depth: depth,
      index: seriesData.length
    });

    for (var key in source) {
      if (source.hasOwnProperty(key) && !key.match(/^\$/)) {
        var path = basePath + '.' + key;
        convert(source[key], path, depth + 1);
      }
    }
  }

  convert(rawData, 'option', 0);

  return {
    seriesData: seriesData,
    maxDepth: maxDepth
  };
}

function initChart(seriesData, maxDepth) {
  var displayRoot = stratify();

  function stratify() {
    return d3
      .stratify()
      .parentId(function (d) {
        return d.id.substring(0, d.id.lastIndexOf('.'));
      })(seriesData)
      .sum(function (d) {
        return d.value || 0;
      })
      .sort(function (a, b) {
        return b.value - a.value;
      });
  }

  function overallLayout(params, api) {
    var context = params.context;
    d3
      .pack()
      .size([api.getWidth() - 2, api.getHeight() - 2])
      .padding(3)(displayRoot);

    context.nodes = {};
    displayRoot.descendants().forEach(function (node, index) {
      context.nodes[node.id] = node;
    });
  }

  function renderItem(params, api) {
    var context = params.context;

    // Only do that layout once in each time `setOption` called.
    if (!context.layout) {
      context.layout = true;
      overallLayout(params, api);
    }

    var nodePath = api.value('id');
    var node = context.nodes[nodePath];

    if (!node) {
      // Reder nothing.
      return;
    }

    var isLeaf = !node.children || !node.children.length;

    var focus = new Uint32Array(
      node.descendants().map(function (node) {
        return node.data.index;
      })
    );

    var nodeName = isLeaf
      ? nodePath
          .slice(nodePath.lastIndexOf('.') + 1)
          .split(/(?=[A-Z][^A-Z])/g)
          .join('\n')
      : '';

    var z2 = api.value('depth') * 2;

    return {
      type: 'circle',
      focus: focus,
      shape: {
        cx: node.x,
        cy: node.y,
        r: node.r
      },
      transition: ['shape'],
      z2: z2,
      textContent: {
        type: 'text',
        style: {
          // transition: isLeaf ? 'fontSize' : null,
          text: nodeName,
          fontFamily: 'Arial',
          width: node.r * 1.3,
          overflow: 'truncate',
          fontSize: node.r / 3
        },
        emphasis: {
          style: {
            overflow: null,
            fontSize: Math.max(node.r / 3, 12)
          }
        }
      },
      textConfig: {
        position: 'inside'
      },
      style: {
        fill: api.visual('color')
      },
      emphasis: {
        style: {
          fontFamily: 'Arial',
          fontSize: 12,
          shadowBlur: 20,
          shadowOffsetX: 3,
          shadowOffsetY: 5,
          shadowColor: 'rgba(0,0,0,0.3)'
        }
      }
    };
  }

  option = {
    dataset: {
      source: seriesData
    },
    tooltip: {},
    visualMap: [
      {
        show: false,
        min: 0,
        max: maxDepth,
        dimension: 'depth',
        inRange: {
          color: ['#006edd', '#e0ffff']
        }
      }
    ],
    hoverLayerThreshold: Infinity,
    series: {
      type: 'custom',
      renderItem: renderItem,
      progressive: 0,
      coordinateSystem: 'none',
      encode: {
        tooltip: 'value',
        itemName: 'id'
      }
    }
  };

  myChart.setOption(option);

  myChart.on('click', { seriesIndex: 0 }, function (params) {
    drillDown(params.data.id);
  });

  function drillDown(targetNodeId) {
    displayRoot = stratify();
    if (targetNodeId != null) {
      displayRoot = displayRoot.descendants().find(function (node) {
        return node.data.id === targetNodeId;
      });
    }
    // A trick to prevent d3-hierarchy from visiting parents in this algorithm.
    displayRoot.parent = null;

    myChart.setOption({
      dataset: {
        source: seriesData
      }
    });
  }

  // Reset: click on the blank area.
  myChart.getZr().on('click', function (event) {
    if (!event.target) {
      drillDown();
    }
  });
}