Report - Lucene Group By

var div = $("#chart");
var table = d3.select(div.parent().get(0)).append('table')
var thead = table.append('thead')
var tbody = table.append('tbody');
 
$("#chart ~ table").addClass("table")
thead.append('tr').selectAll('th').data(chartData.columns[1]).enter().append('th')
                  .text(function(column) { return column; });
$('thead > tr > th:first').text(chartData.ytype + " \\ " + chartData.xtype)
 
var tr = tbody.selectAll('tr').data(chartData.groups[0]).enter().append("tr");
 
var td = tr.selectAll("td").data(function(d) {
    var result = new Array();
    $.each(chartData.columns, function(index, value) {
        if (value[0] == d) {
            result.push.apply(result, value);
        }
    });
    return result;
}).enter().append("td").text(function(d, i) {
    return d;
});

import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.text.DateFormat;
  
import org.apache.lucene.document.Document;
  
import com.atlassian.jira.component.ComponentAccessor;
import com.atlassian.jira.issue.DocumentIssueImpl;
import com.atlassian.jira.issue.Issue;
import com.atlassian.jira.jql.parser.JqlQueryParser;
import com.atlassian.jira.user.ApplicationUser;
import com.atlassian.query.Query;
  
import com.decadis.jira.xchart.api.model.Period;
import com.decadis.jira.xchart.api.util.DateUtils;
import com.decadis.jira.xchart.api.model.ChartData;
  
DateFormat dateFormat = DateUtils.SimpleDateFormat;
   
JqlQueryParser jqlQueryParser = ComponentAccessor.getComponent(JqlQueryParser.class);
Query query = jqlQueryParser.parseQuery(Jql_Param); //this is the parameter we created
    
Period selectedPeriod = Period.MONTH;
def countGroup = chartBuilder.newDataCollector();
  
def groupValueExtractorX = chartBuilder.getGrouper(GroupBy_Picker); //must be a fieldid, so either Group By Picker, or hardcoded fieldid
def groupValueExtractorY = chartBuilder.getGrouper("issuetype"); //can be replaced by a parameter
  
Field documentField;
documentField = DocumentIssueImpl.class.getDeclaredField("document");
documentField.setAccessible(true);
   
for ( Issue issue : chartBuilder.getFilterUtils().performSearch(query, user) )
{
  for ( String groupX : groupValueExtractorX.getGroups((Document) documentField.get(issue)) )
  {
    for ( String groupY : groupValueExtractorY.getGroups((Document) documentField.get(issue)) )
    {
      groupY = (groupY != null) ? groupValueExtractorY.getResolvedValue(groupY, issue) : groupY;
      groupX = (groupX != null) ? groupValueExtractorX.getResolvedValue(groupX, issue) : groupX;
      countGroup.addValue(BigDecimal.ONE, groupY, groupX);
    }
  }
}
   
countGroup.fillMissingValues();
  
ChartData chartData = chartBuilder.newChartData("issuetype");
chartData.setXType("project");
chartData.setType("table");
  
chartBuilder.getChartUtil().transformResult(countGroup, chartData, true);
  
return chartData;