define([
   "dojo/_base/declare",
   "dojo/dom",
   "dojo/dom-construct",
   "dijit/_WidgetBase",
   "dijit/_TemplatedMixin",
   "dijit/_WidgetsInTemplateMixin",
   "chartjs/Chart.bundle",
   "dojo/text!./templates/vuConcurrencyChartWidget.html",
   "app/performanceTest/common/dateTimeFormat"
], function(
   declare,
   dom,
   domConstruct,
   _WidgetBase,
   _TemplatedMixin,
   _WidgetsInTemplateMixin,
   Chart,
   template
) {
   return declare([_WidgetBase, _TemplatedMixin, _WidgetsInTemplateMixin], {
      templateString: template,

      baseClass: "vuConcurrencyChartWidget",
      vuConcurrencyChart: null,
      vuConcurrencyChartData: null,

      actionName: undefined,
      height: 200,

      constructor: function(
         actionName,
         height
      ) {
         this.actionName = actionName;
         this.height = height;

         this.vuConcurrencyChartData = {
            datasets: [
               // Data defined here
            ]
         };
      },

      postCreate: function() {
         // Make sure any parent widget's postCreate functions get called.
         this.inherited(arguments);

         // Create a canvas element to draw the chart, and insert it into the dom
         var canvas = domConstruct.create("canvas");
         domConstruct.place(canvas, this.chartNode);

         this.vuConcurrencyChart = new Chart(canvas, {
            type: "line",
            data: this.vuConcurrencyChartData,
            options: {
               maintainAspectRatio: false
            }
         });

         // There seems to be a bug in the Chart.options.maintainAspectRatio attribute where the height
         // is set to zero if the container is hidden: https://github.com/apertureless/vue-chartjs/issues/235.
         // Workaround is to set the height after creating the chart.
         canvas.height = this.height;

         if (this.actionName !== undefined) {
            this.subscribe(this.actionName, "onGotData");
         }
      },

      onGotData: function(data) {

         if (this.vuConcurrencyChart !== null) {
             
            // Update the vuConcurrencyChartData object
            
            this.vuConcurrencyChart.update();
         }
      }
   });
});