import { ajax } from "discourse/lib/ajax";
import AsyncReport from "admin/mixins/async-report";
import Report from "admin/models/report";
import { number } from 'discourse/lib/formatter';
import loadScript from "discourse/lib/load-script";

function collapseWeekly(data, average) {
  let aggregate = [];
  let bucket, i;
  let offset = data.length % 7;
  for(i = offset; i < data.length; i++) {

    if (bucket && (i % 7 === offset)) {
      if (average) {
        bucket.y = parseFloat((bucket.y / 7.0).toFixed(2));
      }
      aggregate.push(bucket);
      bucket = null;
    }

    bucket = bucket || { x: data[i].x, y: 0 };
    bucket.y += data[i].y;
  }
  return aggregate;
}

export default Ember.Component.extend(AsyncReport, {
  classNames: ["dashboard-mini-chart"],
  total: 0,

  init() {
    this._super();

    this._colorsPool = ["rgb(0,136,204)", "rgb(235,83,148)"];
  },

  pickColorAtIndex(index) {
    return this._colorsPool[index] || this._colorsPool[0];
  },

  fetchReport() {
    this._super();

    let payload = {
      data: { cache: true, facets: ["prev_period"] }
    };

    if (this.get("startDate")) {
      payload.data.start_date = this.get("startDate").locale('en').format('YYYY-MM-DD[T]HH:mm:ss.SSSZZ');
    }

    if (this.get("endDate")) {
      payload.data.end_date = this.get("endDate").locale('en').format('YYYY-MM-DD[T]HH:mm:ss.SSSZZ');
    }

    if (this._chart) {
      this._chart.destroy();
      this._chart = null;
    }

    this.set("reports", Ember.Object.create());

    return Ember.RSVP.Promise.all(this.get("dataSources").map(dataSource => {
      return ajax(dataSource, payload)
        .then(response => {
          this.set(`reports.${response.report.report_key}`, this.loadReport(response.report));
        });
    }));
  },

  loadReport(report, previousReport) {
    Report.fillMissingDates(report);

    if (report.data && report.data.length > 40) {
      report.data = collapseWeekly(report.data, report.average);
    }

    if (previousReport && previousReport.color.length) {
      report.color = previousReport.color;
    } else {
      const dataSourceNameIndex = this.get("dataSourceNames").split(",").indexOf(report.type);
      report.color = this.pickColorAtIndex(dataSourceNameIndex);
    }

    return Report.create(report);
  },

  renderReport() {
    this._super();

    Ember.run.schedule("afterRender", () => {
      const $chartCanvas = this.$(".chart-canvas");
      if (!$chartCanvas.length) return;
      const context = $chartCanvas[0].getContext("2d");

      const reports = _.values(this.get("reports"));

      const labels = Ember.makeArray(reports.get("firstObject.data")).map(d => d.x);

      const data = {
        labels,
        datasets: reports.map(report => {
          return {
            data: Ember.makeArray(report.data).map(d => d.y),
            backgroundColor: "rgba(200,220,240,0.3)",
            borderColor: report.color
          };
        })
      };

      if (this._chart) {
        this._chart.destroy();
        this._chart = null;
      }

      loadScript("/javascripts/Chart.min.js").then(() => {
        if (this._chart) {
          this._chart.destroy();
        }
        this._chart = new window.Chart(context, this._buildChartConfig(data));
      });
    });
  },

  _buildChartConfig(data) {
    return {
      type: "line",
      data,
      options: {
        legend: {
          display: false
        },
        responsive: true,
        layout: {
          padding: {
            left: 0,
            top: 0,
            right: 0,
            bottom: 0
          }
        },
        scales: {
          yAxes: [{
            display: true,
            ticks: { callback: (label) => number(label) }
          }],
          xAxes: [{
            display: true,
            gridLines: { display: false },
            type: "time",
            time: {
              parser: "YYYY-MM-DD"
            }
          }],
        }
      },
    };
  }
});