grafana-chartwerk-panel/src/models/options.ts

import _ from 'lodash';
import { PanelOptions, Aggregation, Threshold } from 'types';

import { filterMetricListByAlias, getAggregatedValueFromSerie } from '../utils';

// Convert Grafana options into Chartwerk Gauge options
export class Options {
  private minValue: number | undefined;
  private maxValue: number | undefined;
  private thresholds: { value: number, color: string }[] = [];

  constructor(private grafanaSeriesList: any[], private grafanaOptions: PanelOptions) {
    this._setMin();
    this._setMax();
    this._setThresholds();
  }

  private _setMin(): void {
    if (!this.grafanaOptions.gauge.min.useMetric) {
      this.minValue = this.grafanaOptions.gauge.min.value;
      return;
    }
    const aggregatedValue = this.getLastValueFromMetrics(this.grafanaOptions.gauge.min.metricName, 'Min');
    this.minValue = aggregatedValue ? aggregatedValue : undefined;
  }

  private _setMax(): void {
    if (!this.grafanaOptions.gauge.max.useMetric) {
      this.maxValue = this.grafanaOptions.gauge.max.value;
      return;
    }
    const aggregatedValue = this.getLastValueFromMetrics(this.grafanaOptions.gauge.max.metricName, 'Max');
    this.maxValue = aggregatedValue ? aggregatedValue : undefined;
  }

  private _setThresholds(): void {
    if (_.isEmpty(this.grafanaOptions.gauge.thresholds.thresholds)) {
      return;
    }
    for (let [idx, threshold] of this.grafanaOptions.gauge.thresholds.thresholds.entries()) {
      this._setThreshold(threshold, idx);
    }
  }

  private _setThreshold(threshold: Threshold, idx: number): void {
    const value = threshold.useMetric ? this.getLastValueFromMetrics(threshold.metricName, `Threshold ${idx}`) : threshold.value;
    if(value === null || value === undefined) {
      // TODO: may be throw an error
      return;
    }
    this.thresholds.push({
      value,
      color: threshold.color
    });
  }

  private _valueFormatter(value: number): string {
    const decimals = this.grafanaOptions.gauge.decimals || 2;
    return `${value.toFixed(decimals)} ${this.grafanaOptions.gauge.unit}`;
  }

  getChartwerkOptions(): any {
    console.log('opt', this.maxValue, this.minValue);
    return {
      maxValue: this.maxValue,
      minValue: this.minValue,
      valueFormatter: (val: number) => this._valueFormatter(val),
      defaultColor: this.grafanaOptions.gauge.thresholds.defaultColor,
      valueArcBackgroundColor: this.grafanaOptions.gauge.thresholds.arcBackground,
      reversed: this.grafanaOptions.gauge.reversed,
      stops: this.thresholds,
      valueFontSize: this.grafanaOptions.gauge.valueSize,
      // @ts-ignore
      icons: [{ src: 'https://cityhost.ua/upload_img/blog5ef308ea5529c_trash2-01.jpg', position: 'middle', size: 30 }],
    };
  }

  getLastValueFromMetrics(metricName: string | undefined, optionName: string): number | null {
    const filteredSeries = filterMetricListByAlias(
      this.grafanaSeriesList,
      metricName,
      optionName
    );
    const serie = filteredSeries[0];
    // Last value for now
    return getAggregatedValueFromSerie(serie, Aggregation.LAST);
  }
}