core/src/state.ts

import { TimeSerie, Options, yAxisOrientation } from './types';

import cloneDeep from 'lodash/cloneDeep';
import min from 'lodash/min';
import minBy from 'lodash/minBy';
import max from 'lodash/max';
import maxBy from 'lodash/maxBy';


const DEFAULT_AXIS_RANGE = [0, 1];
const DEFAULT_TRANSFORM = {
  x: 0,
  y: 0,
  k: 1
}

// TODO: replace all getters with fields. Because getters will be recalculated on each call
// TODO: remove duplicates in max/min values.
// TODO: add scales
// TODO: PodState can be divided in two classes, but it is hard now. 
export class PodState<T extends TimeSerie, O extends Options> {
  private _xValueRange: [number, number];
  private _yValueRange: [number, number];
  private _y1ValueRange: [number, number] | undefined = undefined; // can be undefined, because y1 - is an optional param
  private _transform: { x: number, y: number, k: number } = cloneDeep(DEFAULT_TRANSFORM);

  constructor(
    protected series: T[],
    protected options: O,
  ) {
    this.initRanges();
  }

  protected initRanges(): void {
    this._xValueRange = [this.minValueX, this.maxValueX];
    this._yValueRange = [this.minValueY, this.maxValueY];
    if(this.options.axis.y1.isActive) {
      this._y1ValueRange = [this.minValueY1, this.maxValueY1];
    }
  }

  get xValueRange(): [number, number] | undefined {
    return this._xValueRange;
  }

  get yValueRange(): [number, number] | undefined {
    return this._yValueRange;
  }

  get y1ValueRange(): [number, number] | undefined {
    return this._y1ValueRange;
  }

  get transform(): { x?: number, y?: number, k?: number } {
    return this._transform;
  }

  set xValueRange(range: [number, number]) {
    this._xValueRange = range;
  }

  set yValueRange(range: [number, number]) {
    this._yValueRange = range;
  }

  set y1ValueRange(range: [number, number]) {
    this._y1ValueRange = range;
  }

  set transform(transform: { x?: number, y?: number, k?: number }) {
    this._transform.x = transform.x !== undefined ? transform.x : this._transform.x;
    this._transform.y = transform.y !== undefined ? transform.y : this._transform.y;
    this._transform.k = transform.k !== undefined ? transform.k : this._transform.k;
  }

  get minValueY(): number {
    if(this.isSeriesUnavailable) {
      return DEFAULT_AXIS_RANGE[0];
    }
    if(this.options.axis.y !== undefined && this.options.axis.y.range !== undefined) {
      return min(this.options.axis.y.range);
    }
    const minValue = min(
      this.series
        .filter(serie => serie.visible !== false && this.filterSerieByYAxisOrientation(serie, yAxisOrientation.LEFT))
        .map(
          serie => minBy<number[]>(serie.datapoints, dp => dp[1])[1]
        )
    );
    return minValue;
  }

  get maxValueY(): number {
    if(this.isSeriesUnavailable) {
      return DEFAULT_AXIS_RANGE[1];
    }
    if(this.options.axis.y !== undefined && this.options.axis.y.range !== undefined) {
      return max(this.options.axis.y.range);
    }
    const maxValue = max(
      this.series
        .filter(serie => serie.visible !== false && this.filterSerieByYAxisOrientation(serie, yAxisOrientation.LEFT))
        .map(
          serie => maxBy<number[]>(serie.datapoints, dp => dp[1])[1]
        )
    );
    return maxValue;
  }

  get minValueX(): number {
    if(this.isSeriesUnavailable) {
      return DEFAULT_AXIS_RANGE[0];
    }

    if(this.options.axis.x !== undefined && this.options.axis.x.range !== undefined) {
      return min(this.options.axis.x.range);
    }
    const minValue = min(
      this.series
        .filter(serie => serie.visible !== false)
        .map(
          serie => minBy<number[]>(serie.datapoints, dp => dp[0])[0]
        )
    );
    return minValue;
  }

  get maxValueX(): number {
    if(this.isSeriesUnavailable) {
      return DEFAULT_AXIS_RANGE[1];
    }
    if(this.options.axis.x !== undefined && this.options.axis.x.range !== undefined) {
      return max(this.options.axis.x.range)
    }
    const maxValue = max(
      this.series
        .filter(serie => serie.visible !== false)
        .map(
          serie => maxBy<number[]>(serie.datapoints, dp => dp[0])[0]
        )
    );
    return maxValue;
  }

  get minValueY1(): number {
    if(this.isSeriesUnavailable || this.options.axis.y1 === undefined || this.options.axis.y1.isActive === false) {
      return DEFAULT_AXIS_RANGE[0];
    }
    if(this.options.axis.y1.range !== undefined) {
      return min(this.options.axis.y1.range);
    }
    const minValue = min(
      this.series
        .filter(serie => serie.visible !== false && this.filterSerieByYAxisOrientation(serie, yAxisOrientation.RIGHT))
        .map(
          serie => minBy<number[]>(serie.datapoints, dp => dp[1])[1]
        )
    );
    return minValue;
  }

  get maxValueY1(): number {
    if(this.isSeriesUnavailable || this.options.axis.y1 === undefined || this.options.axis.y1.isActive === false) {
      return DEFAULT_AXIS_RANGE[1];
    }
    if(this.options.axis.y1 !== undefined && this.options.axis.y1.range !== undefined) {
      return max(this.options.axis.y1.range);
    }
    const maxValue = max(
      this.series
        .filter(serie => serie.visible !== false && this.filterSerieByYAxisOrientation(serie, yAxisOrientation.RIGHT))
        .map(
          serie => maxBy<number[]>(serie.datapoints, dp => dp[1])[1]
        )
    );
    return maxValue;
  }

  get isSeriesUnavailable(): boolean {
    return this.series === undefined || this.series.length === 0 ||
      max(this.series.map(serie => serie.datapoints.length)) === 0;
  }

  protected filterSerieByYAxisOrientation(serie: T, orientation: yAxisOrientation): boolean {
    if(serie.yOrientation === undefined || serie.yOrientation === yAxisOrientation.BOTH) {
      return true;
    }
    return serie.yOrientation === orientation;
  }
}