core/src/state.ts

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

import * as d3 from 'd3';

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';
import sortBy from 'lodash/sortBy';
import reverse from 'lodash/reverse';


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. Use scales as example.
// TODO: remove duplicates in max/min values.
// TODO: PodState can be divided in two classes, but it is hard now.
// TODO: PodState.transform has conflicts with d3.zoom.event.transform. It should be synchronized.
export class PodState<T extends CoreSerie, O extends Options> {
  private _xValueRange: [number, number];
  private _yValueRange: [number, number];
  private _y1ValueRange: [number, number];
  private _transform: { x: number, y: number, k: number | string } = cloneDeep(DEFAULT_TRANSFORM);
  private _xScale: d3.ScaleLinear<number, number>;
  private _yScale: d3.ScaleLinear<number, number>;
  private _y1Scale: d3.ScaleLinear<number, number>;

  constructor(
    protected boxParams: { height: number, width: number },
    protected series: T[],
    protected options: O,
  ) {
    this.setInitialRanges();
    this.initScales();
  }

  protected setInitialRanges(): void {
    this._xValueRange = [this.getMinValueX(), this.getMaxValueX()];
    this._yValueRange = [this.getMinValueY(), this.getMaxValueY()];
    this._y1ValueRange = [this.getMinValueY1(), this.getMaxValueY1()];
  }

  protected initScales(): void {
    this.setXScale();
    this.setYScale();
    this.setY1Scale();
  }

  protected setYScale(): void {
    let domain = this._yValueRange;
    domain = sortBy(domain) as [number, number];
    if(this.options.axis.y.invert === true) {
      domain = reverse(domain);
    }
    this._yScale = d3.scaleLinear()
      .domain(domain)
      .range([this.boxParams.height, 0]); // inversed, because d3 y-axis goes from top to bottom;
  }

  protected setXScale(): void {
    const domain = this._xValueRange;
    this._xScale = d3.scaleLinear()
      .domain(domain)
      .range([0, this.boxParams.width]);
  }

  protected setY1Scale(): void {
    let domain = this._y1ValueRange;
    domain = sortBy(domain) as [number, number];
    if(this.options.axis.y1.invert === true) {
      domain = reverse(domain);
    }
    this._y1Scale = d3.scaleLinear()
      .domain(domain)
      .range([this.boxParams.height, 0]); // inversed, because d3 y-axis goes from top to bottom
  }

  public clearState(): void {
    this.setInitialRanges();
    this.initScales();
    this._transform = { x: 0, y: 0, k: 1 };
  }

  get yScale(): d3.ScaleLinear<number, number> {
    return this._yScale;
  }

  get xScale(): d3.ScaleLinear<number, number> {
    return this._xScale;
  }

  get y1Scale(): d3.ScaleLinear<number, number> {
    return this._y1Scale;
  }

  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 | string } {
    return this._transform;
  }

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

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

  set y1ValueRange(range: [number, number]) {
    this._y1ValueRange = range;
    this.setY1Scale();
  }

  set transform(transform: { x?: number, y?: number, k?: number | string }) {
    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;
  }

  public getMinValueY(): 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;
  }

  public getMaxValueY(): 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;
  }

  public getMinValueX(): 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;
  }

  public getMaxValueX(): 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;
  }

  public getMinValueY1(): 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;
  }

  public getMaxValueY1(): 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) {
      return true;
    }
    return serie.yOrientation === orientation;
  }
}