/* *
 *
 *  (c) 2010-2021 Torstein Honsi
 *
 *  License: www.highcharts.com/license
 *
 *  !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
 *
 * */

'use strict';

/* *
 *
 *  Imports
 *
 * */

import type SplinePoint from './SplinePoint';
import type SplineSeriesOptions from './SplineSeriesOptions';
import type SVGPath from '../../Core/Renderer/SVG/SVGPath';
import SeriesRegistry from '../../Core/Series/SeriesRegistry.js';
const {
    seriesTypes: {
        line: LineSeries
    }
} = SeriesRegistry;
import U from '../../Core/Utilities.js';
const {
    merge,
    pick
} = U;

/**
 * Spline series type.
 *
 * @private
 */
class SplineSeries extends LineSeries {

    /* *
     *
     *  Static Properties
     *
     * */

    /**
     * A spline series is a special type of line series, where the segments
     * between the data points are smoothed.
     *
     * @sample {highcharts} highcharts/demo/spline-irregular-time/
     *         Spline chart
     * @sample {highstock} stock/demo/spline/
     *         Spline chart
     *
     * @extends      plotOptions.series
     * @excluding    step, boostThreshold, boostBlending
     * @product      highcharts highstock
     * @optionparent plotOptions.spline
     */
    public static defaultOptions: SplineSeriesOptions = merge(LineSeries.defaultOptions);

    /* *
     *
     *  Properties
     *
     * */

    public data: Array<SplinePoint> = void 0 as any;

    public options: SplineSeriesOptions = void 0 as any;

    public points: Array<SplinePoint> = void 0 as any;

    /* *
     *
     *  Functions
     *
     * */

    /* eslint-disable valid-jsdoc */

    /**
     * Get the spline segment from a given point's previous neighbour to the
     * given point.
     *
     * @private
     * @function Highcharts.seriesTypes.spline#getPointSpline
     *
     * @param {Array<Highcharts.Point>}
     *
     * @param {Highcharts.Point} point
     *
     * @param {number} i
     *
     * @return {Highcharts.SVGPathArray}
     */
    public getPointSpline(
        points: Array<SplinePoint>,
        point: SplinePoint,
        i: number
    ): SVGPath.CurveTo {
        let
            // 1 means control points midway between points, 2 means 1/3
            // from the point, 3 is 1/4 etc
            smoothing = 1.5,
            denom = smoothing + 1,
            plotX = point.plotX || 0,
            plotY = point.plotY || 0,
            lastPoint = points[i - 1],
            nextPoint = points[i + 1],
            leftContX: number | undefined,
            leftContY: number | undefined,
            rightContX: number,
            rightContY: number,
            ret: SVGPath.CurveTo;

        /**
         * @private
         */
        function doCurve(otherPoint: SplinePoint): boolean {
            return otherPoint &&
                !otherPoint.isNull &&
                otherPoint.doCurve !== false &&
                // #6387, area splines next to null:
                !point.isCliff;
        }

        // Find control points
        if (doCurve(lastPoint) && doCurve(nextPoint)) {
            let lastX = lastPoint.plotX || 0,
                lastY = lastPoint.plotY || 0,
                nextX = nextPoint.plotX || 0,
                nextY = nextPoint.plotY || 0,
                correction = 0;

            leftContX = (smoothing * plotX + lastX) / denom;
            leftContY = (smoothing * plotY + lastY) / denom;
            rightContX = (smoothing * plotX + nextX) / denom;
            rightContY = (smoothing * plotY + nextY) / denom;

            // Have the two control points make a straight line through main
            // point
            if (rightContX !== leftContX) { // #5016, division by zero
                correction = (
                    ((rightContY - leftContY) *
                    (rightContX - plotX)) /
                    (rightContX - leftContX) + plotY - rightContY
                );
            }

            leftContY += correction;
            rightContY += correction;

            // to prevent false extremes, check that control points are
            // between neighbouring points' y values
            if (leftContY > lastY && leftContY > plotY) {
                leftContY = Math.max(lastY, plotY);
                // mirror of left control point
                rightContY = 2 * plotY - leftContY;

            } else if (leftContY < lastY && leftContY < plotY) {
                leftContY = Math.min(lastY, plotY);
                rightContY = 2 * plotY - leftContY;
            }

            if (rightContY > nextY && rightContY > plotY) {
                rightContY = Math.max(nextY, plotY);
                leftContY = 2 * plotY - rightContY;

            } else if (rightContY < nextY && rightContY < plotY) {
                rightContY = Math.min(nextY, plotY);
                leftContY = 2 * plotY - rightContY;
            }

            // record for drawing in next point
            point.rightContX = rightContX;
            point.rightContY = rightContY;


        }

        // Visualize control points for debugging
        /*
        if (leftContX) {
            this.chart.renderer.circle(
                    leftContX + this.chart.plotLeft,
                    leftContY + this.chart.plotTop,
                    2
                )
                .attr({
                    stroke: 'red',
                    'stroke-width': 2,
                    fill: 'none',
                    zIndex: 9
                })
                .add();
            this.chart.renderer.path(['M', leftContX + this.chart.plotLeft,
                leftContY + this.chart.plotTop,
                'L', plotX + this.chart.plotLeft, plotY + this.chart.plotTop])
                .attr({
                    stroke: 'red',
                    'stroke-width': 2,
                    zIndex: 9
                })
                .add();
        }
        if (rightContX) {
            this.chart.renderer.circle(
                    rightContX + this.chart.plotLeft,
                    rightContY + this.chart.plotTop,
                    2
                )
                .attr({
                    stroke: 'green',
                    'stroke-width': 2,
                    fill: 'none',
                    zIndex: 9
                })
                .add();
            this.chart.renderer.path(['M', rightContX + this.chart.plotLeft,
                rightContY + this.chart.plotTop,
                'L', plotX + this.chart.plotLeft, plotY + this.chart.plotTop])
                .attr({
                    stroke: 'green',
                    'stroke-width': 2,
                    zIndex: 9
                })
                .add();
        }
        // */
        ret = [
            'C',
            pick(lastPoint.rightContX, lastPoint.plotX, 0),
            pick(lastPoint.rightContY, lastPoint.plotY, 0),
            pick(leftContX, plotX, 0),
            pick(leftContY, plotY, 0),
            plotX,
            plotY
        ];

        // reset for updating series later
        lastPoint.rightContX = lastPoint.rightContY = void 0;
        return ret;
    }

    /* eslint-enable valid-jsdoc */

}

/* *
 *
 *  Prototype Properties
 *
 * */

interface SplineSeries {
    pointClass: typeof SplinePoint;
}

/* *
 *
 *  Registry
 *
 * */

declare module '../../Core/Series/SeriesType' {
    interface SeriesTypeRegistry {
        spline: typeof SplineSeries;
    }
}
SeriesRegistry.registerSeriesType('spline', SplineSeries);

/* *
 *
 *  Default Export
 *
 * */

export default SplineSeries;

/* *
 *
 *  API Options
 *
 * */

/**
 * A `spline` series. If the [type](#series.spline.type) option is
 * not specified, it is inherited from [chart.type](#chart.type).
 *
 * @extends   series,plotOptions.spline
 * @excluding dataParser, dataURL, step, boostThreshold, boostBlending
 * @product   highcharts highstock
 * @apioption series.spline
 */

/**
 * An array of data points for the series. For the `spline` series type,
 * points can be given in the following ways:
 *
 * 1. An array of numerical values. In this case, the numerical values will be
 *    interpreted as `y` options. The `x` values will be automatically
 *    calculated, either starting at 0 and incremented by 1, or from
 *    `pointStart` and `pointInterval` given in the series options. If the axis
 *    has categories, these will be used. Example:
 *    ```js
 *    data: [0, 5, 3, 5]
 *    ```
 *
 * 2. An array of arrays with 2 values. In this case, the values correspond to
 *    `x,y`. If the first value is a string, it is applied as the name of the
 *    point, and the `x` value is inferred.
 *    ```js
 *    data: [
 *        [0, 9],
 *        [1, 2],
 *        [2, 8]
 *    ]
 *    ```
 *
 * 3. An array of objects with named values. The following snippet shows only a
 *    few settings, see the complete options set below. If the total number of
 *    data points exceeds the series'
 *    [turboThreshold](#series.spline.turboThreshold),
 *    this option is not available.
 *    ```js
 *    data: [{
 *        x: 1,
 *        y: 9,
 *        name: "Point2",
 *        color: "#00FF00"
 *    }, {
 *        x: 1,
 *        y: 0,
 *        name: "Point1",
 *        color: "#FF00FF"
 *    }]
 *    ```
 *
 * @sample {highcharts} highcharts/chart/reflow-true/
 *         Numerical values
 * @sample {highcharts} highcharts/series/data-array-of-arrays/
 *         Arrays of numeric x and y
 * @sample {highcharts} highcharts/series/data-array-of-arrays-datetime/
 *         Arrays of datetime x and y
 * @sample {highcharts} highcharts/series/data-array-of-name-value/
 *         Arrays of point.name and y
 * @sample {highcharts} highcharts/series/data-array-of-objects/
 *         Config objects
 *
 * @type      {Array<number|Array<(number|string),(number|null)>|null|*>}
 * @extends   series.line.data
 * @product   highcharts highstock
 * @apioption series.spline.data
 */

''; // adds doclets above intro transpilat
