/**
 * @license  Highcharts JS v6.0.4 (2017-12-15)
 *
 * Indicator series type for Highstock
 *
 * (c) 2010-2017 Kacper Madej
 *
 * License: www.highcharts.com/license
 */
'use strict';
(function(factory) {
    if (typeof module === 'object' && module.exports) {
        module.exports = factory;
    } else {
        factory(Highcharts);
    }
}(function(Highcharts) {
    (function(H) {
        /**
         * (c) 2010-2017 Kacper Madej
         *
         * License: www.highcharts.com/license
         */


        var seriesType = H.seriesType,
            isArray = H.isArray;

        // Utils:
        function populateAverage(xVal, yVal, i, period, index) {
            /**
             * Calculated as:
             * (Closing Price [today] - Closing Price [n days ago]) /
             * Closing Price [n days ago] * 100
             *
             * Return y as null when avoiding division by zero
             */
            var nDaysAgoY,
                rocY;

            if (index < 0) {
                // y data given as an array of values
                nDaysAgoY = yVal[i - period];
                rocY = nDaysAgoY ?
                    (yVal[i] - nDaysAgoY) / nDaysAgoY * 100 :
                    null;
            } else {
                // y data given as an array of arrays and the index should be used
                nDaysAgoY = yVal[i - period][index];
                rocY = nDaysAgoY ?
                    (yVal[i][index] - nDaysAgoY) / nDaysAgoY * 100 :
                    null;
            }

            return [xVal[i], rocY];
        }

        /**
         * The ROC series type.
         *
         * @constructor seriesTypes.roc
         * @augments seriesTypes.sma
         */
        seriesType('roc', 'sma',
            /**
             * Rate of change indicator (ROC). The indicator value for each point
             * is defined as:
             *
             * `(C - Cn) / Cn * 100`
             *
             * where: `C` is the close value of the point of the same x in the
             * linked series and `Cn` is the close value of the point `n` periods
             * ago. `n` is set through [period](#plotOptions.roc.params.period).
             *
             * This series requires `linkedTo` option to be set.
             * 
             * @extends {plotOptions.sma}
             * @product highstock
             * @sample {highstock} stock/indicators/roc
             *                     Rate of change indicator
             * @since 6.0.0
             * @optionparent plotOptions.roc
             */
            {
                name: 'Rate of Change (9)',
                params: {
                    index: 3,
                    period: 9
                }
            }, {
                getValues: function(series, params) {
                    var period = params.period,
                        xVal = series.xData,
                        yVal = series.yData,
                        yValLen = yVal ? yVal.length : 0,
                        ROC = [],
                        xData = [],
                        yData = [],
                        i,
                        index = -1,
                        ROCPoint;

                    // Period is used as a number of time periods ago, so we need more
                    // (at least 1 more) data than the period value
                    if (xVal.length <= period) {
                        return false;
                    }

                    // Switch index for OHLC / Candlestick / Arearange
                    if (isArray(yVal[0])) {
                        index = params.index;
                    }

                    // i = period <-- skip first N-points
                    // Calculate value one-by-one for each period in visible data
                    for (i = period; i < yValLen; i++) {
                        ROCPoint = populateAverage(xVal, yVal, i, period, index);
                        ROC.push(ROCPoint);
                        xData.push(ROCPoint[0]);
                        yData.push(ROCPoint[1]);
                    }

                    return {
                        values: ROC,
                        xData: xData,
                        yData: yData
                    };
                }
            });

        /**
         * A `ROC` series. If the [type](#series.wma.type) option is not
         * specified, it is inherited from [chart.type](#chart.type).
         *
         * Rate of change indicator (ROC). The indicator value for each point
         * is defined as:
         *
         * `(C - Cn) / Cn * 100`
         *
         * where: `C` is the close value of the point of the same x in the
         * linked series and `Cn` is the close value of the point `n` periods
         * ago. `n` is set through [period](#series.roc.params.period).
         *
         * This series requires `linkedTo` option to be set.
         * 
         * For options that apply to multiple series, it is recommended to add
         * them to the [plotOptions.series](#plotOptions.series) options structure.
         * To apply to all series of this specific type, apply it to
         * [plotOptions.wma](#plotOptions.wma).
         * 
         * @type {Object}
         * @since 6.0.0
         * @extends series,plotOptions.roc
         * @excluding data,dataParser,dataURL
         * @product highstock
         * @apioption series.roc
         */

        /**
         * @extends series.sma.data
         * @product highstock
         * @apioption series.roc.data
         */

    }(Highcharts));
}));
