/**
 * (c) 2010-2018 Torstein Honsi
 *
 * License: www.highcharts.com/license
 */

'use strict';

import H from './Globals.js';
import './Utilities.js';

var doc = H.doc,
    each = H.each,
    extend = H.extend,
    format = H.format,
    isNumber = H.isNumber,
    map = H.map,
    merge = H.merge,
    pick = H.pick,
    splat = H.splat,
    syncTimeout = H.syncTimeout,
    timeUnits = H.timeUnits;

/**
 * Tooltip of a chart.
 *
 * @class
 * @name Highcharts.Tooltip
 *
 * @param {Highcharts.Chart} chart
 *        The chart instance.
 *
 * @param {Highcharts.TooltipOptions} options
 *        Tooltip options.
 */
H.Tooltip = function () {
    this.init.apply(this, arguments);
};

H.Tooltip.prototype = {

    /**
     * @private
     * @function Highcharts.Tooltip#init
     *
     * @param {Highcharts.Chart} chart
     *        The chart instance.
     *
     * @param {Highcharts.TooltipOptions} options
     *        Tooltip options.
     */
    init: function (chart, options) {

        /**
         * Chart of the tooltip.
         *
         * @readonly
         * @name Highcharts.Tooltip#chart
         * @type {Highcharts.Chart}
         */
        this.chart = chart;

        /**
         * Used tooltip options.
         *
         * @readonly
         * @name Highcharts.Tooltip#options
         * @type {Highcharts.TooltipOptions}
         */
        this.options = options;

        /**
         * List of crosshairs.
         *
         * @private
         * @readonly
         * @name Highcharts.Tooltip#crosshairs
         * @type {Array<*>}
         */
        this.crosshairs = [];

        /**
         * Current values of x and y when animating.
         *
         * @private
         * @readonly
         * @name Highcharts.Tooltip#now
         * @type {*}
         */
        this.now = { x: 0, y: 0 };

        /**
         * Tooltips are initially hidden.
         *
         * @readonly
         * @name Highcharts.Tooltip#isHidden
         * @type {boolean}
         */
        this.isHidden = true;

        /**
         * True, if the tooltip is splitted into one label per series, with the
         * header close to the axis.
         *
         * @readonly
         * @name Highcharts.Tooltip#split
         * @type {boolean}
         */
        this.split = options.split && !chart.inverted;

        /**
         * When the tooltip is shared, the entire plot area will capture mouse
         * movement or touch events.
         *
         * @readonly
         * @name Highcharts.Tooltip#shared
         * @type {boolean}
         */
        this.shared = options.shared || this.split;

        /**
         * Whether to allow the tooltip to render outside the chart's SVG
         * element box. By default (false), the tooltip is rendered within the
         * chart's SVG element, which results in the tooltip being aligned
         * inside the chart area.
         *
         * @readonly
         * @name Highcharts.Tooltip#outside
         * @type {boolean}
         *
         * @todo
         * Split tooltip does not support outside in the first iteration. Should
         * not be too complicated to implement.
         */
        this.outside = options.outside && !this.split;

    },

    /**
     * Destroy the single tooltips in a split tooltip.
     * If the tooltip is active then it is not destroyed, unless forced to.
     *
     * @private
     * @function Highcharts.Tooltip#cleanSplit
     *
     * @param {boolean} force
     *        Force destroy all tooltips.
     */
    cleanSplit: function (force) {
        each(this.chart.series, function (series) {
            var tt = series && series.tt;
            if (tt) {
                if (!tt.isActive || force) {
                    series.tt = tt.destroy();
                } else {
                    tt.isActive = false;
                }
            }
        });
    },

    

    /**
     * In styled mode, apply the default filter for the tooltip drop-shadow. It
     * needs to have an id specific to the chart, otherwise there will be issues
     * when one tooltip adopts the filter of a different chart, specifically one
     * where the container is hidden.
     *
     * @private
     * @function Highcharts.Tooltip#applyFilter
     */
    applyFilter: function () {

        var chart = this.chart;
        chart.renderer.definition({
            tagName: 'filter',
            id: 'drop-shadow-' + chart.index,
            opacity: 0.5,
            children: [{
                tagName: 'feGaussianBlur',
                in: 'SourceAlpha',
                stdDeviation: 1
            }, {
                tagName: 'feOffset',
                dx: 1,
                dy: 1
            }, {
                tagName: 'feComponentTransfer',
                children: [{
                    tagName: 'feFuncA',
                    type: 'linear',
                    slope: 0.3
                }]
            }, {
                tagName: 'feMerge',
                children: [{
                    tagName: 'feMergeNode'
                }, {
                    tagName: 'feMergeNode',
                    in: 'SourceGraphic'
                }]
            }]
        });
        chart.renderer.definition({
            tagName: 'style',
            textContent: '.highcharts-tooltip-' + chart.index + '{' +
                'filter:url(#drop-shadow-' + chart.index + ')' +
            '}'
        });
    },

    


    /**
     * Creates the Tooltip label element if it does not exist, then returns it.
     *
     * @function Highcharts.Tooltip#getLabel
     *
     * @return {Highcharts.SVGElement}
     */
    getLabel: function () {

        var renderer = this.chart.renderer,
            options = this.options,
            container;

        if (!this.label) {

            if (this.outside) {
                this.container = container = H.doc.createElement('div');
                container.className = 'highcharts-tooltip-container';
                H.css(container, {
                    position: 'absolute',
                    top: '1px',
                    pointerEvents: options.style && options.style.pointerEvents
                });
                H.doc.body.appendChild(container);

                this.renderer = renderer = new H.Renderer(container, 0, 0);
            }


            // Create the label
            if (this.split) {
                this.label = renderer.g('tooltip');
            } else {
                this.label = renderer.label(
                        '',
                        0,
                        0,
                        options.shape || 'callout',
                        null,
                        null,
                        options.useHTML,
                        null,
                        'tooltip'
                    )
                    .attr({
                        padding: options.padding,
                        r: options.borderRadius
                    });

                
            }

            
            // Apply the drop-shadow filter
            this.applyFilter();
            this.label.addClass('highcharts-tooltip-' + this.chart.index);
            

            if (this.outside) {
                this.label.attr({
                    x: this.distance,
                    y: this.distance
                });
                this.label.xSetter = function (value) {
                    container.style.left = value + 'px';
                };
                this.label.ySetter = function (value) {
                    container.style.top = value + 'px';
                };
            }

            this.label
                .attr({
                    zIndex: 8
                })
                .add();
        }
        return this.label;
    },

    /**
     * Updates the tooltip with the provided tooltip options.
     *
     * @function Highcharts.Tooltip#update
     *
     * @param {Highcharts.TooltipOptions} options
     */
    update: function (options) {
        this.destroy();
        // Update user options (#6218)
        merge(true, this.chart.options.tooltip.userOptions, options);
        this.init(this.chart, merge(true, this.options, options));
    },

    /**
     * Removes and destroys the tooltip and its elements.
     *
     * @function Highcharts.Tooltip#destroy
     */
    destroy: function () {
        // Destroy and clear local variables
        if (this.label) {
            this.label = this.label.destroy();
        }
        if (this.split && this.tt) {
            this.cleanSplit(this.chart, true);
            this.tt = this.tt.destroy();
        }
        if (this.renderer) {
            this.renderer = this.renderer.destroy();
            H.discardElement(this.container);
        }
        H.clearTimeout(this.hideTimer);
        H.clearTimeout(this.tooltipTimeout);
    },

    /**
     * Moves the tooltip with a soft animation to a new position.
     *
     * @function Highcharts.Tooltip#move
     *
     * @param {number} x
     *
     * @param {number} y
     *
     * @param {number} anchorX
     *
     * @param {number} anchorY
     */
    move: function (x, y, anchorX, anchorY) {
        var tooltip = this,
            now = tooltip.now,
            animate = tooltip.options.animation !== false &&
                !tooltip.isHidden &&
                // When we get close to the target position, abort animation and
                // land on the right place (#3056)
                (Math.abs(x - now.x) > 1 || Math.abs(y - now.y) > 1),
            skipAnchor = tooltip.followPointer || tooltip.len > 1;

        // Get intermediate values for animation
        extend(now, {
            x: animate ? (2 * now.x + x) / 3 : x,
            y: animate ? (now.y + y) / 2 : y,
            anchorX: skipAnchor ?
                undefined :
                animate ? (2 * now.anchorX + anchorX) / 3 : anchorX,
            anchorY: skipAnchor ?
                undefined :
                animate ? (now.anchorY + anchorY) / 2 : anchorY
        });

        // Move to the intermediate value
        tooltip.getLabel().attr(now);


        // Run on next tick of the mouse tracker
        if (animate) {

            // Never allow two timeouts
            H.clearTimeout(this.tooltipTimeout);

            // Set the fixed interval ticking for the smooth tooltip
            this.tooltipTimeout = setTimeout(function () {
                // The interval function may still be running during destroy,
                // so check that the chart is really there before calling.
                if (tooltip) {
                    tooltip.move(x, y, anchorX, anchorY);
                }
            }, 32);

        }
    },

    /**
     * Hides the tooltip with a fade out animation.
     *
     * @function Highcharts.Tooltip#hide
     *
     * @param {number} [delay]
     *        The fade out in milliseconds. If no value is provided the value
     *        of the tooltip.hideDelay option is used. A value of 0 disables
     *        the fade out animation.
     */
    hide: function (delay) {
        var tooltip = this;
        // disallow duplicate timers (#1728, #1766)
        H.clearTimeout(this.hideTimer);
        delay = pick(delay, this.options.hideDelay, 500);
        if (!this.isHidden) {
            this.hideTimer = syncTimeout(function () {
                tooltip.getLabel()[delay ? 'fadeOut' : 'hide']();
                tooltip.isHidden = true;
            }, delay);
        }
    },

    /**
     * Extendable method to get the anchor position of the tooltip
     * from a point or set of points
     *
     * @private
     * @function Highcharts.Tooltip#getAnchor
     *
     * @param {Array<Highchart.Points>} points
     *
     * @param {global.Event} [mouseEvent]
     */
    getAnchor: function (points, mouseEvent) {
        var ret,
            chart = this.chart,
            pointer = chart.pointer,
            inverted = chart.inverted,
            plotTop = chart.plotTop,
            plotLeft = chart.plotLeft,
            plotX = 0,
            plotY = 0,
            yAxis,
            xAxis;

        points = splat(points);

        // When tooltip follows mouse, relate the position to the mouse
        if (this.followPointer && mouseEvent) {
            if (mouseEvent.chartX === undefined) {
                mouseEvent = pointer.normalize(mouseEvent);
            }
            ret = [
                mouseEvent.chartX - chart.plotLeft,
                mouseEvent.chartY - plotTop
            ];
        // Pie uses a special tooltipPos
        } else if (points[0].tooltipPos) {
            ret = points[0].tooltipPos;
        // When shared, use the average position
        } else {
            each(points, function (point) {
                yAxis = point.series.yAxis;
                xAxis = point.series.xAxis;
                plotX += point.plotX +
                    (!inverted && xAxis ? xAxis.left - plotLeft : 0);
                plotY +=
                    (
                        point.plotLow ?
                            (point.plotLow + point.plotHigh) / 2 :
                            point.plotY
                    ) +
                    (!inverted && yAxis ? yAxis.top - plotTop : 0); // #1151
            });

            plotX /= points.length;
            plotY /= points.length;

            ret = [
                inverted ? chart.plotWidth - plotY : plotX,
                this.shared && !inverted && points.length > 1 && mouseEvent ?
                    // place shared tooltip next to the mouse (#424)
                    mouseEvent.chartY - plotTop :
                    inverted ? chart.plotHeight - plotX : plotY
            ];
        }

        return map(ret, Math.round);
    },

    /**
     * Place the tooltip in a chart without spilling over
     * and not covering the point it self.
     *
     * @private
     * @function Highcharts.Tooltip#getPosition
     *
     * @param {number} boxWidth
     *
     * @param {number} boxHeight
     *
     * @param {Highcharts.Point} point
     *
     * @return {*}
     */
    getPosition: function (boxWidth, boxHeight, point) {

        var chart = this.chart,
            distance = this.distance,
            ret = {},
            // Don't use h if chart isn't inverted (#7242)
            h = (chart.inverted && point.h) || 0, // #4117
            swapped,
            outside = this.outside,
            outerWidth = outside ?
                // substract distance to prevent scrollbars
                doc.documentElement.clientWidth - 2 * distance :
                chart.chartWidth,
            outerHeight = outside ?
                Math.max(
                    doc.body.scrollHeight,
                    doc.documentElement.scrollHeight,
                    doc.body.offsetHeight,
                    doc.documentElement.offsetHeight,
                    doc.documentElement.clientHeight
                ) :
                chart.chartHeight,
            chartPosition = chart.pointer.chartPosition,
            first = [
                'y',
                outerHeight,
                boxHeight,
                (outside ? chartPosition.top - distance : 0) +
                    point.plotY + chart.plotTop,
                outside ? 0 : chart.plotTop,
                outside ? outerHeight : chart.plotTop + chart.plotHeight
            ],
            second = [
                'x',
                outerWidth,
                boxWidth,
                (outside ? chartPosition.left - distance : 0) +
                    point.plotX + chart.plotLeft,
                outside ? 0 : chart.plotLeft,
                outside ? outerWidth : chart.plotLeft + chart.plotWidth
            ],
            // The far side is right or bottom
            preferFarSide = !this.followPointer && pick(
                point.ttBelow,
                !chart.inverted === !!point.negative
            ), // #4984

            /*
             * Handle the preferred dimension. When the preferred dimension is
             * tooltip on top or bottom of the point, it will look for space
             * there.
             *
             * @private
             */
            firstDimension = function (
                dim,
                outerSize,
                innerSize,
                point,
                min,
                max
            ) {
                var roomLeft = innerSize < point - distance,
                    roomRight = point + distance + innerSize < outerSize,
                    alignedLeft = point - distance - innerSize,
                    alignedRight = point + distance;

                if (preferFarSide && roomRight) {
                    ret[dim] = alignedRight;
                } else if (!preferFarSide && roomLeft) {
                    ret[dim] = alignedLeft;
                } else if (roomLeft) {
                    ret[dim] = Math.min(
                        max - innerSize,
                        alignedLeft - h < 0 ? alignedLeft : alignedLeft - h
                    );
                } else if (roomRight) {
                    ret[dim] = Math.max(
                        min,
                        alignedRight + h + innerSize > outerSize ?
                            alignedRight :
                            alignedRight + h
                    );
                } else {
                    return false;
                }
            },

            /*
             * Handle the secondary dimension. If the preferred dimension is
             * tooltip on top or bottom of the point, the second dimension is to
             * align the tooltip above the point, trying to align center but
             * allowing left or right align within the chart box.
             *
             * @private
             */
            secondDimension = function (dim, outerSize, innerSize, point) {
                var retVal;

                // Too close to the edge, return false and swap dimensions
                if (point < distance || point > outerSize - distance) {
                    retVal = false;
                // Align left/top
                } else if (point < innerSize / 2) {
                    ret[dim] = 1;
                // Align right/bottom
                } else if (point > outerSize - innerSize / 2) {
                    ret[dim] = outerSize - innerSize - 2;
                // Align center
                } else {
                    ret[dim] = point - innerSize / 2;
                }
                return retVal;
            },

            /*
             * Swap the dimensions
             */
            swap = function (count) {
                var temp = first;
                first = second;
                second = temp;
                swapped = count;
            },
            run = function () {
                if (firstDimension.apply(0, first) !== false) {
                    if (
                        secondDimension.apply(0, second) === false &&
                        !swapped
                    ) {
                        swap(true);
                        run();
                    }
                } else if (!swapped) {
                    swap(true);
                    run();
                } else {
                    ret.x = ret.y = 0;
                }
            };

        // Under these conditions, prefer the tooltip on the side of the point
        if (chart.inverted || this.len > 1) {
            swap();
        }
        run();

        return ret;

    },

    /**
     * In case no user defined formatter is given, this will be used. Note that
     * the context here is an object holding point, series, x, y etc.
     *
     * @private
     * @function Highcharts.Tooltip#defaultFormatter
     *
     * @param {Highcharts.Tooltip} tooltip
     *
     * @return {Array<string>}
     */
    defaultFormatter: function (tooltip) {
        var items = this.points || splat(this),
            s;

        // Build the header
        s = [tooltip.tooltipFooterHeaderFormatter(items[0])];

        // build the values
        s = s.concat(tooltip.bodyFormatter(items));

        // footer
        s.push(tooltip.tooltipFooterHeaderFormatter(items[0], true));

        return s;
    },

    /**
     * Refresh the tooltip's text and position.
     *
     * @function Highcharts.Tooltip#refresh
     *
     * @param {Highcharts.Point|Array<Highcharts.Point>} pointOrPoints
     *        Either a point or an array of points.
     *
     * @param {global.Event} [mouseEvent]
     *        Mouse event, that is responsible for the refresh and should be
     *        used for the tooltip update.
     */
    refresh: function (pointOrPoints, mouseEvent) {
        var tooltip = this,
            label,
            options = tooltip.options,
            x,
            y,
            point = pointOrPoints,
            anchor,
            textConfig = {},
            text,
            pointConfig = [],
            formatter = options.formatter || tooltip.defaultFormatter,
            shared = tooltip.shared,
            currentSeries;

        if (!options.enabled) {
            return;
        }

        H.clearTimeout(this.hideTimer);

        // get the reference point coordinates (pie charts use tooltipPos)
        tooltip.followPointer = splat(point)[0].series.tooltipOptions
            .followPointer;
        anchor = tooltip.getAnchor(point, mouseEvent);
        x = anchor[0];
        y = anchor[1];

        // shared tooltip, array is sent over
        if (shared && !(point.series && point.series.noSharedTooltip)) {
            each(point, function (item) {
                item.setState('hover');

                pointConfig.push(item.getLabelConfig());
            });

            textConfig = {
                x: point[0].category,
                y: point[0].y
            };
            textConfig.points = pointConfig;
            point = point[0];

        // single point tooltip
        } else {
            textConfig = point.getLabelConfig();
        }
        this.len = pointConfig.length; // #6128
        text = formatter.call(textConfig, tooltip);

        // register the current series
        currentSeries = point.series;
        this.distance = pick(currentSeries.tooltipOptions.distance, 16);

        // update the inner HTML
        if (text === false) {
            this.hide();
        } else {

            label = tooltip.getLabel();

            // show it
            if (tooltip.isHidden) {
                label.attr({
                    opacity: 1
                }).show();
            }

            // update text
            if (tooltip.split) {
                this.renderSplit(text, splat(pointOrPoints));
            } else {

                // Prevent the tooltip from flowing over the chart box (#6659)
                
                    label.css({
                        width: this.chart.spacingBox.width
                    });
                

                label.attr({
                    text: text && text.join ? text.join('') : text
                });

                // Set the stroke color of the box to reflect the point
                label.removeClass(/highcharts-color-[\d]+/g)
                    .addClass(
                        'highcharts-color-' +
                        pick(point.colorIndex, currentSeries.colorIndex)
                    );

                

                tooltip.updatePosition({
                    plotX: x,
                    plotY: y,
                    negative: point.negative,
                    ttBelow: point.ttBelow,
                    h: anchor[2] || 0
                });
            }

            this.isHidden = false;
        }
    },

    /**
     * Render the split tooltip. Loops over each point's text and adds
     * a label next to the point, then uses the distribute function to
     * find best non-overlapping positions.
     *
     * @private
     * @function Highcharts.Tooltip#renderSplit
     *
     * @param {Array<Highcharts.Label>} labels
     *
     * @param {Array<Highcharts.Point>} points
     */
    renderSplit: function (labels, points) {
        var tooltip = this,
            boxes = [],
            chart = this.chart,
            ren = chart.renderer,
            rightAligned = true,
            options = this.options,
            headerHeight = 0,
            headerTop,
            tooltipLabel = this.getLabel(),
            distributionBoxTop = chart.plotTop;

        // Graceful degradation for legacy formatters
        if (H.isString(labels)) {
            labels = [false, labels];
        }
        // Create the individual labels for header and points, ignore footer
        each(labels.slice(0, points.length + 1), function (str, i) {
            if (str !== false) {
                var point = points[i - 1] ||
                        // Item 0 is the header. Instead of this, we could also
                        // use the crosshair label
                        { isHeader: true, plotX: points[0].plotX },
                    owner = point.series || tooltip,
                    tt = owner.tt,
                    series = point.series || {},
                    colorClass = 'highcharts-color-' + pick(
                        point.colorIndex,
                        series.colorIndex,
                        'none'
                    ),
                    target,
                    x,
                    bBox,
                    boxWidth;

                // Store the tooltip referance on the series
                if (!tt) {
                    owner.tt = tt = ren.label(
                            null,
                            null,
                            null,
                            'callout',
                            null,
                            null,
                            options.useHTML
                        )
                        .addClass(
                            'highcharts-tooltip-box ' + colorClass +
                            (point.isHeader ? ' highcharts-tooltip-header' : '')
                        )
                        .attr({
                            'padding': options.padding,
                            'r': options.borderRadius
                            
                        })
                        .add(tooltipLabel);
                }

                tt.isActive = true;
                tt.attr({
                    text: str
                });
                

                // Get X position now, so we can move all to the other side in
                // case of overflow
                bBox = tt.getBBox();
                boxWidth = bBox.width + tt.strokeWidth();
                if (point.isHeader) {
                    headerHeight = bBox.height;
                    if (chart.xAxis[0].opposite) {
                        headerTop = true;
                        distributionBoxTop -= headerHeight;
                    }
                    x = Math.max(
                        0, // No left overflow
                        Math.min(
                            point.plotX + chart.plotLeft - boxWidth / 2,
                            // No right overflow (#5794)
                            chart.chartWidth +
                            (
                                // Scrollable plot area
                                chart.scrollablePixels ?
                                    chart.scrollablePixels - chart.marginRight :
                                    0
                            ) -
                            boxWidth
                        )
                    );
                } else {
                    x = point.plotX + chart.plotLeft -
                        pick(options.distance, 16) - boxWidth;
                }


                // If overflow left, we don't use this x in the next loop
                if (x < 0) {
                    rightAligned = false;
                }

                // Prepare for distribution
                target = (point.series && point.series.yAxis &&
                    point.series.yAxis.pos) + (point.plotY || 0);
                target -= distributionBoxTop;

                if (point.isHeader) {
                    target = headerTop ?
                        -headerHeight :
                        chart.plotHeight + headerHeight;
                }
                boxes.push({
                    target: target,
                    rank: point.isHeader ? 1 : 0,
                    size: owner.tt.getBBox().height + 1,
                    point: point,
                    x: x,
                    tt: tt
                });
            }
        });

        // Clean previous run (for missing points)
        this.cleanSplit();

        // Distribute and put in place
        H.distribute(boxes, chart.plotHeight + headerHeight);
        each(boxes, function (box) {
            var point = box.point,
                series = point.series;

            // Put the label in place
            box.tt.attr({
                visibility: box.pos === undefined ? 'hidden' : 'inherit',
                x: (rightAligned || point.isHeader ?
                    box.x :
                    point.plotX + chart.plotLeft + pick(options.distance, 16)),
                y: box.pos + distributionBoxTop,
                anchorX: point.isHeader ?
                    point.plotX + chart.plotLeft :
                    point.plotX + series.xAxis.pos,
                anchorY: point.isHeader ?
                    chart.plotTop + chart.plotHeight / 2 :
                    point.plotY + series.yAxis.pos
            });
        });
    },

    /**
     * Find the new position and perform the move
     *
     * @private
     * @function Highcharts.Tooltip#updatePosition
     *
     * @param {Highcharts.Point} point
     */
    updatePosition: function (point) {
        var chart = this.chart,
            label = this.getLabel(),
            pos = (this.options.positioner || this.getPosition).call(
                this,
                label.width,
                label.height,
                point
            ),
            anchorX = point.plotX + chart.plotLeft,
            anchorY = point.plotY + chart.plotTop,
            pad;

        // Set the renderer size dynamically to prevent document size to change
        if (this.outside) {
            pad = (this.options.borderWidth || 0) + 2 * this.distance;
            this.renderer.setSize(
                label.width + pad,
                label.height + pad,
                false
            );
            anchorX += chart.pointer.chartPosition.left - pos.x;
            anchorY += chart.pointer.chartPosition.top - pos.y;
        }

        // do the move
        this.move(
            Math.round(pos.x),
            Math.round(pos.y || 0), // can be undefined (#3977)
            anchorX,
            anchorY
        );
    },

    /**
     * Get the optimal date format for a point, based on a range.
     *
     * @private
     * @function Highcharts.Tooltip#getDateFormat
     *
     * @param {number} range
     *        The time range
     *
     * @param {number|Date} date
     *        The date of the point in question
     *
     * @param {number} startOfWeek
     *        An integer representing the first day of the week, where 0 is
     *        Sunday.
     *
     * @param {Highcharts.Dictionary<string>} dateTimeLabelFormats
     *        A map of time units to formats.
     *
     * @return {string}
     *         The optimal date format for a point.
     */
    getDateFormat: function (range, date, startOfWeek, dateTimeLabelFormats) {
        var time = this.chart.time,
            dateStr = time.dateFormat('%m-%d %H:%M:%S.%L', date),
            format,
            n,
            blank = '01-01 00:00:00.000',
            strpos = {
                millisecond: 15,
                second: 12,
                minute: 9,
                hour: 6,
                day: 3
            },
            lastN = 'millisecond'; // for sub-millisecond data, #4223
        for (n in timeUnits) {

            // If the range is exactly one week and we're looking at a
            // Sunday/Monday, go for the week format
            if (
                range === timeUnits.week &&
                +time.dateFormat('%w', date) === startOfWeek &&
                dateStr.substr(6) === blank.substr(6)
            ) {
                n = 'week';
                break;
            }

            // The first format that is too great for the range
            if (timeUnits[n] > range) {
                n = lastN;
                break;
            }

            // If the point is placed every day at 23:59, we need to show
            // the minutes as well. #2637.
            if (
                strpos[n] &&
                dateStr.substr(strpos[n]) !== blank.substr(strpos[n])
            ) {
                break;
            }

            // Weeks are outside the hierarchy, only apply them on
            // Mondays/Sundays like in the first condition
            if (n !== 'week') {
                lastN = n;
            }
        }

        if (n) {
            format = time.resolveDTLFormat(dateTimeLabelFormats[n]).main;
        }

        return format;
    },

    /**
     * Get the best X date format based on the closest point range on the axis.
     *
     * @private
     * @function Highcharts.Tooltip#getXDateFormat
     *
     * @param {Highcharts.Point} point
     *
     * @param {Highcharts.TooltipOptions} options
     *
     * @param {Highcharts.Axis} xAxis
     *
     * @return {string}
     */
    getXDateFormat: function (point, options, xAxis) {
        var xDateFormat,
            dateTimeLabelFormats = options.dateTimeLabelFormats,
            closestPointRange = xAxis && xAxis.closestPointRange;

        if (closestPointRange) {
            xDateFormat = this.getDateFormat(
                closestPointRange,
                point.x,
                xAxis.options.startOfWeek,
                dateTimeLabelFormats
            );
        } else {
            xDateFormat = dateTimeLabelFormats.day;
        }

        return xDateFormat || dateTimeLabelFormats.year; // #2546, 2581
    },

    /**
     * Format the footer/header of the tooltip
     * #3397: abstraction to enable formatting of footer and header
     *
     * @private
     * @function Highcharts.Tooltip#tooltipFooterHeaderFormatter
     *
     * @param {*} labelConfig
     *
     * @param {boolean} isFooter
     *
     * @return {string}
     */
    tooltipFooterHeaderFormatter: function (labelConfig, isFooter) {
        var footOrHead = isFooter ? 'footer' : 'header',
            series = labelConfig.series,
            tooltipOptions = series.tooltipOptions,
            xDateFormat = tooltipOptions.xDateFormat,
            xAxis = series.xAxis,
            isDateTime = (
                xAxis &&
                xAxis.options.type === 'datetime' &&
                isNumber(labelConfig.key)
            ),
            formatString = tooltipOptions[footOrHead + 'Format'];

        // Guess the best date format based on the closest point distance (#568,
        // #3418)
        if (isDateTime && !xDateFormat) {
            xDateFormat = this.getXDateFormat(
                labelConfig,
                tooltipOptions,
                xAxis
            );
        }

        // Insert the footer date format if any
        if (isDateTime && xDateFormat) {
            each(
                (labelConfig.point && labelConfig.point.tooltipDateKeys) ||
                    ['key'],
                function (key) {
                    formatString = formatString.replace(
                        '{point.' + key + '}',
                        '{point.' + key + ':' + xDateFormat + '}'
                    );
                }
            );
        }

        return format(formatString, {
            point: labelConfig,
            series: series
        }, this.chart.time);
    },

    /**
     * Build the body (lines) of the tooltip by iterating over the items and
     * returning one entry for each item, abstracting this functionality allows
     * to easily overwrite and extend it.
     *
     * @private
     * @function Highcharts.Tooltip#bodyFormatter
     *
     * @param {Array<Highcharts.Point>} items
     *
     * @return {string}
     */
    bodyFormatter: function (items) {
        return map(items, function (item) {
            var tooltipOptions = item.series.tooltipOptions;
            return (
                tooltipOptions[
                    (item.point.formatPrefix || 'point') + 'Formatter'
                ] ||
                item.point.tooltipFormatter
            ).call(
                item.point,
                tooltipOptions[(item.point.formatPrefix || 'point') + 'Format']
            );
        });
    }

};