/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-05-16 14:36:50 (f9be68accb407158ba2b1be2c226a6ce1f649314)
*/
/**
 * Labels is a mixin to the Series class. Labels methods are implemented
 * in each of the Series (Pie, Bar, etc) for label creation and placement.
 *
 * The 2 methods that must be implemented by the Series are:
 *
 * - {@link #onCreateLabel}
 * - {@link #onPlaceLabel}
 *
 * The application can override these methods to control the style and
 * location of the labels. For instance, to display the labels in green and
 * add a '+' symbol when the value of a Line series exceeds 50:
 *
 *      Ext.define('Ext.chart.series.MyLine', {
 *          extend: 'Ext.chart.series.Line',
 *          alias: ['series.myline', 'Ext.chart.series.MyLine'],
 *          type: 'MYLINE',
 *     
 *          onPlaceLabel: function(label, storeItem, item, i, display, animate){
 *              if (storeItem.data.y >= 50) {
 *                  label.setAttributes({
 *                      fill: '#080',
 *                      text: "+" + storeItem.data.y
 *                  }, true);
 *              }
 *              return this.callParent(arguments);
 *          }
 *      });
 *
 * Note that for simple effects, like the example above, it is simpler
 * for the application to provide a label.renderer function in the config:
 *
 *       label: {
 *           renderer: function(value, label, storeItem, item, i, display, animate, index) {
 *               if (value >= 50) {
 *                   label.setAttributes({fill:'#080'});
 *                   value = "+" + value;
 *               }
 *               return value;
 *           }
 *       }
 *
 * The rule of thumb is that to customize the value and modify simple visual attributes, it
 * is simpler to use a renderer function, while overridding `onCreateLabel` and `onPlaceLabel`
 * allows the application to take entire control over the labels.
 * 
 */
Ext.define('Ext.chart.Label', {

    /* Begin Definitions */

    requires: ['Ext.draw.Color'],

    /* End Definitions */

    /**
     * @method onCreateLabel
     * @template
     * 
     * Called each time a new label is created.
     * 
     * **Note:** This method must be implemented in Series that mixes
     * in this Label mixin.
     * 
     * @param {Ext.data.Model} storeItem The element of the store that is
     * related to the sprite.
     * @param {Object} item The item related to the sprite.
     * An item is an object containing the position of the shape
     * used to describe the visualization and also pointing to the
     * actual shape (circle, rectangle, path, etc).
     * @param {Number} i The index of the element created
     * (i.e the first created label, second created label, etc).
     * @param {String} display The label.display type.
     * May be `false` if the label is hidden
     * @return {Ext.draw.Sprite} The created sprite that will draw the label.
     */
    
    /**
     * @method onPlaceLabel
     * @template
     * 
     * Called for updating the position of the label.
     * 
     * **Note:** This method must be implemented in Series that mixes
     * in this Label mixin.
     * 
     * @param {Ext.draw.Sprite} label The sprite that draws the label.
     * @param {Ext.data.Model} storeItem The element of the store
     * that is related to the sprite.
     * @param {Object} item The item related to the
     * sprite. An item is an object containing the position of
     * the shape used to describe the visualization and also
     * pointing to the actual shape (circle, rectangle, path, etc).
     * @param {Number} i The index of the element to be updated
     * (i.e. whether it is the first, second, third from the
     * labelGroup)
     * @param {String} display The label.display type.
     * May be `false` if the label is hidden
     * @param {Boolean} animate A boolean value to set or unset
     * animations for the labels.
     * @param {Number} index The series index.
     */
    
    /**
     * @cfg {Object} label
     * Object with the following properties:
     *
     * @cfg {String} label.display
     *
     * Specifies the presence and position of the labels. The possible values depend on the chart type. 
     * For Line and Scatter charts: "under" | "over" | "rotate".
     * For Bar and Column charts: "insideStart" | "insideEnd" | "outside".
     * For Pie charts: "outside" | "rotate".
     * For all charts: "none" hides the labels and "middle" is reserved for future use.
     * On stacked Bar and stacked Column charts, if 'stackedDisplay' is set, the values
     * "over" or "under" can be passed internally to {@link #onCreateLabel} and {@link #onPlaceLabel}
     * (however they cannot be used by the application as config values for label.display).
     *
     * Default value: 'none'.
     *
     * @cfg {String} label.stackedDisplay
     *
     * The type of label we want to display as a summary on a stacked
     * bar or a stacked column.  If set to 'total', the total amount
     * of all the stacked values is displayed on top of the column.
     * If set to 'balances', the total amount of the positive values
     * is displayed on top of the column and the total amount of the
     * negative values is displayed at the bottom.
     *
     * Default value: 'none'.
     *
     * @cfg {String} label.color
     *
     * The color of the label text.
     *
     * Default value: '#000' (black).
     *
     * @cfg {Boolean} label.contrast
     *
     * True to render the label in contrasting color with the backround of a column
     * in a Bar chart or of a slice in a Pie chart. The label color should be specified
     * in hex values (eg. '#f00' or '#ff0000'), not as a CSS color name (eg. 'red').
     *
     * Default value: false.
     *
     * @cfg {String|String[]} label.field
     *
     * The name(s) of the field(s) to be displayed in the labels. If your chart has 3 series
     * that correspond to the fields 'a', 'b', and 'c' of your model and you only want to
     * display labels for the series 'c', you must still provide an array `[null, null, 'c']`.
     *
     * Default value: 'name'.
     *
     * @cfg {Number} label.minMargin
     *
     * Specifies the minimum distance from a label to the origin of
     * the visualization.  This parameter is useful when using
     * PieSeries width variable pie slice lengths.
     *
     * Default value: 50.
     *
     * @cfg {String} label.font
     *
     * The font used for the labels.
     *
     * Default value: `"11px Helvetica, sans-serif"`.
     *
     * @cfg {String} label.orientation
     *
     * Either "horizontal" or "vertical".
     *
     * Default value: `"horizontal"`.
     *
     * @cfg {Function} label.renderer
     *
     * Optional function for formatting the label into a displayable value.
     *
     * The arguments to the method are:
     *
     *   - *`value`* The value
     *   - *`label`*, *`storeItem`*, *`item`*, *`i`*, *`display`*, *`animate`*, *`index`*
     *
     *     Same arguments as {@link #onPlaceLabel}.
     *
     *     Default value: `function(v) { return v; }`
     */

    // @private a regex to parse url type colors.
    colorStringRe: /url\s*\(\s*#([^\/)]+)\s*\)/,

    // @private the mixin constructor. Used internally by Series.
    constructor: function(config) {
        var me = this;
        me.label = Ext.applyIf(me.label || {},
        {
            display: "none",
            stackedDisplay: "none",
            color: "#000",
            field: "name",
            minMargin: 50,
            font: "11px Helvetica, sans-serif",
            orientation: "horizontal",
            renderer: Ext.identityFn
        });

        if (me.label.display !== 'none') {
            me.labelsGroup = me.chart.surface.getGroup(me.seriesId + '-labels');
        }
    },

    // @private a method to render all labels in the labelGroup
    renderLabels: function() {
        var me = this,
            chart = me.chart,
            gradients = chart.gradients,
            items = me.items,
            animate = chart.animate,
            config = me.label,
            display = config.display,
            stackedDisplay = config.stackedDisplay,
            format = config.renderer,
            color = config.color,
            field = [].concat(config.field),
            group = me.labelsGroup,
            groupLength = (group || 0) && group.length,
            store = me.chart.getChartStore(),
            len = store.getCount(),
            itemLength = (items || 0) && items.length,
            ratio = itemLength / len,
            gradientsCount = (gradients || 0) && gradients.length,
            Color = Ext.draw.Color,
            hides = [],
            gradient, i, count, groupIndex, index, j, k, colorStopTotal, colorStopIndex, colorStop, item, label,
            storeItem, sprite, spriteColor, spriteBrightness, labelColor, colorString,
            total, totalPositive, totalNegative, topText, bottomText;

        if (display == 'none' || !group) {
            return;
        }
        // no items displayed, hide all labels
        if(itemLength == 0){
            while(groupLength--) {
                hides.push(groupLength);
            }
        } else {
            for (i = 0, count = 0, groupIndex = 0; i < len; i++) {
                index = 0;
                for (j = 0; j < ratio; j++) {
                    item = items[count];
                    label = group.getAt(groupIndex);
                    storeItem = store.getAt(i);
                    //check the excludes
                    while(this.__excludes && this.__excludes[index]) {
                        index++;
                    }

                    if (!item && label) {
                        label.hide(true);
                        groupIndex++;
                    }

                    if (item && field[j]) {
                        if (!label) {
                            label = me.onCreateLabel(storeItem, item, i, display);
                            if (!label) {
                                break;
                            }
                        }

                        // set color (the app can override it in onPlaceLabel)
                        label.setAttributes({
                            fill: String(color)
                        }, true);

                        // position the label
                        me.onPlaceLabel(label, storeItem, item, i, display, animate, index);
                        groupIndex++;

                        // set contrast
                        if (config.contrast && item.sprite) {
                            sprite = item.sprite;
                            //set the color string to the color to be set, only read the
                            // _endStyle/_to if we're animating, otherwise they're not relevant
                            if (animate && sprite._endStyle) {
                                colorString = sprite._endStyle.fill;
                            } else if (animate && sprite._to) {
                                colorString = sprite._to.fill;
                            } else {
                                colorString = sprite.attr.fill;
                            }
                            colorString = colorString || sprite.attr.fill;

                            spriteColor = Color.fromString(colorString);
                            //color wasn't parsed property maybe because it's a gradient id
                            if (colorString && !spriteColor) {
                                colorString = colorString.match(me.colorStringRe)[1];
                                for (k = 0; k < gradientsCount; k++) {
                                    gradient = gradients[k];
                                    if (gradient.id == colorString) {
                                        //avg color stops
                                        colorStop = 0; colorStopTotal = 0;
                                        for (colorStopIndex in gradient.stops) {
                                            colorStop++;
                                            colorStopTotal += Color.fromString(gradient.stops[colorStopIndex].color).getGrayscale();
                                        }
                                        spriteBrightness = (colorStopTotal / colorStop) / 255;
                                        break;
                                    }
                                }
                            }
                            else {
                                spriteBrightness = spriteColor.getGrayscale() / 255;
                            }
                            if (label.isOutside) {
                                spriteBrightness = 1;
                            }
                            labelColor = Color.fromString(label.attr.fill || label.attr.color).getHSL();
                            labelColor[2] = spriteBrightness > 0.5 ? 0.2 : 0.8;
                            label.setAttributes({
                                fill: String(Color.fromHSL.apply({}, labelColor))
                            }, true);
                        }

                        // display totals on stacked charts
                        if (me.stacked && stackedDisplay && (item.totalPositiveValues || item.totalNegativeValues)) {
                            totalPositive = (item.totalPositiveValues || 0);
                            totalNegative = (item.totalNegativeValues || 0);
                            total = totalPositive + totalNegative;

                            if (stackedDisplay == 'total') {
                                topText = format(total);
                            } else if (stackedDisplay == 'balances') {
                                if (totalPositive == 0 && totalNegative == 0) {
                                    topText = format(0);
                                } else {
                                    topText = format(totalPositive);
                                    bottomText = format(totalNegative);
                                }
                            }

                            if (topText) {
                                label = group.getAt(groupIndex);
                                if (!label) {
                                    label = me.onCreateLabel(storeItem, item, i, 'over');
                                }
                                labelColor = Color.fromString(label.attr.color || label.attr.fill).getHSL();
                                label.setAttributes({
                                    text: topText,
                                    style: config.font,
                                    fill: String(Color.fromHSL.apply({}, labelColor))
                                }, true);
                                me.onPlaceLabel(label, storeItem, item, i, 'over', animate, index);
                                groupIndex ++;
                            }

                            if (bottomText) {
                                label = group.getAt(groupIndex);
                                if (!label) {
                                    label = me.onCreateLabel(storeItem, item, i, 'under');
                                }
                                labelColor = Color.fromString(label.attr.color || label.attr.fill).getHSL();
                                label.setAttributes({
                                    text: bottomText,
                                    style: config.font,
                                    fill: String(Color.fromHSL.apply({}, labelColor))
                                }, true);
                                me.onPlaceLabel(label, storeItem, item, i, 'under', animate, index);
                                groupIndex ++;
                            }
                        }
                    }
                    count++;
                    index++;
                }
            }
            groupLength = group.length;
        
            while(groupLength > groupIndex){
                hides.push(groupIndex);
                groupIndex++;
           }
        }
        me.hideLabels(hides);
    },

    hideLabels: function(hides){
        var labelsGroup = this.labelsGroup,
            hlen = !!hides && hides.length;

        if (!labelsGroup) {
            return;
        }

        if (hlen === false) {
            hlen = labelsGroup.getCount();
            while (hlen--) {
              labelsGroup.getAt(hlen).hide(true);
            }
        } else {
            while(hlen--) {
                labelsGroup.getAt(hides[hlen]).hide(true);
            }
        }
    }
});
