/**
 * Slider which supports vertical or horizontal orientation, keyboard adjustments, configurable snapping, axis clicking
 * and animation. Can be added as an item to any container.
 *
 * Sliders can be created with more than one thumb handle by passing an array of values instead of a single one:
 *
 *     @example
 *     Ext.create('Ext.slider.Multi', {
 *         width: 200,
 *         values: [25, 50, 75],
 *         increment: 5,
 *         minValue: 0,
 *         maxValue: 100,
 *
 *         // this defaults to true, setting to false allows the thumbs to pass each other
 *         constrainThumbs: false,
 *         renderTo: Ext.getBody()
 *     });
 */
Ext.define('Ext.slider.Multi', {
    extend: 'Ext.form.field.Base',
    alias: 'widget.multislider',
    alternateClassName: 'Ext.slider.MultiSlider',

    requires: [
        'Ext.slider.Thumb',
        'Ext.slider.Tip',
        'Ext.Number',
        'Ext.util.Format',
        'Ext.Template',
        'Ext.layout.component.field.Slider'
    ],

    childEls: [
        'endEl', 'innerEl'
    ],

    // note: {id} here is really {inputId}, but {cmpId} is available
    fieldSubTpl: [
        '<div id="{id}" class="' + Ext.baseCSSPrefix + 'slider {fieldCls} {vertical}" aria-valuemin="{minValue}" aria-valuemax="{maxValue}" aria-valuenow="{value}" aria-valuetext="{value}">',
            '<div id="{cmpId}-endEl" class="' + Ext.baseCSSPrefix + 'slider-end" role="presentation">',
                '<div id="{cmpId}-innerEl" class="' + Ext.baseCSSPrefix + 'slider-inner" role="presentation">',
                    '{%this.renderThumbs(out, values)%}',
                '</div>',
            '</div>',
        '</div>',
        {
            renderThumbs: function(out, values) {
                var me = values.$comp,
                    i = 0,
                    thumbs = me.thumbs,
                    len = thumbs.length,
                    thumb,
                    thumbConfig;

                for (; i < len; i++) {
                    thumb = thumbs[i];
                    thumbConfig = thumb.getElConfig();
                    thumbConfig.id = me.id + '-thumb-' + i;
                    Ext.DomHelper.generateMarkup(thumbConfig, out);
                }
            },
            disableFormats: true
        }
    ],

    /**
     * @cfg {Number} value
     * A value with which to initialize the slider. Setting this will only result in the creation
     * of a single slider thumb; if you want multiple thumbs then use the {@link #values} config instead.
     *
     * Defaults to #minValue.
     */

    /**
     * @cfg {Number[]} values
     * Array of Number values with which to initalize the slider. A separate slider thumb will be created for each value
     * in this array. This will take precedence over the single {@link #value} config.
     */

    /**
     * @cfg {Boolean} vertical
     * Orient the Slider vertically rather than horizontally.
     */
    vertical: false,

    /**
     * @cfg {Number} minValue
     * The minimum value for the Slider.
     */
    minValue: 0,

    /**
     * @cfg {Number} maxValue
     * The maximum value for the Slider.
     */
    maxValue: 100,

    /**
     * @cfg {Number/Boolean} decimalPrecision The number of decimal places to which to round the Slider's value.
     *
     * To disable rounding, configure as **false**.
     */
    decimalPrecision: 0,

    /**
     * @cfg {Number} keyIncrement
     * How many units to change the Slider when adjusting with keyboard navigation. If the increment
     * config is larger, it will be used instead.
     */
    keyIncrement: 1,

    /**
     * @cfg {Number} increment
     * How many units to change the slider when adjusting by drag and drop. Use this option to enable 'snapping'.
     */
    increment: 0,

    /**
     * @cfg {Boolean} [zeroBasedSnapping=false]
     * Set to `true` to calculate snap points based on {@link #increment}s from zero as opposed to
     * from this Slider's {@link #minValue}.
     *
     * By Default, valid snap points are calculated starting {@link #increment}s from the {@link #minValue}
     */

    /**
     * @private
     * @property {Number[]} clickRange
     * Determines whether or not a click to the slider component is considered to be a user request to change the value. Specified as an array of [top, bottom],
     * the click event's 'top' property is compared to these numbers and the click only considered a change request if it falls within them. e.g. if the 'top'
     * value of the click event is 4 or 16, the click is not considered a change request as it falls outside of the [5, 15] range
     */
    clickRange: [5,15],

    /**
     * @cfg {Boolean} clickToChange
     * Determines whether or not clicking on the Slider axis will change the slider.
     */
    clickToChange : true,

    /**
     * @cfg {Boolean} animate
     * Turn on or off animation.
     */
    animate: true,

    /**
     * @property {Boolean} dragging
     * True while the thumb is in a drag operation
     */
    dragging: false,

    /**
     * @cfg {Boolean} constrainThumbs
     * True to disallow thumbs from overlapping one another.
     */
    constrainThumbs: true,

    componentLayout: 'sliderfield',

    /**
     * @cfg {Object/Boolean} useTips
     * True to use an {@link Ext.slider.Tip} to display tips for the value. This option may also
     * provide a configuration object for an {@link Ext.slider.Tip}.
     */
    useTips : true,

    /**
     * @cfg {Function} [tipText=undefined]
     * A function used to display custom text for the slider tip.
     *
     * Defaults to null, which will use the default on the plugin.
     */
    tipText : null,

    ariaRole: 'slider',

    // private override
    initValue: function() {
        var me = this,
            extValue = Ext.value,
            // Fallback for initial values: values config -> value config -> minValue config -> 0
            values = extValue(me.values, [extValue(me.value, extValue(me.minValue, 0))]),
            i = 0,
            len = values.length;

        // Store for use in dirty check
        me.originalValue = values;

        // Add a thumb for each value
        for (; i < len; i++) {
            me.addThumb(values[i]);
        }
    },

    // private override
    initComponent : function() {
        var me = this,
            tipPlug,
            hasTip,
            p, pLen, plugins;

        /**
         * @property {Array} thumbs
         * Array containing references to each thumb
         */
        me.thumbs = [];

        me.keyIncrement = Math.max(me.increment, me.keyIncrement);

        me.addEvents(
            /**
             * @event beforechange
             * Fires before the slider value is changed. By returning false from an event handler, you can cancel the
             * event and prevent the slider from changing.
             * @param {Ext.slider.Multi} slider The slider
             * @param {Number} newValue The new value which the slider is being changed to.
             * @param {Number} oldValue The old value which the slider was previously.
             */
            'beforechange',

            /**
             * @event change
             * Fires when the slider value is changed.
             * @param {Ext.slider.Multi} slider The slider
             * @param {Number} newValue The new value which the slider has been changed to.
             * @param {Ext.slider.Thumb} thumb The thumb that was changed
             */
            'change',

            /**
             * @event changecomplete
             * Fires when the slider value is changed by the user and any drag operations have completed.
             * @param {Ext.slider.Multi} slider The slider
             * @param {Number} newValue The new value which the slider has been changed to.
             * @param {Ext.slider.Thumb} thumb The thumb that was changed
             */
            'changecomplete',

            /**
             * @event dragstart
             * Fires after a drag operation has started.
             * @param {Ext.slider.Multi} slider The slider
             * @param {Ext.EventObject} e The event fired from Ext.dd.DragTracker
             */
            'dragstart',

            /**
             * @event drag
             * Fires continuously during the drag operation while the mouse is moving.
             * @param {Ext.slider.Multi} slider The slider
             * @param {Ext.EventObject} e The event fired from Ext.dd.DragTracker
             */
            'drag',

            /**
             * @event dragend
             * Fires after the drag operation has completed.
             * @param {Ext.slider.Multi} slider The slider
             * @param {Ext.EventObject} e The event fired from Ext.dd.DragTracker
             */
            'dragend'
        );

        // Ensure that the maxValue is a snap point, and that the initial value is snapped.
        if (me.increment) {
            me.maxValue = Ext.Number.snapInRange(me.maxValue, me.increment, me.minValue);
            me.value = me.normalizeValue(me.value);
        }

        me.callParent();

        // only can use it if it exists.
        if (me.useTips) {
            if (Ext.isObject(me.useTips)) {
                tipPlug = Ext.apply({}, me.useTips);
            } else {
                tipPlug = me.tipText ? {getText: me.tipText} : {};    
            }

            plugins = me.plugins = me.plugins || [];
            pLen    = plugins.length;
            
            for (p = 0; p < pLen; p++) {
                if (plugins[p].isSliderTip) {
                    hasTip = true;
                    break;
                }
            }

            if (!hasTip) {
                me.plugins.push(new Ext.slider.Tip(tipPlug));
            }
        }
    },

    /**
     * Creates a new thumb and adds it to the slider
     * @param {Number} [value=0] The initial value to set on the thumb.
     * @return {Ext.slider.Thumb} The thumb
     */
    addThumb: function(value) {
        var me = this,
            thumb = new Ext.slider.Thumb({
                ownerCt     : me,
                ownerLayout : me.getComponentLayout(),
                value       : value,
                slider      : me,
                index       : me.thumbs.length,
                constrain   : me.constrainThumbs
            });

        me.thumbs.push(thumb);

        //render the thumb now if needed
        if (me.rendered) {
            thumb.render();
        }

        return thumb;
    },

    /**
     * @private
     * Moves the given thumb above all other by increasing its z-index. This is called when as drag
     * any thumb, so that the thumb that was just dragged is always at the highest z-index. This is
     * required when the thumbs are stacked on top of each other at one of the ends of the slider's
     * range, which can result in the user not being able to move any of them.
     * @param {Ext.slider.Thumb} topThumb The thumb to move to the top
     */
    promoteThumb: function(topThumb) {
        var thumbs = this.thumbs,
            ln = thumbs.length,
            zIndex, thumb, i;

        for (i = 0; i < ln; i++) {
            thumb = thumbs[i];

            if (thumb == topThumb) {
                thumb.bringToFront();
            } else {
                thumb.sendToBack();
            }
        }
    },

    // private override
    getSubTplData : function() {
        var me = this;

        return Ext.apply(me.callParent(), {
            $comp: me,
            vertical: me.vertical ? Ext.baseCSSPrefix + 'slider-vert' : Ext.baseCSSPrefix + 'slider-horz',
            minValue: me.minValue,
            maxValue: me.maxValue,
            value: me.value
        });
    },

    onRender : function() {
        var me = this,
            thumbs = me.thumbs,
            len = thumbs.length,
            i = 0,
            thumb;

        me.callParent(arguments);

        for (i = 0; i < len; i++) {
            thumb = thumbs[i];
            thumb.el = me.el.getById(me.id + '-thumb-' + i);
            thumb.onRender();
        }
    },

    /**
     * @private
     * Adds keyboard and mouse listeners on this.el. Ignores click events on the internal focus element.
     */
    initEvents : function() {
        var me = this;
        me.mon(me.el, {
            scope    : me,
            mousedown: me.onMouseDown,
            keydown  : me.onKeyDown
        });
    },

    /**
     * @private
     * Given an `[x, y]` position within the slider's track (Points outside the slider's track are coerced to either the minimum or maximum value),
     * calculate how many pixels **from the slider origin** (left for horizontal Sliders and bottom for vertical Sliders) that point is.
     *
     * If the point is outside the range of the Slider's track, the return value is `undefined`
     * @param {Number[]} xy The point to calculate the track point for
     */
    getTrackpoint : function(xy) {
        var me = this,
            result,
            positionProperty,
            sliderTrack = me.innerEl,
            trackLength;

        if (me.vertical) {
            positionProperty = 'top';
            trackLength = sliderTrack.getHeight();
        } else {
            positionProperty = 'left';
            trackLength = sliderTrack.getWidth();
        }
        result = Ext.Number.constrain(sliderTrack.translatePoints(xy)[positionProperty], 0, trackLength);
        return me.vertical ? trackLength - result : result;
    },

    /**
     * @private
     * Mousedown handler for the slider. If the clickToChange is enabled and the click was not on the draggable 'thumb',
     * this calculates the new value of the slider and tells the implementation (Horizontal or Vertical) to move the thumb
     * @param {Ext.EventObject} e The click event
     */
    onMouseDown : function(e) {
        var me = this,
            thumbClicked = false,
            i = 0,
            thumbs = me.thumbs,
            len = thumbs.length,
            trackPoint;

        if (me.disabled) {
            return;
        }

        //see if the click was on any of the thumbs
        for (; i < len; i++) {
            thumbClicked = thumbClicked || e.target == thumbs[i].el.dom;
        }

        if (me.clickToChange && !thumbClicked) {
            trackPoint = me.getTrackpoint(e.getXY());
            if (trackPoint !== undefined) {
                me.onClickChange(trackPoint);
            }
        }
        me.focus();
    },

    /**
     * @private
     * Moves the thumb to the indicated position.
     * Only changes the value if the click was within this.clickRange.
     * @param {Number} trackPoint local pixel offset **from the origin** (left for horizontal and bottom for vertical) along the Slider's axis at which the click event occured.
     */
    onClickChange : function(trackPoint) {
        var me = this,
            thumb, index;

        // How far along the track *from the origin* was the click.
        // If vertical, the origin is the bottom of the slider track.

        //find the nearest thumb to the click event
        thumb = me.getNearest(trackPoint);
        if (!thumb.disabled) {
            index = thumb.index;
            me.setValue(index, Ext.util.Format.round(me.reversePixelValue(trackPoint), me.decimalPrecision), undefined, true);
        }
    },

    /**
     * @private
     * Returns the nearest thumb to a click event, along with its distance
     * @param {Number} trackPoint local pixel position along the Slider's axis to find the Thumb for
     * @return {Object} The closest thumb object and its distance from the click event
     */
    getNearest: function(trackPoint) {
        var me = this,
            clickValue = me.reversePixelValue(trackPoint),
            nearestDistance = (me.maxValue - me.minValue) + 5, //add a small fudge for the end of the slider
            nearest = null,
            thumbs = me.thumbs,
            i = 0,
            len = thumbs.length,
            thumb,
            value,
            dist;

        for (; i < len; i++) {
            thumb = me.thumbs[i];
            value = thumb.value;
            dist  = Math.abs(value - clickValue);

            if (Math.abs(dist <= nearestDistance)) {
                nearest = thumb;
                nearestDistance = dist;
            }
        }
        return nearest;
    },

    /**
     * @private
     * Handler for any keypresses captured by the slider. If the key is UP or RIGHT, the thumb is moved along to the right
     * by this.keyIncrement. If DOWN or LEFT it is moved left. Pressing CTRL moves the slider to the end in either direction
     * @param {Ext.EventObject} e The Event object
     */
    onKeyDown : function(e) {
        /*
         * The behaviour for keyboard handling with multiple thumbs is currently undefined.
         * There's no real sane default for it, so leave it like this until we come up
         * with a better way of doing it.
         */
        var me = this,
            k,
            val;

        if(me.disabled || me.thumbs.length !== 1) {
            e.preventDefault();
            return;
        }
        k = e.getKey();

        switch(k) {
            case e.UP:
            case e.RIGHT:
                e.stopEvent();
                val = e.ctrlKey ? me.maxValue : me.getValue(0) + me.keyIncrement;
                me.setValue(0, val, undefined, true);
            break;
            case e.DOWN:
            case e.LEFT:
                e.stopEvent();
                val = e.ctrlKey ? me.minValue : me.getValue(0) - me.keyIncrement;
                me.setValue(0, val, undefined, true);
            break;
            default:
                e.preventDefault();
        }
    },

    /**
     * @private
     * Returns a snapped, constrained value when given a desired value
     * @param {Number} value Raw number value
     * @return {Number} The raw value rounded to the correct d.p. and constrained within the set max and min values
     */
    normalizeValue : function(v) {
        var me = this,
            Num = Ext.Number,
            snapFn = Num[me.zeroBasedSnapping ? 'snap' : 'snapInRange'];

        v = snapFn.call(Num, v, me.increment, me.minValue, me.maxValue);
        v = Ext.util.Format.round(v, me.decimalPrecision);
        v = Ext.Number.constrain(v, me.minValue, me.maxValue);
        return v;
    },

    /**
     * Sets the minimum value for the slider instance. If the current value is less than the minimum value, the current
     * value will be changed.
     * @param {Number} val The new minimum value
     */
    setMinValue : function(val) {
        var me = this,
            i = 0,
            thumbs = me.thumbs,
            len = thumbs.length,
            t;

        me.minValue = val;
        if (me.rendered) {
            me.inputEl.dom.setAttribute('aria-valuemin', val);
        }

        for (; i < len; ++i) {
            t = thumbs[i];
            t.value = t.value < val ? val : t.value;
        }
        me.syncThumbs();
    },

    /**
     * Sets the maximum value for the slider instance. If the current value is more than the maximum value, the current
     * value will be changed.
     * @param {Number} val The new maximum value
     */
    setMaxValue : function(val) {
        var me = this,
            i = 0,
            thumbs = me.thumbs,
            len = thumbs.length,
            t;

        me.maxValue = val;
        if (me.rendered) {
            me.inputEl.dom.setAttribute('aria-valuemax', val);
        }

        for (; i < len; ++i) {
            t = thumbs[i];
            t.value = t.value > val ? val : t.value;
        }
        me.syncThumbs();
    },

    /**
     * Programmatically sets the value of the Slider. Ensures that the value is constrained within the minValue and
     * maxValue.
     * @param {Number} index Index of the thumb to move
     * @param {Number} value The value to set the slider to. (This will be constrained within minValue and maxValue)
     * @param {Boolean} [animate=true] Turn on or off animation
     */
    setValue : function(index, value, animate, changeComplete) {
        var me = this,
            thumb = me.thumbs[index];

        // ensures value is contstrained and snapped
        value = me.normalizeValue(value);

        if (value !== thumb.value && me.fireEvent('beforechange', me, value, thumb.value, thumb) !== false) {
            thumb.value = value;
            if (me.rendered) {
                // TODO this only handles a single value; need a solution for exposing multiple values to aria.
                // Perhaps this should go on each thumb element rather than the outer element.
                me.inputEl.set({
                    'aria-valuenow': value,
                    'aria-valuetext': value
                });

                thumb.move(me.calculateThumbPosition(value), Ext.isDefined(animate) ? animate !== false : me.animate);

                me.fireEvent('change', me, value, thumb);
                me.checkDirty();
                if (changeComplete) {
                    me.fireEvent('changecomplete', me, value, thumb);
                }
            }
        }
    },

    /**
     * @private
     * Given a value within this Slider's range, calculates a Thumb's percentage CSS position to map that value.
     */
    calculateThumbPosition : function(v) {
        return (v - this.minValue) / (this.maxValue - this.minValue) * 100;
    },

    /**
     * @private
     * Returns the ratio of pixels to mapped values. e.g. if the slider is 200px wide and maxValue - minValue is 100,
     * the ratio is 2
     * @return {Number} The ratio of pixels to mapped values
     */
    getRatio : function() {
        var me = this,
            trackLength = this.vertical ? this.innerEl.getHeight() : this.innerEl.getWidth(),
            valueRange = this.maxValue - this.minValue;
        return valueRange === 0 ? trackLength : (trackLength / valueRange);
    },

    /**
     * @private
     * Given a pixel location along the slider, returns the mapped slider value for that pixel.
     * E.g. if we have a slider 200px wide with minValue = 100 and maxValue = 500, reversePixelValue(50)
     * returns 200
     * @param {Number} pos The position along the slider to return a mapped value for
     * @return {Number} The mapped value for the given position
     */
    reversePixelValue : function(pos) {
        return this.minValue + (pos / this.getRatio());
    },

    /**
     * @private
     * Given a Thumb's percentage position along the slider, returns the mapped slider value for that pixel.
     * E.g. if we have a slider 200px wide with minValue = 100 and maxValue = 500, reversePercentageValue(25)
     * returns 200
     * @param {Number} pos The percentage along the slider track to return a mapped value for
     * @return {Number} The mapped value for the given position
     */
    reversePercentageValue : function(pos) {
        return this.minValue + (this.maxValue - this.minValue) * (pos / 100);
    },

    //private
    onDisable: function() {
        var me = this,
            i = 0,
            thumbs = me.thumbs,
            len = thumbs.length,
            thumb,
            el,
            xy;

        me.callParent();

        for (; i < len; i++) {
            thumb = thumbs[i];
            el = thumb.el;

            thumb.disable();

            if(Ext.isIE) {
                //IE breaks when using overflow visible and opacity other than 1.
                //Create a place holder for the thumb and display it.
                xy = el.getXY();
                el.hide();

                me.innerEl.addCls(me.disabledCls).dom.disabled = true;

                if (!me.thumbHolder) {
                    me.thumbHolder = me.endEl.createChild({cls: Ext.baseCSSPrefix + 'slider-thumb ' + me.disabledCls});
                }

                me.thumbHolder.show().setXY(xy);
            }
        }
    },

    //private
    onEnable: function() {
        var me = this,
            i = 0,
            thumbs = me.thumbs,
            len = thumbs.length,
            thumb,
            el;

        this.callParent();

        for (; i < len; i++) {
            thumb = thumbs[i];
            el = thumb.el;

            thumb.enable();

            if (Ext.isIE) {
                me.innerEl.removeCls(me.disabledCls).dom.disabled = false;

                if (me.thumbHolder) {
                    me.thumbHolder.hide();
                }

                el.show();
                me.syncThumbs();
            }
        }
    },

    /**
     * Synchronizes thumbs position to the proper proportion of the total component width based on the current slider
     * {@link #value}. This will be called automatically when the Slider is resized by a layout, but if it is rendered
     * auto width, this method can be called from another resize handler to sync the Slider if necessary.
     */
    syncThumbs : function() {
        if (this.rendered) {
            var thumbs = this.thumbs,
                length = thumbs.length,
                i = 0;

            for (; i < length; i++) {
                thumbs[i].move(this.calculateThumbPosition(thumbs[i].value));
            }
        }
    },

    /**
     * Returns the current value of the slider
     * @param {Number} index The index of the thumb to return a value for
     * @return {Number/Number[]} The current value of the slider at the given index, or an array of all thumb values if
     * no index is given.
     */
    getValue : function(index) {
        return Ext.isNumber(index) ? this.thumbs[index].value : this.getValues();
    },

    /**
     * Returns an array of values - one for the location of each thumb
     * @return {Number[]} The set of thumb values
     */
    getValues: function() {
        var values = [],
            i = 0,
            thumbs = this.thumbs,
            len = thumbs.length;

        for (; i < len; i++) {
            values.push(thumbs[i].value);
        }

        return values;
    },

    getSubmitValue: function() {
        var me = this;
        return (me.disabled || !me.submitValue) ? null : me.getValue();
    },

    reset: function() {
        var me = this,
            arr = [].concat(me.originalValue),
            a     = 0,
            aLen  = arr.length,
            val;

        for (; a < aLen; a++) {
            val = arr[a];

            me.setValue(a, val);
        }

        me.clearInvalid();
        // delete here so we reset back to the original state
        delete me.wasValid;
    },

    // private
    beforeDestroy : function() {
        var me     = this,
            thumbs = me.thumbs,
            t      = 0,
            tLen   = thumbs.length,
            thumb;

        Ext.destroy(me.innerEl, me.endEl, me.focusEl);

        for (; t < tLen; t++) {
            thumb = thumbs[t];

            Ext.destroy(thumb);
        }

        me.callParent();
    }
});
