YUI.add('axis-stacked-base', function (Y, NAME) {

/**
 * Provides core functionality for the handling of stacked numeric axis data for a chart.
 *
 * @module charts
 * @submodule axis-stacked-base
 */

/**
 * StackedImpl contains logic for managing stacked numeric data. StackedImpl is used by the following classes:
 * <ul>
 *      <li>{{#crossLink "StackedAxisBase"}}{{/crossLink}}</li>
 *      <li>{{#crossLink "StackedAxis"}}{{/crossLink}}</li>
 *  </ul>
 *
 * @submodule axis-stacked-base
 * @class StackedImpl
 * @constructor
 */
function StackedImpl()
{
}

StackedImpl.NAME = "stackedImpl";

StackedImpl.prototype = {
    /**
     * Type of data used in `Data`.
     *
     * @property _type
     * @readOnly
     * @private
     */
    _type: "stacked",

    /**
     * Calculates the maximum and minimum values for the `Data`.
     *
     * @method _updateMinAndMax
     * @private
     */
    _updateMinAndMax: function()
    {
        var max = 0,
            min = 0,
            pos = 0,
            neg = 0,
            len = 0,
            i = 0,
            key,
            num,
            keys = this.get("keys"),
            setMin = this.get("setMin"),
            setMax = this.get("setMax");

        for(key in keys)
        {
            if(keys.hasOwnProperty(key))
            {
                len = Math.max(len, keys[key].length);
            }
        }
        for(; i < len; ++i)
        {
            pos = 0;
            neg = 0;
            for(key in keys)
            {
                if(keys.hasOwnProperty(key))
                {
                    num = keys[key][i];
                    if(isNaN(num))
                    {
                        continue;
                    }
                    if(num >= 0)
                    {
                        pos += num;
                    }
                    else
                    {
                        neg += num;
                    }
                }
            }
            if(pos > 0)
            {
                max = Math.max(max, pos);
            }
            else
            {
                max = Math.max(max, neg);
            }
            if(neg < 0)
            {
                min = Math.min(min, neg);
            }
            else
            {
                min = Math.min(min, pos);
            }
        }
        this._actualMaximum = max;
        this._actualMinimum = min;
        if(setMax)
        {
            max = this._setMaximum;
        }
        if(setMin)
        {
            min = this._setMinimum;
        }
        this._roundMinAndMax(min, max, setMin, setMax);
    }
};

Y.StackedImpl = StackedImpl;

/**
 * StackedAxisBase manages stacked numeric data for an axis.
 *
 * @class StackedAxisBase
 * @constructor
 * @extends AxisBase
 * @uses StackedImpl
 * @param {Object} config (optional) Configuration parameters.
 * @submodule axis-stacked-base
 */
Y.StackedAxisBase = Y.Base.create("stackedAxisBase", Y.NumericAxisBase, [Y.StackedImpl]);


}, '@VERSION@', {"requires": ["axis-numeric-base"]});
