/**
 * @class Ext.core.Element
 */
Ext.applyIf(Ext.core.Element, {
    unitRe: /\d+(px|em|%|en|ex|pt|in|cm|mm|pc)$/i,
    camelRe: /(-[a-z])/gi,
    opacityRe: /alpha\(opacity=(.*)\)/i,
    cssRe: /([a-z0-9-]+)\s*:\s*([^;\s]+(?:\s*[^;\s]+)*);?/gi,
    propertyCache: {},
    defaultUnit : "px",
    borders: {l: 'border-left-width', r: 'border-right-width', t: 'border-top-width', b: 'border-bottom-width'},
    paddings: {l: 'padding-left', r: 'padding-right', t: 'padding-top', b: 'padding-bottom'},
    margins: {l: 'margin-left', r: 'margin-right', t: 'margin-top', b: 'margin-bottom'},

    // Reference the prototype's version of the method. Signatures are identical.
    addUnits : Ext.core.Element.prototype.addUnits,

    /**
     * Parses a number or string representing margin sizes into an object. Supports CSS-style margin declarations
     * (e.g. 10, "10", "10 10", "10 10 10" and "10 10 10 10" are all valid options and would return the same result)
     * @static
     * @param {Number|String} box The encoded margins
     * @return {Object} An object with margin sizes for top, right, bottom and left
     */
    parseBox : function(box) {
        if (Ext.isObject(box)) {
            return {
                top: box.top || 0,
                right: box.right || 0,
                bottom: box.bottom || 0,
                left: box.left || 0
            };
        } else {
            if (typeof box != 'string') {
                box = box.toString();
            }
            var parts  = box.split(' '),
                ln = parts.length;
    
            if (ln == 1) {
                parts[1] = parts[2] = parts[3] = parts[0];
            }
            else if (ln == 2) {
                parts[2] = parts[0];
                parts[3] = parts[1];
            }
            else if (ln == 3) {
                parts[3] = parts[1];
            }
    
            return {
                top   :parseFloat(parts[0]) || 0,
                right :parseFloat(parts[1]) || 0,
                bottom:parseFloat(parts[2]) || 0,
                left  :parseFloat(parts[3]) || 0
            };
        }
        
    },
    
    /**
     * Parses a number or string representing margin sizes into an object. Supports CSS-style margin declarations
     * (e.g. 10, "10", "10 10", "10 10 10" and "10 10 10 10" are all valid options and would return the same result)
     * @static
     * @param {Number|String} box The encoded margins
     * @param {String} units The type of units to add
     * @return {String} An string with unitized (px if units is not specified) metrics for top, right, bottom and left
     */
    unitizeBox : function(box, units) {
        var A = this.addUnits,
            B = this.parseBox(box);
            
        return A(B.top, units) + ' ' +
               A(B.right, units) + ' ' +
               A(B.bottom, units) + ' ' +
               A(B.left, units);
        
    },

    // private
    camelReplaceFn : function(m, a) {
        return a.charAt(1).toUpperCase();
    },

    /**
     * Normalizes CSS property keys from dash delimited to camel case JavaScript Syntax.
     * For example:
     * <ul>
     *  <li>border-width -> borderWidth</li>
     *  <li>padding-top -> paddingTop</li>
     * </ul>
     * @static
     * @param {String} prop The property to normalize
     * @return {String} The normalized string
     */
    normalize : function(prop) {
        if (prop == 'float') {
            prop = Ext.supports.Float ? 'cssFloat' : 'styleFloat';
        }
        return this.propertyCache[prop] || (this.propertyCache[prop] = prop.replace(this.camelRe, this.camelReplaceFn));
    },

    /**
     * Retrieves the document height
     * @static
     * @return {Number} documentHeight
     */
    getDocumentHeight: function() {
        return Math.max(!Ext.isStrict ? document.body.scrollHeight : document.documentElement.scrollHeight, this.getViewportHeight());
    },

    /**
     * Retrieves the document width
     * @static
     * @return {Number} documentWidth
     */
    getDocumentWidth: function() {
        return Math.max(!Ext.isStrict ? document.body.scrollWidth : document.documentElement.scrollWidth, this.getViewportWidth());
    },

    /**
     * Retrieves the viewport height of the window.
     * @static
     * @return {Number} viewportHeight
     */
    getViewportHeight: function(){
        return window.innerHeight;
    },

    /**
     * Retrieves the viewport width of the window.
     * @static
     * @return {Number} viewportWidth
     */
    getViewportWidth : function() {
        return window.innerWidth;
    },

    /**
     * Retrieves the viewport size of the window.
     * @static
     * @return {Object} object containing width and height properties
     */
    getViewSize : function() {
        return {
            width: window.innerWidth,
            height: window.innerHeight
        };
    },

    /**
     * Retrieves the current orientation of the window. This is calculated by
     * determing if the height is greater than the width.
     * @static
     * @return {String} Orientation of window: 'portrait' or 'landscape'
     */
    getOrientation : function() {
        if (Ext.supports.OrientationChange) {
            return (window.orientation == 0) ? 'portrait' : 'landscape';
        }
        
        return (window.innerHeight > window.innerWidth) ? 'portrait' : 'landscape';
    },

    /** 
     * Returns the top Element that is located at the passed coordinates
     * @static
     * @param {Number} x The x coordinate
     * @param {Number} x The y coordinate
     * @return {String} The found Element
     */
    fromPoint: function(x, y) {
        return Ext.get(document.elementFromPoint(x, y));
    },
    
    /**
     * Converts a CSS string into an object with a property for each style.
     * <p>
     * The sample code below would return an object with 2 properties, one
     * for background-color and one for color.</p>
     * <pre><code>
var css = 'background-color: red;color: blue; ';
console.log(Ext.core.Element.parseStyles(css));
     * </code></pre>
     * @static
     * @param {String} styles A CSS string
     * @return {Object} styles
     */
    parseStyles: function(styles){
        var out = {},
            cssRe = this.cssRe,
            matches;
            
        if (styles) {
            // Since we're using the g flag on the regex, we need to set the lastIndex.
            // This automatically happens on some implementations, but not others, see:
            // http://stackoverflow.com/questions/2645273/javascript-regular-expression-literal-persists-between-function-calls
            // http://blog.stevenlevithan.com/archives/fixing-javascript-regexp
            cssRe.lastIndex = 0;
            while ((matches = cssRe.exec(styles))) {
                out[matches[1]] = matches[2];
            }
        }
        return out;
    }
});
