define([
    "../core",
    "../var/rcssNum"
], function (jQuery, rcssNum) {

    "use strict";

    function adjustCSS(elem, prop, valueParts, tween) {
        var adjusted,
            scale = 1,
            maxIterations = 20,
            currentValue = tween ?
                function () {
                    return tween.cur();
                } :
                function () {
                    return jQuery.css(elem, prop, "");
                },
            initial = currentValue(),
            unit = valueParts && valueParts[3] || ( jQuery.cssNumber[prop] ? "" : "px" ),

            // Starting value computation is required for potential unit mismatches
            initialInUnit = ( jQuery.cssNumber[prop] || unit !== "px" && +initial ) &&
                rcssNum.exec(jQuery.css(elem, prop));

        if (initialInUnit && initialInUnit[3] !== unit) {

            // Trust units reported by jQuery.css
            unit = unit || initialInUnit[3];

            // Make sure we update the tween properties later on
            valueParts = valueParts || [];

            // Iteratively approximate from a nonzero starting point
            initialInUnit = +initial || 1;

            do {

                // If previous iteration zeroed out, double until we get *something*.
                // Use string for doubling so we don't accidentally see scale as unchanged below
                scale = scale || ".5";

                // Adjust and apply
                initialInUnit = initialInUnit / scale;
                jQuery.style(elem, prop, initialInUnit + unit);

                // Update scale, tolerating zero or NaN from tween.cur()
                // Break the loop if scale is unchanged or perfect, or if we've just had enough.
            } while (
            scale !== ( scale = currentValue() / initial ) && scale !== 1 && --maxIterations
                );
        }

        if (valueParts) {
            initialInUnit = +initialInUnit || +initial || 0;

            // Apply relative offset (+=/-=) if specified
            adjusted = valueParts[1] ?
                initialInUnit + ( valueParts[1] + 1 ) * valueParts[2] :
                +valueParts[2];
            if (tween) {
                tween.unit = unit;
                tween.start = initialInUnit;
                tween.end = adjusted;
            }
        }
        return adjusted;
    }

    return adjustCSS;
});
