/**
 * TextAreaExpander plugin for jQuery
 * v1.0
 * Expands or contracts a textarea height depending on the
 * quatity of content entered by the user in the box.
 *
 * By Craig Buckler, Optimalworks.net
 *
 * As featured on SitePoint.com:
 * http://www.sitepoint.com/blogs/2009/07/29/build-auto-expanding-textarea-1/
 *
 * Please use as you wish at your own risk.
 */

/**
 * Usage:
 *
 * From JavaScript, use:
 *     $(<node>).TextAreaExpander(<min_height>, <max_height>);
 *     where:
 *       <node> is the DOM node selector, e.g. "textarea"
 *       <min_height> is the minimum textarea height in pixels (optional)
 *       <max_height> is the maximum textarea height in pixels (optional)
 *
 * Alternatively, in you HTML:
 *     Assign a class of "expand" to any <textarea> tag.
 *     e.g. <textarea name="textarea1" rows="3" cols="40" class="expand"></textarea>
 *
 *     Or assign a class of "expandMIN-MAX" to set the <textarea> minimum and maximum height.
 *     e.g. <textarea name="textarea1" rows="3" cols="40" class="expand50-200"></textarea>
 *     The textarea will use an appropriate height between 50 and 200 pixels.
 */

(function($) {

    // jQuery plugin definition
    $.fn.higit_textarea_expander = function(min_height, max_height) {

        var hCheck = !($.browser.msie || $.browser.opera);

        // resize a textarea
        function resize_textarea(e) {
            el = $(e);
            var vlen = el.val().length, ewidth = e.offsetWidth;

            if (vlen != e.valLength || ewidth != e.boxWidth) {
                if (hCheck && (vlen < e.valLength || ewidth != e.boxWidth)) e.height = "0px";
                var h = Math.max(e.expandMin, Math.min(e.scrollHeight, e.expandMax));                

                e.style.overflow = (e.scrollHeight > h ? "auto" : "hidden");

                e.style.height = h + "px";

                e.valLength = vlen;
                e.boxWidth = e.width;
            }

            return true;
        };

        function textarea_keydown(event){
            element = event.currentTarget || event;
//
            var code = (event.keyCode ? event.keyCode : event.which);
            if (code == 13 && event.shiftKey) {
                console.log('enter');
            }else if(code == 13) {
                event.stopPropagation();
                event.preventDefault();
                $(element).closest('form').submit();
                resize_textarea(element);
                return false;
            }
            resize_textarea(element);
            return true;
        }

        function textarea_keyup(event){
            element = event.currentTarget || event;
            var code = (event.keyCode ? event.keyCode : event.which);            
            if (code == 13 && event.shiftKey) {

            }else if(code == 13) {
                event.stopPropagation();
                event.preventDefault();
                return false;
            }
            resize_textarea(element);
            return true;
        }

        // initialize
        $(this).each(function(key, element) {
            // is a textarea?
            if (element.nodeName.toLowerCase() != "textarea") {
                return;
            }


            // set height restrictions
            var p = element.className.match(/expand(\d+)\-*(\d+)*/i);
            element.expandMin = min_height || (p ? parseInt('0'+p[1], 10) : 0);
            element.expandMax = max_height || (p ? parseInt('0'+p[2], 10) : 99999);

            // initial resize
            resize_textarea(element);

            // zero vertical padding and add events
            if (!element.Initialized) {
                element.Initialized = true;
                $(element).css("padding-top", 0).css("padding-bottom", 0);
                $(element).bind("keydown", textarea_keydown).bind("focus", textarea_keydown);
                $(element).bind("keyup", textarea_keyup);
            }
        });
        return this;
    };

})(jQuery);

// initialize all expanding textareas
jQuery(document).ready(function() {
    jQuery("textarea[class*=expand]").higit_textarea_expander();
});