/* 
* Auto Expanding Text Area (1.2.2)
* by Chrys Bader (www.chrysbader.com)
* chrysb@gmail.com
*
* Version 1.2.3 update
* by Richard Vallee
* richardvallee@gmail.com
*
* Special thanks to:
* Jake Chapa - jake@hybridstudio.com
* John Resig - jeresig@gmail.com
*
* Copyright (c) 2008 Chrys Bader (www.chrysbader.com)
* Licensed under the GPL (GPL-LICENSE.txt) license. 
*
*
* NOTE: This script requires jQuery to work.  Download jQuery at www.jquery.com
*
*/

(function(jQuery) {

	var self = null;

	jQuery.fn.autogrow = function(o) {
		return this.each(function() {
			new jQuery.autogrow(this, o);
		});
	};


	/**
	* The autogrow object.
	*
	* @constructor
	* @name jQuery.autogrow
	* @param Object e The textarea to create the autogrow for.
	* @param Hash o A set of key/value pairs to set as configuration properties.
	* @cat Plugins/autogrow
	*/

	jQuery.autogrow = function(e, o) {
		this.options = o || {};
		this.dummy = null;
		this.interval = null;
		this.line_height = this.options.lineHeight || parseInt(jQuery(e).css('line-height'));
		this.min_height = this.options.minHeight || parseInt(jQuery(e).css('min-height'));
		this.max_height = this.options.maxHeight || parseInt(jQuery(e).css('max-height')); ;
		this.textarea = jQuery(e);
		this.expand_tolerance = (!isNaN(this.options.expandTolerance) && this.options.expandTolerance > 0) ? this.options.expandTolerance : 4;

		if (isNaN(this.line_height))
			this.line_height = 0;

		// Only one textarea activated at a time, the one being used
		this.init();
	};

	jQuery.autogrow.fn = jQuery.autogrow.prototype = {
		autogrow: '1.2.3'
	};

	jQuery.autogrow.fn.extend = jQuery.autogrow.extend = jQuery.extend;

	jQuery.autogrow.fn.extend({
		init: function() {
			var self = this;
			this.textarea.css({ overflow: 'hidden', display: 'block' });
			this.textarea.bind('focus', function() { self.startExpand() }).bind('blur', function() { self.stopExpand() });
			this.checkExpand();
		},

		startExpand: function() {
			var self = this;
			this.interval = window.setInterval(function() { self.checkExpand() }, 400);
		},

		stopExpand: function() {
			clearInterval(this.interval);
		},

		checkExpand: function() {
			if (this.dummy == null) {
				this.dummy = jQuery('<div class="axero-textbox-expender-phantom"></div>');
				this.dummy.css({
					'font-size': this.textarea.css('font-size'),
					'font-family': this.textarea.css('font-family'),
					'width': this.textarea.css('width'),
					'padding': this.textarea.css('padding'),
					'line-height': this.line_height + 'px',
					'overflow-x': 'hidden',
					'position': 'static',
					'top': 0,
					'left': -9999
				}).appendTo('body');
			} else {
				// If the dummy was already created, show it as it is hidden after expansion
				this.dummy.show();
			}

			// Strip HTML tags
			var html = this.textarea.val().replace(/(<|>)/g, '');
			//debugger;
			// IE is different, as per usual
			if (jQuery.browser.msie) {
				html = html.replace(/\n/g, '<BR/>new');
			}
			else {
				html = html.replace(/\n/g, '<br/>new');
			}

			this.dummy.css("font-size", "14px");

			if (this.dummy.html() != html) {
				this.dummy.html(html);
				this.dummy.css("font-size", "14px");
				if (this.max_height > 0 && (this.dummy.height() + (this.expand_tolerance * this.line_height) > this.max_height)) {
					this.textarea.css('overflow-y', 'auto');
					if (this.textarea.height() < this.max_height) {
						this.textarea.animate({ height: (this.max_height + (this.expand_tolerance * this.line_height)) + 'px' }, 100);
					}
				}
				else {
					this.textarea.css('overflow-y', 'hidden');
					if (this.textarea.height() < this.dummy.height() + (this.expand_tolerance * this.line_height) || (this.dummy.height() < this.textarea.height())) {
						if (this.dummy.height() < this.min_height) {
							this.textarea.animate({ height: (this.min_height + (this.expand_tolerance * this.line_height)) + 'px' }, 100);
						} else {

							//this.textarea.animate({ height: (this.dummy.height() + (this.expand_tolerance * this.line_height)) + 'px' }, 100);
							this.textarea.height((this.dummy.height() + (this.expand_tolerance * this.line_height)) + 'px')
						}
					}
				}
			}

			// Hide the dummy, as otherwise it overflows the body when the content is long
			this.dummy.hide();
		}

	});
})(jQuery);