/**
*    Json key/value autocomplete for jQuery 
*    Provides a transparent way to have key/value autocomplete
*    Copyright (C) 2008 Ziadin Givan www.CodeAssembly.com  
*
*    This program is free software: you can redistribute it and/or modify
*    it under the terms of the GNU Lesser General Public License as published by
*    the Free Software Foundation, either version 3 of the License, or
*    (at your option) any later version.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU General Public License for more details.
*
*    You should have received a copy of the GNU Lesser General Public License
*    along with this program.  If not, see http://www.gnu.org/licenses/
*    
*    Examples 
*	 $("input#example").autocomplete("autocomplete.php");//using default parameters
*	 $("input#example").autocomplete("autocomplete.php",{minChars:3,timeout:3000,validSelection:false,parameters:{'myparam':'myvalue'},before : function(input,text) {},after : function(input,text) {}});
*    minChars = Minimum characters the input must have for the ajax request to be made
*	 timeOut = Number of miliseconds passed after user entered text to make the ajax request   
*    validSelection = If set to true then will invalidate (set to empty) the value field if the text is not selected (or modified) from the list of items.
*    parameters = Custom parameters to be passed
*    after, before = a function that will be caled before/after the ajax request
*/
jQuery.fn.autocomplete = function(url, settings)
{
	return this.each(function()//do it for each matched element
	{
		//this is the original input
		var textInput = $(this);
		//create a new hidden input that will be used for holding the return value when posting the form, then swap names with the original input
		//-textInput.after('<input type=hidden name="' + textInput.attr("name") + '"/>').attr("name", textInput.attr("name") + "_text");
		textInput.after('<input type=hidden name="' + textInput.attr("name") + '_value"/>');
		var valueInput = $(this).next();
		//create the ul that will hold the text and values
		valueInput.after('<ul class="autocomplete"></ul>');
		var list = valueInput.next().css({ });
		//{ top: textInput.offset().top + textInput.outerHeight(), left: textInput.offset().left, width: textInput.width() }
		var oldText = '';
		var typingTimeout;
		var size = 0;
		var selected = 0;

		settings = jQuery.extend(//provide default settings
		{
		minChars: 2,
		timeout: 1000,
		after: null,
		before: null,
		validSelection: true,
		parameters: { 'inputName': valueInput.attr('name'), 'inputId': textInput.attr('id') }
	}, settings);

	function getData(text)
	{
		window.clearInterval(typingTimeout);
		if (text != oldText && (settings.minChars != null && text.length >= settings.minChars))
		{
			clear();
			if (settings.before == "function")
			{ 
				settings.before(textInput, text);
			}
			textInput.addClass('autocomplete-loading');
			settings.parameters.suggestString = text;
			$.getJSON(url, settings.parameters, function(data)
			{
				var items = '';
				if (data)
				{
					size = data.length;
					for (i = 0; i < data.length; i++)//iterate over all options
					{
						for (key in data[i])//get key => value
						{
							items += '<li value="' + key + '">' + data[i][key].replace(new RegExp("(" + text + ")", "i"), "<strong>$1</strong>") + '</li>';
						}
						list.html(items);
						//on mouse hover over elements set selected class and on click set the selected value and close list
						list.show().children().
						  hover(function() { $(this).addClass("selected").siblings().removeClass("selected"); }, function() { $(this).removeClass("selected") }).
						  //click(function() { valueInput.val($(this).attr('value')); textInput.val($(this).text()); clear(); });
						  click(function() { valueInput.val($(this).text()); textInput.val($(this).text()); clear(); });
					}
					if (settings.after == "function")
					{
						settings.after(textInput, text);
					}
				}
				textInput.removeClass('autocomplete-loading');
			});
			oldText = text;
		}
	}

	function clear()
	{
		list.hide();
		size = 0;
		selected = 0;
	}

	textInput.keydown(function(e)
	{
		window.clearInterval(typingTimeout);
		if (e.which == 27)//escape
		{
			clear();
		} else if (e.which == 46 || e.which == 8)//delete and backspace
		{
			clear();
			//invalidate previous selection
			if (settings.validSelection) valueInput.val('');
		}
		else if (e.which == 13)//enter 
		{
			if (list.css("display") == "none")//if the list is not visible then make a new request, otherwise hide the list
			{
				//getData(textInput.val());
				return true;
			} else
			{
				clear();
			}
			e.preventDefault();
			return false;
		}
		else if (e.which == 40 || e.which == 9 || e.which == 38)//move up, down 
		{
			switch (e.which)
			{
				case 40:
				case 9:
					selected = selected >= size - 1 ? 0 : selected + 1; break;
				case 38:
					selected = selected <= 0 ? size - 1 : selected - 1; break;
				default: break;
			}
			//set selected item and input values
			textInput.val(list.children().removeClass('selected').eq(selected).addClass('selected').text());
			valueInput.val(list.children().eq(selected).attr('value'));
		} else
		{
			//invalidate previous selection
			if (settings.validSelection) valueInput.val('');
			typingTimeout = window.setTimeout(function() { getData(textInput.val()) }, settings.timeout);
		}
	});
});

};