(function($){
	var defaults = {
		reNumbers: /(-|-\$)?(\d+(,\d{3})*(\.\d{1,})?|\.\d{1,})/g
		, cleanseNumber: function (v){
			return v.replace(/[^0-9.\-]/g, "");
		}
		, useFieldPlugin: (!!$.fn.getValue)
		, onParseError: null
		, onParseClear: null
	};
	$.Calculation = {
		version: "0.4.07",
		setDefaults: function(options){
			$.extend(defaults, options);
		}
	};
	$.fn.parseNumber = function(options){
		var aValues = [];
		options = $.extend(options, defaults);
		
		this.each(
			function (){
				var
					$el = $(this),
					sMethod = ($el.is(":input") ? (defaults.useFieldPlugin ? "getValue" : "val") : "text"),
					v = $.trim($el[sMethod]()).match(defaults.reNumbers, "");

				if( v == null ){
					v = 0; // update value
					if( jQuery.isFunction(options.onParseError) ) options.onParseError.apply($el, [sMethod]);
					$.data($el[0], "calcParseError", true);
				} else {
					v = options.cleanseNumber.apply(this, [v[0]]);
					if( $.data($el[0], "calcParseError") && jQuery.isFunction(options.onParseClear) ){
						options.onParseClear.apply($el, [sMethod]);
						// clear the error flag
						$.data($el[0], "calcParseError", false);
					} 
				}
				aValues.push(parseFloat(v, 10));
			}
		);
		return aValues;
	};
	$.fn.calc = function(expr, vars, cbFormat, cbDone){
		var
			$this = this
			, exprValue = ""
			, precision = 0
			, $el
			, parsedVars = {}
			, tmp
			, sMethod
			, _
			, bIsError = false;			
		for( var k in vars ){
			expr = expr.replace( (new RegExp("(" + k + ")", "g")), "_.$1");
			if( !!vars[k] && !!vars[k].jquery ){
				parsedVars[k] = vars[k].parseNumber();
			} else {
				parsedVars[k] = vars[k];
			}
		}
		this.each(
			function (i, el){
				var p, len;
				$el = $(this);
				sMethod = ($el.is(":input") ? (defaults.useFieldPlugin ? "setValue" : "val") : "text");
				_ = {};
				for( var k in parsedVars ){
					if( typeof parsedVars[k] == "number" ){
						_[k] = parsedVars[k];
					} else if( typeof parsedVars[k] == "string" ){
						_[k] = parseFloat(parsedVars[k], 10);
					} else if( !!parsedVars[k] && (parsedVars[k] instanceof Array) ) {
						tmp = (parsedVars[k].length == $this.length) ? i : 0;
						_[k] = parsedVars[k][tmp];
					}
					if( isNaN(_[k]) ) _[k] = 0;
					p = _[k].toString().match(/\.\d+$/gi);
					len = (p) ? p[0].length-1 : 0;
					if( len > precision ) precision = len; 
				}
				try {
					exprValue = eval( expr );
					if( precision ) exprValue = Number(exprValue.toFixed(Math.max(precision, 4)));
					if( jQuery.isFunction(cbFormat) ){
						var tmp = cbFormat.apply(this, [exprValue])
						if( !!tmp ) exprValue = tmp;
					}
				} catch(e){
					exprValue = e;
					bIsError = true;
				}
				$el[sMethod](exprValue.toString());
			}
		);
		if( jQuery.isFunction(cbDone) ) cbDone.apply(this, [this]);
		return this;
	};

	$.each(["sum", "avg", "min", "max"], function (i, method){
		$.fn[method] = function (bind, selector){
			if( arguments.length == 0 )
				return math[method](this.parseNumber());
			var bSelOpt = selector && (selector.constructor == Object) && !(selector instanceof jQuery);
			var opt = bind && bind.constructor == Object ? bind : {
				  bind: bind || "keyup"
				, selector: (!bSelOpt) ? selector : null
				, oncalc: null
			};
			if( bSelOpt ) opt = jQuery.extend(opt, selector);
			if( !!opt.selector ) opt.selector = $(opt.selector);
			
			var self = this
				, sMethod
				, doCalc = function (){
					var value = math[method](self.parseNumber(opt));			
					if( !!opt.selector ){
						sMethod = (opt.selector.is(":input") ? (defaults.useFieldPlugin ? "setValue" : "val") : "text");
						opt.selector[sMethod](value.toString());
					}
					if( jQuery.isFunction(opt.oncalc) ) opt.oncalc.apply(self, [value, opt]);
				};
			doCalc();
			return self.bind(opt.bind, doCalc);
		}
	});
	var math = {
		sum: function (a){
			var total = 0, precision = 0;
			$.each(a, function (i, v){
				var p = v.toString().match(/\.\d+$/gi), len = (p) ? p[0].length-1 : 0;
				if( len > precision ) precision = len; 
				total += v;
			});
			if( precision ) total = Number(total.toFixed(precision));
			return total;
		},
		avg: function (a){
			return math.sum(a)/a.length;
		},
		min: function (a){
			return Math.min.apply(Math, a);
		},
		max: function (a){
			return Math.max.apply(Math, a);
		}
	};
})(jQuery);