// NativeEnergy Simple Carbon Footprint Calculator


var Calculator = {
	total:21,
	p_wind:50,
	p_meth:50,
	increment:function(which){
		var v = parseInt(document.forms["calculations"].elements[which].value); 
				document.forms["calculations"].elements[which].value = (v + 1);
		Calculator.calc();		
	},
	decrement:function(which){			
			var v = parseInt(document.forms["calculations"].elements[which].value); 
				if(v == 0) return false;
				document.forms["calculations"].elements[which].value = (v - 1);					  
		Calculator.calc();
	},
	manual:function(which, value){
		document.forms["calculations"].elements[which].value = value;				  
		Calculator.calc();
	},
	calc:function(){
		//total up homes
		var h  = parseInt(document.forms["calculations"].elements["homes"].value); 
		var ht = (h*12);
		document.getElementById("total_home").innerHTML = " = <span>"+ht+" tons CO<sub>2</sub></span>";
		
		//total up small cars
		var sc  = parseInt(document.forms["calculations"].elements["vehicle_s"].value); 
		var tsc = (sc*3);
		document.getElementById("total_vehicle_s").innerHTML = " = <span>"+tsc+" tons CO<sub>2</sub></span>";
		
		//total up med cars
		var mc  = parseInt(document.forms["calculations"].elements["vehicle_m"].value); 
		var tmc = (mc*6);
		document.getElementById("total_vehicle_m").innerHTML = " = <span>"+tmc+" tons CO<sub>2</sub></span>";
		
		//total up big cars
		var lc  = parseInt(document.forms["calculations"].elements["vehicle_l"].value); 
		var tlc = (lc*8);		
		document.getElementById("total_vehicle_l").innerHTML = " = <span>"+tlc+" tons CO<sub>2</sub></span>";
		
		//update overall total and prices
		Calculator.total = ht + tsc + tmc + tlc;
			
			document.getElementById("totaltons").value = Calculator.total;
			document.getElementById("pounds").value = Calculator.total * 2000;						
			
			
		var yr_price = Calculator.total * 14;
			document.getElementById("price_mo").innerHTML = Calculator.dollar_format(yr_price/12);
			document.getElementById("price_yr").innerHTML = Calculator.dollar_format(yr_price);
		
	},
	manual_update:function(val, tons){
			Calculator.total = tons ? val : Math.ceil(parseInt(val)/2000);
			//alert(Calculator.total);
			var yr_price = Calculator.total * 14;
			document.getElementById("price_mo").innerHTML = Calculator.dollar_format(yr_price/12);
			document.getElementById("price_yr").innerHTML = Calculator.dollar_format(yr_price);
			
			var lbs = Calculator.total * 2000;
			if(tons) document.getElementById("pounds").value = Calculator.total * 2000;
			else document.getElementById("totaltons"). value = Calculator.total;
	},
	offset_year:function(){
		var OneTime = document.forms["OneTime"];
		
		var wind_qty = Math.floor(Calculator.total * (Calculator.p_wind/100));
		var meth_qty = Calculator.total - wind_qty;	
			
			document.getElementById("ot_wind_qty").value = Calculator.total; //wind_qty;
			//document.getElementById("ot_farm_qty").value = meth_qty;
			
			OneTime.submit();
	},
	offset_month:function(){
		var Monthly = document.forms["Monthly"];
				
		var wind_qty = Math.floor(Calculator.total * (Calculator.p_wind/100));
		var meth_qty = Calculator.total - wind_qty;	
			
		document.getElementById("mn_wind_qty").value = Calculator.total; //wind_qty;
			//document.getElementById("mn_farm_qty").value = meth_qty;
		
		Monthly.submit();
	},
	set_blend:function(slider){
		var p_meth = Math.floor(slider.value);
		var p_wind = 100 - p_meth;
			if(p_meth == 1){ 
				p_wind = 100;
				p_meth = 0;
			}
		document.getElementById("pc_wind").innerHTML = p_wind + '%';
		document.getElementById("pc_meth").innerHTML = p_meth + '%';
		
		Calculator.p_wind = p_wind;
		Calculator.p_meth = p_meth;
		
	},
	dollar_format:function(num, nosign){
		num = num.toString().replace(/\$|\,/g,'');
		if(isNaN(num))
		num = "0";
		sign = (num == (num = Math.abs(num)));
		num = Math.floor(num*100+0.50000000001);
		cents = num%100;
		num = Math.floor(num/100).toString();
		if(cents<10)
		cents = "0" + cents;
		for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
		num = num.substring(0,num.length-(4*i+3))+','+
		num.substring(num.length-(4*i+3));
		var ds = nosign ? '' : '$';
		return (((sign)?'':'-') + ds + num + '.' + cents);	
	}
}