/*
 * Adapted from: http://javascript.internet.com/math-related/16-function-scientific-calcula.html
 */
var Result = 0, Operator = 0, Second = 0, Ready = 0, Done = 1, Complete = 0, Integer, CurrentValue;
function reset(value) 
{
	$j("#LED").attr("value", value);
	Result = 0, Operator = 0, Second = 0, Ready = 0;
	Done = 1;
	Complete = 0;
}

function SetValue(NewValue) 
{
	Integer = 1;
	
	if (Second || Done) {
		Second = 0;
		Done = 0;
		CurrentValue = NewValue;
	}
	
	for (var i = 0; i < CurrentValue.length; i++) {
		if (CurrentValue[i] == ".") {
			Integer = 0;
		}
	}
}

function Click(Caption) 
{
	CurrentValue = $j("#LED").attr("value");
	if (Caption == ".") 
	{
		SetValue("0");
		
		if (Integer) 
		{
			CurrentValue += Caption;
			$j("#LED").attr("value", CurrentValue);
			Complete = 0;
		}
	}
	
	if (Caption.length == 1 && (Caption >= "0" && Caption <= "9") || (Caption >= 0 && Caption <= 9)) 
	{
		SetValue("");
		
		if (CurrentValue == "0") 
		{
			CurrentValue = "";
		}
		
		CurrentValue += Caption;
		$j("#LED").attr("value", CurrentValue);
		Complete = 1;
	}
	
	if (Caption == "pi") 
	{
		CurrentValue = Math.PI;
		$j("#LED").attr("value", CurrentValue);
		Complete = 1;
	}
	
	if (Caption == "e") 
	{
		CurrentValue = Math.E;
		$j("#LED").attr("value", CurrentValue);
		Complete = 1;
	}
	
	if (Caption == "-" || Caption == "+" || Caption == "/" || Caption == "*" || Caption == "^") 
	{
		if (Second) 
		{
			Operator = Caption;
		} 
		else 
		{
			if (!Ready) 
			{
				Operator = Caption;
				Result = CurrentValue;
				Ready = 1;
			} 
			else 
			{
				if (Operator == "^") 
				{
					Result = Math.pow(Result, CurrentValue);
				} 
				else 
				{
					Result = eval(Result + Operator + CurrentValue);
				}
				Operator = Caption;
				$j("#LED").attr("value", Result);
			}
			Complete = 0;
			Second = 1;
		}
	}
	
	if (Caption == "1/x") 
	{
		Result = eval("1/" + CurrentValue);
		reset(Result);
	}
	
	if (Caption == "sqrt") 
	{
		Result = Math.sqrt(CurrentValue);
		reset(Result);
	}
	
	if (Caption == "exp") 
	{
		Result = Math.exp(CurrentValue);
		reset(Result);
	}
	
	if (Caption == "log") 
	{
		Result = Math.log(CurrentValue) / Math.LN10;
		reset(Result);
	}
	
	if (Caption == "ln") 
	{
		Result = Math.log(CurrentValue);
		reset(Result);
	}
	
	if (Caption == "sin") 
	{
		Result = CurrentValue;
		
		if ($j('#angle_deg').attr('checked')) 
		{
			Result = Result * Math.PI / 180;
		}
		
		if ($j('#angle_grad').attr('checked')) 
		{
			Result = Result * Math.PI / 200;
		}
		Result = Math.sin(Result);
		reset(Result);
	}
	
	if (Caption == "cos") 
	{
		Result = CurrentValue;
		if ($j('#angle_deg').attr('checked')) 
		{
			Result = Result * Math.PI / 180;
		}
		
		if ($j('#angle_grad').attr('checked')) 
		{
			Result = Result * Math.PI / 200;
		}
		Result = Math.cos(Result);
		reset(Result);
	}
	
	if (Caption == "tan") 
	{
		Result = CurrentValue;
		if ($j('#angle_deg').attr('checked')) 
		{
			Result = Result * Math.PI / 180;
		}
		if ($j('#angle_grad').attr('checked')) 
		{
			Result = Result * Math.PI / 200;
		}
		Result = Math.tan(Result);
		reset(Result);
	}
	
	if (Caption == "asin") 
	{
		Result = Math.asin(CurrentValue);
		if ($j('#angle_deg').attr('checked')) 
		{
			Result = Result * 180 / Math.PI;
		}
		if ($j('#angle_grad').attr('checked')) {
			Result = Result * 200 / Math.PI;
		}
		reset(Result);
	}
	if (Caption == "acos") 
	{
		Result = Math.acos(CurrentValue);
		if ($j('#angle_deg').attr('checked')) 
		{
			Result = Result * 180 / Math.PI;
		}
		if ($j('#angle_grad').attr('checked')) 
		{
			Result = Result * 200 / Math.PI;
		}
		reset(Result);
	}
	if (Caption == "atan") 
	{
		Result = Math.atan(CurrentValue);
		
		if ($j('#angle_deg').attr('checked')) 
		{
			Result = Result * 180 / Math.PI;
		}
		
		if ($j('#angle_grad').attr('checked')) 
		{
			Result = Result * 200 / Math.PI;
		}
		reset(Result);
	}
	
	if (Caption == "sinh") 
	{
		Result = Math.exp(CurrentValue);
		Result = (Result - 1 / Result) / 2;
		reset(Result);
	}
	
	if (Caption == "cosh") 
	{
		Result = Math.exp(CurrentValue);
		Result = (Result + 1 / Result) / 2;
		reset(Result);
	}
	
	if (Caption == "tanh") 
	{
		Result = Math.exp(CurrentValue);
		Result = (Result - 1 / Result) / (Result + 1 / Result);
		reset(Result);
	}
	
	if (Caption == "asinh") 
	{
		Result = CurrentValue / Math.abs(CurrentValue) * Math.log(Math.abs(CurrentValue) + Math.sqrt(CurrentValue * CurrentValue + 1));
		reset(Result);
	}
	
	if (Caption == "acosh") 
	{
		Result = 2 * Math.log(Math.sqrt((CurrentValue + 1) / 2) + Math.sqrt((CurrentValue - 1) / 2));
		reset(Result);
	}
	
	if (Caption == "atanh") 
	{
		Result = Math.log((CurrentValue - 1) / (CurrentValue + 1)) / 2;
		reset(Result);
	}
	
	if (Caption == "+/-") 
	{
		$j("#LED").attr("value", eval(-CurrentValue));
	}
	
	if (Caption == "=" && Complete && Operator != "0") 
	{
		if (Operator == "^") 
		{
			Result = Math.pow(Result, CurrentValue);
			reset(Result);
		} 
		else 
		{
			reset(eval(Result + Operator + CurrentValue));
		}
	}
	
	if (Caption == "C") 
	{
		reset(0);
	}
	
	if ($j("#LED").attr("value")[0] == ".") 
	{
		$j("#LED").attr("value", "0" + $j("#LED").attr("value"));
	}
}

function processKey(e)
{
	//alert(e.which);
	
	if (e.which >= 48 && e.which <= 57)
	{
		Click("" + e.which - 48);
	}
	else
	{
		switch(e.which)
		{
			// Math Operators
			
			// +
			case 43:	Click("+");
						break;	
			//-
			case 45:	Click("-");
						break;
			// *			
			case 42:	Click("*");
						break;	
			// /			
			case 47:	Click("/");
						break;	
			// =			
			case 61:	Click("=");
						break;
			// esc			
			case 0:	    Click("C");
						break;	
			// <enter> - treated as =			
			case 13:    Click("=");
						break;												
		}
	}
}