var num=0;
var txtloanamount=0;
var rateofinterest=0;
var months=0;
var nls="";
var EMItoCalculate;
var emiType;

var ns ="01234567890";
var cr="";
var str="";

function validateInputs()
{
	str=document.getElementById('txtloanamount').value;
	bl=str.length+3;
	dp=2;
	txtloanamount=str;
	
	str=document.getElementById('interestRate').value;
	dp=4;
	rateofinterest=str;
	
	var re = /^[0-9]*.?[0-9]*$/
	
	if (txtloanamount == "")
	{
		alert("Enter Loan Amount");
		document.getElementById('txtloanamount').focus();
		return true;
	}
	else
	{
		if ( !re.test(txtloanamount) || txtloanamount < 1 || txtloanamount > 100000000 )
		{
			alert("Invalid Loan Amount");
			document.getElementById('txtloanamount').select();
			document.getElementById('txtloanamount').focus();
			return true;
		}
	}

	if (rateofinterest == "")
	{
		alert("Enter Rate of Interest");
		document.getElementById('interestRate').focus();
		return true;
	}
	else
	{
		if ( !re.test(rateofinterest) || rateofinterest<.0001||rateofinterest>99)
		{
			alert("Invalid Interest Rate");
			document.getElementById('rateofinterest').select();
			document.getElementById('rateofinterest').focus();
			return true;
		}
	}
	
	if ( document.getElementById('txtEmi') )
	{
		if ( document.getElementById('txtEmi').value == "" )
		{
			alert( "Please provide valid EMI to calculate Interest" );	
			document.getElementById('txtEmi').focus();
			return true;
		}
		else
		{
			if ( !re.test(document.getElementById('txtEmi').value) || document.getElementById('txtEmi').value < 1 || document.getElementById('txtEmi').value > 10000000 )
			{
				alert( "Please provide valid EMI to calculate Interest" );	
				document.getElementById('txtEmi').focus();
				return true;	
			}
		}
	}
}

function calculateAllEMI()
{
	if ( validateInputs() ) return;
	for ( var noMonths=12; noMonths<=84; noMonths+=12 )
	{
		computeEMI( noMonths );	
	}
}

function computeEMI( months )
{
	var interest = rateofinterest / ( 12 * 100 );
	
	var finalEmi = 0;
	
	if ( document.getElementById('R1').checked )
	{
		finalEmi = (txtloanamount * interest * Math.pow(1 + interest, months - 1))/(Math.pow(1 + interest, months) - 1);	
	}
	else
	{
		finalEmi = (txtloanamount * interest * Math.pow(1 + interest, months))/(Math.pow(1 + interest, months) - 1);	
	}

	document.getElementById( months + 'months' ).innerHTML 	= 'Rs. ' + Math.round( finalEmi ) + '/-';
	document.getElementById( months + 'print' ).innerHTML	= '<a style="cursor:pointer;" title="Click to view/print EMI Schedule." onClick="printEMISchedule(' + months + ')">View Chart</a>';
	return finalEmi;
	
}

function printEMISchedule( months )
{
	prtSched( months );
}

function prtSched( months )
{
	if ( validateInputs() ) return;
	var totalInterest = 0;
	fpv = computeEMI( months );

	var str = "";
	str=fpv;
	str = Math.round(str);
	
	pct=rateofinterest/12/100;
	
	if ( document.getElementById('R2').checked )
	{
		emiType = "Arrears(i.e. Rear Ended EMI's).";
	}
	else
	{
		emiType = "Advance."
	}
	
	if ( document.getElementById('R1').checked )
	{
		months -= 1;
		txtloanamount -= fpv;
	}
	
	ls = "<h3 style='border-bottom:2px solid #555555;font-family:arial, verdana;'>CarWale EMI Schedule</h3>";
	ls += "<div align='right' class='doNotPrint' style='padding:5px;'><a href='javascript:print()' title='Print the EMI schedule'><img border='0' src='/images/icons/print.gif' />&nbsp;Print</a></div>";
	ls +="<p align='justify'>Following  Schedule Is For : " + document.getElementById('txtloanamount').value
	  + " to repay in " + months
	  + " months.<br>"
	  + "All calculations are based on EMI in " + emiType + "</p>"
	  + "<table border='1' cellpadding='0'><tr>"
	  + "<th>EMI Number</th>"
	  + "<th>EMI Amount</th>"
	  + "<th>Interest Amount</th>"
	  +" <th>Principal Reduction</th>"
	  +" <th>Balance Due</th></tr>";
	
	for (var j=0;j<months;j++)
	{
		ntr=(txtloanamount*pct);
		// Next Line is added by Banwari to calculate Total Interest Amount.
		totalInterest = Number( totalInterest ) + Number( ntr );
		
		prp=fpv-ntr;
		
		if (prp>txtloanamount)
		{
			prp=txtloanamount;
		}
		
		txtloanamount-=prp;
				
		if (fpv>(ntr+prp))
		{
			fpv=ntr+prp;
		}
		
		str = (j+1)+".";

		ls += '<tr>'
			+ '<td>' + str + '</td>'
			+ '<td>' + 'Rs.' + Math.round(fpv) + '</td>'
			+ '<td>' + 'Rs.' + Math.round(ntr) + '</td>'
			+ '<td>' + 'Rs.' + Math.round(prp) + '</td>'
			+ '<td>' + 'Rs.' + Math.round(txtloanamount) + '</td>'
			+ '</tr>';
	}
	
	ls += '</table>';
	
	var emiChart = document.getElementById('emiChart').innerHTML;

	document.getElementById('divChartVal').innerHTML = ls
		+ '<p>Total Interest Amount : Rs. ' + Math.round( totalInterest ) + '</p>'
		+ '<p>Complete EMI List</p>'
	 	+ emiChart
		+ '<p>Note: Interest calculated at 1/12th of annual interest rate on'
		+ "    the remaining principal amount. (Rounding errors "
		+ "possible)</p>";
		
	printSchedule();

}

function advanceEMI( calculatedEMI , monthsEMI )
{
	EMItoCalculate = calculatedEMI
	document.getElementById('txtloanamount').value = document.getElementById('txtloanamount').value - calculatedEMI;
	document.getElementById('txtloanamount').value = parseInt(document.getElementById('txtloanamount').value) + parseInt(EMItoCalculate);
}

function printSchedule()
{
	var myWindow = window.open('','myWindow','toolbars=no,width=650,height=500,scrollbars=yes');
	myWindow.document.write('<html><head><title>CarWale : EMI Schedule</title>');
	myWindow.document.write('<style>body, table, p { font-family:arial, verdana;font-size:11px; }');
	myWindow.document.write('p { align:justify;padding:10px 0 10px 0; } table { border-collapse:collapse; }');
	myWindow.document.write('td, th { padding:2px; } .doNotShow { display:none; } th { background-color:#f3f3f3; } @media print { .doNotShow { display:none; } .doNotPrint { display:none;} }</style>');
	myWindow.document.write('</head><body>');
	myWindow.document.write('<pre>' + document.getElementById('divChartVal').innerHTML + '</pre>');
	myWindow.document.write('</body></html>')
	myWindow.document.close();
}

// Compute Loan Interest.
function getLoanInterest( carPrice, months, emi, rate )
{
	// First verify that the inputs are correct!
	if ( validateInputs() )
		return "";
		
	var totalInterest = 0;

	var loanAmount = carPrice;
					
	var interest = rate / ( 12 * 100 );
	var prp = 0, fpv = emi, ntr = 0;
					
	for (var i = 0; i < months; i++)
	{
		ntr = loanAmount * interest;
		
		totalInterest += ntr;
		
		prp = fpv - ntr;

		if ( prp > loanAmount )
		{
			prp = loanAmount;
		}
		
		loanAmount -= prp;
				
		if ( fpv > ( ntr + prp ) )
		{
			fpv = ntr + prp;
		}
		
		totalInterest = Math.round( totalInterest, 2 );
	}
	
	return totalInterest;
}