#!/usr/bin/perl
#********************************************************************
#
#  loan_recur.pl :  Script computes an amortization of a potential loan.
#                   and generates recurrent transactions
#
#  Michel Verdier 12/1998
#  based on loan.pl from G. K. Fenton  1/1997
#
#********************************************************************
#
# Definitions of main variables...
#   $price    = Total Cost of Item.
#   $down_pmt = Down Payment which takes away from Price.
#   $N        = Term of Loan in units of (Months).
#   $I        = Interest Rate divided by 12 for units of Months then
#               divided by 100 to put into a percentage format.
#   $dataout  = Plot file name used by GnuPlot, Default name
#               is 'data'.
#
#********************************************************************

package CBB;
$CBB::cbb_incl_dir = "/usr/X11R6/lib/X11/cbb";
unshift(@INC, $CBB::cbb_incl_dir);
require "common.pl";

$dataout = "data";


#  Process the Command Line Arguments
# print @ARGV,"\n";
# print $#ARGV+1,"\n";

if ($#ARGV+1 < 8) {
	print "\n\n loan.pl :  This Script computes an amortization of a potential loan.\n\n";
	print " Usage: loan.pl [-p <price>] [-d <down_pmt>] [-t <term>] [-i <int_rate>] [-o <name>]\n\n";
	print "\n Example: loan -p 100000 -d 10000 -t 360 -i 7.0 \n\n";
	print " Where :\n";
	print "   -p --> Price to be financed.\n";
	print "   -d --> Down Payment.\n";
	print "   -t --> Loan Term in Months.\n";
	print "   -i --> Annual Percentage Rate.\n";
	print "   -s --> Starting date (format JJ/MM/AAAA).\n\n";
	print "   -o --> Output data file name.\n\n";
	print "   -des --> Description for generated transaction.\n\n";
	print "   -com --> Comment for generated transaction.\n\n";
	print "   -icat --> Interest category for generated transaction (no transfer).\n\n";
	print "   -pcat --> Principal category for generated transaction (account to transfer founds from).\n\n";
	exit(1);
} 

$i = 0;
foreach (@ARGV) {
	if ($ARGV[$i] eq "-p") {  # Get the Price or Cost of Loan.
        $price = $ARGV[$i+1];
	}
	if ($ARGV[$i] eq "-d") {  # Get the Down Payment for Loan.
        $down_pmt = $ARGV[$i+1];
	}
	if ($ARGV[$i] eq "-t") {  # Get the Term of the Loan in Months.
        $N = $ARGV[$i+1];
	} 
	if ($ARGV[$i] eq "-i") {  # Get the Interest Rate of the Loan.
        $I = $ARGV[$i+1];
        $I = $I/12.0/100.0;    # Put into Monthly percentage Units.
	}
	if ($ARGV[$i] eq "-o") {  # Get the output data file name.
        $dataout = $ARGV[$i+1];
	} 
	if ($ARGV[$i] eq "-s") {  # Get the starting date.
	    ($day,$month,$year) = split(/\//,$ARGV[$i+1]);
		if ($year>100) {
			$year=$year%100;
		}
	} 
	if ($ARGV[$i] eq "-des") {  # Get the Description.
        $description = $ARGV[$i+1];
	}
	if ($ARGV[$i] eq "-com") {  # Get the Comment.
        $comment = $ARGV[$i+1];
	}
	if ($ARGV[$i] eq "-icat") {  # Get the Interest category.
        $int_categ = $ARGV[$i+1];
	}
	if ($ARGV[$i] eq "-pcat") {  # Get the Principal category.
        $princ_categ = $ARGV[$i+1];
	}
	$i++;
}

$loan_amt = $price;
$tmp_var  = (1.0 + $I)**$N;
$payment  = $loan_amt * $I * $tmp_var/($tmp_var - 1.0);

open(FOUT, ">$dataout") || die "\n\n Warning: Can't open output file '$dataout' !\n\n";

$balance[0]  = $loan_amt;
for( $i=1 ; $i<=$N ; $i++ ) {
	$balance[$i]   = $balance[$i-1] * (1 + $I) - $payment;
	$interest[$i]  = $balance[$i-1] * $I;
	$principal[$i] = $payment - $interest[$i];
	
	# no transfer via a split, too bad
	#print FOUT &pad($day) . "\t" . &pad($month) . "\t" . &pad($year);
	#print FOUT "\t$description\t0.0\t" . int($payment*100)/100;
	#print FOUT "\t$comment\t|$int_categ| |" . int($interest[$i]*100)/100;
	#print FOUT "|$princ_categ| |" . int($principal[$i]*100)/100 . "|\n";
	
	# write transfer from an account
	print FOUT &pad($day) . "\t" . &pad($month) . "\t" . &pad($year);
	print FOUT "\t$description\t0.0\t" . int($payment*100)/100;
	print FOUT "\t$comment\t$princ_categ\n";

	# get out interests
	print FOUT &pad($day) . "\t" . &pad($month) . "\t" . &pad($year);
	print FOUT "\t$description\t" . int($interest[$i]*100)/100;
	print FOUT "\t0.0\t$comment\t$int_categ\n";

	$month++;
	if ($month>12) {
		$year++;
		if ($year==100) {
			$year=01;
		}
		$month=1;
	}
}
close(FOUT);

$sum_payment   = 0.0;
$sum_principal = 0.0;
$sum_interest  = 0.0;
for( $i=1 ; $i<=$N ; $i++ ) {
	$sum_payment   += $payment;
	$sum_principal += $principal[$i];
	$sum_interest  += $interest[$i];
}


printf("\n     Cost Amount     = \$%7.2f\n", $price);
printf("     Down Payment    = \$%7.2f\n", $down_pmt);
printf("     Loan Amount     = \$%7.2f\n", $loan_amt);
printf(" >>> Monthly Payment = \$%7.2f <<<\n\n", $payment);
printf("------- Data over Life of Loan -------\n");
printf("     Principal Only  = \$%7.2f\n", $sum_principal);
printf("     Interest Only   = \$%7.2f\n", $sum_interest);
printf("     Total Payment   = \$%7.2f\n", $sum_payment);

printf("\n  Created recurrent transactions in < $dataout >!\n");

exit(0);