# Last update: 2008/02/15
# 
# RENAMER V 0.1
#
# (p) Jerry Nagasaki
#
#
# Generates a Rename-Batch-File of an input file list
#
# INPUT:  brwlist       (file list)
# OUTPUT: renfiles.bat  (renamer batch file with reanmed file format:
#                       [String][Formated Running Number].[Extension])
#
# NOTE: File names with "double extension" like "abc.def.jpg"
#  are NOT allowed!

# set different input file name here if desired
$inputfile = "brwlist";

open(FILE, "<$inputfile") || die "Could not open '$inputfile'\n"; 
my @infile = <FILE>;	
close(FILE);

my $length = @infile;
if ($length == 0)
{
	die "'$inputfile' is empty!\n";
}

# Get file names and extensions
my @files="";
my @ext="";

foreach (@infile)
{
	my $foo = $_;		# get file name
	$foo =~ s/\..+$//go;
	chomp ($foo);
	push (@files, $foo);

	print "$foo : ";

	$foo = $_;		# get extension
	$foo =~ s/.+\.//go;
	chomp ($foo);
	push (@ext, $foo);
	
	print "$foo\n";
}

# user dialog
print "\nEnter desired renaming file name letter(s): ";
my $letter = <STDIN>;
chomp ($letter);

print "Enter desired renaming start number: ";
my $startnum = <STDIN>;
chomp ($startnum);

print "Enter desired number of chars per numbering (1 - 4): ";
my $maxnum = <STDIN>;
chomp ($maxnum);

# generate batch file
my @outfile = "";

push (@outfile, "rem =========================================================================\n");
push (@outfile, "rem                 RENFILES.BAT - generated by RENAMER.PL\n");
push (@outfile, "rem                       (p) 2008 by Jerry Nagasaki\n");
push (@outfile, "rem =========================================================================\n\n");
push (@outfile, "rem -------------------------------------------------------------------------\n");
push (@outfile, "rem FIRST STAGE:\n");
push (@outfile, "rem Rename files into dummy file names to prevent double names\n");
push (@outfile, "rem -------------------------------------------------------------------------\n\n");

for (my $i = 1; $i <= $length; $i++)
{
	my $filename = $files[$i].".".$ext[$i];
	
	my $number = zeroextend($i - 1, 4);
	
	my $foo = "ren $filename \@\@\@$number.$ext[$i]\n";
	push (@outfile, $foo);
}

push (@outfile, "\nrem -----------------------------------------------------------------------\n");
push (@outfile, "rem SECOND STAGE:\n");
push (@outfile, "ren Rename dummy names to desired file names\n");
push (@outfile, "rem -------------------------------------------------------------------------\n\n");

for (my $i = 1; $i <= $length; $i++)
{
	my $number1 = zeroextend($i - 1, 4);
	my $number2 = zeroextend($i - 1 + $startnum, $maxnum);
	
	my $foo = "ren \@\@\@$number1.$ext[$i] $letter$number2.$ext[$i]\n";
	push (@outfile, $foo);
}

open(FILE, ">./renfiles.bat");
print FILE @outfile;	
close(FILE);


# Sub routines

# add necessary leading zeros
sub zeroextend
{
	$num = shift;
	$maxnum = shift;
	
	# may to be optimized by "use switch"	
	if ($maxnum == 4)
	{
		$retnum = sprintf ("%.4d", $num);
	}
	elsif ($maxnum == 3)
	{
		$retnum = sprintf ("%.3d", $num);
	}	
	elsif ($maxnum == 2)
	{
		$retnum = sprintf ("%.2d", $num);
	}
	else
	{
		$retnum = sprintf ($num);
	}
	
	return $retnum;
}