#!/usr/bin/perl
# Versioning control program
# Given filename arguments, searches for existing .<filename>.### files
# and increments ### accordingly.
$debug = 0;

sub usage {
	print "Usage:\n";
	print "versioner [-c cache_dir] file(s)\n";
	exit;
} # end subroutine usage definition
unless($ARGV[0]) {
	usage();
	};
if($ARGV[0] eq "-c") {
	# cache directory
	shift(@ARGV);
	$cache_dir = shift(@ARGV);
	$use_cache = 1;
	}
foreach $name (@ARGV)
	{
	# To allow for files coming from multiple directories,
	# need to get the name from the file path.
	if($debug){print "filename is:  $name\n";};
	unless(-e $name)
		{
		warn "\"$name\" does not exist\n";
		next;
		}
	if(-l $name)
		{
		print "$name is a link\n";
		next;
		}
	if($name =~ m/(.*\/)(.*?)$/)
		{
		$directory = $1;
		$name = $2;
		}
	else
		{
		$directory = "./";
		};

	if($debug){print "directory is:  $directory\n";};
	if($debug){print "name is:  $name\n";};
	unless($use_cache) {
		$cache_dir = $directory;		# now use $cache_dir for all output and oldfiles
		}
	opendir(DIRHANDLE,$cache_dir);
	$#filelist = 0;
	$filelist[0] = "";
	@filelist = readdir(DIRHANDLE);
	$new_num = "000";

	foreach $file (@filelist)
		{
		if($file =~ m/\.$name\.(\d{3})/)
			{
			$num = $1;
			if($num >= $new_num)
				{
				$new_num = sprintf("%03d",$num+1);
				};
			};
		};
	if($debug){print "number is:  $new_num\n";};
	# got number and path, etc so now we can open the output
	# and input files and make our copy
	open(INFILE, "$directory/$name");		# this is the original
	if($new_num ne "000")
		{
		$last_num = sprintf("%03d",$new_num - 1);
		open(LASTFILE, "$cache_dir.$name.$last_num");
		$nothing = <LASTFILE>; # read the first line to get rid of the date and note.
		$last = join("", <LASTFILE>);
		if($nothing !~ m/^original/)
			{
			$last = $nothing . $last; 	# backup was created before we started adding comments and date strings.
			};
		}
	else
		{
		$last = 0;
		};

	$line = join("", <INFILE>);
	if( ($last != 0) || ($line ne $last) )	# file has changed, so make a backup copy
		{
		# only add note if it is a text file
		if(0 or -T "$directory/$name") { # Mon Aug 21, 2006 -- now I know better
			($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = localtime( (stat("$directory/$name") )[9] );
			if($debug){print "stat gives:  ", (stat("$directory/$name") )[8], "\n";	};
			$year +=1900;
			$created_date = sprintf("%02d/%02d/%02d",$mon+1,$mday,$year);
			($sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst) = localtime;
			$year +=1900;
			$now_date = sprintf("%02d/%02d/%02d",$mon+1,$mday,$year);
			$note = "original file last modified on $created_date" .
					" backed up by versioner on:  $now_date\n";
			}
		else {
			$note = "";
			}
		(open(OUTFILE, ">$cache_dir.$name.$new_num") ) or die "couldn't open outfile\n";
		print OUTFILE "$note" . "$line";
		print "$cache_dir.$name.$new_num\t";
		$success++;
		} # end if new
	else {
		print "no\t";
		$success++;	# not really success, but better than failure
		};
	}; #end foreach
$success && print "revisions saved\n";