#!/usr/bin/perl -w

# $Dwarf: safe_mv,v 1.5 2002/10/26 20:20:00 ward Exp $
# $Source$

#
# Scriptje om bestanden te moven, en bij het reeds bestaan van een bestand
# op de plek waar het naartoe gemoved wordt eerst even te vergelijken
# of ze identiek zijn. Zo nee, gaat de move niet door. Zo ja, delete
# te moven bestand.
#
# (C) 2001-2002 Ward Wouts
#

use File::Copy;
use Digest::MD5 qw(md5);
use Getopt::Long;

$DEBUG = 0;

&cmdline;
&process;

$opt_r = 1; # just get rid of that stupid message from -w

sub process {
	foreach ( @sources ) {
		$source = "$_";
		$target = "$_";
		$target =~ s/.*\///;
		$target = $targetdir."/".$target;
		if ( -e "$target" ) {
			&compare($source, $target);
		} elsif ( ! $opt_r ) {
			if ( $DEBUG ) { print "mv $_ -> $target\n"; }
			else { move("$_", "$target") or die "move failed: $!"; }
		}
	}
}

sub compare($$) {
	my ($source_size, $target_size);
	my (@source_stat, @target_stat);
	print "Comparing... ";
# First compare size. If this differs, we're done quickly.
	if ( (-s $source) == (-s $target) ) {
		@source_stat = stat $source;
		@target_stat = stat $target;
		if (( $source_stat[1] == $target_stat[1] ) &&
			( $source_stat[0] == $target_stat[0] )) {
			print "Skipped $source & $target are one and the same!\n"
		} else {
			print "$source and $target are the same size\n" if $DEBUG;
			$source_digest = &calc_md5($source);
			print "source digest $source_digest\n" if $DEBUG;
			$target_digest = &calc_md5($target);
			print "source digest $target_digest\n" if $DEBUG;
			if ( $source_digest eq $target_digest ) {
				print "Files are the same. Deleting $source.\n";
				unlink($source)
					or die "Can't delete $source: $!\n";
			} else {
				print "Skipped mv $source -> $target files differ\n"
			}
		}
	} else {
		print "Skipped mv $source -> $target files differ\n";
	}
}

sub calc_md5($) {
	my ($file, $digest);
	$file = shift;
	$md5 = Digest::MD5->new;
	open FILE, "<$file" or die "couldn't open file: $!\n";
	seek(FILE, 0, 0);
	$md5->reset;
	$md5->addfile(FILE);
	$digest = $md5->hexdigest;
	close(FILE);
	return $digest;
}

sub cmdline {
	&GetOptions("h", "r");

	&help if $opt_h;

	if ($#ARGV < 1) { &help; }

	$targetdir=pop(@ARGV);
	if ( ! -d $targetdir ) { &help; }
	if ( $DEBUG ) { print "$targetdir\n"; }

	@sources = @ARGV;
}

sub help {
	$opt_h = 1; # just get rid of that stupid message from -w
	print << "EOT";

$0 [options] <files> <destination>

-h		this help message
-r		remove duplicates only, don't move files

EOT
	exit 1;
}