#!/usr/bin/perl -w
my $usage = "Usage: $0 -adjust [-][hh:m]m:ss [-file wwwww.www] [-start hh:mm:ss]";

use Date::Calc qw( Decode_Date_US Add_Delta_DHMS Delta_DHMS);

my $debug;
##my $debug = 1;
my ($adjsec,$startsec);
my %trans;

while(@ARGV) {
	my ($opt,$val) = (shift,shift);
	$opt =~ s/^(\-\w)\w*$/$1/;
	if($opt eq "-a") {
		($adjsec) = &hhmmss_toseconds($val) or die "Cannot convert $opt $val: $!\n";
		print STDERR "adjusting by $adjsec seconds\n";
	} elsif ($opt eq "-f") {
		&get_trans("$val");
	} elsif ($opt eq "-s") {
		($startsec) = &hhmmss_toseconds($val) or die "Cannot convert $opt $val: $!\n";
	} else {
		die "Unknown option $opt\n",$usage;
	}
}

while(<>) {
###	48778 Thu Feb 22 15:42:39 2001 546.jpg
	chomp;
	my ($size,$day,$mo,$date,$time,$year,$file) = split;
###	print STDERR "time is $time\n";
	my ($timesec) = &hhmmss_toseconds($time);
###	print STDERR "timesec is $timesec\n";
	my $fn = $file;
	$fn =~ s/\..*$//;
	if(exists $trans{$fn}) {
		my $tr = $trans{$fn};
		if($tr =~ /^-?\d{1,2}$/) {
			$timesec += $tr;
			print STDERR "$fn:	Time adjusted by $tr\n";
		} elsif($tr =~ /:/ and $tr =~ /^[\d:]+/) {
			my $oldsec = $timesec;
			$timesec = $startsec + &hhmmss_toseconds($tr);
			my $change = $timesec - $oldsec;
			print STDERR "$fn:	Time changed  by $change\n";
		} else {
			print STDERR "$fn: 	Cannot parse transition $tr\n";
		}
	} elsif (defined $adjsec) {
		$timesec += $adjsec;
	} else {
		print STDERR "$fn:	No change\n";
	}
	($time) = &seconds_tohmmss($timesec);
	print join(' ',$size,$day,$mo,$date,$time,$year,$file),"\n";
}
exit;

sub hhmmss_toseconds {
my ($t) = @_;
my $sign = ($t =~ s|^\s*-||) ? -1 : +1;
if ($t =~ m|^([\d]+):([\d]+):([\d\.]+)$|) {
	$t = 3600*$1 + 60*$2 + $3;
} elsif ($t =~ m|^([\d]+):([\d\.]+)$|) {
	$t = 60*$1 + $2;
} else {
	die "hhmmss_toseconds: bad arg <$t> sign <$sign>";
}
return ($sign*$t);
}

sub seconds_tohmmss {
my ($t) = @_;
### print STDERR  "stoh: $t\n";
my (undef,undef,$day,$hour,$minute,$second) = Add_Delta_DHMS(1,1,1,0,0,0,0,0,0,$t);
return (sprintf("%02i:%02i:%02i",$hour,$minute,$second));
if($hour) {
	$t = sprintf("%i:%02i:%02i",$hour,$minute,$second)
} elsif ($minute) {
	$t = sprintf("%i:%02i",$minute,$second)
} else {
	$t = sprintf("%i",$second)
} 
return ($t);
}

sub pretty_date {
return (join('/',$_[1],$_[2],$_[0]).' '.sprintf("%02i:%02i:%02i",@_[3..$#_]));
}

sub get_trans {
my ($infile) = @_;
open(TS,"<$infile") or die "Cannot open <$infile: $!";
while(<TS>) {
	chomp;
	next unless $_;
	my @a = split;
	my ($i,$tr) = ($a[0],$a[$#a]);
	if($tr =~ /^[\d:]+$/) {
		$trans{$i} = $tr;
	} else {
		print STDERR "Bad time in $_\n";
	}
}
if($debug) {for my $i (sort {$a<=>$b}keys %trans) {print STDERR "$i     $trans{$i}\n"}}
close(TS) and print STDERR "Read transition file $infile\n";
return
}