#!/usr/bin/perl

(our $VERSION) = q(Id: genhdlist2 20460 2006-11-23 13:19:11Z pixel ) =~ /(\d+\.\d+)/;

use URPM;
use MDV::Packdrakeng;
use Getopt::Long;

main();

sub usage () {
    require Pod::Usage;
    Pod::Usage::pod2usage({ '-verbose' => 1 });
}

sub main() {
    my %options;

    GetOptions(
	'clean' => \$options{no_incremental},
	'no-bad-rpm' => \$options{no_bad_rpm},
	'no-md5sum' => \$options{no_md5sum},
	'nolock' => \$options{nolock},
	'allow-empty-media' => \$options{allow_empty_media},
	'file-deps=s' => \$options{file_deps},
	'h|help' => sub { usage(); exit 0 },
	'q|quiet' => sub { $options{verbose} = -1 },
	'v|verbose' => sub { $options{verbose}++ },
	'version' => sub { warn "$0 version $VERSION\n"; exit 0 },
    );

    @ARGV == 1 or usage();
    my $rpms_dir = $ARGV[0];

    do_it($rpms_dir, %options);
}

# global vars
my ($no_bad_rpm, $verbose);
my $tmp_header;

sub do_it {
    my ($rpms_dir, %options) = @_;

    $verbose  = $options{verbose};
    $no_bad_rpm = $options{no_bad_rpm};

    my @rpms = grep { /\.rpm$/ } all($rpms_dir);
    @rpms || $options{allow_empty_media} or die "no *.rpm found in $rpms_dir (use --allow-empty-media?)\n";

    my $media_info_dir = "$rpms_dir/media_info";
    -e $media_info_dir || mkdir $media_info_dir or die "Can't mkdir $media_info_dir: $!n";
    -d $media_info_dir && -w _ && -x _ or die "$media_info_dir isn't a writable directory, bailing out\n";

    my $hdlist = "$media_info_dir/hdlist.cz";
    my $synthesis = "$media_info_dir/synthesis.hdlist.cz";
    my $lock_file = "$media_info_dir/UPDATING";
    $tmp_header = "$media_info_dir/.tmp-header";

    my $lock = !$options{nolock} && lock_file($lock_file);

    $SIG{INT} = sub { 
	unlink "$hdlist.tmp", "$synthesis.tmp", $tmp_header;
	unlink $lock_file if $lock;
	exit 1;
    };
    END { unlink $lock_file if $lock }

    my %rpms_todo = map { /(.*)\.rpm/ => 1 } @rpms;

    my $urpm = new URPM;

    read_file_deps($urpm, $options{file_deps}) if $options{file_deps};

    build_hdlist($urpm, \%rpms_todo, $hdlist, $rpms_dir, $options{no_incremental});
    build_synthesis($urpm, "$synthesis.tmp");

    if (1) {
	print "replacing $hdlist with $hdlist.tmp\n" if $verbose >= 0;
	rename "$hdlist.tmp", $hdlist or die "rename $hdlist failed: $?\n";
	print "replacing $synthesis with $synthesis.tmp\n" if $verbose >= 0;
	rename "$synthesis.tmp", $synthesis or die "ERROR: this should not happen: rename $synthesis failed\n";
	generate_md5sum($media_info_dir) if !$options{no_md5sum};
    }
}

sub lock_file {
    my ($file) = @_;
    #- avoid putting a require on Fcntl ':flock' (which is perl and not perl-base).
    my ($LOCK_EX, $LOCK_NB) = (2, 4);

    print "locking $file\n" if $verbose > 0;
    open(my $lock, '>', $file) or die "lock_file $file failed\n";
    flock $lock, $LOCK_EX|$LOCK_NB or die "another genhdlist2 already running\n";
    $lock;
}

sub read_file_deps {
    my ($urpm, $file_deps) = @_;

    -r $file_deps or die "can't read $file_deps: $?\n";

    foreach (cat_($file_deps)) {
	chomp;
	$urpm->{provides}{$_} = undef;
    }
}

sub build_hdlist {
    my ($urpm, $rpms_todo, $hdlist, $rpms_dir, $b_no_incremental) = @_;

    my $out = MDV::Packdrakeng->new(
	archive => "$hdlist.tmp",
	compress => "gzip",
	uncompress => "gzip -d",
	comp_level => 9,
    ) or die "Can't create archive";

    if (-e $hdlist && !$b_no_incremental) {
	print "filtering $hdlist into $hdlist.tmp\n" if $verbose >= 0;
	filter_existing_hdlist($urpm, $rpms_todo, $hdlist, $out);
    }

    add_new_rpms_to_hdlist($urpm, $rpms_todo, $out, $rpms_dir);
}

sub filter_existing_hdlist {
    my ($urpm, $rpms_todo, $in_hdlist, $out) = @_;

    $urpm->parse_hdlist($in_hdlist, packing => 1, callback => sub {
	my (undef, $pkg) = @_;
	my $fullname = $pkg->fullname;
	if (delete $rpms_todo->{$fullname}) {
	    print "keeping $fullname\n" if $verbose > 1;
	    add_pkg_header($out, $pkg);
	    1; # do keep in memory
	} else {
	    print "removing $fullname\n" if $verbose > 0;
	    0; # don't keep in memory
	}
    });
}

sub add_new_rpms_to_hdlist {
    my ($urpm, $rpms_todo, $out, $rpms_dir) = @_;

    my @rpms = keys %$rpms_todo or return;
    if ($verbose >= 0) {
	if (@rpms > 100 || $verbose == 0) {
	    print "adding ", int(@rpms), " new rpms not available in existing hdlist\n";
	} else {
	    print "adding ", join(' ', @rpms), "\n";
	}
    }

    foreach (@rpms) {
	print "adding $_\n" if $verbose > 1;

	my $rpm = "$rpms_dir/$_.rpm";
	my ($id, undef) = $urpm->parse_rpm($rpm);
	if (!defined $id) {
	    if ($no_bad_rpm) {
		print STDERR "bad rpm $rpm\n";
		next;
	    } else {
		die "bad rpm $rpm\n";
	    }
	}
	my $pkg = $urpm->{depslist}[$id];
	add_pkg_header($out, $pkg);

	$pkg->pack_header; # for synthesis
    }
}

sub add_pkg_header {
    my ($out, $pkg) = @_;
    {
	open(my $fh, ">", $tmp_header);
	$pkg->build_header(fileno $fh);
    }
    {
	open(my $fh, "<", $tmp_header);
	$out->add_virtual('f', scalar($pkg->fullname), $fh);
    }
    unlink $tmp_header;
}

sub build_synthesis {
    my ($urpm, $synthesis) = @_;
    # for compatibility with perl-URPM < 1.48 (ie < 2007.1),
    # creating empty synthesis by hand. This is only needed to run on old distros
    if (@{$urpm->{depslist}} == 0) {
        open(my $hsynth, "| /bin/gzip > $synthesis");
	close $hsynth or die "Can't create empty synthesis $synthesis: $!\n";
    } else {
	$urpm->build_synthesis(
	    start     => 0,
	    end       => $#{$urpm->{depslist}},
	    synthesis => $synthesis,
	) or die "build_synthesis failed (disk full?)\n";
    }
}

sub generate_md5sum {
    my ($media_info_dir) = @_;
    print "updating $media_info_dir/MD5SUM\n" if $verbose >= 0;
    my $m = `cd '$media_info_dir' ; /usr/bin/md5sum hdlist.cz synthesis.hdlist.cz`;
    unlink "$media_info_dir/MD5SUM"; # ensure no hard link is used
    open my $f, '>', "$media_info_dir/MD5SUM" or die "Can't write MD5SUM: $!\n";
    print $f $m;
}


sub cat_ { my @l = map { my $F; open($F, '<', $_) ? <$F> : () } @_; wantarray() ? @l : join '', @l }

sub all {
    my $d = shift;

    local *F;
    opendir F, $d or return;
    my @l = grep { $_ ne '.' && $_ ne '..' } readdir F;
    closedir F;

    @l;
}

__END__

=head1 NAME

genhdlist2 - generates an hdlist and a synthesis file

=head1 SYNOPSIS

    genhdlist2 [options] dir

=head1 OPTIONS

=over 4

=item B<--clean>

Do not use existing hdlist.cz, build hdlist from scratch.

=item B<--file-deps>

Use the given file to know which file dependencies are used by other media.
Here is an example of use:

    package foo in medium contrib requires /bin/bar
    package bar in medium main has file /bin/bar

    % echo /bin/bar > media/media_info/file-deps
    % genhdlist2 --file-deps media/media_info/file-deps media/main/release

    without file-deps, media/main/release/media_info/synthesis.hdlist.cz would not provide /bin/bar.

This option is not needed for file-deps inside a same medium.

=item B<--no-md5sum>

Do not generate MD5SUM file.

=item B<--no-bad-rpm>

Do not abort on bad rpms.

=item B<--nolock>

Don't lock the media (can be useful when locks fail, eg NFS). Since the lock
is used to verify no other genhdlist2 process is running on the same media, it
is a dangerous option.

=item B<--allow-empty-media>

By default if no *.rpm files are found, F<genhdlist2> will exit on error.
To allow building empty media, use this option.

=item B<-v>

Be verbose. Use one more B<-v> to get even more verbose.

=item B<--quiet>

Quiet mode.

=back

=head1 DESCRIPTION

F<genhdlist2> is used to generate an hdlist and an associated synthesis file
from a set of RPM packages found in the directory passed on the command-line.
It will put the hdlist and synthesis files in media_info/ sub-directory.

Without B<--clean>, F<genhdlist2> is incremental, ie it will modify existing
media_info/hdlist.cz: it will first remove package headers for packages that
are no more in the directory. It will then add new packages. This makes an
important assumption: name-version-release-arch is enough to uniquely
indentify a package. So if foo-1-1 is in hdlist, genhdlist2 will keep it and
not bother verifying if it really is the same package.

Contrary to F<gendistrib>, F<genhdlist2> doesn't have to be work on all media
at once. For this, it assumes no inter media file dependencies are used. If
you still have inter media file dependencies, you can use option
B<--file-deps>.

=head1 SEE ALSO

gendistrib(1), parsehdlist(1)

=head1 COPYRIGHT

Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005 MandrakeSoft SA

Copyright (C) 2005, 2006, 2007 Mandriva SA

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

=cut