#!/usr/bin/perl -w

use strict;
use Compress::Zlib;
use File::stat;

my $mirror  = $ENV{'MIRROR'}  || die "Set the MIRROR var ...\n";
my $localdebs = $ENV{'LOCALDEBS'} || $mirror;
my $security = $ENV{'SECURITY'} || $mirror;
my $basedir = $ENV{'BASEDIR'} || die "Set the BASEDIR var ...\n";
my $codename = $ENV{'CODENAME'} || die "Set the CODENAME var ...\n";
my $tdir = $ENV{'TDIR'} || die "Set the TDIR var ...\n";

require "$basedir/tools/link.pl";

my $iso_blksize = 2048;
my $log_opened = 0;
my $old_split = $/;

sub msg_ap {
    my $level = shift;
    if (!$log_opened) {
        open(AP_LOG, ">> $tdir/$codename/log.add_packages")
            || die "Can't write in $tdir/log.add_packages!\n";
    }
    print AP_LOG @_;
}

sub size_in_blocks {
    my $size_in_bytes = shift;
    return (1 + int(($size_in_bytes + $iso_blksize - 1) / $iso_blksize));
}

# From a package name and section, work out the directory where its
# corresponding Packages file should live
sub Packages_dir {
    my $dir = shift;
    my $file = shift;
    my $section = shift;

    my ($pdir, $dist);

    if ($file =~ /\/main\//) {
        $dist = "main";
    } elsif ($file =~ /\/contrib\//) {
        $dist = "contrib";
    } elsif ($file =~ /\/non-free\//) {
        $dist = "non-free";
    } elsif ($file =~ /\/local\//) {
        $dist = "local";
    }	

    $pdir = "$dir/dists/$codename/$dist";
    if ($section eq "debian-installer") {
        $pdir = "$dir/dists/$codename/$dist/debian-installer";
    }
    return $pdir;
}

# Dump the apt-cached data into a Packages file; make the parent dir
# for the Packages file if necesssary
sub add_Packages_entry {
    my ($p, $file, $section, $pdir, $pkgfile, $gz);
    my $dir = shift;
    my $arch = shift;
    my ($st1, $st2, $size1, $size2);
    my $blocks_added = 0;
    my $old_blocks = 0;
    my $new_blocks = 0;

    m/^Package: (\S+)/m and $p = $1;
    m/^Section: (\S+)/m and $section = $1;

    if ($arch eq "source") {
        m/^Directory: (\S+)/mi and $file = $1;
        $pdir = Packages_dir($dir, $file, $section) . "/source";
        $pkgfile = "$pdir/Sources";
    } else {
        m/^Filename: (\S+)/mi and $file = $1;
        $pdir = Packages_dir($dir, $file, $section) . "/binary-$arch";
        $pkgfile = "$pdir/Packages";
    }

    msg_ap(0, "  Adding $p to $pkgfile(.gz)\n");
    
    if (! -d $pdir) {
        system("mkdir -p $pdir");
        $blocks_added++;
    }	

    if (-e $pkgfile) {
        $st1 = stat("$pkgfile");
        $old_blocks = size_in_blocks($st1->size);
    }

    if (-e "$pkgfile.gz") {
        $st1 = stat("$pkgfile.gz");
        $old_blocks += size_in_blocks($st1->size);
    }

    open(PFILE, ">>$pkgfile");
    print PFILE $_;
    close(PFILE);

    $gz = gzopen("$pkgfile.gz", "ab9") or die "Failed to open $pkgfile.gz: $gzerrno\n";
    $gz->gzwrite($_) or die "Failed to write $pkgfile.gz: $gzerrno\n";
    $gz->gzclose();
    $st1 = stat("$pkgfile");
    $st2 = stat("$pkgfile.gz");
    $size1 = $st1->size;
    $size2 = $st2->size;

    $new_blocks += size_in_blocks($st1->size);
    $new_blocks += size_in_blocks($st2->size);
    $blocks_added += ($new_blocks - $old_blocks);
    msg_ap(0, "    now $size1 / $size2 bytes, $blocks_added blocks added\n");
    return $blocks_added;
}

sub add_md5_entry {
    my $dir = shift;
    my $arch = shift;
    my ($pdir, $file, $md5);
    my $md5file = "$dir/md5sum.txt";
    my ($st, $size);
    my $p;
    my $blocks_added = 0;
    my $old_blocks = 0;
    my $new_blocks = 0;

    m/^Package: (\S+)/mi and $p = $1;

    if (-e $md5file) {
        $st = stat("$md5file");
        $old_blocks = size_in_blocks($st->size);
    }

    open(MD5FILE, ">>$md5file");

    if ($arch eq "source") {
        m/^Directory: (\S+)/mi and $pdir = $1;
        m/^ (\S+) (\S+) ((\S+).*dsc)/m and print MD5FILE "$1  ./$pdir/$3\n";
        m/^ (\S+) (\S+) ((\S+).*tar.gz)/m and print MD5FILE "$1  ./$pdir/$3\n";
        m/^ (\S+) (\S+) ((\S+).*diff.gz)/m and print MD5FILE "$1  ./$pdir/$3\n";
    } else {
        m/^Filename: (\S+)/m and $file = $1;
        m/^MD5sum: (\S+)/m and print MD5FILE "$1  ./$file\n";
    }

    close(MD5FILE);
    msg_ap(0, "  Adding $p to $md5file\n");
    $st = stat("$md5file");
    $size = $st->size;
    $new_blocks = size_in_blocks($st->size);
    $blocks_added = $new_blocks - $old_blocks;
    msg_ap(0, "    now $size bytes, added $blocks_added blocks\n");

    return $blocks_added;
}

# Roll back the results of add_Packages_entry()
sub remove_Packages_entry {
    my ($p, $file, $section, $pdir, $pkgfile, $tmp_pkgfile, $match, $gz);
    my $dir = shift;
    my $arch = shift;
    my ($st1, $st2, $size1, $size2);
    my $blocks_removed = 0;
    my $old_blocks = 0;
    my $new_blocks = 0;

    m/^Package: (\S+)/m and $p = $1;
    m/^Section: (\S+)/m and $section = $1;

    if ($arch eq "source") {
        m/^Directory: (\S+)/mi and $file = $1;
        $pdir = Packages_dir($dir, $file, $section) . "/source";
        $pkgfile = "$pdir/Sources";
    } else {
        m/^Filename: (\S+)/mi and $file = $1;
        $pdir = Packages_dir($dir, $file, $section) . "/binary-$arch";
        $pkgfile = "$pdir/Packages";
    }

    if (-e $pkgfile) {
        $st1 = stat("$pkgfile");
        $old_blocks += size_in_blocks($st1->size);
    }

    if (-e "$pkgfile.gz") {
        $st2 = stat("$pkgfile.gz");
        $old_blocks += size_in_blocks($st2->size);
    }

    $tmp_pkgfile = "$pkgfile" . ".rollback";

    msg_ap(0, "  Removing $p from $pkgfile(.gz)\n");

    open(IFILE, "<$pkgfile");
    open(OFILE, ">>$tmp_pkgfile");

    $gz = gzopen("$pkgfile.gz", "wb9");

    while (defined($match = <IFILE>)) {
        if (! ($match =~ /^Package: \Q$p\E$/m)) {
            print OFILE $match;
            $gz->gzwrite($match) or die "Failed to write $pkgfile.gz: $gzerrno\n";
        }
    }

    $gz->gzclose();
    close(IFILE);
    close(OFILE);

    rename $tmp_pkgfile, $pkgfile;
    $st1 = stat("$pkgfile");
    $st2 = stat("$pkgfile.gz");
    $size1 = $st1->size;
    $size2 = $st2->size;
    $new_blocks += size_in_blocks($st1->size);
    $new_blocks += size_in_blocks($st2->size);
    $blocks_removed += ($old_blocks - $new_blocks);
    msg_ap(0, "    now $size1 / $size2 bytes, $blocks_removed blocks removed\n");
    return $blocks_removed;
}

sub remove_md5_entry {
    my $dir = shift;
    my $arch = shift;
    my ($pdir, $file, $md5, $match, $present);
    my $md5file = "$dir/md5sum.txt";
    my $tmp_md5file = "$dir/md5sum.txt.tmp";
    my @fileslist;
    my ($st, $size, $p);
    my $blocks_removed = 0;
    my $old_blocks = 0;
    my $new_blocks = 0;

    $/ = $old_split; # Browse by line again

    m/^Package: (\S+)/mi and $p = $1;
    if ($arch eq "source") {
        m/^Directory: (\S+)/mi and $pdir = $1;
        m/^ (\S+) (\S+) ((\S+).*dsc)/m and push(@fileslist, "$1  ./$pdir/$3");
        m/^ (\S+) (\S+) ((\S+).*diff.gz)/m and push(@fileslist, "$1  ./$pdir/$3");
        m/^ (\S+) (\S+) ((\S+).*tar.gz)/m and push(@fileslist, "$1  ./$pdir/$3");
    } else {
        m/^Filename: (\S+)/m and $file = $1;
        m/^MD5Sum: (\S+)/mi and push(@fileslist, "$1  ./$file");
    }

    if (-e $md5file) {
        $st = stat("$md5file");
        $old_blocks = size_in_blocks($st->size);
    }

    open(IFILE, "<$md5file");
    open(OFILE, ">>$tmp_md5file");
    while (defined($match = <IFILE>)) {
        $present = 0;
        foreach my $entry (@fileslist) {
            if (($match =~ /\Q$entry\E$/m)) {
                $present++;
            }
        }
        if (!$present) {
            print OFILE $match;
        }
    }
    close(IFILE);
    close(OFILE);

    $/ = ''; # Browse by paragraph again
    rename $tmp_md5file, $md5file;
    msg_ap(0, "  Removing $p from md5sum.txt\n");
    $st = stat("$dir/md5sum.txt");
    $size = $st->size;
    $new_blocks = size_in_blocks($st->size);
    $blocks_removed = $old_blocks - $new_blocks;
    msg_ap(0, "    now $size bytes, $blocks_removed blocks removed\n");
    return $blocks_removed;
}

sub get_file_blocks {
    my $realfile = shift;
    my $st;
    $st = stat($realfile) or die "unable to stat file $realfile: $!\n";
    return size_in_blocks($st->size);
}

sub add_packages {
    my ($p, @files, $d, $realfile, $source, $section, $name, $pkgfile, $pdir);
    my $dir;

    my $total_blocks = 0;
    my $rollback = 0;
    my $option = shift;	
    if ($option =~ /--rollback/) {
        $rollback = 1;
        $dir = shift;
    } else {	
        $dir = $option;
    }

    if (! -d $dir) { 
        die "add_packages: $dir is not a directory ..."; 
    }

    my $pkg = shift;
    my ($arch, $pkgname) = split /:/, $pkg;

    msg_ap(0, "Looking at $pkg: arch $arch, package $pkgname, rollback $rollback\n");
    
    $/ = ''; # Browse by paragraph

    $ENV{'ARCH'} = $arch;
    if ($arch eq "source") {
        open (LIST, "$basedir/tools/apt-selection cache showsrc $pkgname |")
            || die "Can't fork : $!\n";
    } else {
        open (LIST, "$basedir/tools/apt-selection cache show $pkgname |")
            || die "Can't fork : $!\n";
    }

    while (defined($_ = <LIST>)) {
        undef @files;

        m/^Package: (\S+)/m and $p = $1;
        m/^Section: (\S+)/m and $section = $1;

        $source = $mirror;
        if ($arch eq "source") {
            m/^Directory: (\S+)/m and $pdir = $1;
            $source=$localdebs if $pdir=~m:local/:;
            $source=$security if $pdir=~m:updates/:;
            m/^ (\S+) (\S+) ((\S+).*dsc)/m and push(@files, "$pdir/$3");
            m/^ (\S+) (\S+) ((\S+).*diff.gz)/m and push(@files, "$pdir/$3");
            m/^ (\S+) (\S+) ((\S+).*tar.gz)/m and push(@files, "$pdir/$3");
        } else {
            m/^Filename: (\S+)/mi and push(@files, $1);
            $source=$localdebs if $1=~m:local/:;
            $source=$security if $1=~m:updates/:;
        }

        if ($rollback) {
            # Remove the Packages entry/entries for the specified package
            $total_blocks -= remove_Packages_entry($dir, $arch, $_);
            $total_blocks -= remove_md5_entry($dir, $arch, $_);

            foreach my $file (@files) {
                # Count how big the file is we're removing, for checking if the disc is full
                $realfile = real_file ("$source/$file");
                $total_blocks -= get_file_blocks($realfile);

                # Remove the link
                unlink ("$dir/$file") or die "Failed to remove $dir/$file\n";
                msg_ap(0, "  Rollback: removing $dir/$file\n");
            }
        } else {
            $total_blocks += add_Packages_entry($dir, $arch, $_);
            $total_blocks += add_md5_entry($dir, $arch, $_);

            foreach my $file (@files) {
                # And put the file in the CD tree (with a (hard) link)
                $realfile = real_file ("$source/$file");

                if (! -e "$dir/$file") {
                    # Count how big the file is, for checking if the disc
                    # is full. ONLY do this if the file is not already
                    # linked in - consider binary-all packages on a
                    # multi-arch disc
                    $total_blocks += get_file_blocks($realfile);
                    $total_blocks += good_link ($realfile, "$dir/$file");
                    msg_ap(0, "  Linked $dir/$file\n");
                } else {
                    msg_ap(0, "  $dir/$file already linked in\n");
                }
            }
        }
    }
    close LIST or die "Something went wrong with apt-cache : $@ ($!)\n";
    msg_ap(0, "  size $total_blocks\n");
    $/ = $old_split; # Return to line-orientation
    return $total_blocks;
}

1;