#!/usr/bin/perl -w
#
# which_deb
#
# Simple helper tool to find the appropriate version of a package in
# the archive to meet a requirement in the debian-cd build

use strict;

my ($mirror, $codename, $pkg, $pth, $output);

$mirror = shift;
$codename = shift;
$pkg = shift;
$output = shift;
$pth = "$mirror/dists/$codename/main";

if (!defined ($output)) {
    $output = "binary";
}

sub grab_bin_info {
    my $pth = shift;
    my $arch = shift;
    my $pkgname = shift;
    my $old_split = $/;
    my $match;
    my $result = "";
    
    my $pgz = "$pth/binary-$arch/Packages.gz";

    $/ = ''; # Browse by paragraph    

    if (-e $pgz) {
        open(PFILE, "zcat $pgz |") or
            die "Failed to read Packages file $pgz";

        while (defined($match = <PFILE>)) {
            if (($match =~ /^Package: \Q$pkgname\E$/m)) {
                $result = $match;
                close PFILE;
                return $result;
            }
        }
        # Fell through
        close PFILE;
    }
    return "";
}

sub grab_src_info {
    my $pth = shift;
    my $pkgname = shift;
    my $old_split = $/;
    my $match;
    my $result = "";
    
    my $pgz = "$pth/source/Sources.gz";

    $/ = ''; # Browse by paragraph    

    if (-e $pgz) {
        open(PFILE, "zcat $pgz |") or
            die "Failed to read Sources file $pgz";

        while (defined($match = <PFILE>)) {
            if (($match =~ /^Package: \Q$pkgname\E$/m)) {
                $result = $match;
                close PFILE;
                return $result;
            }
        }
        # Fell through
        close PFILE;
    }
    return "";
}

my $bin_deb = "";
my $pkgdata = "";
my $srcname = "";

if ($pkg eq "debootstrap") {
    $pkgdata = grab_bin_info($pth, "i386", $pkg);

} elsif ($pkg eq "silo") {
    $pkgdata = grab_bin_info($pth, "sparc", $pkg);

} elsif ($pkg eq "syslinux") {
    $pkgdata = grab_bin_info($pth, "i386", "syslinux-common");
    if (length($pkgdata) < 3) {        
        $pkgdata = grab_bin_info($pth, "i386", "syslinux");
    }
} elsif ($pkg eq "yaboot") {
    $pkgdata = grab_bin_info($pth, "powerpc", $pkg);
}

if (length($pkgdata) > 2) {
    if ($output eq "binary") {
        $pkgdata =~ m/^Filename: (\S+)/m and $bin_deb = $1;
        print "$bin_deb\n";
    }
    elsif ($output eq "source") {
        $srcname = $pkg;
        $pkgdata =~ m/^Source: (\S+)/m and $srcname = $1;
        $pkgdata = grab_src_info($pth, $srcname);
        if (length($pkgdata) > 2) {
            my $dir;
            $pkgdata =~ m/^Directory: (\S+)/m and $dir = $1;
            $pkgdata =~ m/^ (\S+) (\S+) ((\S+).*dsc)/m and print "$dir/$3\n";
            $pkgdata =~ m/^ (\S+) (\S+) ((\S+).*diff.gz)/m and print "$dir/$3\n";
            $pkgdata =~ m/^ (\S+) (\S+) ((\S+).*tar.gz)/m and print "$dir/$3\n";
        }
    }
}