#!/usr/bin/perl
#
# dd-list: Generate a list of maintainers of packages.
#
# Written by Joey Hess <joeyh@debian.org>
# Modifications by James McCoy <jamessan@debian.org>
# Based on a python implementation by Lars Wirzenius.
# Copyright 2005 Lars Wirzenius, Joey Hess
#
# 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 of the License, 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, see <https://www.gnu.org/licenses/>.

use strict;
use warnings;
use FileHandle;
use Getopt::Long qw(:config bundling permute no_getopt_compat);
use Dpkg::Version;
use Dpkg::IPC;

my $uncompress;

BEGIN {
    $uncompress = eval {
        require IO::Uncompress::AnyUncompress;
        IO::Uncompress::AnyUncompress->import('$AnyUncompressError');
        1;
    };
}

my $version = '###VERSION###';

sub normalize_package {
    my $name = shift;
    # Remove any arch-qualifier
    $name =~ s/:.*//;
    return lc($name);
}

sub sort_developers {
    return map { $_->[0] }
      sort     { $a->[1] cmp $b->[1] }
      map      { [$_, uc] } @_;
}

sub help {
    print <<"EOF";
Usage: dd-list [options] [package ...]

    -h, --help
        Print this help text.

    -i, --stdin
        Read package names from the standard input.

    -d, --dctrl
        Read package list in Debian control data from standard input.

    -z, --uncompress
        Try to uncompress the --dctrl input before parsing.  Supported
        compression formats are gz, bzip2 and xz.

    -s, --sources SOURCES_FILE
        Read package information from given SOURCES_FILE instead of all files
        matching /var/lib/apt/lists/*_source_Sources.  Can be specified
        multiple times.  The files can be gz, bzip2 or xz compressed.

    -u, --uploaders
        Also list Uploaders of packages, not only the listed Maintainers
        (this is the default behaviour, use --nouploaders to prevent this).

    -nou, --nouploaders
        Only list package Maintainers, do not list Uploaders.

    -b, --print-binary
        If binary package names are given as input, print these names
        in the output instead of corresponding source packages.

    -V, --version
        Print version (it\'s $version by the way).
EOF
}

my $use_stdin      = 0;
my $use_dctrl      = 0;
my $source_files   = [];
my $show_uploaders = 1;
my $opt_uncompress = 0;
my $print_binary   = 0;
GetOptions(
    "help|h"         => sub { help(); exit },
    "stdin|i"        => \$use_stdin,
    "dctrl|d"        => \$use_dctrl,
    "sources|s=s@"   => \$source_files,
    "uploaders|u!"   => \$show_uploaders,
    'z|uncompress'   => \$opt_uncompress,
    "print-binary|b" => \$print_binary,
    "version"        => sub { print "dd-list version $version\n" })
  or do {
    help();
    exit(1);
  };

if ($opt_uncompress && !$uncompress) {
    warn
"You must have the libio-compress-perl package installed to use the -z option.\n";
    exit 1;
}

my %dict;
my $errors = 0;
my %package_name;

sub parsefh {
    my ($fh, $fname, $check_package) = @_;
    local $/ = "\n\n";
    my $package_names;
    if ($check_package) {
        $package_names = sprintf '(?:^| )(%s)(?:,|$)',
          join '|', map { "\Q$_\E" }
          keys %package_name;
    }
    my %sources;
    while (<$fh>) {
        my ($package, $source, $binaries, $maintainer, @uploaders);

        # These source packages are only kept around because of stale binaries
        # on old archs or due to Built-Using relationships.
        if (/^Extra-Source-Only:\s+yes/m) {
            next;
        }

     # Binary is shown in _source_Sources and contains all binaries produced by
     # that source package
        if (/^Binary:\s+(.*(?:\n .*)*)$/m) {
            $binaries = $1;
            $binaries =~ s/\n//;
        }
        # Package is shown both in _source_Sources and _binary-*.  It is the
        # name of the package, source or binary respectively, being described
        # in that control stanza
        if (/^Package:\s+(.*)$/m) {
            $package = $1;
        }
        # Source is shown in _binary-* and specifies the source package which
        # produced the binary being described
        if (/^Source:\s+(.*)$/m) {
            $source = $1;
        }
        if (/^Maintainer:\s+(.*)$/m) {
            $maintainer = $1;
        }
        if (/^Uploaders:\s+(.*(?:\n .*)*)$/m) {
            my $matches = $1;
            $matches =~ s/\n//g;
            @uploaders = split /(?<=>)\s*,\s*/, $matches;
        }
        my $version = '0~0~0';
        if (/^Version:\s+(.*)$/m) {
            $version = $1;
        }

        if (defined $maintainer
            && (defined $package || defined $source || defined $binaries)) {
            $source   ||= $package;
            $binaries ||= $package;
            my @names;
            if ($check_package) {
                my @pkgs;
                if (@pkgs = ($binaries =~ m/$package_names/g)) {
                    $sources{$source}{$version}{binaries} = [@pkgs];
                } elsif ($source !~ m/$package_names/) {
                    next;
                }
            } else {
                $sources{$source}{$version}{binaries} = [$binaries];
            }
            $sources{$source}{$version}{maintainer} = $maintainer;
            $sources{$source}{$version}{uploaders}  = [@uploaders];
        } else {
            warn "E: parse error in stanza $. of $fname\n";
            $errors = 1;
        }
    }

    for my $source (keys %sources) {
        my @versions
          = sort map { Dpkg::Version->new($_) } keys %{ $sources{$source} };
        my $version = $versions[-1];
        my $srcinfo = $sources{$source}{$version};
        my @names;
        if ($check_package) {
            $package_name{$source}--;
            $package_name{$_}-- for @{ $srcinfo->{binaries} };
        }
        @names = $print_binary ? @{ $srcinfo->{binaries} } : $source;
        push @{ $dict{ $srcinfo->{maintainer} } }, @names;
        if ($show_uploaders && @{ $srcinfo->{uploaders} }) {
            foreach my $uploader (@{ $srcinfo->{uploaders} }) {
                push @{ $dict{$uploader} }, map "$_ (U)", @names;
            }
        }
    }
}

if ($use_dctrl) {
    my $fh;
    if ($uncompress) {
        $fh = IO::Uncompress::AnyUncompress->new('-')
          or die "E: Unable to decompress STDIN: $AnyUncompressError\n";
    } else {
        $fh = \*STDIN;
    }
    parsefh($fh, 'STDIN');
} else {
    my @packages;
    if ($use_stdin) {
        while (my $line = <STDIN>) {
            chomp $line;
            $line =~ s/^\s+|\s+$//g;
            push @packages, split(' ', $line);
        }
    } else {
        @packages = @ARGV;
    }
    for my $name (@packages) {
        $package_name{ normalize_package($name) } = 1;
    }

    my $apt_version;
    spawn(
        exec       => ['dpkg-query', '-W', '-f', '${source:Version}', 'apt'],
        to_string  => \$apt_version,
        wait_child => 1,
        nocheck    => 1
    );

    my $useAptHelper = 0;
    if (defined $apt_version) {
        $useAptHelper
          = version_compare_relation($apt_version, REL_GE, '1.1.8');
    }

    unless (@{$source_files}) {
        if ($useAptHelper) {
            my ($sources, $err);
            spawn(
                exec => [
                    'apt-get',  'indextargets',
                    '--format', '$(FILENAME)',
                    'Created-By: Sources'
                ],
                to_string       => \$sources,
                error_to_string => \$err,
                wait_child      => 1,
                nocheck         => 1
            );
            if ($? >> 8) {
                die "Unable to get list of Sources files from apt: $err\n";
            }

            $source_files = [split(/\n/, $sources)];
        } else {
            $source_files = [glob('/var/lib/apt/lists/*_source_Sources')];
        }
    }

    foreach my $source (@{$source_files}) {
        my $fh;
        if ($useAptHelper) {
            my $good = open($fh, '-|', '/usr/lib/apt/apt-helper', 'cat-file',
                $source);
            if (!$good) {
                warn
"E: Couldn't run apt-helper to get contents of '$source': $!\n";
                $errors = 1;
                next;
            }
        } else {
            if ($opt_uncompress
                || ($uncompress && $source =~ m/\.(?:gz|bz2|xz)$/)) {
                $fh = IO::Uncompress::AnyUncompress->new($source);
            } else {
                $fh = FileHandle->new("<$source");
            }
            unless (defined $fh) {
                warn "E: Couldn't open $source\n";
                $errors = 1;
                next;
            }
        }
        parsefh($fh, $source, 1);
        close $fh;
    }
}

foreach my $developer (sort_developers(keys %dict)) {
    print "$developer\n";
    my %seen;
    foreach my $package (sort @{ $dict{$developer} }) {
        next if $seen{$package};
        $seen{$package} = 1;
        print "   $package\n";
    }
    print "\n";
}

foreach my $package (grep { $package_name{$_} > 0 } keys %package_name) {
    warn "E: Unknown package: $package\n";
    $errors = 1;
}

exit($errors);