path: root/Distribconf.pm

##- Nanar <nanardon@mandrake.org>
##-
##- 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.
#
# $Id$

package Distribconf;

=head1 NAME

Distribconf - perl module to get config from a mandrakelinux distribution tree

=head1 SYNOPSIS

    use Distribconf;

    my $d = Distribconf->new("/path/to/the/distribution/root");
    $d->load() and die "The dir does not seems to be a distribution tree";

    print $d->getpath(undef, "root") ."\n";
    foreach ($d->listmedia) {
        printf "%s -> %s\n", $d->getpath($_, "hdlist"), $d->getpath($_, path);
    }

=head1 DESCRIPTION

Distribconf is a little module to get/write configuration of mandrakelinux.

The goal is to manage both configuration of old tree configuration
(Mandrake/base/ ie 10.0 and older) and the new configuration tree
(media/media_info/ ie 10.1 and newer).

Another point about the hdlists file: the format is limited and does not permit
to add new value whithout breaking compatiblity. This module is able to find a 
'media.cfg' which allow to add new parameter. See L<media.cfg> section. To keep
compatiblity with old tools, this module is able to generate an 'hdlists' files
based on this media.cfg.

=head1 C<media.cfg>

The media.cfg is like an ini file. All parameter are optionnal, this means
a readable empty file is ok, if this is what you want :).

The media.cfg contain section, each section is a media, except the [media_info]
section wich is used to store global info. The section name is the path where
are located the rpms. The section name is sufficiant to identify a media.

Few values have specific signification:

=over 4

=item media specifics values:

=over 4

=item B<hdlist>

    the path or basename of the hdlist, if not specified by default is
    hdlist_mediapath.cz, '/' character are replaced by '_',

=item B<synthesis>

    the path or basename of the synthesis, by default is hdlist name
    prefixed by 'synthesis',

=item B<name>

    the name of the media, by default is media path, '/' character are
    replaced by '_',

=back

=item global specifics values:

=over 4

=item B<root>

    the root of the distribution tree, this value is not set in 
    media.cfg, can't be owerwritten, is only use internaly

=item B<mediadir>

    the default directory from 'root' path where medium are
    located, automatically found by Distribconf.

=item B<infodir>

    the default directory from 'root' path where distrib informations
    are located, automatically found by Distribconf.

=back

=back

For section name (path) hdlist and synthesis, if there is only the basename,
the path is relative to the mediadir or infodir, else the path is relative
to the 'root'one :
- hdlist.cz is root/infodir/hdlist.cz,
- ./hdlist.cz is root/./hdlist.cz.
    
The media.cfg should be located at the same location than hdlists,
so Mandrake/base won't happen (this tree form is no longer used)
and media/media_info will. 

Let's start, first a very basic (but valid) media.cfg:

    [main]
    [contrib]
    [jpackage]
 
Simple, isn't it ? :)
Now a more complex but more realist media.cfg:

    # Comment
    [media_info]
    # if one tools want to use these values
    version=10.2
    branch=cooker
    
    [main]
    hdlist=hdlist_main.cz
    name=Main
    size=3400m

    [../SRPMS/main]
    hdlist=hdlist_main.src.cz
    name=Main Sources
    noauto=1

    [contrib]
    hdlist=hdlist_contrib.cz
    name=Contrib
    size=4300m

    [../SRPMS/contrib]
    hdlist=hdlist_contrib.src.cz
    name=Contrib Sources
    noauto=1

    [jpackage]
    hdlist=hdlist_jpackage.cz
    name=Jpackage
    size=360m
    noauto=1

    [../SRPMS/jpackage]
    hdlist=hdlist_jpackage.src.cz
    name=Jpackage Sources
    noauto=1

=head1 METHODS
    
=cut

use strict;
use warnings;

use Config::IniFiles;

=head2 new(root_of_distrib)

Return a new Distribconf object having "root_of_distrib" as top level of the
tree.

=cut

sub new {
    my ($class, $path) = @_;

    my $distrib = {
        root => $path,
        medium => {},
        cfg => new Config::IniFiles( -default => 'media_info', -allowcontinue => 1),
    };

    bless($distrib, $class);
}

=head2 load

Find and load the configuration of the distrib:

=over 4

=item find the path where are located information

=item if availlable load media.cfg

=item if availlable load hdlists

=back

Return 0 on success, 1 if no directory containing media information is found,
2 if no media.cfg, neither hdlists are found.

See also L<loadtree>, L<parse_hdlists> and L<parse_mediacfg>.

=cut

sub load {
    my ($distrib) = @_;
    $distrib->loadtree() or return 1;

    $distrib->parse_mediacfg() || $distrib->parse_hdlists() or return 2;

    return 0;
}

=head2 loadtree

Try to find a valid media information directory, on success set infodir
and mediadir.

Return 1 on success, O if no media information directory were found.

=cut

sub loadtree {
    my ($distrib) = @_;
    
    if (-d "$distrib->{root}/media/media_info") {
        $distrib->{infodir} = "media/media_info";
        $distrib->{mediadir} = "media";
    } elsif (-d "$distrib->{root}/Mandrake/base") {
        $distrib->{infodir} = "Mandrake/base";
        $distrib->{mediadir} = "Mandrake";
    } else {
        return 0;
    }
    return 1;
}

=head2 parse_hdlists($hdlists)

Read the hdlists file found in the media information directory of the
distribution, otherwise set the hdlists file given as argument.

Return 1 on success, 0 if hdlists can't be found or is invalid.

=cut

# what to return if hdlists is found but invalid
sub parse_hdlists {
    my ($distrib, $hdlists) = @_;
    $hdlists ||= "$distrib->{root}/$distrib->{infodir}/hdlists";
    
    open(my $h_hdlists, "<", $hdlists) or return 0;
    $distrib->{cfg} = new Config::IniFiles( -default => 'media_info', -allowcontinue => 1);
    my $i = 0;
    foreach (<$h_hdlists>) {
        chomp;
        my ($options, %media);
        ($options, @media{qw/hdlist path name size/}) =
            $_ =~ m/^\s*(?:(.*):)?(\S+)\s+(\S+)\s+([^(]*)(?:\s+\((\w+)\))?$/;
        if ($options) { $media{$_} = 1 foreach(split(':', $options)) }
        $media{name} =~ s/\s*$//;
        $media{path} =~ s!^$distrib->{mediadir}/+!!;
        foreach (qw/hdlist name size/, $options ? split(':', $options) : ()) {
            $distrib->{cfg}->newval($media{path}, $_, $media{$_}) or die "Can't set value";
        }
    }
    close($h_hdlists);
    return 1;
}

=head2 write_hdlists($hdlists)

Write the hdlists file into the media information directory, or into the
$hdlists given as argument. $hdlists can be a file path, or a glob reference
(\*STDOUT for example).

Return 1 on success, 0 on error.

=cut

sub write_hdlists {
    my ($distrib, $hdlists) = @_;
    my $h_hdlists;
    if (ref($hdlists) eq 'GLOB') {
        $h_hdlists = $hdlists;
    } else {
        $hdlists ||= "$distrib->{root}/$distrib->{infodir}/hdlists";
        open(my $h_hdlists, ">", $hdlists) or return 0;
    }
    foreach my $media ($distrib->listmedia) {
        printf($h_hdlists "%s%s\t%s\t%s\t%s\n",
            join('', map { "$_:" } grep { $distrib->getvalue($media, $_) } qw/askmedia suppl noauto/) || "",
            $distrib->getvalue($media, 'hdlist'),
            $distrib->getpath($media, 'path'),
            $distrib->getvalue($media, 'name'),
            $distrib->getvalue($media, 'size') ? '('.$distrib->getvalue($media, 'size'). 'm)' : "",
        ) or return 0;
    }
    
    if (ref($hdlists) ne 'GLOB') {
        close($h_hdlists);
    }
    return 1;
}

=head2 parse_mediacfg($mediacfg)

Read the media.cfg file found in the media information directory of the
distribution, otherwise set the $mediacfg file given as argument.

Return 1 on success, 0 if media.cfg can't be found or is invalid.

=cut

sub parse_mediacfg {
    my ($distrib, $mediacfg) = @_;
    $mediacfg ||= "$distrib->{root}/$distrib->{infodir}/media.cfg";
    ($distrib->{cfg} = new Config::IniFiles( -file => $mediacfg, -default => 'media_info', -allowcontinue => 1)) or return 0;
    return 1;
}

=head2 write_mediacfg($mediacfg)

Write the media.cfg file into the media information directory, or into the
$mediacfg given as argument. $mediacfg can be a file path, or a glob reference
(\*STDOUT for example).

Return 1 on success, 0 on error.

=cut

sub write_mediacfg {
    my ($distrib, $hdlistscfg) = @_;
    $hdlistscfg ||= "$distrib->{root}/$distrib->{infodir}/media.cfg";
    $distrib->{cfg}->WriteConfig($hdlistscfg);
}

=head2 listmedia

Return an array of existing medium in the configuration

=cut

sub listmedia {
    my ($distrib) = @_;
    return grep { $_ ne 'media_info' } $distrib->{cfg}->Sections;
}

=head2 getvalue($media, $var)

Return the $var value for $media, return undef if the value is not set.

If $var is name, hdlist or synthesis, and the value is not explicity defined,
the return value is expanded from $media.

If $media is 'media_info' or undef, you'll get the global value.

This function does not take care about path, see L<getpath>.

=cut

sub getvalue {
    my ($distrib, $media, $var) = @_;
    $media ||= 'media_info';
   
    my $default;
    SWITCH: for ($var) {
        /^synthesis$/ and do { $default = 'synthesis.' . $distrib->getvalue($media, 'hdlist'); last; };
        /^hdlist$/    and do { $default = 'hdlist_' . $distrib->getvalue($media, 'name') . '.cz'; last; };
        /^name$/      and do { $default = $media; $default =~ s!/!_!g; last; };
        /^path$/      and return $media;
        /^root$/      and return $distrib->{root};
        /^mediadir$|^infodir$/  and do { $default = $distrib->{$var}; last; };
    }
    return $distrib->{cfg}->val($media, $var, $default);
}

=head2 setvalue($media, $var, $val)

Set or add $var parameter from $media to $val.

If $media does not exists, it is implicitly created.
If $var is not defined, a new media is create without parameters defined.

=cut

sub setvalue {
    my ($distrib, $media, $var, $val) = @_;
    if ($var) {
        $var =~ /^mediadir$|^infodir$/ and do {
            $distrib->{$var} = $val;
            return;
        };
        $distrib->{cfg}->newval($media, $var, $val) or die "Can't set value";
    } else {
        $distrib->{cfg}->AddSection($media);
    }
}

=head2 getpath($media, $var)

Give relative path from the root of the distrib.

This function is usefull to know where are really located files, it take care
of location of medium, the location of index files, and the path set in the
configuration.

=cut

sub getpath {
    my ($distrib, $media, $var) = @_;

    my $val = $distrib->getvalue($media, $var);
    $var =~ /^root$/ and return $val;
    return ($val =~ m!/! ? "" : ($var eq 'path' ? $distrib->{mediadir} : $distrib->{infodir} ) . "/") . $val;
}

1;

__END__

=head1 AUTHOR

The code has been written by Olivier Thauvin <nanardon@mandrake.org>.

The media.cfg has been improved by Warly <warly@mandrakesoft.com>.

Special thanks to Rafael Garcia-Suarez <rgarciasuarez@mandrakesoft.com> for
suggesting to use Config::IniFiles.

Thanks to Sylvie Terjan <erinmargault@mandrake.org> for the spell checking. 

=head1 ChangeLog

    $Log$
    Revision 1.1  2005/02/20 21:15:50  othauvin
    - initials release for managing mandrakelinux distro tree


=cut