#!/usr/bin/perl -w

=head1 NAME

dh_gstscancodecs - enumerate and classify gstreamer codecs

=cut

use strict;
use Debian::Debhelper::Dh_Lib;
use File::Temp;

=head1 SYNOPSIS

  dh_gstscancodecs [debhelper options]

=head1 DESCRIPTION

This program is meant to assist in building a package that provides
codecs, demultiplexers and other media-handling components for
gstreamer-based applications.

dh_gstscancodecs generates substitution variable for debian/control,
by scanning libraries /usr/lib/gstreamer-0.11/*.so.

The generated substitution variables are

=over 4

=item gstreamer:Version

Should be added to XB-GStreamer-Version

=item gstreamer:Elements

Should be added to XB-GStreamer-Elements

=item gstreamer:Provides

Should be added to Provides

=item gstreamer:URISources

Should be added to XB-GStreamer-URI-Sources

=item gstreamer:URISinks

Should be added to XB-GStreamer-URI-Sinks

=item gstreamer:Encoders

Should be added to XB-GStreamer-Encoders

=item gstreamer:Decoders

Should be added to XB-GStreamer-Decoders

=back

This control fields will be used by the /usr/bin/gstreamer-codec-install
helper to install required missing GStreamer elements.

=head1 OPTIONS

The standard debhelper options are supported.

=cut

init();

$::pluginlibdirprefix = '/usr/lib/gstreamer-';

foreach my $package (@{$dh{DOPACKAGES}}) {
  my $tmp = tmpdir($package);

  delsubstvar($package, "gstreamer:Version");
  delsubstvar($package, "gstreamer:URISinks");
  delsubstvar($package, "gstreamer:URISources");
  delsubstvar($package, "gstreamer:Encoders");
  delsubstvar($package, "gstreamer:Decoders");

  foreach my $sodir (glob "$tmp$::pluginlibdirprefix*") {
    my $gstversion= substr($sodir, length("$tmp$::pluginlibdirprefix"));
    verbose_print("# gstreamer version $gstversion");

    my (undef, $tmpfile) = File::Temp::tempfile("/tmp/".basename($0).".XXXX", UNLINK => 1);
    my (undef, $registryfile) = File::Temp::tempfile("/tmp/".basename($0).".XXXX", UNLINK => 1);

    my $command="GST_REGISTRY=$registryfile GST_PLUGIN_SYSTEM_PATH= GST_PLUGIN_PATH=$sodir gst-codec-info-$gstversion " . join(' ', (glob "$sodir/*.so")) . " > $tmpfile";

    system($command);
    if ($?) {
      my $output;
      {
          local *F;
          open(F, $tmpfile);
          local $/;
          $output = <F>;
          close(F);
      }
      die("gst-codec-info-$gstversion call failed: '".$command."' rc: $? output: $output");
    }

    local *F;
    open(F, $tmpfile);
    my ($variable, $value);
    while(<F>) {
      $variable = $1 if /([a-zA-Z]*:[a-zA-Z]*)=/;
      $value = $2 if /([a-zA-Z]*:[a-zA-Z]*)=(.*)\n/;
      addsubstvar($package, $variable, $value);
    }
  }
}

=head1 SEE ALSO

L<debhelper(1)>

This program is an extension to debhelper.

=head1 AUTHOR

Ian Jackson <iwj@ubuntu.com>
Sebastian Dröge <sebastian.droege@collabora.co.uk>

=cut