#!/usr/bin/perl
# © 2021 Cyril Brulebois <kibi@debian.org>
#
# Generate ready-to-use .patterns files so that one can use grep to
# perform hardware to firmware-package lookups in the installer
# (see MODALIAS= lines in `udevadm info --export-db`), see the
# hw-detect component.
#
# Parameters: dists/<suite>/*/dep11/Components-<arch>.yml.(gz|xz)
#
# We're limiting ourselves to packages announcing Type: firmware, and
# they need to include such information in their metadata, e.g.
# src:firmware-nonfree.
#
# See: https://salsa.debian.org/kernel-team/firmware-nonfree/-/merge_requests/19

use strict;
use warnings;

use File::Path qw(make_path);
use File::Slurp;
use Getopt::Long;
use YAML::XS;


my $output_dir = '.';
my $verbose;
my $pkgname = "ALL";

GetOptions( "output-dir=s" => \$output_dir,
            "verbose"      => \$verbose,
            "package=s"    => \$pkgname)
    or die "Error in command line arguments";


sub format_alias {
    return map { $a = $_; $a =~ s/[*]/.*/g; "^$a\$\n" } @_;
}


sub process_components {
    my $input = shift;
    my $content;
    print STDERR "processing $input\n"
        if $verbose;

    if ($input =~ /\.gz$/) {
        $content = `zcat $input`;
    }
    elsif ($input =~ /\.xz$/) {
        $content = `xzcat $input`;
    }
    else {
        die "only gz and xz suffixes are supported";
    }

    my @packages;
    foreach my $array (Load $content) {
        # XXX: Drop the condition once we have the required metadata
        # in the archive.
        next if not defined $array->{Provides};
        next if not defined $array->{Provides}->{modaliases};

        print STDERR "found modaliases entries for firmware package ", $array->{Package}, "\n"
            if $verbose;

	if ($pkgname eq "ALL" or $pkgname eq $array->{Package}) {

	    my $patterns_file = $output_dir . "/" . $array->{Package} . ".patterns";
	    printf STDERR "writing %d entries to %s\n",
		(scalar @{ $array->{Provides}->{modaliases} }),
		$patterns_file;

	    # For each alias, anchor the pattern on the left (^) and on
	    # the right ($), and replace each '*' with '.*':
	    write_file($patterns_file,
		       format_alias( @{ $array->{Provides}->{modaliases} } ));
	    push @packages, $array->{Package};
	}
    }
    return @packages;
}


# Prepare output directory:
if (! -d $output_dir) {
    print STDERR "creating output directory $output_dir\n"
        if $verbose;
    make_path($output_dir, { verbose => $verbose });
}

write_file("$output_dir/README.txt",
           "These files help Debian Installer detect helpful firmware packages (via hw-detect).\n");

# Generate .patterns file to match firmware packages found in
# Components-* files:
my @all_packages;
foreach my $component (@ARGV) {
    my @packages = process_components($component);
    push @all_packages, @packages;
}
@all_packages = sort @all_packages;
print STDERR "firmware packages found across all components: @all_packages\n"
    if $verbose;

# Workaround for firmware-sof-signed, which doesn't advertise firmware
# files it might need through the MODULE_FIRMWARE() macro (meaning no
# chance to generate DEP-11 info from there): alias info manually
# extracted on 2021-07-25 (linux-image-5.10.0-8-amd64, 5.10.46-2).
#
# XXX: To be kept in sync!
my $SOF = 'firmware-sof-signed';
if (! grep { $_ eq $SOF } @all_packages) {

    if ($pkgname eq 'ALL' or $pkgname eq 'firmware-sof-signed') {

	# Extract on amd64, from the installed package, with the following
	# command. Note that descending under intel/ would lead to no
	# aliases, so stick to the top-level directory for sof:
	#
	#     for x in $(dpkg -L linux-image-5.10.0-8-amd64 | grep kernel/sound/soc/sof/.*\.ko$); do /usr/sbin/modinfo $x | awk '/^alias:/ { print $2 }'; done | sort
	#
	# XXX: If that's not enough, there are other modules matching the
	#      kernel/sound/soc/intel/boards/snd-soc-sof*.ko pattern.

	my @sof_aliases = qw(
	    pci:v00008086d000002C8sv*sd*bc*sc*i*
	    pci:v00008086d000006C8sv*sd*bc*sc*i*
	    pci:v00008086d0000119Asv*sd*bc*sc*i*
	    pci:v00008086d00001A98sv*sd*bc*sc*i*
	    pci:v00008086d00003198sv*sd*bc*sc*i*
	    pci:v00008086d000034C8sv*sd*bc*sc*i*
	    pci:v00008086d000038C8sv*sd*bc*sc*i*
	    pci:v00008086d00003DC8sv*sd*bc*sc*i*
	    pci:v00008086d000043C8sv*sd*bc*sc*i*
	    pci:v00008086d00004B55sv*sd*bc*sc*i*
	    pci:v00008086d00004B58sv*sd*bc*sc*i*
	    pci:v00008086d00004DC8sv*sd*bc*sc*i*
	    pci:v00008086d00005A98sv*sd*bc*sc*i*
	    pci:v00008086d00009DC8sv*sd*bc*sc*i*
	    pci:v00008086d0000A0C8sv*sd*bc*sc*i*
	    pci:v00008086d0000A348sv*sd*bc*sc*i*
	    pci:v00008086d0000A3F0sv*sd*bc*sc*i*
	    platform:jsl_rt5682_max98360a
	    platform:jsl_rt5682_rt1015
	    platform:sof-audio
	    platform:sof_rt5682
	    platform:sof_sdw
	    platform:tgl_max98357a_rt5682
	    platform:tgl_max98373_rt5682
	);

	print STDERR "deploying manual workaround for $SOF\n"
	    if $verbose;

	my $sof_file = $output_dir . "/" . $SOF . ".patterns";
	printf STDERR "writing %d entries to %s\n",
	    (scalar @sof_aliases),
	    $sof_file;

	write_file($sof_file,
		   format_alias(@sof_aliases));
	push @all_packages, $SOF;
    }
}