#!/usr/bin/perl -w
#
# generate_firmware_task
#
# Work out which firmware packages we need
# Several steps:
#
# 1. Look for packages which contain "firmware" or "microcode" in
# their package names
# 2. Check each of those packages to see if they contain files in
# /lib/firmware or /usr/lib/firmware
# 3. For those that do, output the package name into the firmware task
#
# Copyright Steve McIntyre <93sam@debian.org> 2011
# Copyright Cyril Brulebois <kibi@debian.org> 2023
#
# GPL 2
#

use strict;
use File::Basename;

my ($mirror, $codename, $archlist, $excludelist, $outfile, $localdebs, $backports);
my $date;
my $tasksdir;
my (@pkgfiles, @bp_pkgfiles);
my ($pkg, $filename, $arch);
my %seen;
my @components;
my $cpp_command;
my %excluded;

sub contains_firmware($$) {
    my ($mirror, $filename) = @_;
    my $count = 0;
    open (PKGLISTING, "dpkg --contents $mirror/$filename |") or
	die "Can't check package file $filename: $!\n";
    while ($_ = <PKGLISTING>) {
	$_ =~ /\.\/lib\/firmware\// and $count++;
	$_ =~ /\.\/usr\/lib\/firmware\// and $count++;
    }
    close PKGLISTING;
    if ($count) {
	return 1;
    } else {
	return 0;
    }
}

sub check_packages($$@) {
    my ($use_bp, $orig_mode, @pkgfiles) = @_;

    for my $pkgfile (@pkgfiles) {
	open (INPKG, "\$BASEDIR/tools/catz $pkgfile |") or die "Can't read input package files: $!\n";
	$/ = ''; # Browse by paragraph

	while (defined($_ = <INPKG>)) {
	    m/^Package: (\S+)/m and $pkg = $1;
	    m/^Filename: (\S+)/m and $filename = $1;

	    if (! ($pkg =~ /(microcode|firmware)/)) {
		next;
	    }

	    if (!exists $seen{$filename}) {
		$seen{$filename} = 1;

		# Don't include packages that we're told to exclude
		if ($excluded{$pkg}) {
		    print STDERR "  Ignoring $pkg\n";
		    next;
		}

		if (contains_firmware($mirror, $filename)) {
		    printf STDERR "  %-35s (%s)\n", $pkg, $filename;
		    if ($orig_mode) {
			if ($use_bp) {
			    print OUT "$pkg/$codename-backports\n";
			} else {
			    print OUT "$pkg\n";
			}
		    } else {
			print "$filename $pkgfile\n";
		    }
		}
	    }
	}
	close INPKG;
    }
}


# Either the caller tells us explicitly which components to use, or we make this
# determination on our own, based on various environment variables:
sub read_env {
    my $env_var = shift;
    my $default = shift;

    if (exists($ENV{$env_var})) {
	return $ENV{$env_var};
    }
    # else
    return $default;
}

# Either the caller tells us explicitly which components to use, or we make this
# determination on our own, based on various environment variables, just like
# tools/apt-selection does:
@components = split /\ /, read_env('FIRMWARE_COMPONENTS', '');
if (!@components) {
    @components = qw(main);
    if (read_env('CONTRIB', 0) == 1) {
	push @components, qw(contrib);
    }
    if (read_env('NONFREE', 0) == 1 or read_env('EXTRANONFREE', 0) == 1 or read_env('FORCE_FIRMWARE', 0) == 1) {
	push @components, (split / /, read_env('NONFREE_COMPONENTS', ''));
    }
}
$codename = $ENV{'CODENAME'};
$mirror = $ENV{'MIRROR'};
$localdebs = $ENV{'LOCALDEBS'};
$backports = $ENV{'BACKPORTS'};
$archlist = shift;
$excludelist = shift;
$outfile = shift;

if (!defined($codename) || !defined($mirror) ||
    !defined($excludelist) ||
    !defined($archlist) || !defined($outfile)) {
    die "Error in arguments\n";
}

$tasksdir = dirname($outfile);
$cpp_command = "cpp -traditional -undef -P -C -Wall -nostdinc -I$tasksdir";

foreach $arch (split(' ', $archlist)) {
    for my $component (@components) {
	if (defined($backports)) {
	    push @bp_pkgfiles, "$mirror/dists/$codename-backports/$component/binary-$arch/Packages.gz";
	    push @bp_pkgfiles, "$mirror/dists/$codename-backports/$component/binary-$arch/Packages.xz";
	}
	push @pkgfiles, "$mirror/dists/$codename/$component/binary-$arch/Packages.gz";
	push @pkgfiles, "$mirror/dists/$codename/$component/binary-$arch/Packages.xz";
    }
    $cpp_command .= " -DARCH$arch";
}

if (defined($localdebs)) {
    for my $component (@components) {
	foreach $arch (split(' ', $archlist)) {
	    if (defined($backports)) {
		push @bp_pkgfiles, "$localdebs/dists/$codename-backports/$component/binary-$arch/Packages.gz";
		push @bp_pkgfiles, "$localdebs/dists/$codename-backports/$component/binary-$arch/Packages.xz";
	    }
	    push @pkgfiles, "$localdebs/dists/$codename/$component/binary-$arch/Packages.gz";
	    push @pkgfiles, "$localdebs/dists/$codename/$component/binary-$arch/Packages.xz";
	}
    }
}

# Build the hash of excluded packages
open (EXLIST, "$cpp_command $excludelist |") or
    die "Can't parse exclude list: $!\n";
while (defined (my $exc = <EXLIST>)) {
    chomp $exc;
    $excluded{$exc} = 1;
}
close EXLIST;

# This special filename is an crude but easy way to distinguish the historical
# caller (top-level Makefile) from tools/make-firmware-image which should use
# the same logic, but is interested in the Filename for interesting firmware
# packages:
my $orig_mode = $outfile ne '--list-filenames-and-indices' ? 1 : 0;
if ($orig_mode) {
    # Prepare the output file:
    open (OUT, "> $outfile") or die "Can't open outfile for writing: $!\n";

    $date = `date -u`;
    chomp $date;

    print OUT "/*\n";
    print OUT " * 'firmware' task file; generated automatically by generate_firmware_task\n";
    print OUT " * for \"$archlist\" on $date\n";
    print OUT " * Do not edit - changes will not be preserved\n";
    print OUT " */\n";
}

# Those function calls will either write the task to OUT (historical mode) or
# filenames to stdout (for make-firmware-image):
if (defined($backports)) {
    check_packages(1, $orig_mode, @bp_pkgfiles);
}
check_packages(0, $orig_mode, @pkgfiles);

if ($orig_mode) {
    close OUT;
}