#!/usr/bin/perl -w
#
# Copyright 1999 Raphaėl Hertzog <hertzog@debian.org>
# See the README file for the license
#
# This script takes 1 argument on input :
# - a filename listing all the packages to include
#
# and it sorts those packages such that dependencies are met in order
#

use strict;

my $list = shift;

my $nonfree = $ENV{'NONFREE'} || 0;
my $extranonfree = $ENV{'EXTRANONFREE'} || 0;
my $local = $ENV{'LOCAL'} || 0;
my $complete = $ENV{'COMPLETE'} || 0;
my $exclude = "$list.exclude";
my $norecommends = $ENV{'NORECOMMENDS'} || 0;
my $nosuggests = $ENV{'NOSUGGESTS'} || 1;

my $apt = "$ENV{'BASEDIR'}/tools/apt-selection";
my $adir = "$ENV{'APTTMP'}/$ENV{'CODENAME'}-$ENV{'ARCH'}";
my $arch = "$ENV{'ARCH'}";
my $dir = "$ENV{'TDIR'}/$ENV{'CODENAME'}";
my $verbose = $ENV{'VERBOSE'} || 0;

my @output;

$| = 1; # Autoflush for debugging

open(LOG, ">$dir/log.list2cds.$arch")
       || die "Can't write in $dir/log.list2cds.$arch !\n";

sub msg {
	my $level = shift;
	if ($verbose >= $level) {
		print @_;
	}
	print LOG @_;
}

my %included;
my %excluded;
my %packages;

msg(0, "Running list2cds to sort packages for $arch:\n");
msg(1, "======================================================================
Here are the settings you've chosen for making the list:
Architecture: $arch
List of prefered packages: $list
Exclude file: $exclude
Output file: $dir/packages.$arch
");
msg(1, "Complete selected packages with all the rest: ");
msg(1, yesno($complete)."\n");
msg(1, "Include non-free packages: ");
msg(1, yesno($nonfree)."\n");
msg(1, "======================================================================
");

# Get the information on all packages
my $oldrs = $/;
$/ = '';
open(AVAIL, "$apt cache dumpavail |") || die "Can't fork : $!\n";
my ($p, $re);
while (defined($_=<AVAIL>)) {
	next if not m/^Package: (\S+)\s*$/m;
	$p = $1;
	$included{$p} = 0;
	$packages{$p}{"Package"} = $p;
	foreach $re (qw(Version Priority Section Filename Size MD5sum)) {
		(m/^$re: (\S+)\s*$/m and $packages{$p}{$re} = $1)
		|| msg(1, "Header field '$re' missing for package '$p'.\n");
	}
	$packages{$p}{"Depends"} = [];
	$packages{$p}{"Suggests"} = [];
	$packages{$p}{"Recommends"} = [];
	$packages{$p}{"IsUdeb"} = ($packages{$p}{"Filename"} =~ /.udeb$/) ? 1 : 0;
	if ($packages{$p}{"Section"} =~ /contrib\//) {
		$packages{$p}{"Component"} = "contrib";
	} elsif ($packages{$p}{"Section"} =~ /non-free\//) {
		$packages{$p}{"Component"} = "non-free";
	} else {
		$packages{$p}{"Component"} = "main";
	}

}
close AVAIL or die "apt-cache failed : $@ ($!)\n";
$/ = $oldrs;

# Get the list of excluded packages
%excluded = %included;
my $count_excl = 0;

# Now exclude packages because of the non-free rules
if (not $nonfree) {
	foreach (grep { $packages{$_}{"Section"} =~ /non-free/ }
	              (keys %packages)) {
		$excluded{$_} = 'nonfree';
		$count_excl++;
	}
}

msg(1, "Statistics:
Number of packages: @{ [scalar(keys %packages)] }
Number of excluded: $count_excl of @{ [scalar(keys %excluded)] }
======================================================================

");

open(STATS, "> $dir/stats.excluded.$arch") 
                       || die "Can't write in stats.excluded.$arch: $!\n";
foreach (keys %excluded) {
	print STATS "$_ => $excluded{$_}\n";
}
close (STATS);

# Browse the list of packages to include
my ($output_size, $size) = (0, 0, 0);
my %cds;

# Generate a dependency tree for each package
msg(0, "  Generating dependency tree with apt-cache depends...\n");
my (@list) = keys %packages;
while (@list) {
	my (@pkg) = splice(@list,0,200);
	$ENV{'LC_ALL'} = 'C'; # Required since apt is now translated
	open (APT, "$apt cache depends @pkg |") || die "Can't fork : $!\n";
	my (@res) = (<APT>);
	close APT or die "« apt-cache depends » failed ... \n" . 
	                 "you must have apt >= 0.3.11.1 !\n";
	# Getting rid of conflicts/replaces/provides
	my $i = 0;
	my $nb_lines = scalar @res;
	push @res, ""; # Avoid warnings ...
	while ($i < $nb_lines) {
		if ($res[$i] !~ m/^(\S+)\s*$/) {
			msg(0, "UNEXPECTED: Line `$res[$i]' while parsing " .
			       "end of deptree from '$p'\n");
		}
		$p = lc $1; $i++;
		msg(2, "   Dependency tree of `$p' ...\n");
		read_depends (\$i, \@res, $p);
	}
	
}

msg(0, "  Adding standard, required, important and base packages first\n");
# Automatically include packages listed in the status file
open(STATUS, "< $adir/status") || die "Can't open status file $adir/status: $!\n";
while (defined($_ = <STATUS>)) {
       next if not m/^Package: (\S+)/;
       $p = $1;
       if (not exists $packages{$p}) {
               msg(1, "WARNING: Package `$p' is listed in the status file "
                      . "but doesn't exist ! (ignored) \n",
                      "    TIP: Try to generate the status file with " .
                       "make (correct)status (after a make distclean)...\n");
                next;
       }
       next if $excluded{$p};
       add_package($p, ! $norecommends, ! $nosuggests);
}
close STATUS;
msg(0, "  S/R/I/B packages take $output_size bytes\n");

# Now start to look for packages wanted by the user ...
msg(0, "  Adding the rest of the requested packages\n");
open (LIST, "< $list") || die "Can't open $list : $!\n";
while (defined($_=<LIST>)) {
	chomp;
	next if m/^\s*$/;
	if (not exists $packages{$_}) { 
	    msg(1, "WARNING: '$_' does not appear to be available ... " . 
	           "(ignored)\n");
	    next;
	}
	next if $excluded{$_};
	if ($included{$_}) {
	    msg(3, "$_ has already been included.\n");
	    next;
	}
	# This is because udebs tend to have bad dependencies but work
	# nevertheless ... this may be removed once the udebs have a
	# better depencency system
	if ($packages{$_}{"IsUdeb"}) {
	    add_to_output($packages{$_}{"Size"}, [$_]);
	} else {
	    add_package ($_, ! $norecommends, ! $nosuggests);
	}
}
close LIST;

msg(0, "  Now up to $output_size bytes\n");
# All requested packages have been included
# But we'll continue to add if $complete was requested
if ($complete) {
    msg(0, "  COMPLETE=1; add all remaining packages\n");
    # Try to sort them by section even if packages from
    # other sections will get in through dependencies
    # With some luck, most of them will already be here
    foreach my $p (sort { ($packages{lc $a}{"Section"} cmp $packages{lc $b}{"Section"})
                       || (lc $a cmp lc $b) }
             grep { not ($included{$_} or $excluded{$_}) } keys %packages) {
	# At this point, we should *not* be adding any more udebs,
	# as they're no use to anybody.
	if ($packages{lc $p}{"IsUdeb"}) {
	    msg(2, "  Ignoring udeb $p ...\n");
	} else {
	    add_package (lc $p, 0, 0);
	}
    }
}

# Now select the non-free packages for an extra CD
if ($extranonfree and (! $nonfree))
{
	my ($p, @toinclude);
	
	msg(0, "  Adding non-free packages now\n");

	# Finally accept non-free packages ...
	foreach $p (grep { $excluded{$_} eq "nonfree" } (keys %excluded))
	{
		$excluded{$p} = 0;
		push @toinclude, $p;
	}
	
	# Include non-free packages
	foreach $p (@toinclude)
	{
		add_package(lc $p, 1, 1);
	}

	# If a contrib package was listed in the list of packages to
	# include and if COMPLETE=0 there's a chance that the package
	# will not get included in any CD ... so I'm checking the complete
	# list again
	open (LIST, "< $list") || die "Can't open $list : $!\n";
	while (defined($_=<LIST>)) {
		chomp;
		next if m/^\s*$/;
		next if $included{$_};
		next if $included{lc $_};
		next if $excluded{$_};
		next if $excluded{lc $_};
		if (not exists $packages{$_} && not exists $packages{lc $_}) { 
		  msg(1, "WARNING: '$_' does not appear to be available ... " . 
	          	 "(ignored)\n");
		  next;
		}
		if ($packages{lc $p}{"IsUdeb"}) {
			msg(2, "  Ignoring udeb $p ...\n");
		} else {
			add_package (lc $_, 1, 1);
		}
	}
	close LIST;

	# Try to include other packages that could not be included
	# before (because they depends on excluded non-free packages)
	if ($complete)
	{
	    foreach $p (sort { ($packages{$a}{"Section"} 
				cmp $packages{$b}{"Section"}) || ($a cmp $b) }
			grep { not ($included{$_} or $excluded{$_}) } 
			keys %packages) 
	    {
			if ($packages{lc $p}{"IsUdeb"}) {
				msg(2, "  Ignoring udeb $p ...\n");
			} else {
				add_package (lc $p, 0, 0);
			}
		}
	}

}

# Remove old files
foreach (glob("$dir/*.packages*")) {
	unlink $_;
}

# Now write the list down
my $count = 0;
open(CDLIST, "> $dir/packages.$arch") 
    || die "Can't write in $dir/$_.packages.$arch: $!\n";
foreach (@output) {
    my $component = $packages{$_}{"Component"};
    print CDLIST "$arch:$component:$_\n";
    $count++;
}
close CDLIST;
msg(0, "Done: processed/sorted $count packages, total size $output_size bytes.\n");

close LOG;

## END OF MAIN
## BEGINNING OF SUBS

sub read_depends {
	my $i = shift;     # Ref
	my $lines = shift; # Ref
	my $pkg = shift;   # string
	my $types = "(?:Pre)?Depends|Suggests|Recommends|Replaces|Conflicts";
	my (@dep, @rec, @sug);
	my ($type, $or, $elt);

	while ($lines->[$$i] =~ m/^\s([\s\|])($types):/) {
		$type = $2; $or = $1;
		# Get rid of replaces and conflicts ...
		if (($type eq "Replaces") or ($type eq "Conflicts")) {
			$$i++;
			while ($lines->[$$i] =~ m/^\s{4}/) {
				$$i++;
			}
			next;
		}
		# Check the kind of depends : or, virtual, normal
		if ($or eq '|') {
			$elt = read_ordepends ($i, $lines);
		} elsif ($lines->[$$i] =~ m/^\s\s$type: <([^>]+)>/) {
			$elt = read_virtualdepends ($i, $lines);
		} elsif ($lines->[$$i] =~ m/^\s\s$type: (\S+)/) {
			$elt = $1; $$i++;
			# Special case for packages providing not
			# truely virtual packages
			if ($lines->[$$i] =~ m/^\s{4}/) {
				$elt = [ $elt ];
				while ($lines->[$$i] =~ m/\s{4}(\S+)/) {
					push @{$elt}, $1;
					$$i++;
				}
			}
		} else {
			msg(0, "ERROR: Unknown depends line : $lines->[$$i]\n");
			foreach ($$i - 3 .. $$i + 3) {
				msg(0, "      ", $lines->[$_]);
			}
		}
		$type =~ s/^Pre//; # PreDepends are like Depends for me 
		next if dep_satisfied($elt);
		push @{$packages{$pkg}{$type}}, $elt;
	}
}

sub dep_satisfied {
	my $p = shift;
	if (ref $p) {
		foreach (@{$p}) {
			return 1 if $included{$_};
		}
	} else {
		return $included{$p};
	}
	return 0;
}

sub read_ordepends {
	my $i = shift;
	my $lines = shift;
	my @or = ();
	my ($val,$dep, $last) = ('','',0);
	
	while ($lines->[$$i] 
	            =~ m/^\s([\s\|])((?:Pre)?Depends|Suggests|Recommends): (\S+)/) {
		$val = $3;
		$last = 1 if $1 ne '|'; #Stop when no more '|'
		if ($val =~ m/^<.*>$/) {
			$dep = read_virtualdepends ($i, $lines);
			if (ref $dep) {
				push @or, @{$dep};
			} else {
				push @or, $dep;
			}
		} else {
			push @or, $val; $$i++;
			# Hack for packages providing not a truely
			# virtual package
			while ($lines->[$$i] =~ m/^\s{4}(\S+)/) {
				push @or, $1;
				$$i++;
			}
		}
		last if $last;
	}
	return \@or;
}

sub read_virtualdepends {
	my $i = shift;
	my $lines = shift;
	my $virtual;
	my @or = ();

	#Check for the lines with <>
	if ($lines->[$$i] 
	    =~ m/^\s[\s\|]((?:Pre)?Depends|Recommends|Suggests): <([^>]+)>/) {
	    $virtual = $2;
	    $$i++
	}
	# Now look at the alternatives on the following lines
	while ($lines->[$$i] =~ m/^\s{4}(\S+)/) {
		push @or, $1;
		$$i++;
	}
	if (@or) {
		return \@or;
	} else {
		return $virtual;
	}
}

sub add_package {
	my $p = shift;
	my $add_rec = shift; # Do we look for recommends
	my $add_sug = shift; # Do we look for suggests
	
	msg(2, "+ Trying to add $p...\n");
	if ($included{$p}) {
		msg(2, "  Already included ...\n");
		return;
	}
	
	# Get all dependencies (not yet included) of each package
	my (@dep) = (get_missing ($p));

	# Stop here if apt failed
	if (not scalar(@dep)) {
		msg(2, "Can't add $p ... dependency problem.\n");
		return;
	}
	
	msg(3, "  \@dep before checklist = @dep\n");
	
	# Check if all packages are allowed (fail if one cannot)
	if (not check_list (\@dep, 1)) {
		msg(2, "Can't add $p ... one of the package needed has " .
		       "been refused.\n"); 
		return;
	}
	
	msg(3, "  \@dep after checklist = @dep\n");
	
	if ($add_rec) {
	    #TODO: Look for recommends (not yet included !!)
		add_recommends (\@dep);
	    	# Check again but doesn't fail if one of the package cannot be
	    	# installed, just ignore it (it will be removed from @dep)
	    	if (not check_list (\@dep, 0)) {
	    		msg(0, "UNEXPECTED: It shouldn't fail here !\n");
	    		return;
	    	}
		msg(3, "  \@dep after checklist2 = @dep\n");
	}
	
	if ($add_sug) {
	    #TODO: Look for suggests (not yet included !!)
		add_suggests (\@dep);
	    	# Check again but doesn't fail if one of the package cannot be
	    	# installed, just ignore it (it will be removed from @dep)
	    	if (not check_list (\@dep, 0)) {
	    		msg(0, "UNEXPECTED: It shouldn't fail here !\n");
	    		return;
	    	}
		msg(3, "  \@dep after checklist3 = @dep\n");
	}
	
	# All packages are ok, now check for the size issue
	$size = get_size (\@dep);
	add_to_output ($size, \@dep);
}

sub accepted {
	my $p = shift;
	return not $excluded{$p} if (exists $excluded{$p});
	# Return false for a non-existant package ...
	msg(1, "WARNING: $p cannot be accepted, it doesn't exist ...\n");
	return 0;
}

sub add_suggests {
	my $list = shift;
	my $p; # = shift;
	my @copy = @{$list}; # A copy is needed since I'll modify the array
	
	foreach $p (@copy) {
		add_missing($list, $packages{$p}{"Suggests"}, $p);
	}
		
}

sub add_recommends {
	my $list = shift;
	my $p; # = shift;
	my @copy = @{$list}; # A copy is needed since I'll modify the array
	
	foreach $p (@copy) {
		add_missing($list, $packages{$p}{"Recommends"}, $p);
	}
		
}

sub get_missing {
	my $p = shift;
	my @list = ($p);
	
	if (not add_missing (\@list, $packages{$p}{"Depends"}, $p)) {
		return ();
	}
	
	return (@list);
}

# Recursive function adding to the 
sub add_missing {
	my $list = shift;
	my $new = shift;
	my $pkgin = shift;
	my @backup = @{$list};
	my $ok = 1;
	
	# Check all dependencies 
	foreach (@{$new}) {
		if (ref) {
			my $textout = "";
			foreach my $orpkg (@{$_}) {
				$textout .= "$orpkg ";
			}
			msg(3, "    $pkgin Dep: ( OR $textout)\n");
		} else {
			msg(3, "    $pkgin Dep: $_\n");
		}
		next if dep_satisfied ($_);
		# If it's an OR
		if (ref) {
			my $or_ok = 0;
			# Loop over each package in the OR
			# We always add the first package in the OR to allow
			# APT to figure out which is the better one to install
			# for any combination of packages that have similar
			# alternative dependencies, but in different order.
			# Having the first alternative available should be good
			# enough for all cases we care about.
			foreach my $pkg (@{$_}) {
				next if not accepted ($pkg);
				# If the package is already included
				# then don't worry
				if ($included{$pkg}) {
					$or_ok = 1;
					last;
				}
				# Check we don't already have the package
				if (is_in ($pkg, $list)) {
					$or_ok = 1;
					last;
				# Otherwise try to add it
				} else {
					# Stop after the first package that is
					# added successfully
					push (@{$list}, $pkg);
					if (add_missing ($list, $packages{$pkg}{"Depends"}, $pkg)) {
						$or_ok = 1;
						last;
					} else {
						pop @{$list};
					}
				}
			}
			$ok &&= $or_ok;
			if (not $ok) {
				msg(1, "  $pkgin failed, couldn's satisfy OR dep\n");
			}				
		# Else it's a simple dependency
		} else {
			if (not exists $packages{lc $_}) {
				msg(1, "  $_ doesn't exist...\n");
				msg(1, "  $pkgin failed, couldn't satisfy dep on $_\n");
				$ok = 0;
				last;
			}
			next if $included{lc $_}; # Already included, don't worry
			next if is_in (lc $_, $list);
			push @{$list}, lc $_;
			if (not add_missing ($list, $packages{lc $_}{"Depends"}, lc $_)) {
				msg(1, "couldn't add $_ ...\n");
				msg(1, "$pkgin failed, couldn't satisfy dep on $_\n");
				pop @{$list};
				$ok = 0;
			}
		}
	}
	# If a problem has come up, then restore the original list
	if (not $ok) {
		@{$list} = @backup;
	}
	return $ok;
}

# Check if $value is in @{$array}
sub is_in {
	my $value = shift;
	my $array = shift;
	foreach my $key (@{$array}) {
		return 1 if ($key eq $value);
	}
	return 0;		
}

# The size of a group of packages
sub get_size {
	my $arrayref = shift;
	my $size = 0;
	foreach (@{$arrayref}) {
		$size += $packages{$_}{"Size"};
	}
	return $size;
}

# Check a list of packages
sub check_list {
	my $ref = shift;
	my $fail = shift;
	my $ok = 1;
	my @to_remove = ();
	foreach (@{$ref}) {
		if (not exists $excluded{$_}) {
		  msg(1,"  $_ has been refused because it doesn't exist ...\n");
		  $ok = 0;
		  push @to_remove, $_;
		  next;
		}
		if (not accepted($_)) {
		  msg(1,"  $_ has been refused because of $excluded{$_} ...\n");
		  $ok = 0;
		  push @to_remove, $_;
		  next;
		}
		if ($included{$_}) {
		  msg(1, 
		      "  $_ has already been included in CD $included{$_}.\n");
		  push @to_remove, $_;
		  next;
		}
	}
	foreach my $removed (@to_remove) {
		msg(2, "  Removing $removed ...\n");
		@{$ref} = grep { $_ ne $removed } @{$ref};
	}
	return ($fail ? $ok : 1);
}

# Add packages to the output list
sub add_to_output {
	my $size = shift;
	my $ref = shift;

	msg(2, "  \$output_size = $output_size, \$size = $size\n");

	$output_size += $size;

	foreach my $pkg (@{$ref}) {
	    $included{$pkg} = 1;
	}
	push(@output, @{$ref});
}

sub yesno {
  my $in = shift;
  return $in ? "yes" : "no";
}