# $NetBSD: tflat,v 1.15 2005/10/26 16:54:04 tv Exp $
#
# Copyright (c) 2001, 2005 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Dan McMahill and Todd Vierling.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#        This product includes software developed by the NetBSD
#        Foundation, Inc. and its contributors.
# 4. Neither the name of The NetBSD Foundation nor the names of its
#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

#
# This perl version is very fast compared to other alternatives, which would
# likely use things like forking "sort" subprocesses.
#
use strict;

sub usage () {
	print STDERR <<EOF ;
tflat -- flatten a depends tree.  tflat is used to show all
         packages which depend upon a given package, and
         all packages which are depend upon by a given package.

usage: $0 upfile downfile < depfile

Input file format is in the form
foo	bar
foo	baz
libbar	bar

meaning "foo is depended upon by bar,
         foo is depended upon by baz,
         libbar is depended upon by bar"

The typical use is:
cd /usr/pkgsrc
./mk/bulk/printdepends > .depends
perl ./mk/bulk/tflat .supports .requires < .depends

EOF
	exit 1;
}

my $upfile = shift(@ARGV) || usage();
my $downfile = shift(@ARGV) || usage();
scalar(@ARGV) && usage();

open(UPF, ">$upfile") || die $!;
open(DOWNF, ">$downfile") || die $!;

# read in dependstree file

my %depended;
my %depends;
while (<>) {
	chomp;
	my ($dep, $pkg) = split;

	push(@{$depended{$dep}}, $pkg);
	push(@{$depends{$pkg}}, $dep);
}

# print out upfile and downfile

sub getdeps ($$$@) {
	my $curhash = shift;
	my $alldeps = shift;
	my $what = shift;

	foreach my $dep (@{$curhash->{$what}}) {
		if ($what eq $dep) {
			next;
		} elsif (grep { $_ eq $dep } @_) {
			print STDERR "circular dependency in $dep\n";
		} elsif (!grep { $_ eq $dep } @$alldeps) {
			push(@$alldeps, $dep);
			getdeps($curhash, $alldeps, $dep, $what, @_);
		}
	}
}

foreach my $pkg (sort(keys(%depended))) {
	my @alldeps;
	getdeps(\%depended, \@alldeps, $pkg);
	print UPF "$pkg is depended on by:  ".join(' ', @alldeps)."\n";
}

foreach my $pkg (sort(keys(%depends))) {
	my @alldeps;
	getdeps(\%depends, \@alldeps, $pkg);
	print DOWNF "$pkg depends on:  ".join(' ', @alldeps)."\n";
}

close(UPF);
close(DOWNF);